The Posterior Neck and Cervical Spine
From R. C. Schafer, DC, PhD, FICC's best-selling book:
“Symptomatology and Differential Diagnosis”
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to chiropractic research. Please review the complete list of available books.Introduction Anomalies and Deformities Inflammatory Musculoskeletal Syndromes Intervertebral Disc Syndromes Postural Syndromes Postural Syndromes Subluxation/Fixation Syndromess Trauma: Cervical Spine Syndromes
Chapter 5: The Posterior Neck and Cervical Spine
With the important exception of neurologic and vertebral artery syndromes, most of the disorders witnessed in the osterior aspect of the neck are musculoskeletal conditions. Of particular significance are the symptom complexes of cervical arthritis, deformities, disorders of muscle tone, IVD syndromes, spondylosis, vertebral subluxation, tumors, and the effects of trauma. It is helpful to keep in mind that tumors of the cervical spine are usually secondary and that chronic degenerative disc disease and congenital anomalies may be asymptomatic for many years.
Nowhere in the spine is the relationship between the osseous structures and the surrounding neurologic and vascular beds as intimate or subject to disturbance as it is in the neck. Many peripheral nerve symptoms in the shoulder, arm, and hand will find their origin in the brachial plexus and cervical spine.
The gross mechanical function of the neck is determined by analysis of joint motion and muscle strength.
EVALUATING JOINT MOTION OF THE NECK
Gross joint motion is roughly screened by inspection during active motions. When a record is helpful, it is usually measured by goniometry. The prime movers and accessories responsible for voluntary joint motion in the cervical region are shown in Table 5.1.
Table 5.1. Neck Motion and Responsible Movers
Joint Motion Prime Movers AccessoriesExtension Trapezius, upper Transverse spinalis group Splenius capitis Levator scapulae Splenius cervicis Semispinalis capitis Semispinalis cervicis Erector spinae capitis Erector spinae cervicis Flexion Sternocleidomastoid Scalenes Longus colli Hyoid muscles Longus capitis Rectus capitis anterior Rectus capitis lateralis Lateral Scalenes Transverse spinalis group flexion Levator scapulae Rectus capitis lateralis Rotation Sternocleidomastoid Scalenes Trapezius, upper Transverse spinalis group Splenius capitis Splenius cervicis
EVALUATING MUSCLE STRENGTH OF THE NECK
Muscle strength is recorded as from 5 to 0 or in a percentage and compared bilaterally whenever possible. The major muscles of the neck, their primary function, and their innervation are listed in Table 5.2.
Table 5.2. Function and Innervation of the Major Muscles of the Neck
Spinal Muscle Major Function SegmentsErector spinae, upper Extension, rotation C1–T1 Longus capitis Flexion C1–C3 Longus colli Flexion C2–C6 Rectus capitis anterior Flexion C1–C2 Rectus capitis lateral Flexion C1–C2 Scalenes Flexion, rotation C4–C8 Semispinalis capitis Extension, rotation C1–T1 Semispinalis cervicis Extension, rotation C1–T1 Splenius capitis Extension, rotation C1–C8 Splenius cervicis Extension, rotation C1–C8 Sternocleidomastoid Flexion, rotation C2, XI Trapezius, upper Extension, rotation C3–C4
Note: Spinal innervation varies somewhat in different people. The spinal nerves listed here are averages and may differ in a particular patient; thus, an allowance of a segment above and below those listed in most text tables should be considered.
Structural and Neurologic Considerations
The healthy posterior neck provides stability and support for the cranium, a flexible and protective spine for movement, balance adaptation, and housing for the spinal cord and vertebral artery. From a biomechanical viewpoint, primary cervical subluxation syndromes may reflect themselves in the total habitus; from a neurologic viewpoint, insults may manifest throughout the motor, sensory, and autonomic nervous systems. Unlike the lumbar region, cervical disc herniations are not frequently associated with severe trauma; however, traumatic nerve root or cord compression has a high incidence in this area.
A general classification of musculoskeletal disorders of the neck is shown in Table 5.3, and the function of the nerves of the cervical plexus and the brachial plexus is shown in Tables 5.4 and 5.5.
Table 5.3. Classification of Musculoskeletal Disorders of the Neck
Adulthood Cervical Disorders Childhood Cervical DisordersCongenital anomalies Acquired torticollis Cervical ribs Congenital deformities Congenital stenosis Inflammatory disease Degenerative disc disease Ankylosing spondylitis Geriatric Juvenile rheumatoid arthritis Spondylosis Vertebral/disc infections Traumatic Metabolic disease and bone dysplasias Inflammatory diseases Central disc calcification Ankylosing spondylitis Diastrophic dwarfism Infections Morquio's disease Rheumatoid arthritis Spondyloepiphyseal dysplasia Systemic disease causing bone texture Trauma alterations Cervical sprain Anemia Cervical strain Hodgkin's disease Fracture or dislocation Leukemia Soft tissue or disc injury Osteoporosis Subluxation Paget's disease Tumors of the cervical spine Trauma of the cervical spine and cord Primary (uncommon) Acute herniated disc Secondary (rare) Fracture or dislocation With neural deficit Complete quadriplegia Infantile Cervical Disorders Incomplete quadriplegia Birth Injuries Anterior cord syndromes Bone injuries Brown-Sequard syndrome Cord injuries Central cord syndromes Delivery-related subluxations Nerve root injury Epidural hemorrhages Without neural deficit Nerve injuries Stable Congenital disorders of cervical spine Unstable Atlanto-occipitalization Soft tissue or disc injury Basilar invagination With neural deficit Congenital torticollis Cord signs Odontoid process dysplasia Root signs Spinal dystrophia Without neural deficit Vertebral fusion Subluxation-fixation Tumors Primary, of bone Secondary, metastatic Men: lung, prostate Women: breast
Table 5.4. The Cervical Plexus
Segment Function C1 Motor to head and neck extensors, infrahyoid, rectus capitis anterior and lateral, and longus capitis. C2 Sensory to lateral occiput and submandibular area; motor, same as C1 plus longus colli. C3 Sensory to lateral occiput and lateral neck, overlapping C2 area; motor to head and neck extensors, infrahyoid, longus capitus, longus colli, levator scapulae, scaleni, and trapezius. C4 Sensory to lower lateral neck and medial shoulder area; motor to head and neck extensors, longus coli, levator scapulae, scaleni, trapezius, and diaphragm. Nerve Function Cervical cutaneous Sensory to skin over anterolateral portion of neck. Greater auricular Sensory to skin over parotid, jaw angle, ear lobe, and front of mastoid process. Lesser occipital Sensory to skin behind ear and mastoid process. Muscular branches Motor to capitus anterior and lateralis, longus capitus, longus colli, hyoid muscles, sternocleidomastoideus, trapezius, levator scapulae, scalenus medius. Phrenic Sensory to costal and mediastinal pleura and pericardium. Motor to diaphragm. Supraclaviculars Sensory to skin over medial infraclavicular area, pectoralis major and deltoid.
Table 5.5. The Brachial PlexusSegment FunctionC5 Sensory to clavicle level and lateral arm (axillary nerve); motor to deltoid, biceps; biceps tendon reflex. Primary root for shoulder abduction, exits between C4–C5 discs. C6 Sensory to lateral forearm, thumb, index and half of 2nd finger (sensory branches of musculocutaneous nerve); motor to biceps, wrist extensors; brachioradialis tendon reflex. Primary root for wrist extension, exits between C5–C6 discs. C7 Sensory to second finger; motor to wrist flexors, finger extensors, triceps; triceps tendon reflex. Primary root for finger extension, exits between C6–C7 discs. C8 Sensory to medial forearm (medial antebrachial nerve), ring and little fingers (ulnar nerve); motor to finger flexors, interossei; no reflex applicable. Primary root for finger flexion, exits between C7–T1 discs. T1 Sensory to medial arm (medial brachial cutaneous nerve); motor to interossei; no reflex applicable. Primary root for finger abduction, exits between T1–T2 discs. Nerve Function Axillary Motor to deltoid muscle; sensory to lateral arm and deltoid (silver dollar) patch on upper arm. Median Motor for thumb opposition and abduction; sensory to distal radial aspect of index finger. Musculo- Motor to biceps muscle; sensory to lateral forearm. cutaneous Radial Motor for wrist and thumb extension; sensory to dorsal web space between thumb and index finger. Ulnar Motor for little finger abduction; sensory to distal ulnar aspect of little finger.
Miscellaneous-Syndromes Involving the Posterior Neck
See Table 5.6.
Table 5.6. Miscellaneous-Syndromes Involving the Posterior Neck
Name of Syndrome Symptom ComplexCostoclavicular Compression, irritation, or stretching on the nerves or vessels at the cervicobrachial outlet resulting in pain or other disturbances in the arm and/or hand. Klippel-Feil's Limited neck motion, low hairline, and shortness of neck as a result of a reduction in the normal number of cervical vertebrae or fusion of multiple hemivertebrae into one mass. Radicular Restricted mobility of the spine and root pain as the result of lesion of the roots of the spinal nerve. Rust's Stiff neck, restricted head carriage, and the necessity of grasping the head with both hands in lying down or arising from a recumbent position. It occurs in phthsis, cancer, spinal fracture, rheumatism, arthritis, and syphilitic periostitis. Sudeck-Leriche's Osteoporosis and vasospasm following trauma. Weinberg's This syndrome of spinal cord tumor at the foramen magnum is characterized by the presence of pain in the cervical or occipital regions, tending to extend down both arms to the elbows and aggravated by coughing, sneezing, and other extreme movements. The evolution of other symptoms epends on the extent of the tumor and direction of its growth. Tumors projecting into the posterior fossa produce symptoms of intracranial pressure such as nystagmus, papilledema, vertigo, ataxia, past pointing, and asteriognosis. Signs occurring in this syndrome, not specifically characteristic of spinal cord tumors, are paresis of infrabuccal facial nerves, atrophy of the muscles of the upper extremities, and speech difficulties.
Anomalies and Deformities
Gross anomalies are rarely seen in chiropractic practice unless well adapted to the individual's life-style. Those cases that have biomechanical significance vary in severity from minor to severe and occur multiply or singly. The cause is purely genetic transmission in about 35% of cases, and the remainder is due to environmental factors or a mixture of genetic and environmental factors.
BASIC INVESTIGATIVE APPROACH
Subtle and asymptomatic anomalies in the cervical area frequently predispose subluxations from minor stress and underlie a pathologic process. Many anomalies do not become symptomatic unless the effects of trauma or degeneration are added. The primary concerns are whether the deformity will increase with growth and normal activity and how much does the deformity contribute to the degree of cervical instability and neurologic deficit present.
A listing of the bony anomalies of the cervical spine of which all practitioners should be acquainted is shown in Table 5.7.
Table 5.7. Types of Bony Anomalies of the Cervical Spine
Region of Anomaly Type of DefectAtlas and Axis Atlas arch dysplasia Odontoid dysplasia Cranio-occipital Atlantoid assimilation Occipital dysplasia Basilar coarction Occipital vertebrae Condylar hypoplasia Lower Cervical Cervical rib Fusion failure (eg, spina Failure of segmentation bifida, spondylolisthesis) (eg, Klippel-Feil syndrome)
BASIC LABORATORY WORKUP CONSIDERATIONSBlood smear Serum alkaline phosphatase Tuberculin test CBC and differential Serum calcium Urinalysis EEG Serum growth hormone Urine amino acids R-A text Serum parathyroid hormone Urine mucopolysaccarides Sedimentation rate Skull x-ray Serum acid phosphatase Spinal roentgenography
Cervical Rib and Related Syndromes
Anomalous development of extra ribs in the region of the cervical vertebrae may be found singularly, bilaterally, or multiple bilaterally. The condition is usually seen at C7, and the cause is a variation in the position of the limb buds. It may vary from a small nubbin to a fully developed rib. A small rudimentary rib may give rise to more symptoms than a well-developed rib because of a fibrous band attached between the cervical rib and sternum or 1st thoracic rib. The incidence of cervical rib is more frequent in women in the ratio of 3 to 1.
BASIC INVESTIGATIVE APPROACH
A cervical rib rising from C7 and ending free or attached to the T1 rib appears in the neck as an angular fullness that may pulsate because of the presence of the subclavian artery above it. It rarely produces symptoms, and it is usually first noticed when percussing the apex of the lung. The bone can be felt behind the artery by careful palpation in the supraclavicular fossa. It can also be readily demonstrated by roentgenography. Pain or wasting in the arm and occasionally thrombosis may occur from the impaired circulation effected.
Grieve points out that some clinicians are far too anxious to blame upper limb paresthesiae on the presence of a cervical rib just because it is there. Many patients with a cervical rib have no complaints, many without a cervical rib have similar complaints, and many with complaints have symptoms on the contralateral side of a unilateral cervical rib. However, when any anomaly such as a cervical rib is seen roentgenographically, the examiner should be suspicious that other anomalies not as evident may be associated.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
The 4th and 5th decades mark the highest incidence of the cervical rib syndrome, probably because of regressive muscular changes. Trauma is a common precipitating factor. Associated aneurysms of the subclavian artery are rare.
Symptoms usually occur at age 12 or later, after the ribs have ossified. Two groups of symptoms are seen, those of scalenus anticus syndrome and those due to cervical-rib pressure. Also see Neurovascular Compression Syndromes.
When symptoms are exhibited, they are usually from compression of the lower cord of the brachial plexus and subclavian vessels such as numbness and pain of varying intensity in the ulnar nerve distribution. This pain is worse at night because of pressure from the recumbent position. Tiredness and weakness of the extremity, finger cramps, numbness, tingling, coldness of the hand, areas of hyperesthesia, muscle degeneration in the hand, a lump at the base of the neck, tremor, and discoloration of the fingers are also characteristic. Work and exercise accentuate these symptoms, while rest and elevation of the extremity relieve them.
Congenital Spinal Stenosis
A degree of congenital narrowing of the cervical vertebral canal, for some reason seen only in males, will easily mimic cervical spondylosis in the young. Progressive thickening of the laminae is often initially diagnosed in error as multiple sclerosis because of the progressive tetraplegic spasticity produced.
A large number of varied anomalies arise from occipital malformations. They are usually characterized by an abnormal shift upward of the atlas and axis with the odontoid protruding above Chamberlain's line. Such anomalies are frequently associated with congenital neural malformations and with other osseous deformities (eg, Klippel-Feil syndrome). As they may remain asymptomatic unless precipitated by compressive forces following trauma or of degeneration, a concern is that these anomalies may easily be confused with the root/cord signs and symptoms of lower cervical spondylosis. Headache, sensory loss, limb pain, and ataxia are often associated.
APLASIA OF THE ARCH OF THE ATLAS
This rare deformity may vary from a slight opening to a complete loss of the anterior arch. Quite often the anomaly is asymptomatic unless precipitated by trauma.
BASILAR IMPRESSION AND PLATYBASIA
Basilar impression is the result of a congenital or an acquired invagination of the odontoid process into the foramen magnum, as measured by the height of the odontoid above Chamberlain's line or McGregor's line on a lateral film. The diagnostic A-P line of Fischgold-Metzger is used to differentiate basilar impression from an abnormally long dens and/or high palate.
In basilar impression, the atlas appears to indent the base of the skull on an A-P film as the odontoid approaches the brain stem. During inspection, the ears will be closer to the shoulders even though the length of the cervical spine is normal. The congenital form is usually associated with other defects such as atlanto-occipital fusion, aplasia of the posterior arch of the atlas, and atlantoaxial dislocation. The acquired form is seen in Paget's disease and bone weakening (eg, osteomalacia, rickets). It is then the result of head weight superimposed on softened structures at the base of the skull. Symptoms do not often appear until later life, and then they can mimic a number of acquired neurologic disturbances.
Basilar impression should not be confused with platybasia, an anthropometric flattening of the base of the skull. It is often associated with congenital atlantoaxial subluxation and occurs in 20% of mongoloid children. Platybasia is found by measuring the angle extend°ing from the clivus and the episthion and finding that it is greater than 130°.
CONGENITAL ATLANTOAXIAL INSTABILITY
Various precipitating factors may be involved in congenital predisposition to atlantoaxial instability. Most common are an abnormal odontoid, a loose cruciate ligament, and atlanto-occipital fusion -- all of which can produce transient narrowing of the spinal canal and compression of its contents.
The normal anterior atlas-dens interval is 3 mm in the adult and 4 mm in the child, particularly during flexion. A distance greater than this indicates a ruptured or stretched transverse cruciate ligament following acute trauma. It should be kept in mind that a hypermobile odontoid is also seen in mongoloids and rheumatoid arthritis. Of equal importance is the corresponding posterior dens-atlas interval that indicates the space available for the tissues within the spinal canal. It is rare to find an adult patient with less than 19 mm of posterior dens-atlas space who is asymptomatic, and cord compression is possible when the space is less than 17 mm.
Atlanto-occipital fusion (atlantal assimilation) is the most common anomaly of this joint, and C2–C3 fusion is associated in 70% of the cases. The gross features are those of Klippel-Feil syndrome.
These rare deformities vary from an abnormally small size (hypoplasia) to a bifid odontoid, os odontoideum (suggesting congenital dysplasia or traumatic nonunion), or complete absence (agenesis). It is easy to confuse congenital absence to that of absorbed nonunion after fracture in early life.
This symptom set, which varies in degree of severity, classically consists of a short neck, a low hair line, and severe neck stiffness associated with fusion of the cervical (and possibly upper thoracic) vertebrae into bony blocks. It is sometimes referred to as congenital cervical synostosis. A case may be structurally severe yet asymptomatic of commonly associated neurologic signs (eg, paresthesia, mirror movements of hands from an underlying neural defect) unless precipitated by trauma. Idiopathic deafness occurs in 30% of cases.
Associated deformities frequently include degrees of scoliosis and kyphosis; hemivertebrae; cervical rib; spina bifida; Sprengel's deformity, which is a small, elevated scapula often connected to the cervical spine; and Turner's syndrome, featuring webbing of the neck, gonadal hypoplasia, and cubitus valgus.
Acquired fusions are differentiated by the facts that
(1) in acquired fusions, the margins of the vertebral body tend to be irregular, disc lines are wider than the adjacent vertebral bodies, the posterior arches are frequently subluxated,
(2) congenital fusions are narrow, the disc remnants are no wider than the adjacent bodies, bony trabeculae tend to cross the disc line, and
(3) associated deformities are not found.
Congenital torticollis is a counterpart of club foot. It is due to shortness of cervical muscles and not spasm. For an unknown reason, it is almost always right-handed. The clinical picture of this deformity is one of contracture of the sternocleidomastoideus, where the head tilts toward the involved side and the chin rotates towards the contralateral side. There is usually a palpable mass of fibrous tissue in the midline of the affected muscle in the infant. The congenital form of torticollis is commonly associated with Klippel-Feil syndrome, atlanto-occipital fusion, and pterygium colli.
Exclusion should be made from acquired muscular torticollis. The birth history will often portray a forceps delivery, and a related, progressing facial deformity is often exhibited in later life. In skeletal torticollis, compensatory scoliosis below the defect may hide the physical picture or asymmetry of the occipital condyles that produces tilting of the atlanto-occipital and atlantoaxial joints. Also see Torticollis: Acquired.
Excessive hypertonicity of a muscle, confirmed by palpatory tone and soreness, will tend to subluxate its site of osseous attachment. The major effects of cervical hypertonicity are shown in Table 5.8.
Table 5.8. Selected Effects of Cervical Area Hypertonicity
Muscle Effect of Prolonged HypertonicityInterspinales Excessive muscle tone between the spinous processes tends to hyperextend the motion unit. Obliquus capitis Increased tone tends to produce a rotary torque of the inferior atlas-axis motion unit. Obliquus capitis Contraction tends to roll the occiput anterior and superior inferior and pull the atlas posterior and superior to produce a lateral occiput tilt and condyle jamming. Rectus capitis Hypertonicity tends to pull the occiput posterior, posterior major inferior, and medial and the spinous of the axis superior, lateral, and anterior. Strong hypertonicity will lock the occiput and axis together so that they appear to act as one unit even though they are not con- tiguous. Scalenus anterior Contraction tends to pull the C3–C6 transverse pro- cesses inferior, lateral, and anterior and the 1st rib superior and medial. Scalenus medius Excessive tone tends to pull the C1–C7 transverse pro- cesses inferior, lateral, and anterior and the 1st rib superior and medial. Scalenus posterior Hypertonicity tends to pull the C4–C6 transverse pro- cesses inferior, lateral, and anterior and the 2nd rib superior and medial. Splenius capitis Increased tone tends to pull the C5–T3 spinous pro- cesses lateral, superior, and anterior and to subluxate the occiput inferior, medial, and posterior. Sternocleidomas- Contraction tends to pull the sternum and clavicle toideus posterior and superior and the occiput inferior and anterior. Upper trapezius Hypertonicity tends to pull the occiput posteroinferior, the C7–T5 spinous processes lateral, and the shoulder girdle medial and superior.
Inflammatory Musculoskeletal Syndromes
Rheumatoid arthritis, ankylosing spondylitis, and various infectious diseases may attack the cervical spine during infancy, childhood, or adulthood.
Cervical Ankylosing Spondylitis
Ankylosing spondylitis is a common adolescent and adult arthritic disorder, attacking the spine and larger joints. It is characterized by ankylosis, joint deformity, spinal pain and rigidity, muscle spasm, and loss of chest expansion. There may be loose ligaments above a rigid axis leading to atlantoaxial dislocation. Disc spaces are rarely narrowed as the ligaments and discs ossify. The patient moves as if his spine were a metal rod, with head and shoulders moving as a unit. A related fracture (usually lower cervical) through an ossified disc produces a characteristic chin-on-chest deformity, without or with paralysis from an associated epidural hemorrhage.
In ankylosing spondylitis, the tissues subjacent to articular cartilage are the first to be affected. Thus, the cartilage is invaded and erodes from below as contrasted to the surface erosion of rheumatoid arthritis. Early diagnosis and management are important to reduce gross deformity. The first signs are not often cervical but found in the dorsal spine (reduced chest expansion), lumbar spine (vertebral body "squaring"), and sacroiliac joints (erosion). The first cervical sign is usually that of reduced lateral flexion, followed by increasing gross neck flexion at rest and upper cervical subluxation. Deformity is usually greatest at the lumbar spine and hips, but spinal motion is lost in the lower cervical region first.
In addition to the disease process itself, a great danger in the ankylosing spine is the addition of trauma. Because the neck is unable to properly extend, any anteriorly directed force to the head can easily inflict a vertebral fracture. This usually occurs through a fused disc area, with or without residual displacement. Regardless, instability is great. Cord damage can readily result from impact if the shear forces produce posterior displacement.
Cervical Pott's Disease
Cervical tuberculosis has the characteristics of joint tuberculosis elsewhere; viz, stiffness due to muscular spasm, malposition of the bones and of the head, and abscess formation. Physical diagnosis depends greatly on wry neck with stiffness of the muscles of the back and neck and pain in the occiput -- a characteristic symptom group. The patient is very protective of neck motion. The chin is often supported by the hand if an abscess is present. Tenderness is present posteriorly on percussion and anteriorly on palpation where an abscess may be felt. Neck pain exists both day and night. It is often relieved somewhat when recumbent and frequently radiates to the occiput and shoulders. Rheumatic or traumatic torticollis, however, may present all these symptoms, and diagnosis may be impossible without the aid of other tests and roentgenology. If in Pott's disease of bone the abscess causes pressure on the anterior spinal cord, a usually spastic paralysis occurs that is characterized by hyperactive reflexes, a positive Babinski, sustained clonus, and difficulty or inability to void.
Cervical Pyogenic Infection
Pyogenic infection, most common in middle age, produces an exudative inflammation with hyperemia leading to osteoporosis and osteomyelitis. Early diagnosis is vital. The first clues are neck pain (possibly referred to the scapula or shoulder), fever, muscle spasm, and sometimes dysphagia with a large prevertebral abscess that may be palpable. In time, the end-plate becomes involved and the infection enters the disc space. Bone destruction leads to collapse. The abscess may enter the cord or a paravertebral abscess may extend into the thorax, or vice versa.
Cervical Rheumatic Disease
This common and highly deforming disorder is a generalized disease of connective tissue that begins in joint synovium. It manifests as neck pain, severe but paroxysmal, that is associated with a mono- or poly-arthritis. In time, ankylosis develops, especially in the upper cervicals, and is demonstrated by restricted motion from ossification of the posterior facets and interspinous igaments. During this process, ligaments loosen in the upper and lower cervical areas encouraging gross vertebral subluxations and dislocations that may possibly be asymptomatic. In late stages, the odontoid may migrate into the foramen magnum and produce cord pressure with various neurologic signs.
The length of the cervical cord and cervical discs is greatest during flexion and least during extension in the normal spine. The opposite is true in the rheumatic spine due to loss of disc and vertebral body height from destruction and absorption.
Even when cervical symptoms are absent, periodic cervical roentgenographs should be taken to assess progress. The initial target areas in the cervical spine are the apophyseal joints and the synovial tissues anterior and posterior to the dens where it articulates with the anterior arch of the atlas and the cruciate ligament. Other tissues affected include the IVDs, spinal ligaments, and extradural alveolar tissue. A genetic susceptibility factor has been shown to be involved in most cases.
DIFFERENTIATION FROM SPONDYLOSIS
In both degenerative and rheumatic spondylosis, involvement of the cervical cord first involves the anterolateral tracts and central gray matter of the cord. The effect is signs of an upper motor (pressure ischemia) lesion with a degree of tetraparesis produced by the reduced A-P dimension of the vertebral canal. Degenerative spondylosis is differentiated from rheumatoid spondylosis in that the latter frequently involves the upper cervical area. Osteophyte formation and end-plate sclerosis are usually absent in rheumatoid spondylosis, unless the two disorders are superimposed. The small peripheral joints are usually also involved in rheumatoid arthritis.
Nerve roots may become entrapped within one or more IVFs from a combination of subluxation, perivascular adhesions, dural adhesions, rheumatoid nodules, granulation tissue, and sequestrated disc tissue. Neck pain, with or without radiation to the arms, weakness, feelings of instability, ataxia, and paresthesiae are common symptoms. However, these cervical symptoms are difficult to differentiate if the disease initiates in the peripheral joints where signs of peripheral entrapment, myositis, tenosynovitis, and subluxated joints from tendon rupture exist. Related giddiness and fainting spells suggest an associated vertebral artery ischemia that is usually associated with the upward migration of the dens that produces a kinking of the vertebral artery at the atlas level.
RHEUMATIC ATLANTOAXIAL SUBLUXATION
Orthopedic subluxation is always a danger, proceeding from the synovitis, apophyseal erosion, and erosion of the vertebral bodies involved that lead to instability from joint destruction and ligamentous laxity. As apophyseal erosion progresses, the dens migrates into the foramen magnum and the atlas becomes fixed to the axis to reduce the possibility of dislocation. These signs determine the severity and prognosis of the general disease.
The characteristic anterior subluxation of the atlas on the axis is generally considered to be an adaptation change to help increase the capacity of the spinal canal as rheumatoid tissue accumulates. If this is true, the decision for clinical reduction presents a dilemma. This anterior subluxation usually occurs only in flexion unless granulation tissue between the atlas and dens prevents reduction during extension. Thus, direct reduction of the orthopedic rheumatic subluxation by either manipulation or traction is usually contraindicated. Jeffreys states: "The incidence of neurological damage in subluxated (rheumatic) spines is very low" and "not infrequently the cord only becomes compromised when the subluxation is reduced."
Intervertebral Disc Syndromes
The two most common disorders of cervical intervertebral discs are degenera- tive disease processes and disc protrusion. These disorders may manifest singularly or be combined.
The clinical picture of cervical disc disorders, states Grieve, is typically a combination of "a hard osseocartilaginous spur, produced by the disc together with the adjacent margins of the vertebral bodies." Furthermore, “the mechanism by which pain and disability originate in the neck region,” contends Cailliet, “can be considered broadly to result from encroachment of space or faulty movement in the region of the neck through which the nerves or blood vessels pass.” This encroachment of space or faulty movement commonly comprises apophyseal subluxation with osteophyte formation, contributing to, or superimposed upon disc degeneration and/or protrusion. This occurs most frequently in the C4–C6 area.
Degenerative Disc Disease
The cervical spine is readily subject to degenerative disc disease because of its great mobility and because it serves as a common site for various congenital defects. Cervical degenerative changes can be demonstrated in about half the population at 40 years of age and 70% of those at 65 years, many of which may be asymptomatic. Bone changes are more common posteriorly in the upper cervicals and anteriorly in the lower cervicals.
Various situations, individually or in combination, may be involved in initiating the process. Typical factors include trauma, postural and occupational stress, biochemical abnormalities (eg, hydration, mucopolysaccharide, collagen, lipid changes), biologic changes (eg, aging), autoimmune responses, psychophysiologic effects (eg, the sodium retention of depression), and genetic predisposition (eg, identical development in twins).
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
Cervical stiffness, muscle spasm, spinous process tenderness, and restricted motion are common features. When pain is present, it is usually poorly localized and often referred to the occiput, shoulder, between the scapulae, arm or forearm (lower cervical lesion), and may be accompanied with paresthesias. Radicular symptoms rarely manifest unless a herniation is present.
Disc Protrusion or Herniation
The discs below C3 exhibit a higher incidence and the greatest severity of herniation. The C5 disc is the most frequently involved, followed by the C6 disc. The C2 disc is the least frequently involved. Pure encroachment of a disc upon the spinal canal or IVF as seen in the lumbar region is not frequently seen in the cervical area.
In acute disorders, interspace narrowing, straightening of the cervical curve, and instability may be the only roentgenographic signs present. Instability will be most evident as aberrant segmental movement in comparative lateral films made during full flexion and extension.
Several structural changes occur in chronic disorders. The vertebral bodies involved become elongated, the normal cervical lordosis flattens, the anterosuperior angle of the vertebral bodies becomes rounded, the involved body interspace narrows, the total height of the neck is reduced, and the inferior apophyseal facet above tends to subluxate posteriorly on the superior facet below and erode the lamina.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
Generally, central herniation produces local neck pain while lateral herniation produces upper extremity pain. If the protrusion is central, cord signs and symptoms exhibit as lower extremity spasticity and hyperactive reflexes. Sensory changes are rarely evident, but the gait may be ataxic. If the protrusion is posterolateral, the nerve root will be involved rather than the cord.
Posterior osteophytes form at the disc attachment peripherally, often compromising the IVFs and vertebral canal. This may be noted by narrowing of the A-P dimension of the spinal canal in lateral films and foraminal encroachment on oblique films. These signs most frequently occur at the C6–C7 level. Anterior osteophytes are considered the result of abnormal ligamentous stress rather than part of the disc degeneration process. They occur most frequently below the C4 level, as do alterations of the covertebral joints.
DIFFERENTIAL DIAGNOSIS TIPS
Specific sensory and motor symptoms of acute disc herniation are shown in Table 5.9. These features vary depending upon the direction of the disc bulge; eg, upon the nerve root, IVF vessels, spinal cord, or combinations of involvement. In some acute and many chronic cases, numbness may manifest without pain. In acute disorders, the cervical signs may be confused with those of shoulder or elbow bursitis, epicondylitis, or subluxation, especially when no local cervical symptoms exist.
Table 5.9. Neurologic Signs in the Cervical RadiculopathiesDisc Nerve Protrusion Root Level FeaturesC2 C3 Posterior neck numbness and pain radiating to the mastoid and ear. The reflexes test normal. C3 C4 Posterior neck numbness and pain radiating along the levator scapulae muscle and sometimes to the pectorals. The reflexes are normal. C4 C5 Lateral neck, shoulder, and arm pain and paresthesia, deltoid weakness and possible atrophy, hypesthesia of C5 root distribution over middle deltoid area (axillary nerve distribution). The reflexes test normal. C5 C6 Pain radiating down the lateral arm and forearm into the thumb and index finger; hypesthesia of the lateral forearm and thumb; decreased brachio- radialis reflex; brachioradialis, biceps, and supinator weakness. C6 C7 Pain radiating down the middle forearm to the middle and index fingers, hypesthesia of the middle fingers, decreased triceps and radial reflexes, triceps and grip weakness. C7 C8 Possible pain radiating down the medial forearm and hand to the little finger, ulnar hypesthesia, intrinsic muscle weakness of the triceps and grip. However, these symptoms are uncommon. The reflexes are normal.
Autonomic Involvement. Vague autonomic symptoms may be exhibited such as dizziness, blurred vision, and hearing difficulties. These can usually be attributed to involvement of the plexus around the vertebral artery or intermittent disruption of the blood flow.
Lhermitte's Sign. With the patient seated, flexing the patient's neck and hips simultaneously with the patient's knees in full extension may produce sharp pain radiating down the spine and into the upper or lower extremities. When pain is elicited, it is a positive sign that suggests irritation of the spinal dura matter either by a protruded cervical disc, a tumor, a fracture, or multiple sclerosis.
Vertebral Artery Compression. Associated subluxation and osteophyte development may produce vertebral artery compression, especially if a degree of arteriosclerosis is present. Symptoms of unsteadiness, dizziness, and fainting spells occur. This is especially true when the head is rotated to the opposite side.
Masses and Swellings
Carbuncles, lipomas, and neoplasms are the common masses found in the area of the posterior neck.
Metastatic tumors are more common in adulthood than in youth. In men, metastasis is usually from the prostate gland or lung; in women, from the breast. In metastatic lesions, pain is constant, day and night, and not relieved with rest. The pain is increased by palpation, percussion, and movement. Cord tumors usually present pain with an insidious onset, but other early neurologic symptoms and signs are not always present during the early stages.
Most cancerous tumors are associated with some degree of bone destruction, and a mass may or may not be palpable. Osseous tumors, benign or malignant, intramedullary or extramedullary, infrequently occur in youth. Neck pain is typical, and paralysis may or may not be present.
Neurovascular Compression Syndromes
There are several syndromes to consider under the classification of neurovascular compression syndromes (also termed thoracic outlet or inlet syndromes), each of which may produce the symptom complex of radiating pain over the shoulders and down the arms, atrophic disturbance, paresthesias, and vasomotor disturbances. These syndromes, however, do not necessarily indicate the specific cause of the problem.
BASIC INVESTIGATIVE APPROACH
The cervicothoracic junction area is a unique area of the spine. It is a common site of developmental anomalies; it is a major site of arterial, lymphatic, and neurologic traffic; and it presents the juncture of the highly mobile cervical spine with the very limited thoracic spine. The area of cervicothoracic transition is a complex of prevertebral and postvertebral fascia and ligaments subject to shortening. It offers a multitude of attaching and crossing muscles -- all of which are subject to spastic shortening and fibrotic changes that tether normal motion.
The etiologic theories of cervicobrachial syndromes are numerous; eg, compression of nerve trunks, trauma to nerve trunks, injuries to the sympathetic and vasomotor nerves, trauma to the scalenus anterior muscle, embryologic defects, postural or functional defects, narrowing of the upper thoracic cap as a result of adjacent infections or anatomic defects, acute infection producing myositis, intermittent trauma to the subclavian artery, or a cervical rib.
The 4th and 5th decades mark the highest incidence of trouble in this area, probably because of regressive muscular changes. The incidence is more frequent in females in the order of 3:1. This is probably due to weaker upper-extremity development.
Trauma to the head, neck, or shoulder girdle is a common precipitating factor. In some cases, poor posture, anomalies, or muscle contractures may be involved. Reduced tone in the muscles of the shoulder girdle, by itself, has been shown to allow depression of the clavicle that narrows the thoracic outlet and compresses the neurovascular bundle. In addition, subluxation syndromes (eg, retrolisthesis) may initiate these and other disturbances of the shoulder girdle and must be further evaluated.
Cervical pathology such as spinal canal or IVF encroachment by a buckling ligamentum flavum, spinal stenosis, or spurs should be a consideration. During degeneration, the dura and dentates become thickened, dura and arachnoid adhesions become prevalent, osteochondrophytes may develop from the borders of the canal or foramen -- all of which tend to restrict the cord and/or nerve root during cervical motions. Osteochondrophytes near the foramen can readily compress the vertebral artery and root together.
Differential diagnosis should exclude a cervical rib etiology from infectious neuritis, binding adhesions, arthritis of the shoulder joint, clavicle fracture callus, bifid clavicle, cervical arthritis, subacromial bursitis, 1st rib subluxation and posttraumatic deformities, spinal or shoulder girdle tumors, Pancoast's tumor of the lung apex, and cardiac disease. Aneurysms of the subclavian artery are rarely involved.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
Symptoms usually do not occur until after the ribs have ossified. Two groups of symptoms are seen, those of scalenus anticus syndrome and those due to cervical rib pressure. The symptoms of cervical rib and scalenus syndrome are similar, but the scalenus anticus muscle is the primary factor in the production of neurocirculatory compression whether a cervical rib is present or not.
When symptoms are present, they are usually from compression of the lower cord of the brachial plexus and subclavian vessels such as numbness and pain in the ulnar nerve distribution. See Table 5.5. Pain is worse at night because of pressure from the recumbent position, and its intensity varies throughout the day. Tiredness and weakness of the arm, finger cramps, numbness, tingling, coldness of the hand, areas of hyperesthesia, muscle degeneration in the hand, a lump at the base of the neck, tremor, and discoloration of the fingers are characteristic. Work and exercise accentuate symptoms, while rest and elevation of the extremity relieve symptoms.
Neurologic vs Vascular Compression. Compression of nerve tissue results in numbness, pain, paralysis, and loss of function. Compression of vascular structures results in moderate pain, edema, swelling, and obstruction of circulation that may result in clotting within the vessels with possible consequent infarction in the tissues supplied. Adson's and similar signs will be positive. These unilateral phenomena are limited to the cervicobrachial distribution.
DIFFERENTIAL DIAGNOSIS TIPS
Several pertinent tests are described below. X-ray films should always be taken before performing a cervical compression test, especially when the patient has experienced trauma or shows physical signs of advanced degeneration. It is important to rule out possible conditions that would be aggravated by any testing procedure.
Active Cervical Rotary Compression Test. With the patient seated, he or she should be observed while voluntarily laterally flexing the head toward the side being examined. With the neck flexed, the patient is then instructed to rotate the chin toward the same side, which narrows the IVF diameters on the side of concavity. Pain or reduplication of other symptoms probably indicates a physiologic narrowing of one or more IVFs.
Adson's Test. With the patient seated, the examiner palpates the radial pulse and advises the patient to bend the head obliquely backward to the opposite side being examined, take a deep breath, and tighten the neck and chest muscles on the side tested. This maneuver decreases the interscalene space (anterior and middle scalene muscles) and increases any existing compression of the subclavian artery and lower components (C8 and T1) of the brachial plexus against the 1st rib. Marked weakening of the pulse or increased paresthesiae indicate a positive sign of pressure on the neurovascular bundle, particularly of the subclavian artery as it passes between or through the scaleni musculature, thus indicating a probable cervical rib or scalenus anticus syndrome.
Cervical Distraction Test. With the patient seated, the examiner stands to the side of the patient and places one hand under the patient's chin and the other hand under the base of the occiput. Slowly and gradually the patient's head is lifted to remove weight from the cervical spine. This maneuver elongates the cervical IVFs, decreases the pressure on the joint capsules around the facet joints, and stretches the paravertebral musculature. If the maneuver decreases pain and relieves other symptoms, it is a probable indication of narrowing of one or more IVFs, cervical facet syndrome, or spastic paravertebral muscles.
Eden's Test. With the patient seated, the examiner palpates the radial pulse and instructs the patient to pull the shoulders backward, throw the chest out in a “military posture,” and hold a deep inspiration as the pulse is examined. The test is positive if weakening or loss of the pulse occurs, indicating pressure on the neurovascular bundle as it passes between the clavicle and the 1st rib -- thus indicating a costoclavicular syndrome.
Passive Cervical Compression Tests. Two tests are involved. First, with the patient seated, the examiner stands behind the patient. The patient's head is laterally flexed and rotated slightly toward the side being examined. Interlocked fingers are placed on the patient's scalp and gently pressed caudally. If an IVF is physiologically narrowed, this maneuver will further insult the foramen by compressing the disc and narrowing the foramen, producing pain and reduplication of other symptoms. In the second test, the patient's neck is extended by the examiner who then places interlocked fingers on the patient's scalp and gently presses caudally. If an IVF is physiologically narrowed, this maneuver mechanically compromises the foraminal diameters bilaterally, producing pain and reduplication of other symptoms.
Shoulder Depression Test. With the patient seated, the examiner stands behind the subject. The patient's head is laterally flexed away from the side being examined. The doctor stabilizes the patient's shoulder with one hand and applies pressure alongside the patient's head with the palm of the other hand; stretching the dural root sleeves and nerve roots or aggravating radicular pain if the nerve roots adhere to the foramina. Extravasations, edema, encroachments, and conversion of fibrinogen into fibrin may result in interfascicular, foraminal, and articular adhesions and inflammations that will restrict fascicular glide and the ingress and egress of the foraminal contents. Thus, pain and reduplication of other symptoms during the test suggest adhesions between the nerve's dura sleeve and other structures around the IVF.
Spurling's Test. This is a variation of the passive cervical compression test. The patient's head is turned to the maximum toward one side and then laterally flexed to the maximum. A fist is placed on the patient's scalp, and a moderate blow is delivered to it by the other fist. The patient's position produces reduced IVF spaces, and the blow causes a herniated disc to bulge further into the IVF space or an irritated nerve root to be aggravated, thus increasing the symptoms.
Wright's Test. With the patient seated, the radial pulse is palpated from the posterior in the downward position and as the arm is passively moved through an 180° arc. If the pulse diminishes or disappears in this arc or if neurologic symptoms develop, it may indicate pressure on the axillary artery and vein under the pectoralis minor tendon and coracoid process or compression in the retroclavicular space between the clavicle and 1st rib -- thus indicating a hyperabduction syndrome.
Nuchal rigidity refers to a spasmotic contraction of the posterior muscles of the cervical spine. Also see Stiff Neck and Torticollis.
The most common cause of nuchal rigidity, by far, is meningitis. However, the sign is not pathognomonic. A number of inflammatory conditions may be involved. For example:Carbuncle Epidural abscess Osteomyelitis Cellulitis Encephalitis Retropharyngeal abscess Cervical pyogenic Meningitis Rheumatoid spondylitis infection Myositis/fibrositis Sprain
Several other conditions must also be eliminated. For example:Fracture Pyramidal tract disease Subluxation (acute) Mediastinal emphysema Spinal cord tumor Tuberculosis Metastasis Spondylosis Parkinsonism Subarachnoid hemorrhage
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
See Table 5.10.
Table 5.10. Nuchal Rigidity and Associated Symptoms
Syndrome: Nuchal Rigidity + Primary Suspect Disorder(s)Focal neurologic signs Cerebral hemorrhage Osteomyelitis Cerebral abscess Spondylosis Encephalitis Subluxation (acute) Meningitis Pyrexia Cervical pyogenic in- Osteomyelitis fection Retropharyngeal abscess Meningitis Subarachnoid hemorrhage Retinal hemorrhage and Collagen disease Subarachnoid hemorrhage pyrexia Stroke Tremor and diffuse spasm Parkinsonism
BASIC LABORATORY WORKUP CONSIDERATIONSBlood smear and culture Psychometric tests Tuberculin test CBC and differential Sedimentation rate Urinalysis Chest x-ray Serum ceruloplasmin level Urine culture EEG Serum copper level VD serology Hair analysis Skull x-ray Nose and throat culture Spinal roentgenography
An underlying neurologic insult is considered to be the most frequent cause of posterior neck pain; however, the focus of irritation may be either local or remote. In addition to biomechanical and traumatic causes, neoplasms, cerebrospinal inflammations, and arthritic conditions must always be considered.
Disturbances of nerve function associated with subluxation syndromes manifest as abnormalities in sensory interpretations and/or motor activities. These disturbances may be through one of two primary mechanisms: direct nerve or nerve root disorders, or of a reflex nature.
See Table 5.11.
Table 5.11. Typical Causes of Posterior Neck PainNeurologic Traumatic Inflammatory Psychologic VascularCompression Abscess Brachial neuritis Angina pectoris Contusion Dental infection Cervical subluxa- Dissecting aortic Dislocation Fibrositis tion syndrome aneurysm Fracture Lymphadenitis Multifidi trigger Subarachnoid Hematoma Meningitis point hemorrhage IVD syndrome Myalgia Postural subluxa- Temporal arteritis Rheumatoid arth- tion complex ritis Psychoneurosis Riedel's struma Scalenus anticus Trichinosis syndrome Tuberculosis Sternocleidomas- toid trigger point TMJ dysfunction Trapezius trigger point Degenerative Neoplastic Deficiency Congenital Carcinoma Cervical spondylosis Branchial cyst Cyst Osteoarthritis Cervical rib Hodgkin's disease Pott's disease Congenital diverticulum Metastasis Platybasia Pancoast tumor Other anomalies Spinal cord tumor
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
See Table 5.12.
Table 5.12. Posterior Neck Pain and Associated SymptomsSyndrome: Posterior Neck Pain + Primary Suspect Disorders Mass Bony congenital anomaly Lipoma Carbuncle Lymphadenitis Cyst Metastatic carcinoma Hematoma Tuberculosis Nuchal rigidity Atlantoid fracture Subarachnoid hemorrhage Dens fracture Subluxation (acute) Meningitis Torticollis Radiation absent Angina pectoris Remote subluxation reflex Ankylosing spondylitis Retropharyngeal abscess Cervical spondylosis Subluxation (mild) Fibrositis Sternocleidomastoideus Meningitis trigger point Multifidi trigger point Torticollis (variable) Pyogenic infection Trapezius trigger point Radiation to one or both Angina pectoris Pancoast's tumor upper extremities Cervical IVD syndrome Scalenus anticus syndrome Cervical rib Spinal cord tumor Cervical spondylosis Subluxation complex Cervicobrachial syndrome Trauma (eg, whiplash)
BASIC LABORATORY WORKUP CONSIDERATIONSCBC and differential Serum alkaline phospha- Spinal roentgenography Chest x-ray tase Throat culture EMG Serum calcium Tuberculin test Sedimentation rate Serum phosphorus Urinalysis Serum acid phosphatase Skull x-ray VD serology
The two most common gross reflections of postural distortion in the cervical spine are curve reversal and scoliosis. These disorders many occur singularly or be combined.
Cervical Curve Reversal
As compared with the primary thoracic kyphosis which is a structural curve, the cervical and lumbar anterior curves are functional arcs produced by their wedge-shaped IVDs. They normally flatten in the non-weightbearing supine position and quickly adapt to changes involving the direction of force.
BASIC INVESTIGATIVE APPROACH
A flattened cervical spine in the erect posture resembles a normal spine during flexion. The nucleus of the disc serves as a fulcrum during flexion and return extension. When the spine is subjected to bending loads during flexion, half of the disc on the convex side suffers tension, widens, and contracts, while the other half of the disc on the concave side suffers compression, thins, and bulges. Concurrently, the nucleus bulges on the side of tension and contracts on the side of compression, which increases tension on the adjacent anulus. This creates a self-stabilizing counteracting flexion force to the motion unit that aids a return to the resting position.
A pathologic straightening of the normal anterior curve of the cervical spine, as viewed in a lateral weight-bearing x-ray film, results in mechanical alteration of normal physiologic and structural integrity. The normal vertical A-P line of gravity, as viewed laterally, falls approximately through the odontoid and touches the anterior border of T2. As the cervical spine tends to flatten in the erect position, the gravity line passes closer to the center of the cervical discs.
Although the cervical curve is the first secondary curve to develop in the infant, its maintenance in the erect posture is essentially determined by the integrity of the lumbar curve. A flattened cervical spine that is not compensatory to a flattened lumbar spine may be the result of a local disorder such as a subluxation syndrome caused by posterior shifting of one or more disc nuclei, hypertonicity of anterior musculature, or anterior ligamentous shortening as the result of local overstress, inflammation, occupational posture, or congenital anomaly.
The clinical picture is often the result of trauma-producing whiplash injury, herniated disc, subluxation, dislocation, fracture, or ligamentous injury. Torticollis, arthritis, malignancy, tuberculosis, osteomyelitis, and other pathologies may also be involved. The condition occurs more frequently after the age of 40, and the sexes appear equally affected.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
Cervical flattening is usually the result of paraspinal spasm secondary to an underlying injury, irritation, or inflammatory process. The acute clinical picture is one of torticollis. Other manifestations include headaches (occipital, occipital-frontal, supraorbital), vertigo, tenderness elicited on lateral C4–C6 nerve roots, neuritis involving branches of the brachial plexus due to nerve-root pressure, hyperesthesia of one or more fingers, and loss or lessening of the biceps reflex on the same or contralateral side. Infrequently, the triceps reflex may be involved. One or more symptoms are often aggravated by an abnormal position of the head such as during reading in bed, an awkward sleeping position, or long-distance driving.
The typical radiographic findings include loss of the normal lordotic curve by the straightened cervical spine (78% cases), anterior and posterior subluxation on flexion and extension views, narrowing of IVD spaces at C4–C6 in 46% cases, discopathy at the affected vertebral level as the injury progresses, and osteoarthritic changes that are often accompanied by foraminal spurring.
Cervical scoliosis is often mechanically predisposed by flattening rather than exaggeration of the cervical lordosis. This is quite common during youth. The posterior joints become relatively lax during flattening of the cervical spine, and this encourages retropositioning and posterior subluxations that are frequently the first step toward cervical scoliosis.
BASIC INVESTIGATIVE APPROACH
When viewed from the posterior, the vertical line of gravity passes through the occipital protuberance and the vertebrae's spinous processes. In cervical scoliosis, the midcervical spinous processes, especially, tend to deviate laterally from this line.
In typical rotary cervical scoliosis, the spinous processes tend to rotate toward the convex side of the lateral curve, the vertebral bodies rotate toward the concave side, and the discs and articular facets become subjected to abnormal stretching forces as they open on the side of convexity and to compressive forces on the side of concavity. This type of cervical scoliosis is usually the compensatory effect of a lower scoliosis to the other side and a common cause of recurring episodes of nontraumatic torticollis.
When a cervical disc is loaded unilaterally, the disc initially becomes wedge-shaped and the normally parallel vertebral plateaus form an angle. This vertically stretches the anular fibers that are opposite the weight-bearing side, but this action is quickly counteracted by forces transmitted laterally from the resilient nucleus to help the disc return to its normal shape. This self-stabilization factor is the product of a healthy nucleus and anulus working as a mechanical couple.
In cervical scoliosis, there are also disc reactions to rotary forces that must be considered. As the apposing layers of anular fibers run alternately oblique in opposite directions, the oblique disc fibers angled toward the direction of twist become stretched when a vertebra rotates, and the oblique fibers running against the direction of rotation tend to relax. The greatest tension from stretch is seen centrally where the fibers are nearly horizontal. This increases nuclear pressure by compression in proportion to the amount of rotation. If severe, the nucleus can be dislodged from its central position.
Cervical scoliotic rotation is also associated with a lateral tilt that increases the distance between the lateral margins of the vertebral bodies on the convex side of the curve. This stretches the lateral anulus, which produces a contraction of that part of the disc and a compensatory bulging of its contralateral (thinned) aspect. If the anular filaments become stretched, weakened, and the disc loses some of its stiffness property, the nucleus may shift from its central position so that the vertebral segment is unable to return to its normal position. A firmly locked rotational subluxation can result.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
When continuous compression is applied to any active and mobile joint, cartilaginous erosion followed by arthritis can be expected. When continuous stretching is applied to any active and mobile synovial joint, capsulitis can be anticipated.
If scoliotic rotation takes place evenly among the cervical segments and the cervical nuclei hold their relatively central position in the discs, the situation is usually asymptomatic even though erosion and arthritis can be demonstrated on roentgenographs. However, if a nucleus fails to hold its central position and shifts laterally away from the point of maximum compression, the superimposed vertebra is encouraged to produce a fixed clinical subluxation.
Shaken Infant Syndrome
The term shaken infant syndrome is relatively new to health-science literature. Parents who would never strike an infant sometimes have a tendency to shake the child roughly during a moment of irritation or frustration in an attempt to “shake some sense into him.”
It is obvious that infants and young children have disproportionate heavy heads that rest on underdeveloped cervical structures. Severe shaking can result in brain damage, cerebral hemorrhage, mental retardation, brain stem ruptures, spinal cord injury, occipital or cervical subluxation or dislocation and their varied consequences, eye damage, and even death.
Cervical spondylosis is a chronic condition in which there is progressive degeneration of the IVDs leading to secondary changes in the surrounding vertebral structures, including the posterior apophyseal joints. It can be the result of direct trauma (eg, disc injury), occupational stress, aging degeneration, or found in association with and adjacent to congenitally defective vertebrae.
BASIC INVESTIGATIVE APPROACH
Three not infrequent diseases of the cervical spine with biomechanic implications are spondylosis, rheumatic spondylitis, and ankylosing spondylitis. In each of these conditions, severe subluxation is a cardinal manifestation.
Spondylosis may produce compression of either the nerve root or spinal cord. During the degenerative process, intradisc pressure decreases, the anulus protrudes, and the end-plates approximate due to reduction of disc thickness. As the disc protrudes, it loosens the attachment of the posterior longitudinal ligament. This allows the anulus to extrude into the cavity formed between the posterior vertebral body and the ligament, and this portion of the anulus, in time, becomes fibrous and then calcifies. Because of this process, posterior osteophytes prevail in the cervical and lumbar regions, while anterior spurs are more common to the dorsal spine.
The incidence is high in the second half of life with increasing severity in advancing years; 60% at 45 years, 85% at 65 years. The degenerative process, which may or may not progress, appears greatest in those segments below the maximum point of the lordosis because of the loading forces in the upright posture. Signs are most often seen at the C5 level, and next in frequency at the C6 level.
Pre-existing spinal stenosis, a thickened ligamentum flavum, a protruding disc, and spur formation may complicate the picture of cervical spondylosis. The weight of the head in faulty posture (eg, exaggerated dorsal kyphosis and cervical lordosis) along with activity stress may contribute to chronic degenerative spondylosis that is often superimposed upon asymptomatic anomalies. A vicious cycle is often seen in which subluxation contributes to degenerative processes and these processes contribute to subluxation fixation.
Jeffreys points out that there appears to be a correlation of cervical spondylosis to carpal tunnel syndrome, lateral humeral epicondylitis, cervical stenosis, and low back and/or lower extremity osteoarthritis. There is almost no correlation between the degree of pain in the neck and the degree of arthritic changes noted in x-ray films.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
The onset is usually rapid and insidious but may be subjectively and objectively asymptomatic. The classic picture, however, is one of a middle-aged person with greatly restricted cervical motion, marked muscle spasm, positive cervical compression signs, insidious neck and arm pain and paresthesia aggravated by sneezing or coughing, acute radiculopathy from disc herniation, and usually some muscle weakness and fasciculations.
Whiting lists the manifestations that develop in spondylosis to also include neck crepitus, subjective or objective; local neck tenderness; headaches; neck pain radiating to the scapulae, trapezius, upper extremities, occiput, or anterior thorax; extremity muscle weakness; paresthesia of the upper and/or lower extremities; dizziness and fainting; impaired vibration sense at the ankle; hyperactive patellar and Achilles reflexes; and positive Babinski responses.
Due to the constant weight of the head, postural strains, occupational insults, degrees of congenital anomalies, and posttraumatic or postinfection effects with or without an associated disc involvement, the development of chronic degenerative spondylosis offers some distinct progressive characteristics:
(1) flattening of the cervical spine from muscular spasm and adhesion development;
(2) A-P fixation and restricted mobility;
(3) thinning of the atlanto-occipital and atlantoaxial articular plates, resulting in motion restriction;
(4) middle and lower cervical disc wearing and thinning that narrow the IVFs;
(5) disc weakness encouraging nuclear shifting and herniation contributing to nerve encroachment;
(6) osseous lipping and spurs with extensions into the IVFs; and
(7) infiltration and ossification of paravertebral ligaments adding to inflexibility and pain upon movement.
DIFFERENTIAL DIAGNOSIS TIPS
Nelson believes that head weight and postural strains are overemphasized. “It has often been established clinically that unless overt trauma can be shown, most neck problems are the result of reflex vasospasm where the reflex originates in the viscera below the diaphragm. Everyone would be affected if weight of the head and postural strains were common causes.”
Regardless of the merit of this controversial concept, it is important to avoid the pitfall of assuming that all the patient's symptoms involving the neck and upper extremities are caused by a cervical spondylosis when it is found radiographically. Cervical spondylosis is common, and symptoms may thus be associated with unrelated neurologic disorders that may coexist with the spondylosis, making the diagnosis more difficult.
A stiff neck may be exhibited that does not represent a central nervous system involvement (eg, meningitis, subarachnoid hemorrhage) or a spastic contracture. See Nuchal Rigidity and Torticollis.
Diffuse neck stiffness is a common manifestation in subluxation syndromes, children with febrile diseases and tonsillar herniation, chronically ill patients, and elderly patients with fibrositis and/or spondylosis. The following additional etiologies should also be excluded:Amoebic invasion Froin's syndrome Multiple sclerosis Arteritis Fungus infection Mumps Brain abscess Lead poisoning Sarcoidosis Brain carcinomatosis Leukemia Subarachnoid hemorrhage Brain tumor Lymphoma Syphilis Brucellosis Meningism Tuberculosis Cerebral thrombosis Meningitis Ventricular hemorrhage
ASSOCIATED TRIGGER POINTS
The cervical and suprascapular areas of the trapezius, usually a few inches lateral to C7, frequently refer pain and deep tenderness to the lateral neck (especially the submastoid area), temple area, and angle of the jaw. The sternal division of the sternocleidomastoideus refers pain chiefly to the eyebrow, cheek, tongue, chin, pharynx, throat, and sternum. The clavicular division refers pain mainly to the forehead (bilaterally), back of and/or deep within the ear, and rarely to the teeth. Other common trigger points involved in "stiff neck" are in the levator scapulae, the splenius cervicus lateral to the C4–C6 spinous processes, and the splenius capitis over the C1–C2 laminae. These points are not often found unless the cervical muscles are thoroughly relaxed during palpation.
From a neurologic viewpont, segmental insults may manifest themselves throughout the motor, sensory, and autonomic nervous systems. From a biomechanical viewpoint, they may reflect themselves in the total body habitus.
Subluxations, regardless of region, are difficult to classify under normal categories of trauma because they can involve bone, joint, muscle, ligament, disc, nerve, cord, lymphatic and vascular tissues. Thus, subluxation is usually considered a finding and a syndrome and not a diagnosis.
BASIC INVESTIGATIVE APPROACH
A careful study of most clinical subluxations will reveal that they are infrequently "unusual" positions. Commonly, they are normal positions in a state of fixation. In the neutral position, for example, an inferior atlas subluxation-fixation exhibits the posterior arch of the atlas approximating the spinous process of the axis --the normal position of the atlas during extension. The same is true of superior, posterior, and lateral listings: all are normal positions if found in flexion, rotation, or lateral bending, but abnormal if found in other positions.
If subluxation of a vertebra occurs in a superior direction, the contents of the intervertebral foramen become compressed. Anatomic disrelationship by elongating the short diameter of the intervertebral foramen will cause indirect pressure upon the nerve trunk from compression between the fibrous tissue in the anterior portion of the foramen. If there is movement in an inferior direction, enlargement of the foramen occurs. Because the nerve sheath is firmly anchored by tissues connecting it to the borders of the foramen, a stretching effect is exerted on the nerve sheath, altering its shape. It can thus be appreciated that enlarging the intervertebral foramen can cause as much trouble as a reduction in size. In addition, it is impossible to subluxate a vertebra between C2 and L5 inclusive without changing the shape of the intervertebral disc in compensation.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
Once a vertebra loses its ideal relationship with contiguous structures and becomes relatively fixed at some point within its normal scope of movement, it is no longer competent to fully participate in ideal coordinated spinal movement. The affected area becomes the target for unusual weight bearing and traumatic stress. In addition to attending circulatory and static changes in the involved area, there is disturbed neural activity that may be exhibited as changes in superficial and deep reflexes, tremors and spasms, hyperkinesia, and pupillary changes. Autonomic-related symptoms include cardiac arrythmia, glandular disturbances, changes in gastrointestinal activity, etc. These disturbances may be through one of two primary mechanisms: (1) direct nerve or nerve root disorders or (2) of a reflex nature.
Circulatory Changes. Loss of mobility of one or more segments of the spine correspondingly influences circulation within the intervertebral foramen. The resulting partial anoxia has a harmful influence upon nerve function. It is unlikely that circulation to the nerve would be disrupted without first irritating or compressing the nerve because the arteries and veins are much smaller, the blood pressure within the lumen makes them resistant to compression, and nerve tissue is much more responsive to encroachment irritation.
Motor Changes. Nerve root insults from subluxations may also be evident as disturbances in motor reflexes and/or muscular strength. Examples of these reflexes include the deep tendon reflexes such as seen in the reduced biceps reflex when involvement occurs between C5–C6; or the reduced triceps reflex when involvement occurs between C6–C7. These reflexes should be compared bilaterally to judge whether the hyporeflexia is unilateral. Unilateral hyperreflexia is pathognomonic of an upper motor neuron lesion. Prolonged and/or severe nerve root irritation may also cause evidence of trophic changes in the tissues supplied.
Sensory Changes. When direct nerve involvement occurs in the posterior root of a specific neuromere, it manifests as an increase or decrease in sensitivity over the dermatome. A typical example includes foraminal occlusion or irritating factors exhibited clinically as hyperesthesia, particularly on the dorsal and lateral aspects of the thumb and radial side of the hand when involvement occurs between C5–C6. Another example is on the dorsum of the hand, the index and middle fingers, and the ventroradial side of the forearm, thumb, index and middle fingers when involvement occurs between C6–C7. In other instances, this nerve root involvement may cause hypertonicity and the sensation of deep pain in the musculature supplied by the neuromere. For example, in C6 involvement, there is deep pain in the biceps; and in C7 involvement, there is deep pain in the triceps and supinators of the forearm. Direct pressure near the nerve root or along its distribution may be particularly painful.
The typical subluxation picture is rarely pure. It is often superimposed upon subclinical processes in the mature patient such as mild vertebral instability, osteochondrophytic ridges at the uncovertebral joints, apophyseal thickening and exostosis, canal encroachment by a buckling ligamentum flavum, and spinal stenosis. Other factors include posterior vertebral body spurs, disc protrusions, dura and dentate thickening, arachnoid cysts, dura and arachnoid adhesions, and/or ossification of the posterior longitudinal ligament.
Loss of disc space, especially in the lower cervical area, may contribute as a source of chronic irritation to an already inflamed root by altering the angulation of the IVF tunnel. The sequence of inflammation, granulation, fibrosis, adhesion formation, and nerve root stricture may follow, along with a loss in root mobility and elasticity. These degenerative changes are not as pronounced during youth.
Inasmuch as all freely movable articulations are subject to subluxation, the atlanto-occipital diarthrosis is no exception. The stress at this point is unusual when one considers that the total weight of the cranium is supported by the ring of the atlas, about 1/20th the circumference of the skull, and a variety of spinal muscles, subject to spasm and hypertonicity, have their attachments on the occiput.
BASIC INVESTIGATIVE APPROACH
Neurologic disturbances may result from muscular and fibrotic changes along the cranial nerve pathways that emit from the skull and pass intimately between and under suboccipital fasciculi. Five of the cranial nerves are thus vulnerable: the facial, glossopharyngeal, vagus, spinal accessory, and hypoglossal. In addition, circulatory impairment of major and minor nerves of the neck may alter the function of those cranial nerves that do not exit from the skull proper such as the olfactory, optic, oculomotor, trochlear, trigeminal, abducens, and auditory, but which are contained within the cranium and remote from vertebral subluxation encroachment effects.
We should not overlook the fact that it is essentially muscle which produces and maintains the subluxation. Concern must be given to why the subluxation is produced.
COMMON OCCIPITAL SUBLUXATIONS
Right/Left Condyle Inferior or Superior. A unilateral suboccipital muscle spasm causes the affected condyle to be pulled deep into the articulating concavity of the atlantal lateral mass on one side (sunken condyle). This may not be attended by a degree of rotation. Inspection from the back shows a low, medially inclined mastoid process on the side of involvement. Palpation discloses the mastoid riding close to the transverse process of the atlas, tension and tenderness in the groove between the mastoid and the lower jaw, and fullness in the groove between the occiput and the posterior ring of the atlas on the side of involvement. A right or left condyle superior may be considered the converse aspect of a right or left condyle inferior. That is, as one condyle is pulled inferior and anterior, the other condyle presents a superior and posterior picture, or vice versa. There are certain situations, however, that indicate a unilateral abnormality without converse adaptation. This latter condition usually follows a blow to the vertex downward when the head is somewhat laterally flexed and the condyle on the side of the concavity is jammed into the lateral mass of the atlas (eg, spearing tackle).
Right/Left Condyle Inferior with Associated Anterior Rotation. All atlanto- occipital movements tend to be associated with a degree of rotation because the occipital condyles and the articulating surfaces of the lateral masses of the atlas approximate each other more at the anterior than the posterior. Thus, most sunken condyles will be associated with a relative amount of rotation. On the side of involvement, inspection from the back reveals a medial head tilt. Palpa- tion indicates approximation of the mastoid and transverse process of the atlas and approximation of the inferior nuchal ridge and the posterior arch of the atlas on the involved side. These points are widened on the opposite side. A right or left superior condyle with associated posterior rotation is often considered the contralateral aspect of a right or left inferior condyle related to an anterior rotation. Illi feels it is always attended by a degree of arthritis, and he determines the primary subluxation roentgenographically by the side showing the greatest degree of degenerative articular alteration.
Right/Left Condyle Inferior with Associated Posterior Rotation. This type of subluxation or its contralateral representation is less common than that associ- ated with anterior rotation. It usually results from vigorous twisting trauma such as in athletic contact activities. On the side of involvement, inspection from the back shows the head held in a tipped, stiff position with some posteri- or deviation. Palpation discloses a mastoid that is inferior and posterior in relation to the transverse process of the atlas, with the inferior nuchal ridge approximating the posterior arch of the atlas.
Suboccipital Jamming. This common subluxation, frequently caused by a tri- geminal (ophthalmic division) reflex, is often seen in people under severe visual or mental stress. Irritative impulses cause contraction of suboccipital muscles that pull the occiput upon the posterior arch of the atlas, creating a painful bilateral condylar jamming. A compressive vertex blow is a rare cause. Palpation reveals suboccipital spasm, tenderness, nodular swellings, and a closing of the inferior nuchal ridge on the posterior arch of the atlas. Although the condition is usually bilateral, one side may be affected more than the other.
Being near the end of a kinematic chain, the atlanto-occipital joints are subject to numerable degrees of subluxation in flexion, extension, rotation, and laterality. Rotary subluxation is not uncommon, especially if the atlantal cups are shallow. Excessive rotation is allowed by the lax check ligaments and capsules. Head weight, the angle of force, the planes of articulation, and the integrity of the para-articular tissues determine the stability present. There are no bony intervertebral foramina for passage of C1 and C2 spinal nerves, thus avoidance of the IVF encroachments that are produced in the lower spine.
BASIC INVESTIGATIVE APPROACH
Disturbances in this area usually arise from muscular spasm of one or more of the muscle bundles that have attachments on the occiput, atlas, or axis. Unequal tension and ultimate fibrotic changes within the paravertebral structures can readily influence the delicate nerve fibers and vascular flow.
The dura mater of the spinal cord is firmly fixed to the margin of the foramen magnum and to the 2nd and 3rd cervical vertebrae. In other spinal areas, it is separated from the vertebral canal by the epidural space. Since both the C1 nerve and the vertebral artery pass through this membrane and both are under the superior articulation of the atlas and beneath the overhanging occiput, atlanto-occipital distortion may cause traction of the dura mater producing irritation of the artery and nerve unilaterally and compressional occlusion contralaterally. These facts help us understand those cases of suboccipital neuralgia where a patient upon turning his head to one side increases the headache and vertigo that are relieved when the head is turned to the opposite side.
There is also a synapse between the upper cervical nerves and the trigeminal that also supplies the dura mater, which explains why irritation of C1 results in a neuralgia not only confined to a small area at the base of the skull but is also referred to the forehead or eye via the supraorbital branch of the trigeminal. The greater occipital nerve does not tend to do this. It exits between the posterior arch of the atlas and above the lamina of the axis, referring pain to the vertex of the head.
COMMON ATLAS SUBLUXATIONS
Right or Left Lateral Atlas. A sideslip between atlas and axis articulations is invariably attended by a degree of superiority and anteriority because of the inclination of the articulating surfaces. Only in cases of severe force will this not be the case. Ipsilaterally, palpation will reveal the transverse process of the atlas to be more lateral and slightly superior and anterior than its counterpart.
Bilateral Superior or Inferior Atlas. In this type of subluxation, the atlas tips up or down bilaterally in its transverse plane without an attending side- slip. Deep palpation may reveal the posterior arch of the atlas either approximating the occiput with a gap between the posterior tubercle of the atlas and the spinous of the axis or approximating the spinous process of the axis with a gap between the posterior tubercle and the occiput.
Right or Left Anterior Rotations of the Atlas. These subluxations are often associated with vagal syndromes because the anteriorly rotated transverse of the atlas may easily press against the vagus nerve. In such a rotatory state, the counterpart of an atlas listed right anterior would be left posterior. On the side of involvement, inspection from the back reveals suboccipital fullness. Bilateral palpation of the posterior ring of the atlas reveals a prominence on the side of posteriority, with the transverse process of the atlas being closer to the mastoid and its counterpart closer to the lower jaw.
NEUROVASCULAR IMPLICATIONS OF UPPER CERVICAL SUBLUXATIONS
Cerebrospinal Circulation. Any event that would cause constriction in the connecting area between the cerebral subarachnoid space and the vertebral canal limits the escape of cerebrospinal fluid into the inferior vertebral canal. This results in a degree of increased intracranial pressure. An atlanto-occipital subluxation may cause the dura mater of the cisterna cerebellaris to be pressed against the posterior medullary velum and partially occlude the foramina of Luschka and Magendie and interfere with the flow from the 4th ventricle. The resulting increase of intraventricular fluid accumulation may create a large variety of symptoms such as deep-seated, stubborn, "internal pressure" head- aches, nausea, a tendency toward projectile vomiting, bizzare and unusual visual disturbances, and protopathic ataxia.
Greater-Occipital-Nerve. Rotary subluxations of the axis are common mechanical causes of cervical migraine. This cervical neuralgia of C2 is typically unilateral, beginning in the upper neck and extending over the skull into the temporal and possibly the orbital areas. Like other types of migraine, reflex gastrointestinal disturbances are usually associated but visual prodomal disturbances are not.
Medulla Oblongata. The medulla oblongata extends well into the lower reaches of the foramen magnum and the ligamentous ring that connects it with the atlas, thus any type of occipital or atlantal subluxation may produce abnormal pressure on this portion of the brain stem. Bilateral posterior shifting of the occiput or atlas may cause pressure upon the pyramids or adjacent olivary bodies, producing a syndrome of upper motor neuron involvement characterized by a degree of spastic paralysis or ataxia. A lateral shifting of the occiput may cause pressure upon the tubercle of Rolando producing pain in the area of trigeminal nerve distribution, headache, sinus discomforts, ocular neuralgias, and aches in the jaw.
Vagus Nerve. As the vagus lies almost in immediate contact with the trans- verse process of the atlas, rotary subluxation of the atlas may cause pressure which produces a wide range of symptoms. The syndrome produced may exhibit as nasal and sinus congestion, swallowing and speech difficulties, cardiac arrythmias, coronary artery spasm, gastric and intestinal colic, and other symptoms of vagal disturbance.
Vertebral Arteries. Janse states that any cervical subluxation (particular- ly atlantal, axial, or occipital) provoking muscle spasm may produce unilateral or bilateral constriction of the vertebral arteries, resulting in circulatory impairment. A large number of equilibrium, cardiac, respiratory, cranial nerve, extrapyramidal, visual, and auditory symptoms may follow. West points out that the vertebral artery has been completely occluded by just turning the head backward and to the opposite side during postmortem studies. Even without a degree of arteriosclerosis, the vertebral artery can be considered a quite firm tube in the adult that responds poorly to twisting and pressure.
Vertebral Veins and Deep Cervical Veins. Spasm of the suboccipital muscles may cause a decided impediment of venous drainage from the suboccipital area via the vertebral and deep cervical veins, resulting in a passive congestion with consequent pressure upon the sensory nerve endings in the area. This is perceived by the patient as unilateral or bilateral pain and a throbbing discomfort, and may be palpated as knotty lumps within suboccipital muscles.
The vertebral nerve (sympathetic) runs along the vertebral artery within the arterial foramen of the cervical transverse processes. Neuritis is considered to occur from mechanical irritation to the vertebral artery anywhere along its course, producing symptoms of a vasomotor nature; eg, headache, vertigo, tinnitus, nasal disturbances, facial pain, facial flushing, and pharyngeal paresthesias.
Irritative lesions involving the cervical region and its articulations may in turn irritate the sympathetic nerve plexuses ascending into the head via the vertebral and carotid arteries. Many cases of visual and aural symptoms occur with upper cervical distortion where the arch of the atlas snugly hugs the occiput, thus possibly irritating the sympathetic plexus of nerves on the vertebral arteries as well as partial compression of the vessels. To appreciate this, we must remember that the visual cortical area of the occipital lobe (cuneate lobe and calcarine fissure area) require an ideal blood supply that is dependent on the sympathetics ascending the great vessels of the neck, and this holds true for the inner ear as well. To test this syndrome, De Rusha suggests having the supine patient read some printed matter while the examiner places gentle traction on the skull cephally, separating occipital and atlantal articulations. A positive sign is when the patient, often to his surprise, experiences momentarily enhanced visual acuity or a reduction in tinnitus.
Cailliet points out that although sympathetic fibers have not been found along the cervical roots, surgical decompression of an entrapped nerve root relieves symptoms attributed to the sympathetics. The mechanism for this effect is not clear.
With the possible exception of L5, no other vertebra is probably subluxated more frequently than C2. The most common symptom is a unilateral suboccipital neuralgia on the side of posteriority. Sometimes called cervical migraine, the neuralgia typically begins in the upper neck and extends over the skull into the temporal and possibly the orbital areas. On the side of posteriority, palpation discloses a tender prominence over the articulating process and a contralateral deviation of the spinous process away from the midline. Posterior axis (or occipital) subluxations are sometimes misdiagnosed as anterior atlantal subluxations.
Rotary subluxations of one or more of the upper three vertebrae (particularly the axis) may cause pressure upon the superior cervical ganglion. The syndrome produced may incorporate excessive facial and forehead perspiration, dry mouth and nasal mucous membranes, dryness and tightness of the throat, dilated pupils, tendency towards exophthalmos, migrainous attacks due to unilateral angioneurotic edema, facial vasomotor disturbances with possible angioneurotic swelling, and moderate tachycardia with functional arrythmias.
De Rusha points out that dysphagia and dysarthria may at times be due to upper cervical involvement rather than a central nervous system situation. The C1 joins the hypoglossal cranial nerve, which supplies the intrinsic muscles of the tongue. It then descends to join the descending cervical which is derived from C2 and C3. A loop of nerves, the ansi hypoglossi, which supplies muscles necessary for deglutition and speaking, is derived from C1–C3.
The superficial sensory cutaneous set of the cervical plexus (C1–C4) is frequently involved in subluxations of the upper four segments, particularly when there are predisposing spondylotic degenerative changes. See Table 5.4.
Janse describes four resultant neuralgias:
Cervical cutaneous neuralgia: involving the area of the middle third of the platysma to the midline, possibly extending from the chin to the sternum.
Greater auricular neuralgia: extending in front and behind the auricle and the skin over the parotid gland, paralleling the distribution of the auriculotemporal branch of the trigeminus. It is easily misdiagnosed as chronic trifacial neuralgia.
Lesser occipital neuralgia: involving the area of the occipitalis muscle, mastoid process, and upper posterior aspect of the auricle.
Supraclavicular neuralgia: depending upon which rami are affected, this neuralgia may involve the suprasternal area, pectoral area, or deltoid area. Thus, sternoclavicular and acromioclavicular neuralgias may originate in the spinal levels of the supraclavicular nerve.
Lower Cervical Subluxations
A subluxation of one or more of the lower cervical vertebrae often involves the brachial plexus (C4–T1). Inasmuch as the distribution of the brachial plexus is so extensive, a multitude of abnormal reflections may be seen in its areas of distribution which must be appreciated by knowledge of the pathophysi- ology involved. See Table 5.5.
A few of the more common disturbances caused by lower cervical subluxations would include shoulder neuralgias, neuralgias along the medial arm and forearm or elbow, unclassified wrist drop and hand dystrophies, acroparesthesia, weak grip strength, and vague "rheumatic" wrist or hand complaints. A subluxation of one or more of the C3, C4, or C5 segments may involve the phrenic nerve and produce symptoms of severe chronic hiccup and other diaphragmatic disorders.
Subluxation-Induced Reflex Syndromes
Various spinosomatic and spinovisceral syndromes may result from cervical subluxation. For example, the involvement may be in the area of C1–C4. This area includes the cervical portion of the sympathetic gangliated chain and the IX–XII cranial nerves as they exit from the base of the skull and pass into their compartments within the deep cervical fascia. The syndrome may include
(1) suboccipital or postocular migraine,
(2) greater occipital nerve extension neuralgia,
(3) mandibular, cervical, auricular, pectoral, or precordial neuralgia,
(4) paroxysmal torticollis,
(5) congestion of the upper respiratory mucosa, paranasal sinuses, or eustachian tube with hearing loss,
(6) cardiorespiratory attacks,
(7) ocular muscle malfunction,
(8) pathologic hiccups,
(9) scalenus anticus syndrome, and
(10) painful spasms in the suboccipital area.
Phillips states that if a subluxation produces a stretching of the paravertebral musculature, there will be a continuous barrage of afferent impulses in the Ia fibers. “These afferent impulses monosynaptically bombard the alpha motor neurons causing the paravertebral musculature to go into tetany (spasm). There is a cessation of this afferent barrage when the stretch is released. The muscle stretching also initiates afferent impulses in the Group II afferents from flower spray endings which may reinforce the spastic muscle condition.” He goes on to say that trauma to facet joints, disturbed articular relationships, spasms of closely related muscles, and overlying trigger points --all the results of a subluxation-- set up a barrage of flexor-reflex afferent impulses via Group II--IV fibers that converge upon the internuncial pool in lamina seven of the spinal cord. “This abundant supply of flexor-reflex afferent impulses excites the alpha motor neurons through multisynaptic connections causing an excess of excitation of paravertebral muscles resulting in spasm.”
Acquired torticollis (wry neck) is a severely stiff neck syndrome produced by contraction of the neck muscles, causing the head to be drawn to one side with the chin pointing contralaterally. Also see Torticollis: Congenital.
Acquired torticollis may have a traumatic, an inflammatory, or a neuropathic origin, or be of various superimposed factors. The condition may be either continuous (tonic) or spasmodic (clonic). The tonic type is frequently seen in cervical Pott's disease of bone and psychoneurotic states. Considerable care must be taken to determine the etiology and differentiate its many possible causes. See Table 5.13.
Table 5.13. Typical Causes of TorticollisNeurologic Endocrine Traumatic Inflammatory Psychologic Vascular MetabolicDislocation Adenitis Conversion hysteria Fracture Carbuncle Depression Postural overstress Dental abscess Neuritis Scars Fibromyositis Radiculitis Sprain Postinfectious Remote subluxation Sternocleidomas- encephalitis reflex toideus hematoma Retropharyngeal Subphrenic reflex Strain abscess Trigger point(s) Subluxation Tonsillitis Unilateral cold Tuberculosis Degenerative Allergic Neoplastic Deficiency Congenital Autoimmune Toxic Brain stem tumor Spondylosis Cerebral palsy Multiple L-dopa Cerebellar tumor Vertebral caries Cervical rib sclerosis Phenothiazin Spinal cord tumor
Cervical Subluxation. The most common direct cause of torticollis is that from irritating cervical subluxation (eg, trauma, rotational overstress, unilateral chilling, unilateral lifting, instability). Subluxation may also be an asymptomatic complicating factor to various etiologic factors.
Barge believes that the structural cause of torticollis is often a rotatory vertebral malposition and abnormal disc wedging, where the nucleus of an in- volved disc has been forced to shift away from compressive forces. The patient's symptoms are often self-limiting with time and rest that allows the disc to expand in its nonweightbearing (decompressed) state and the vertebral facets to be relieved of their jammed position. It can be theorized, however, that if the neck does not achieve this subluxation correction through disc imbibition a rotatory scoliosis is produced in adaptation so that the victim may at least have a straight eye level. But, as the now chronic subluxation has not been fully corrected, it can serve as a focus for morbid neurologic and degenerative processes, especially at the zygapophyses, covertebral joints, and IVFs.
Inflammation. “Wry neck” spasm (tonic, rarely clonic) of the sternocleido- mastoideus and trapezius may be due to irritation of the spinal accessory nerve or other cervical nerves by swollen glands, abscess, acute upper respiratory infections, scar, or tumor. A spontaneous subluxation of the atlas may follow severe throat infection (eg, bacterial pharyngitis). Neck rigidity may also be the result of a sterile meningitis from blood in the cerebrospinal fluid. Thus, if a patient has slight fever, rapid pulse, and rigid neck muscles, subarachnoid hemorrhage should be suspected. Lateralizing signs are often indefinite.
Neuropathic and Idiopathic Forms. Focal neuropathic causes include ocular dysfunctions, syringomyelia, and tumors of the spinal cord or brain. Idiopathic forms are seen in acute calcification of a cervical disc, rheumatic arthritis, tuberculosis, or "nervous" individuals. Nelson feels that wry neck may also be the result of a subphrenic or subclinical visceral irritation being mediated reflexly into the trapezius and cervical muscles.
Severe Trauma. Traumatic dislocations of upper cervical vertebrae cause a distortion of the neck much like that of torticollis. A rotary fracture- dislocation of a cervical vertebra, especially of the atlas on the axis or the axis on C3, will produce neck rigidity and a fast pulse, but fever is absent. Local and remote trigger points are frequently involved. Even in mildly suspicious cases, the neck should always be x-rayed in two or more planes before it is physically examined.
COMPENSATORY CERVICAL DEVIATIONS
There are four major types of compensatory cervical deviation that resemble true torticollis:
(1) When there is marked lateral curvature of the spine, with or without Pott's disease, the head may be inclined so far to the opposite side that torticollis is simulated.
(2) When the power of the two eyes is markedly different, as in some varieties of astigmatism, the head may be habitually canted to one side to assist vision.
(3) In some cases due to none of the above causes, habitual or occupational postures may produce the physical condition.
(4) Forced attitude from cerebellar disease may resemble torticollis.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
The pain associated with acute torticollis is thought to be attributed essentially to zygapophyseal capsulitis and covertebral joint inflammation. This can generally be confirmed by palpation and should not be confused with the pain from stretching the rigid muscles on the side of the concavity.
See Table 5.14.
Table 5.14. Torticollis and Associated SymptomsSyndrome: Torticollis + Primary Suspect DisordersNeurologic signs absent Adenitis Scars Fibromyositis Trigger point Psychoneurosis Unilateral cold Radiculitis Cervical rib Spondylosis Fracture Subluxation Spinal cord tumor Tuberculosis Other neurologic signs Brain stem tumor Fracture Brain tumor Multiple sclerosis Cerebellar tumor Postinfectious Cerebral palsy encephalitis
BASIC LABORATORY WORKUP CONSIDERATIONSBlood smear and culture Psychometric tests Tuberculin test CBC and differential Sedimentation rate Urinalysis Chest x-ray Serum ceruloplasmin level Urine culture EEG Serum copper level VD serology Hair analysis Skull x-ray Nose and throat culture Spinal roentgenography
DIFFERENTIAL DIAGNOSIS TIPS
Following is a classification, based on Barge's findings, of three major types of torticollis that are the result of disc lesions.
Type I: Lateral Torticollis. In lateral torticollis, the patient's neck is rigidly flexed laterally and locked, and usually accompanied by a degree of rotation of the chin away from the side of tilt. The spinous process of the involved vertebra will usually palpate as being distinctly lateral as compared to its neighbor above and below.
From either traumatic or degenerative causes, the stiffness property of anular filaments may be so weakened as to allow considerable nuclear shifting within the disc. Barge feels that lateral shifting of the firm nucleus and consequent inferior tilting of the superimposed vertebra as it falls on a weakened anulus is the primary cause of lateral torticollis. Thus, a lateral nuclear shift to one side would be accompanied by disc compression on the other side, and the vertebral body above would tend to rotate away from the relatively higher side of the disc (nuclear site), following the plane of its base of support. It should be remembered that the nucleus serves as a ball-bearing-like fulcrum of movement of the superimposed vertebra.
The lateral tipping of the centrum causes the inferior apophyseal facet of the vertebra to ride down on the side of the thinned disc and up on the side to which the nucleus has shifted. This is usually within the range of physiologic movement. However, the added rotation of the centrum causes the inferior facet of the vertebra to separate (open) on the side of rotation, stretching the apophyseal capsule and covertebral synovial tissues beyond their normal limit, while the inferior facet on the other side merely rides up and serves as a pivot point for subluxation. This would encourage apophyseal capsulitis and covertebral inflammation, with profound reflex spasm to splint the affected area locked by the displaced nucleus.
Type II: Anterior Torticollis. With anterior torticollis, the subject's cervical area is rigidly projected forward. In severe cases, all cervical motions are restricted. In mild cases, the complaint may be only a "stiff neck."
It should be kept in mind that the relatively small atlas must provide an upward push equal to the weight of the head. This is about a 14-lb static resistance force for a 200-lb individual. If the head is tilted so that its center of mass is not in line with both atlantal articulations, the cervical muscles opposite the direction of tilt must contract to maintain equilibrium. If the muscles and ligaments at the base of the skull do not check the compressive and shear forces, failure can readily produce a degree of subluxation.
Using the same reasoning as given for lateral torticollis, anterior torticollis is predisposed by a flattened area in the cervical spine that allows laxity of the zygapophyseal check ligaments, a posterior shifting of a nucleus, posterior disc bulge, and anteroinferior displacement of the superimposed vertebra (following the plane of its base of support) as its inferior facets ride up the superior facets of the subjacent vertebra. The spinous process can frequently be palpated as being distinctly superior.
As the inferior facets of the involved vertebra tip anteroinferior on the superior facets below, a pivot action occurs that overstretches the apophyseal capsules posteriorly. If severe, this will produce an apophyseal capsulitis and local tenderness will be acute. If the atlas has displaced anteriorly on the axis, a capsulitis may also occur at the atlantal-dens articulation and/or less frequently at the dens-cruciate junction.
Type III. Anterolateral Torticollis. Anterolateral torticollis is the most frequently seen type. It exhibits a combined lateral and anterior torticollis subluxation. The patient's neck is grossly projected forward and to one side, and the symptoms are usually intense. The disc mechanism involved is the same as that for lateral and anterior torticollis except that the involved nucleus is thought to shift obliquely in a posterolateral direction.
The above described types of torticollis are merely models for points of study. Within an individual case, any type may occur singularly or in combination and may involve one or more vertebral segments.
Trauma: Cervical Spine Syndromes
Many cervical spine injuries can be attributed to the relatively small vertebral bodies, the wide range of movement in many planes, and the more laterally placed intervertebral articulations that require the nerve roots to leave the spinal canal in an anterolateral direction. Fortunately, there is greater space within the cervical canal than below.
Due to its mobility and structure, the cervical spine is one of the most frequent sites of severe spinal nerve injury and subluxations. A wide variety of cervical contusions, strains and sprains, subluxations, disc syndromes, dislocations, and fractures will be seen in clinical practice.
Cervical spine injuries can be classified as being
(1) mild (eg, contusions, strains);
(2) moderate (eg, subluxations, sprain, occult fractures, nerve contusions, neuropraxias);
(3) severe (eg, axonotmesis, dislocation, fracture without neurologic deficit); and
(4) dangerous (eg, fracture and/or dislocation, spinal cord injury).
Contusions in the neck are similar to those of other areas. They often occur in the cervical muscles or spinous processes. Painful bruising and tender swelling will be found without difficulty, especially if the neck is flexed. They present little clinical significance unless severe scarring or deeper fixations occur.
BASIC ROENTGENOLOGIC CONSIDERATIONS
A well-founded appreciation of normal variations, epiphyseal architecture, development defects, and congenital anomalies is a distinct aid in evaluating injuries of the cervical area. After the age of 8 years, the neck, with few exceptions, attains an adult form where growth plates present few diagnostic problems.
If routine cervical views are normal, then oblique, open-mouth odontoid, flexion, and extension views with most extreme care should be taken to verify symptoms. Flexion and extension stress views will indicate the extent of ligament rupture and bony displacement, but the danger of causing further damage is great.
A complete radiographic study of the cervical spine can usually be accom- plished with the views of the Davis or the modified-Davis series. Such a series is recommended when there is a history of trauma to the cervical spine and adjacent tissues or a history of chronic complaint and symptoms of possible pathology. Subtle fractures are often found only on laminagrams or tomograms.
With close inspection, one may sometimes note a lucent line tracking along the anterior margin of the cervical vertebrae, representing fatty tissue between the esophagus and anterior longitudinal ligament. This strip may be displaced anteriorly in spinal trauma and present the only evidence of injury.
CLASSIC EFFECTS OF CERVICAL TRAUMA
See Table 5.15.
Table 5.15. Classic Effects of Cervical Trauma
Force DescriptionCompression Excessive compression forces on the neck commonly lead to facet jamming and fixation, isolated or multiple fractures of the atlantal ring, or vertical, oblique, or bursting fractures of the lower cervical bodies. Hyperextension The effects of posterior bending moments may include hyperflexion sprain of the anterior ligaments, wedging of the posterior anulus and vertebral body, posterior subluxation, horizontal fracture of the anterior arch of the atlas, fracture of the anteroinferior margin of a vertebral body, compression of the posterior arch and associated structures, posterior bilateral or unilateral dislocation, spinous process fracture, and traumatic spondylolisthesis. Hyperflexion Excessive anterior bending forces may produce hyperflexion sprain of the posterior ligaments, compressive wedging of the anterior anulus and vertebral body, anterior subluxation, anterior bilateral or unilateral dislocation with locked facets, and spinous process avulsion. Abnormal widening of a spinous interspace on a lateral roentgenograph should arouse suspicion of ruptured posterior ligaments. Hyperrotation Excessive segmental rotation about the longitudinal axis produces anterior or posterior ligament torsion overstress, rotary subluxation, spiral loosening of the nucleus pulposus, and unilateral or bilateral atlas-axis dislocation. The traumatic moments involved invariably include shear forces. Lateral The effects of excessive lateral bending include transverse hyperflexion process fracture, uncinate process failure, lateral dislocation-fracture of the odontoid process, lateral wedging of the anulus and vertebral body, and brachial plexus trauma. Shear Excessive shearing forces create disruption of the anterior or posterior ligaments, end-plate displacement, anterior or posterior subluxation or dislocation, anterior or posterior fracture displacement of the dens, and anterior compressive fracture of the anterior ring of the atlas or a vertebral body.
Atlas Fractures and Dislocations
Atlanto-occipital dislocations or fractures, often bilateral, are usually quickly incompatible with life. Any severe orthopedic subluxation in the upper cervical area can lead to cord damage that produces sensory loss, quadriplegia, or death, often with little warning and few symptoms to differentiate it initially from a mild strain. Thus, it is always better to be extra cautious (and be accused of being overly concerned in mild injuries) to insure against a possible disaster. Signs and symptoms vary from subtle to severe pain and gross motor involvement. Tenderness may be acute over the posterior atlas, aggravated by mild rotation and extension.
BASIC INVESTIGATIVE APPROACH
The cervical spine has a natural lordosis that normally dissipates axial forces. However, as the neck moves from the extended to the flexed position, a position is reached where the vertebrae are fairly aligned vertically. A rapid compression overload in this position is most likely to result in an exploding- type fracture.
Of all atlantoid fractures, those of the posterior arch are the most common yet easily overlooked as the displacement is usually mild. The common site is at the narrowest portion just posterior to each lateral mass, usually at the groove for the vertebral artery. Retropharyngeal swelling is frequently absent, and oblique views are often necessary for demonstration.
Most authorities state that fractures of the anterior arch are rare, minimally displaced, usually comminuted, and frequently require tomography to be detected. However, Iversen/Clawson feel that fractures to the anterior arch are quite common and found either in the midline or just lateral to the midline.
CLASSES OF ATLAS FRACTURES AND DISLOCATIONS
The atlas may be fractured at its posterior arch, ring, or anterior arch. There are six common types of severe injury, all of which are serious. See Table 5.16. An examiner should keep in mind that nontraumatic dislocations (eg, from congenital anomalies, arthritis, infection) of the upper cervical complex are more common than traumatic dislocations and their possibility should never be overlooked.
Table 5.16. Classic Types of Atlas Fractures and Dislocations
Type DescriptionAtlanto-occipital Usually, but not always, anterior displacement of the occiput Dislocation on the atlas occurs from a severe horizontal force from behind that shears the skull across the atlas, rupturing the articular capsules, and damaging the medulla. This rare occurrence can often be accurately evaluated by computing Powers ratio on a lateral roentgenograph. Atlas dislocation The atlas may displace anteriorly on the axis or the occiput with fractured dens posteriorly on the atlas and fracture the odontoid process if the ligaments hold. The force may be hyperextensive or hyperflexive. The patient may survive if extreme care is taken in transportation to the hospital. If the transverse ligament is avulsed from the atlas, a small fragment of bone may lie between the odontoid and the cord. If the odontoid is displaced posteriorly, the situation is usually fatal because of injury to the cord. Posttraumatic spontaneous fusion of C1 to the occiput is always a potential complication if the patient survives. Fractured posterior Neck hyperextension injuries may cause compression injury arch of the atlas to the vertebral arteries causing a temporary oxygen loss to the brain that may result in unconsciousness, if not greater damage through rupture. Fracture usually occurs from a severe vertical compression force during extension where the lateral masses are fixed between the condyles and the pillars of the axis and the posterior ring fractures and displaces outward. A base fracture of the odontoid is often associated. If a fracture line is not evident on lateral roentgenography (differentiated from congenital clefts), headache, suboccipital pain, stiffness, acute suboccipital jamming, and subtle signs of basilar insufficiency from compression of the vertebral artery should still stimulate suspicions. Jefferson fracture A more severe vertical compression blow may split the Atlas and burst the lateral masses outward, disrupting both the anterior and posterior rings into several fragments. Ring fractures are frequently produced by blows on top of the head where vertical forces are dispersed laterally. Keep in mind that if a severe axial force is produced through the skull downward, the inclined condyles of the occiput serve as a mechanical wedge upon the atlas. This is usually evident in an open-mouth x-ray view. Overhang of the atlantal lateral masses and widening of the paraodontoid space will be associated. Severity depends upon fragment displacement relative to the cord and other vital tissues. That is, if the ligaments do not retain these fragments, death from cord damage will be likely. Atlas-axis In C1–C2 A-P dislocations, C1 most often displaces displacement anteriorly relative to C2. If a force comes from the back, undoubtedly the muscles will be unprepared and the force will meet minimum resistance. Yet, anterior dislocation is rare, and posterior displacement is even more infrequently seen. Forward dislocation widens the predental space and alters a roentgenographic line connecting the cortices of the anterior parts of the spinous processes from C1 to C7, unless the process of C2 is fused or congenitally short. If this is suspected, careful flexion-extension views or a C1–C2 tomogram is recommended. The mechanism of injury is usually hyperflexion or hyperextension; and even in moder- ate cases, signs of trauma to the occipital nerve should be evident. In rare instances where there are sufficient traction forces to rupture the anterior longitudinal ligament, the anterior ring of the atlas may be lifted up and over the dens so that an intact odontoid is seen anterior to the anterior ring. Orthopedic rotary Forced rotation of the upper neck may produce a locked subluxation of the rotary displacement of a lateral mass of the atlas on subluxation of the the subjacent superior facet of the axis. This requires atlantal rotation in excess of 45 ° on the axis. A neurologic deficit is not commonly involved. The patient will appear with his head rotated to one side and canted away from the side of rotation ("cock robin" position). Care must be taken to differentiate this sign which is also so common in acute torticollis.
Any posttraumatic neck spasm should be considered the expression of a cervical fracture or dislocation until proved otherwise. Dislocation or severe subluxation of C1 at the occipital junction may be seen, especially on the lateral view, and be associated with widening of the prespinal soft-tissue space following hemorrhage. Atlantoaxial instability is commonly caused by odontoid fracture, rheumatoid arthritis, and odontoid anomalies.
Cord Space Considerations. The space available for the spinal cord (diameter of spinal canal) is the narrowest distance between the posterior edge of a vertebral body and the anterior edge of the posterior vertebral arch. The width of the odontoid is approximately equal to the width of the spinal cord at the C1 level, and thus is a guide to the space available for the cord. If the space is less than the width of the odontoid, the cord is likely compromised. Up to 3 mm of displacement of the atlas on the axis infers that the transverse ligament is intact, while ligament rupture is implied if displacement is from 3–5 mm. When displacement exceeds 5 mm, it may be assumed that the ligament has ruptured and the accessory ligaments are stretched and partially deficient.
Soft-Tissue Clues. The soft-tissue shadows anterior to the upper cervical vertebrae are normally narrowest in the upper cervical area and seldom wider than a C6 vertebral body's A-P dimension. The retropharyngeal space should not exceed 7 mm, and the retrotracheal space should not exceed 22 mm. Signs of free air, edema, or hemorrhage may be seen in the prespinal and anterior area of the neck. After trauma, an increase in soft-tissue width is presumptive evidence of hemorrhage or edema from fracture.
Axis Fractures and Dislocations
Odontoid fractures are often produced by severe forces directed to the head, and the direction of force invariably determines the direction of displacement. Suboccipital tenderness may be present. A severe extension force may fracture the odontoid at its base, with possible odontoid posterior displacement. The danger of cord pressure is then great.
CLASSES OF ATLAS FRACTURES AND DISLOCATIONS
The classification of Anderson/D'Alonzo in regard to fractures and dislocations of the axis is applicable. See Table 5.17.
Table 5.17. Classic Types of Axis Fractures and Dislocations
Type DescriptionI Avulsion of the upper part of the odontoid. This is rare. II Fracture through the base of the odontoid at or below the level of the superior articular facets of the axis. This is the most common type of axial fracture, and the cruciate ligaments may remain intact. Occasionally the odontoid will not be displaced but be slightly tipped as a result of a toggle effect shown on flexion- extension films. This type fracture is usually quite unstable and leads to nonunion. III Fracture of the body of the axis. Displacement may not occur. A small bone chip separated from the anteroinferior rim of the axis at the point of rupture of the anterior longitudinal ligament may be a clue to hyperextension –associated with retropharyngeal soft- tissue swelling and/or dislocation of the prevertebral fat strip. About 36% of axial fractures occur through the cancellous bone of the body of the axis, are stable, and heal without difficulty. End- plate fracture and displacement are invariably associated.
Hangman's Fracture. This traumatic spondylolisthetic injury by distraction and extension causes fracture of the C2 when the chin is fixed and the forehead is struck. The classic damage is a bilateral fracture through the lateral posterior arch and into the intervertebral notch. The posterior elements of the axis dislocate in relation to C3, and the anterior elements dislocate in relation to the atlas and skull. Survival is not common, but when it occurs without overt spinal cord involvement, only minor complaints such as local pain, stiffness, and tenderness over the spinous process may be expressed.
Vertical Dislocation. This is usually a secondary effect of a pathologic process where the odontoid enters the foramen magnum (eg, in rheumatoid arthritis, spinal tuberculosis, osteogenesis imperfecta, or Paget's disease). The severity of neurologic involvement varies considerably from case to case regardless of roentgenographic findings.
Open-mouth and careful flexion-extension standard roentgenographic views or tomography may be necessary for accurate determination. Care must be taken not to confuse odontoid nonunion with os odontoideum. In os odontoideum, the process is about 50% smaller than normal, round, and separated from the hypoplastic odontoid by a wide gap. The remnant hypoplastic odontoid appears as a hill forming upward from the slope of the superior articular facets. The fracture line in nonunion is narrow and at or below the level of the superior articular facets, and the process is normal in size and shape.
Lower Cervical Fractures and Dislocations
Lower cervical fractures and dislocations are not common except in the elderly where a degree of osteoporosis is evident. They are usually the result of severe trauma. Bruises on the face, scalp, and shoulders may offer clues as to the mechanism of injury.
BASIC INVESTIGATIVE APPROACH
Isolated fractures following trauma occur at all levels of the cervical spine. Vertebral body fractures, however, occur most frequently at C6 and C7 and least frequently at C4. The four common types of vertebral body fractures are anterior marginal fractures from A-P forces, comminuted fractures from axial forces, and lateral wedge fractures and uncinate process fractures from lateral stress. Vertical compression or flexion compression damage is sometimes seen, but extension injuries (eg, whiplash) are more common.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
Signs of vertebral tenderness, limitation in movement, muscle spasm, and neurologic deficit should be sought. Upper extremity pain or numbness and restricted cervical motion at one or more interspace during flexion-extension may be exhibited. Neurologic symptoms may be severe and prolonged without demonstrable roentgenographic evidence.
Cord damage without apparent structural damage may result from a bulge created by a buckled degenerated (nonelastic) ligamentum flavum at the posterior aspect of the spinal canal. The cord may also be pinched between the posteroinferior edge of the superior vertebral body and the laminae of the inferior segment.
CLASSES OF LOWER CERVICAL FRACTURES AND DISLOCATIONS
See Table 5.18.
Table 5.18. Classic Types of Lower Cervical Fractures and Dislocations
Type DescriptionCompression Vertebral body crush fractures are rare, and less common in the injuries cervical spine than elsewhere. They are the result of a vertical force, often during flexion. Compression fractures of articular processes occur in extension injuries to the neck. They are not common with the exception of those occurring from automobile “whiplash” injuries and diving into shallow water. Extension Forceful extension can produce tearing of the anterior injuries longitudinal ligament and anterior anulus which may coexist with an avulsion fracture at the lips of the anterior vertebral body. Tenderness will usually be shown along the lateral musculature. If rupture occurs, further force is absorbed by the articular processes, spinous processes, laminae, and pedicles, in that order. About 50% of all cervical fractures are of the vertebral arch. If the articular processes fracture and the posterior arch fails, the vertebral body will inevitably be displaced anteriorly. Transverse pedicle fracture or severe posterior subluxation may also occur. Flexion In a blow to the occiput directed upward, posterior elements receive injuries the greatest trauma because of the shear component in the hyperflexion force. During forceful cervical flexion, a unilateral facet dislocation and/or fracture may occur with the contralateral side remaining intact, especially if the force is oblique. Bilateral dislocation or fracture-dislocation may occur if the facets are forced to override without rotation. Unilateral dislocation is more common in the lower cervical area than in the upper area. Lateral When the head is forced to severely tilt laterally, there is always flexion a coupled component of rotation involved. Compression wedging of injuries structures on the concave side occurs, and tension on the structures on the convex side is produced. There are our typical severe traumatic effects throughout the cervical area: (1) the dens will fracture and displace laterally; (2) a unilateral compression fracture of the vertebral body will occur; (3) there will be fracture of the uncinate or transverse process or fracture and/or dislocation of the articular process ipsilaterally with ligamentous rupture contralaterally; or (4) there will be brachial plexus avulsion, possibly associated with a cervical and/or thoracic fracture. Rotary These are often found combined with flexion, extension, and lateral Injuries flexion injuries. Keep in mind that while the cervical ligaments are quite resistant to pure flexion and extension stress, they are far less resistant to shear stress. It is for this reason that: (1) the anterior longitudinal ligament is often torn when the neck is overextended and rotated and (2) the posterior ligaments, posterior joint capsules, and posterior longitudinal ligament (in that order) rupture when the neck is overflexed and rotated.
Carefully evaluate the articular facets, spinous processes, and vertebral margins. Any injury to C6–C7 is difficult to view on film because of overlap- ping structures.
Articular Facets. On an oblique view, the facets will normally be shingle- like and the end-on images of the lamina will appear as a chain of ovals. Whether or not a subluxation appears, as indicated by slippage, a fracture may be located in the neural arch or facet joint. Intervertebral joint dislocation, unilateral or bilateral, may result from severe flexion trauma, and lamina fracture may or may not be associated. Facet locking is particularly common in unilateral dislocations, and it is usually associated with severe root and/or cord involvement. Compression fractures of the articular processes are best seen on “pillar” views.
Spinous Processes. Spinous process fractures usually occur at the C6 or C7 level during acute flexion or a blow to the flexed neck, producing ligamentous avulsion. There is immediate "hot" pain in the area of the spinous process that is increased by flexion. Fractures of a spinous process frequently occur without displacement.
Vertebral Margins. Check for possible bony spurs or vertebral compression fractures by evaluating the anterior aspects of the vertebral bodies for collapse and comparing their margins. Posterior vertebral margins should be compared for signs of subluxation or dislocation; ie, a continuous line passing through each posterior vertebral margin should be smooth and unbroken. Compres- sion injuries are not usually demonstrable on A-P or lateral films until deform- ity is severe, but lateral and oblique views will often exhibit them.
Spinal Cord Injuries
Most spinal cord injuries are caused by extreme flexion in which subluxa- tion, fracture, and/or dislocation is associated. Hemorrhage may occur at the site with the same reaction as brain injury (liquefaction, softening, disinte- gration). Congenital fusions and stenosis may predispose a child to spinal cord trauma during a sporting activity.
BASIC INVESTIGATIVE APPROACH
There are direct and indirect classes of injuries:
Direct injury to the cord, the nerve roots, or both may be caused by impact forces or shattered bone fragments. The cord may be crushed, pierced, or cut. This type of injury is generally an open wound.
Indirect injury to the cord may be caused by the disturbance of tissues near the spine by violent forces such as falls, crushes, or blows. This type of injury, which is normally closed with respect to the spinal column and cord, is of a lesser degree than direct injury. It takes the form of concussion, hemorrhage, or edema of the cord. The cord may cease to function below the site at which the force was applied even if the cord itself received no direct injury. Such dysfunction may be temporary or long standing, thus the prognosis must be guarded. Injuries to the spinal column in which the cerebrospinal fluid is rapidly depleted may be fatal.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
If the cervical cord is injured, there is loss of sensation and flaccid paralysis. The lower limbs exhibit a spastic paralysis. If the space in which the spinal fluid flows between the spinal cord and the surrounding vertebral column is either compressed or enlarged, severe headache occurs. Posttraumatic penile erection strongly suggests either cervical or thoracic cord injury.
Sprains and Strains
In the neck especially, strain and sprain may coexist. Severity varies considerably from mild to dangerous. Strains or indirect muscle injuries are common, frequently involving the erectors. Flexion and extension cervical sprains are also common. They usually involve the anterior or posterior longitudinal ligaments, but the capsular ligaments may be involved.
BASIC INVESTIGATIVE APPROACH
Cervical sprains are associated with severe pain and muscle spasm and are more common in adults because of the reduced elasticity of supporting tissues. Pain is often referred when the brachial plexus is involved. Cervical stiffness, muscle spasm, paraspinal tenderness, and restricted motion are also commonly associated. When pain is present, it is often poorly localized and frequently referred to the occiput, shoulder, between the scapulae, arm or forearm (lower cervical lesion), and may be accompanied by paresthesias. Radicular symptoms are rarely present unless a herniation is present.
Special concern should be given to induced subluxations during the initial overstress. Palpation will reveal tenderness and spasm of specific muscles. In acute scalene strain, tenderness and swelling will usually be found. When the longissimus capitis or the trapezius are strained, they stand out like stiff bands.
Although most cervical strains heal spontaneously, many leave a degree of fibrous thickening or trigger points within the injured muscle tissue. Residual joint restriction following acute care is more common in traditional medical care than under mobilizing chiropractic supervision.
Phillips points out the necessity of normally lax ligaments at the atlanto- axial joints to allow for normal articular glidding, thus making tonic muscle action the only means by which head stability is obtained. Also keep in mind that overdiagnosing instability of C2–C3 is a common pitfall. Infants normally exhibit a considerable degree of cervical instability because of the relatively large head weight superimposed on the small underdeveloped spine.
Upper Cervical Instability. Stability is provided the C1–C2 joint by paravertebral ligaments and muscle attachments. When weakening of these supports occurs (eg, in rheumatoid arthritis, trauma, postural stress), a dangerous state of instability can arise. If a complete fixation occurs between C1 and C2, the remaining cervical segments tend to become hypermobile in compensation. Thus, gross inspection of neck rotation (or other motions) should never be used to evaluate the function of individual segments.
Lower Cervical Instability. Subtle instability is rarely obvious in the ambulatory patient. Upon dynamic palpation, any segmental motion exceeding 3 mm should arouse a suspicion of lack of ligament restraint. Angulation of one vertebral segment on a lateral roentgenograph in excess of 11° greater than an adjacent vertebra that is not chronically compressed is also indicative of instability and pathologic displacement.
Neurologic Defict. There is a rough correlation between the degree of structural damage present and the extent of the neurologic deficit. This is more true in the lower cervical area than that of the upper region where severe dam- age may appear without overt neurologic signs. In either case, however, it is doubtful that such a deficit would exhibit without an unstable situation exist- ing. It is not unusual for a patient to exhibit a neurologic deficit without static displacement; ie, the vertebral segment has rebounded back into a normal position of rest.
EXTENSION SPRAINS AND STRAINS
During trauma, the head may be flexed forward so that the chin strikes the sternum or thrown sidewards so that the ear strikes the shoulder and the neck can still be within the normal range of motion. It is most rare, however, that the occiput strikes the back and does not exceed normal cervical extension.
Mechanisms. Other than those in automobile accidents, the forces in whiplash are usually administered from below upward; eg, an uppercut blow to the chin or a blow to the forehead while running forward. This is in contrast to the com- pressive type of hyperextension or hyperflexion injury where the force is usual- ly from above downward. Thus, knowing the direction of force, even if the magnitude is unknown, is important in analyzing the effects. A facial injury usually suggests an accompanying extension injury of the cervical spine as the head is forced backward. In the typical whiplash injury, whether it be from hyperextension or hyperflexion or both, the effects of traumatic elongation and compression are compounded by underlying fixations, arteriosclerosis, spondylosis, ankylosing spondylitis, etc.
Effects. When the head is violently thrown backwards (eg, whiplash), the damage may vary from minor to severe tearing of the anterior and posterior longitudinal ligaments. This flattens the cervical curve in about 80% of cases, and a degree of facet injury must exist even if not evident on film. Stretching to the point of hematoma may occur in the sternocleidomastoideus, longus capitis, longus cervicis, and scalene muscles. Severe cord damage can occur that is usually attributed to momentary pressure by the dura, ligamentum flavum, and laminae posteriorly, even without roentgenographic evidence. Even without any cord deficit, severe damage to the nerve roots may occur as the facets jam together and close upon the IVF, especially if fracture occurs. Incidence is highest in the C4–C6 area. Severe stretching of the vertebral arteries and sympathetic trunk to some degree is inevitable.
FLEXION SPRAINS AND STRAINS
Slight anterior subluxation is usually not serious, but neurologic symptoms may appear locally or extend down the arm.
Mechanisms. An occipital injury usually suggests an accompanying flexion in- jury of the anterior cervical spine and posterior soft tissues as the skull is forced forward. Flexion injury may also be a part of whiplash, superimposed upon an extension injury.
Effects. The posterior paraspinal tissues are overstretched, the facets are sprung open, and the process of bleeding, edema, fibrosis, and adhesions is initiated. Fractures of end-plates may be difficult to assess early. Disc degeneration and posttraumatic osteoarthritis may follow, which leads to spondylosis.
LATERAL FLEXION STRAIN/SPRAIN
These usually occur when the neck is not only severely flexed sideward but also flexed forward and down so that the head is anterior to the shoulder. See Traction Effects on the Brachial Plexus.
Traction Effects on the Brachial Plexus
In brachial plexus trauma, the entire plexus or any of its fibers may be injured. The lateral branches of the brachial plexus lie just anterior to the glenohumeral joint. The axillary nerve lies just below the joint. As the roots of the plexus are fixed at their origin in the spinal cord, any sudden or severe traction of the upper extremity may avulse roots from the cord or stretch the plexus to the point of tearing. Stretching injuries are common; tearing injuries are rare. Such injuries may be divided into three general types: total arm pal- sies, upper arm palsies (most common), and lower arm palsies.
Trauma to the brachial plexus is often seen following severe cervical lateroflexion. The effects vary from mild to severe depending upon the extent of nerve contusion, crush, or laceration. Nerve "pinch" or "stretch" syndromes may also be involved. The specific symptomatology, physical findings, roentgenog- raphy, and electromyography offer clues to the extent of damage, indicated therapy, and prognosis.
BASIC INVESTIGATIVE APPROACH
Painstaking examination is required as multiple nerve injury, related tendon or other soft-tissue damage, and fractured bones may complicate the picture. The immediate site of injury should be first investigated, followed by the part's general appearance, voluntary motion, reflexes, and vasomotor changes. In addition to the degree of motor and sensory loss, the response to electrical stimulation should be evaluated.
Nerve “pinch” or “stretch” syndromes are common. They are often seen in the lower neck from overflexion, but symptoms can appear throughout the cranium, spine, pelvis, and extremities after an accident. Hardly any peripheral nerve is exempt from such an injury.
A nerve stretch syndrome is commonly associated with sprains, excessive lateral cervical flexion with shoulder depression, or dislocations. Nerve fibers may be stretched, partially torn, or ruptured almost anywhere in the nervous system from the cord to peripheral nerve terminals.
A nerve pinch syndrome may be due to direct trauma (contusion), subluxation, a protruded disc resulting in nerve compression, or fracture (callus formation and associated posttraumatic adhesions). Any telescoping, hyperflexion, hyperextension, or hyperrotational blow or force to the spine may result in a nerve “pinch” syndrome where pain may be local or extended distally. Nerve pinch syndromes are less common than nerve stretch syndromes, but they are more serious.
Ipsilateral vs Contralateral Symptoms. If symptoms appear on the opposite side of forceful bending of the cervical spine, undoubtedly a nerve has been "pinched" within the powerful muscles dorsal to the sternocleidomastoid. If this is the case, the symptoms usually subside in a few minutes with only slight residual tenderness and paresthesia that disappears within a few hours. On the other hand, if symptoms appear on the same side as the direction of the forceful bending, deep skeletal injury such as severe rotary subluxation, fracture, dislocation, or nerve compression can be anticipated.
Mild or Moderate Brachial Traction. After lateroflexion injuries of the neck, a sharp burning pain may radiate along the course of one or more cervical nerves, the result of nerve contusion due to stretching. Scalenus anticus syndrome may be exhibited. This nerve stretch is often referred to as a “hot shot” by athletes. Recurring injury is common, especially in contact sports. It is not limited to sports, however, for any severe cervical lateral flexion can produce the syndrome4. Immediate pain may radiate to the back of the head, behind the ear, around the neck, or down toward the clavicle, shoulder, arm or hand. Frequently, there is arm paresthesiae, severe arm weakness, diminished active motion, decreased biceps and triceps reflexes, forearm numbness, and cervical movement restriction. These signs and symptoms may disappear and reappear with greater severity.
Root Avulsion. A similar but more severe nerve injury is that to the brachial plexus or its roots that is usually caused by a fall on the shoulder, a blow to the side of the neck, forceful arm traction, or a combination of these mechanisms. The injury is essentially caused by acute shoulder depression that stretches the brachial plexus especially in the supraclavicular area. The effect may be root tear near the vertebral foramen, spinal cord damage, dural cuff leaks of cerebrospinal fluid, and/or vertebral fracture or dislocation. During avulsion, the spinal cord itself is infrequently damaged and contralateral cord symptoms are found. Such severe manifestations are rarely seen in the well- conditioned patient where the picture is usually limited to pain radiating into the arm and/or hand.
PERTINENT ASSOCIATED COMPLAINTS AND FINDINGS
Damage to an individual peripheral nerve (eg, trauma) is characterized by
(1) flaccid, atrophic paralysis of the muscles supplied by the involved nerve and (2) loss of all sensation, including proprioception, in the skin areas distal to the lesion. When partial destruction to various peripheral nerves occurs, the effects are usually more prominent in the distal extremities. The condition is characterized by muscular weakness and atrophy and poorly demarcated areas of sensory changes. Trophic lesions of the joints, muscles (atrophy), skin, and nails are common in the late stage.
In ulnar nerve damage, sensation is lost on the medial side of the hand, including the little finger and medial half of the ring finger. In median nerve damage, sensation of the remainder of the anterior surface of the hand is lost. However, motor involvement is the main feature as sensory loss is often obscured by overlapping innervation. As time goes by after severe nerve injury, the affected part assumes a posture and atrophy peculiar to the particular nerve involved; for example, “wrist drop” with the radial nerve, “claw hand” with the ulnar nerve, “flat hand” with the median nerve, and “ape hand” with the ulnar and median nerves.
Films are often negative in mild to moderate cases. In severe cases, a unilaterally locked facet may be viewed as a positive sign of dislocation. This is caused by one facet displacing while the opposite side remains in position. It is easy to miss on physical examination because normal active neck movements usually do not increase the dislocation.
On the standard A-P view, the spinous processes above the luxation will be out of alignment with the processes below the lesion. Displacement will be ipsi- lateral on the side of the locked facet. On the lateral view, displacement is usually obvious even though it may not be pronounced. The facets inferior to the lesion are superimposed (often seen as one). Superior to the lesion, the facets are offset and viewed as being one in front of the other (bow-tie sign). In recurring cases, such as in professional athletes, symptomatic or asymptomatic spur formation on cervical vertebrae is common.
Vertebral Artery Syndromes
In this category of symptoms complexes, the major concern is vertebral artery deflection and patency of the vertebrobasilar system.
VERTEBRAL ARTERY DEFLECTION
The vertebral artery is a captive vessel from C6 upward. Extremes of rotation and flexion occur at the upper cervical region, but the four normal curves in the vertebral artery help to compensate during neck motion. Deflection may be caused by any stretching or elongation of the artery during neck injury. In later years, it is commonly associated with bony spurs from the covertebral joints or grossly hyperplastic posterior vertebral articulations from arthrosis.
In discussing this situation, Smith explains that extension of the cervical spine allows the tip of the superior articular process of the posterior joint to glide forward and upward. If sufficiently hyperplastic, the motion may cause encroachment on the vertebral artery and/or the intervertebral foramen. Deflection of the artery and any resulting symptoms are exaggerated by rotation and/or extension of the neck. As a result of pressure against the artery, there may be temporary lessening in the volume of blood flow. Atheromatous changes may occur later within the vascular wall. Symptoms (the Barre-Lieou syndrome) include headache, vertigo, nausea, vomiting, nystagmus, and suboccipital tenderness, which may be exaggerated by cervical extension. Sometimes symptoms are aggravated by dorsal extension and relieved by forward flexion with cervical traction.
Roentgenographic Considerations. When the vertebral bodies of the mid-cervical region are involved, the process of vertebral artery deflection may be visualized either by oblique or A-P projections. Stereoscopic studies are especially valuable. The mid-cervical region shows a predilection for this process. Note that an aneurysm-like condition sometimes occurs within the cancellous lateral mass of C2. The tortuosity is visualized in both A-P and lateral views. Since the erosion develops slowly, there is a radiolucency surrounded by a white curvilinear line in the osseous structures adjacent to the vertebral artery. The significance of the erosions is the implication of vessel wall changes, but these erosions may be mistaken for the results of tumor pressure or other destructive processes involving bone.
VERTEBROBASILAR SYSTEM PATENCY
Although cerebrovascular accidents are extremely rare following cervical manipulation, a few cases have been reported that justify careful evaluation prior to cervical manipulation. Bergmann describes four clinical tests to evaluate the patency of the vertebrobasilar system.
DeKleyn's Test. The patient is placed supine on an adjusting table, and the head rest is lowered. The examiner extends and rotates the patient's head, and this position is held for about 15–40 seconds on each side. A positive sign is indicated by nystagmus or symptoms of vertebrobasilar ischemia.
Hautant's Test. The examiner places a seated patient's upper limbs so that they are abducted forward with the palms turned upward (supinated). The patient is instructed to close the eyes, and the examiner extends and rotates the patient's head. This position is held for about 15–40 seconds on each side. A positive sign is for one or both arms to drop into a pronated position.
Maigne's Test. The examiner places a seated patient's head in extension and rotation. This position is held for about 15–40 seconds on each side. A positive sign is the same as that in DeKleyn's test.
Underburger's Test. The patient is asked to stand with the upper limbs outstretched, the eyes closed, and then to march in place with the head extended and rotated. The examiner should stand close to the patient during the test because a positive sign is a loss of balance.