Fibromyalgia syndrome Definition and Nomenclature Fibromyalgia syndrome (FMS) is characterized by generalized musculoskeletal aching and stiffness, as well as tenderness on palpation at multiple characteristic sites, called tender points (TP's). Fibrositis is a misnomer and a non-specific term, and use of this term should be avoided. Classification The following classifications apply: 1. Primary - no underlying or con- comitant condition tha tmay cause or contribute to FMS features. 2. Concomitant - conditions, such as OA, that may contribute to pain independent of FMS. 3. Secondary - rarely, an under lying condition may cause fibromyalgia features, such as hypothyroidism. FMS includes both primary and concomitant fibromyalgia. Symptoms (1-4) FMS is more common in women (80-90%) than men and the common age range is 30-55 years. Symptoms are: Musculoskeletal: Pain at multiple sites Stiffness "Hurt all over" Swollen feeling in soft tissues Non-musculoskeletal Fatigue (most times of the day) Morning fatigue Poor sleep Paresthesias Associated symptoms: Self-assessed anxiety Headaches Dysmenorrhea Irritable bowel symptoms Self-assessed depression Sicca symptoms Raynaud's phenomenon Female urethral syndrome Physical Examination The examination always shows multiple TP's and occasionally generalized tenderne..s. Cutaneous tenderness and hypermia may also be present. Joint, neurological and muscle strength examination is normal. American College of Rheumatology Criteria for Classification of Fibromyaigia (4) History of widespread pain. Pain is considered widespread when all of the following are present: pain in the left side of the body, pain in the right side of the body, pain above the waist and pain below the waist. In addition, axial skeletal pain (cervical spine or anterior chest or thoracic spine or lower back) must be present. In this definition, shoulder and buttock pain is considered as pain for each involved side. "Lower back" pain is considered lower segment pain. Thus, pain in three sites (right shoulder, lower back, left buttock) will qualify for widespread pain. Pain in 11 of 18 tender point sites on digital palpation. Pain on digital palpation must be present in at least 11 of the following 18 tender point sites: *Occiput*: bilateral, at the suboccipital muscle insertion. Lower cervical: bilateral, at the anterior aspects of.the intertransverse spaces at C5-C7. *Trapezius*: bilateral, at the midpoint of the upper border. Supraspinatus: bilateral, at origins, above the scapula spine near the medial border. Second rib: bilateral at the second costochondral junctions, just lateral to the junctions on upper surfaces. Lateral epicondyle: bilateral, 2 cm distal to the epicondyles. *Gluteal*: bilateral, in upper outer quadrants of buttocks. Greater trochanter: bilateral, posterior to the trochanteric prominence. *Knee*: bilateral, at the medial fat pad proximal to the joint line. Digital palpation should be performed with an approximate force of 4 kg. For a tender point to be considered "positive," the subject must state that the palpation was painful, as compared with mere pressure. For classification purposes, patients will be diagnosed with fibromyalgia if both criteria are satisfied. Widespread pain must have been present for at least three months. The presence of a second clinical disorder does not exclude the diagnosis of fibromyalgia.(4) Laboratory Tests Usual tests (CBC, ESR, ANA, rheumatoid factor, and muscle enzymes) are normal, as are muscle biopsy and EMG. Biophysiological Mechanisms Biophysiological mechanisms involve the following: 1. Physiology of pain - Activation of nociceptors cause pain trans- mission through A-delta and C-fibers, which synapse at the dorsal horn and ascend through spino-thalamic tract, connecting fibers to reticular formation and thalamic nuclei, to somatosen- sory cortex. Substance P is an important neurotransmitter for the C fibers. Inhibitory descend ing pathways from midbrain, pons and medulla modulate pain at dorsal horn and utilize several neurotransmitters including serotonin, noradrenalin and enkephalin. 2. Sympathetic activity may con- tribute to pain. 3. Neurohormonal aberrations in FMS - Increased Substance P, decreased serotonin and decreased noradrenalin status have been reported. 4. Role of sleep - Alpha intrusion of delta sleep by sleep EEG stud ies indicating nonrestorative sleep has been demonstrated. 5. Role of psychologic factors Anxiety, depression and stress are present in about one third of rheumatology clinic patients. These factors serve to aggravate pain, but are not related to FMS per se. 6. In summary, biophysiological mechanisms in FMS involve multiple factors including trauma, poor sleep, and psychological factors that interact to amplify pain and cause fatigue through neuroendocrine mechanisms, perhaps in a genetically predisposed individual. An aberration of the central pain mechanism seems to be the primary problem in FMS (6) FMS as Part of a Spectrum of Dysfunctional Syndromes FMS, irritable bowel, chronic fatigue syndrome, tension-type head aches, migraine, TM dysfunction and primary dysmenorrhea belong to a spectrum of dysfunctional syndromes with many overlapping features.(8-10) Many patients with temporomandibular dysfunction may have FMS, and vice versa.(8-9) The shared mechnisms in these disorders most likely involve a neuroendocrine dysfunction. FMS and Chronic Fatigue Syndrome (CFS) FMS and CFS have many overlapping features and are probably similar syndromes Relative Occurrenees of Selected Features in Chronic Fatigue Syndrome (CFS) vs. Fibromyalgia Syndrome (FMS)* Features CFS FMS Musculoskeletal pain ++ +++ Significant fatigue +++ ++ Tender points ++ +++ Sleep disturbance +++ +++ Chronic headaches ++ ++ Irritable bowel symptoms ++ ++ Cognitive impairment ++(+) +(+) History of viral illness ++(+) +(+) Immune dysfunction +++ + Neurohormonal dysfunction** +++ +++ * + = uncommon, ++ = common, +++ = very common, +(+) = uncommon to common, ++(+) = common to very common Diagnosis and Differential Diagnosis FMS should be diagnosed by its own characteristics and not by mere exclusion of other conditions. ACR criteria (see above) are most helpful. Table 4 notes confounding diagnoses. Management Management should be individualized. Patient education with simple explanation of probable or possible biophysiological mechanisms, reassurance, behavioral changes, physical exercises, physical therapy, addressing psychological factors, use of simple analgesics, prescribing serotonergic and or noradrenergic drugs in small (10-50 mg) doses (amitripth line, imipramine, nortriptyline, cyclobenzaprine, fluoxetine), injection of tender points with local anesthetics and referral to rheumatologists, pain clinics and psychiatrists/psychologists should all be utilized in varying degrees in an individual patient.(3-7) Several serotonergic and noradrenergic drugs are known to have side-effects. Postulated neurohormonal dysfunctions in both FMS and CFS need to be confirmed by further studies. Presenting Features of Fibromyalgia with Confounding Diagnoses and Key Points of Differentiation Presenting features Confounding diagnoses Absent in fibromyalgia Joint pain and swelling Arthritis Objective joint swelling Diffuse muscular Polymyalgia, rheumatica Incr. ESR, decr. Hb, weight loss aching and stiffness Muscle fatigue, weakness - Myopathy Objective weakness, inc. muscle enzymes Fatigue, sensitivity to Hypothyroidism Decr. T4, Incr. TSH cold, muscle pain Back pain/stiffness Ankylosing spondylitis Sacroilitis Sciatica-qpe pain Disk herniation Neurologic & radiologic findings Chest pain Cardiac or pleural pain Typical history of cardiac pain, pleural rub, EKG, chest X-ray or other laboratory findings of an intrathoracic disease Reproduced with permission from Yunus MB, Masi AT: Fibromyalgia, restless legs syn- drome, periodic limb movement disorder and psychogenic pain. In McCarty DJ, Koopman WJ (eds), Arthriris and Allied Conditions, 12th edition, Lea & Febiger, 1993; 1,383-1,405 References 1. Yunus MB Diagnosis, edology and manage- ment of fibromyalgia syndrome: an update Comprehen Ther 1988,14 8-20 2. Goldenberg DL: Fibromynlgia Syndrome an emerging but controversial condition JAMA 1987 257:2,782-2,787 3. Yunus MB, Masi; AT Fibromyalgia, restless legs Syndrome, periodic limb movement dis- order and psychogenic pain In McCarty DJ, Koopman Wl (eds), Arthritis and Allied Conditions, 12th edidon Lea & Febiger,1993 1 ,383-1,405 4. Wolfe D, Smythe HA, Yunus MB, et al The American College of Rheumatology 1990 criteria for the classification of fibromyalgia Arthritis Rheum 1990 33: 160-172 5 Yunus MB, Ahles TA, Aldag JC, Masi AT Relationship of clinical features with psycho- logic status in primary fibromyalgia Arthritis Rheum 1991 34:264-269 6. Yunus M8 Towards a model of pathophysiol- ogy of fibromyalgia: aberrant central pain mechanisms with peripheral modulation J Rheumatolog 1992; 19: 846-850 7. Mui AT, Yunus MB Fibromyalgia - which is the best treatment? A personalized, compre- hensive, ambulatory, patient involved man- agement program Bailliere's Clinical Rheumatology 1990; 4(2) 333-370 8 Eriksson P-0, Lindman R, Stal P, Bengtsson A: Symptoms and signs of mandibular dys- function in primary fibromyalgia syndrome patients SwetDentl 1988;12141-149 9 Blasberg B, Chalmers A: Temporomandibular pain and dysfunction syndnome associated with generalized musculoskeletal pain, a ret- rospective study JRheumatol 1989; 16(suppl 19) 87-90 1 0. Yunus MB, Masi AT, Aldag IC A: controlled study of primary fibromyalgia syndrome Clinical features and association with other functional syndromes J Rheumatol 1989 16(suppl 19): Source: J of Craniomandibular Practice, July 1995, Vol 13 No 3 198-202 Thanks to Dr Moses Jacob for contributing this article to be scanned with OCR technology. NB This article has some graphics which could not be included in this message. Please refer to the original