Fibromyalgia and the Social Construction of Disease

1. Fibromyalgia and the Social Construction of Disease Salahuddin Kazi, MD

2. In 1990 the American College of Rheumatology published criteria for the classification of fibromyalgia • Fibromyalgia was defined as a syndrome of widespread pain associated with characteristic tender points

6. Fibromyalgia is a controversial disorder Valid Disease Construct OR Universal Stress + Doctor + Social Sanction “Fibromyalgia”

7. Doctors are ambivalent about fibromyalgia • Diagnosed by self-report • Objective findings limited to tender points • No characteristic laboratory or imaging abnormalities • Overlap with other syndromes • No specific treatment

8. The argument • If fibromyalgia is a true disease, there ought to be observable pathologic lesions • But what do we mean by “disease”?

9. Fibromyalgia – key features • Fibromyalgia is characterized by widespread chronic muscle pain • The pain worsens with activity • Patients cannot distinguish well between myalgia and arthralgia • often describe joints as being swollen • burning, numbness, tingling and heaviness of the limbs are common complaints

10. Fibromyalgia – key features • Fatigue is very frequent (90%) and may be the presenting complaint • Sleep disorders are universally reported • Mood disturbance, cognitive impairment, headache, Raynaud’s phenomenon and pre-syncope are also very prevalent • Some patients meet formal criteria for depression

11. Fibromyalgia – key features • Many individuals meet criteria for other unexplained clinical syndromes • irritable bowel syndrome, chronic fatigue syndrome, migraine headaches and interstitial cystitis • Physical examination is largely normal except for the finding of characteristic tenderness at defined points • Laboratory studies are within normal limits

12. Fibromyalgia - epidemiology • Fibromyalgia is more common in women • Prevalence increases linearly with age • 2% at age 20 and 8% at age 70 • Peak presentation is in the fourth and sixth decades of life • In 50%, onset is attributed to trauma or a flu-like illness

13. Chronic fatigue syndrome

14. Fibromyalgia Chronic fatigue syndrome Irritable bowel syndrome Multiple chemical sensitivity Migraine headaches Interstitial cystitis Chronic nonbacterial prostatitis Chronic pelvic pain Chronic low back pain Post-concussion syndrome Interstitial cystitis Temporomandibular disorder Unexplained clinical syndromes

16. The history of fibromyalgia and chronic fatigue syndrome • 1869 Neurasthenia • 1904 Fibrositis • 1930’s Epidemic neuromyasthenia Benign myalgic encephalomyelitis Post viral syndrome • 1938 Referred muscle pain • 1976 Fibromyalgia • 1980’s Chronic EBV infection Chronic fatigue syndrome • 1990’s Fibromyalgia – ACR definition Myofascial pain syndrome

17. Pathophysiology of fibromyalgia: evolving views • Disease of muscle • Psychiatric disorder • Disease of pain perception • Neuroendocrine disease

18. Pathophysiology of fibromyalgia: evolving views • Disease of muscle • Psychiatric disorder • Disease of pain perception • Neuroendocrine disease

19. Is there muscle pathology in fibromyalgia? • Stockman,1904 - biopsy studies of palpable tender nodules in patients with fibrositis “inflammatory hyperplasia” • Two subsequent studies could not confirm these findings

20. Is there muscle pathology in fibromyalgia? • Collins,1940 - review of original specimens found no evidence of inflammation • Contemporary muscle biopsy studies have revealed either normal findings or nonspecific ultrastructural changes • Studies of muscle metabolism and MR spectroscopy have also failed to demonstrate abnormalities in muscle metabolism

21. Pathophysiology of fibromyalgia: evolving views • Disease of muscle • Psychiatric disorder • Disease of pain perception • Neuroendocrine disease

22. Is fibromyalgia a psychiatric disorder? • Prior to the 1980’s the concept of “psychogenic rheumatism” was prevalent: • dramatic urgency to be seen by the doctor • written list of complaints • large volume of previous investigations brought to the first clinic visit

23. Fibromyalgia and the MMPI • Payne, 1982 - higher MMPI scores in fibromyalgia patients when compared with patients with arthritis • Fibromyalgia patients scored higher on the hypochondriacal and hysteria scales but not on the depression scale

24. Fibromyalgia and the MMPI • Smythe suggested that the MMPI will rate any patient with chronic pain high on the hysteria and hypochondriasis scales • Pincus reported that elevated MMPI scores for hypochondriasis, depression and hysteria correlated with disease activity in patients with rheumatoid arthritis

25. Fibromyalgia - history of depression • Clarke - fibromyalgia patients from general practice • No increase in rates of psychologic disturbance • 50%-70% of patients with fibromyalgia report a personal history of depression • Current major depression is found in not more than 36% of patients

26. Fibromyalgia and depression: prospective data • A prospective study of 175 women with self-reported pain • designed to examine etiologic factors in the onset of fibromyalgia • Depression developed in 25% of this cohort after a period of 5.5 years • Self-reported depression was the single strongest predictor (six-fold) of new-onset fibromyalgia

27. Fibromyalgia and depression:prevailing views • Depression and fibromyalgia are associated, but the nature of the association and the temporal relationship are unclear • Fibromyalgia and major depression may share a common etiologic abnormality • The greater frequency of depression in fibromyalgia patients in referral-based practices versus fibromyalgia patients in the community reflects differences in health-seeking behaviors

28. Community Clinic Fibromyalgia + Depression Fibromyalgia + Depression Health Seeking Fibromyalgia

29. Severe fatigue Abdominal pain Diarrhea Headaches Dizziness Jaw pain Paraesthesia Raynaud’s phenomenon Dysuria Is fibromyalgia a somatization disorder? Patients have multiple somatic complaints that suggest organic disease:

30. Fibromyalgia and somatization • Most patients with fibromyalgia would not satisfy diagnostic criteria for somatization disorder • Do these patients may have a subsyndromal somatization state?

31. Critics point to the circular nature of the definition of somatization disorder: “a psychiatric diagnosis that depends on the presence of physical symptoms that suggest organic disease and are not explained by a general medical condition would become a nonpsychiatric diagnosis once the general medical condition adequately explains the symptoms”

32. Pathophysiology of fibromyalgia: evolving views • Disease of muscle • Psychiatric disorder • Disease of pain perception • Neuroendocrine disease

33. Fibromyalgia as a chronic pain disorder: epidemiology the number of tender points correlated best with depression, fatigue and poor sleep

34. Fibromyalgia as a chronic pain disorder: epidemiology • Wolfe – rural Kansas • widespread pain was more common in women • increased in prevalence with age • peak 23% by the seventh decade

35. The pain-fibromyalgia spectrum Chronic Pain Fatigue Depression Sleep Disorder Fibromyalgia

36. Fibromyalgia: abnormal central sensory processing • Non-nociceptive pain (NNP) • pain elicited by stimulation of fibers that usually relay non-painful signals to the spinal cord • non-noxious stimuli are subverted by abnormal central processing resulting in the experience of pain

37. Chronic pain in fibromyalgia • Several studies of chronic pain in fibromyalgia patients compared with controls show: • dolorimetry reveals a lower pain threshold • elevated substance P levels in the CSF • with isometric muscle contraction, the pain threshold decreases rather than showing the expected increase seen in controls • somatosensory-induced potentials demonstrate increased amplitude following laser stimulation of skin • distinctive regional cerebral blood flow abnormalities

38. Pathophysiology of fibromyalgia: evolving views • Disease of muscle • Psychiatric disorder • Disease of pain perception • Neuroendocrine disease

39. The hypothalamic-pituitary-adrenal (HPA) axis • Primary endocrine stress axis • Adaptational response to stressors • Patients with fibromyalgia have abnormal stress activation

40. Neuroendocrine abnormalities in fibromyalgia • Elevated cortisol levels with a flattened diurnal pattern that are not suppressed by dexamethasone administration • Low 24 hour urinary free cortisol suggesting elevated cortisol secretion during the day and suppressed secretion at night • Markedly enhanced ACTH release when CRH is injected, but with no increase in cortisol levels (suggesting adrenal hyporesponsiveness)

41. Significance of HPA abnormalities • Chronic CRH hyperactivity is driven by stress and pain • CRH is a pleiotropic hormone • changes in the set points of other hormonal axes like growth hormone, gonadotropin and thyroid stimulating hormone may also be of significance

42. Significance of HPA abnormalities • Whether somatic symptoms in fibromyalgia are caused by these abnormalities is unclear • Is the link between somatic complaints and central nervous system changes bidirectional?

43. Stressful life event HPA Axis Genetic vulnerability Abnormal central sensory processing Chronic pain Acute Pain Somatosensory amplification Psychosocial distress Secondary somatic symptoms

44. Summary of the current concept of fibromyalgia • Theories of the pathophysiology of fibromyalgia have moved from a disorder of soft tissues to one of chronic pain • Diagnosis is largely based on patient self-report but an increasing body of literature points to measurable phenomena in the central nervous system and HPA axis • Psychologic disturbances are common in patients with fibromyalgia but the temporal association with disease onset is still unclear

46. Foucault’s “spaces” • Primary spatialization: disease is described and ordered as a concept • Secondary spatialization: disease is given a place within the body • Tertiary spatialization: the disease and the diseased individual are located within the societal body

47. The birth of biomedicine • Turn of the 18th century • French revolution • Restructuring of French society • Parallel restructuring of the medical paradigm

48. The birth of biomedicine • Medicine changed from a study of symptoms to the precise mapping of signs and symptoms to observable pathologic lesions • Doctors began to care for indigent patients in a hospital setting • The doctor became dominant in the doctor-patient relationship

49. The biomedical model of disease • Disease is caused by an observable pathologic lesion in the body • The presence of a pathologic lesion is revealed in two ways: • symptoms, the patient’s perception that body function is not normal • signs, the physician’s observation that signifies that an underlying lesion exists

50. Assessing symptoms • Patients subject their symptoms to some form of evaluation prior to seeking medical advice • Community surveys suggest that the ratio of symptom episodes to consultation is much higher than one would expect