CFS vs. Fibro - Part 2

Dr. Yunus is a renowned fibromyalgia researcher.  The hard-copy article apparently included charts showing how the symptoms differ between CFS and fibro, but those charts were not included in the online version.  Your local hospital's medical library may be able to help you find the original article with the charts.  If you find an online version with the charts, please add a comment with a link to that version.

As Dr. Yunus notes, symptoms are not as severe in fibro as in CFS.  This has led some people to theorize that fibro is the mild form of the disease and it progresses to full CFS over time, while others think they are not the same disease at all.  Jodi Bassett notes that there are divergent lab tests, and the people who have been given a dual diagnosis have the test results applicable to CFS, not those for fibro. 

Excerpts from:
Chronic Fatigue Syndrome and Fibromyalgia Syndrome:  Similarities and Differences by Muhammad B. Yunus, MD, University of Illinois College of Medicine at Peoria, Peoria, Illinois


The published reports have demonstrated apparent similarities between these two common syndromes, yet it is also clear that these syndromes are not identical.

Clinical Features

     It is clear that these features overlap considerably between the two syndromes.  However, it appears that several features are quantitatively, and perhaps qualitatively, different (Table 3). While data on cognitive impairment in FMS is limited, clinical experience would suggest that symptoms related to such an impairment are not as common or severe in FMS as they appear to be in CFS.   ...  Although fatigue is present in 80 to 90 percent of patients with FMS, it is overall less debilitating in this syndrome than in CFS.


Immunologic and Other Laboratory Findings

    Abnormal immunologic findings are very common in CFS, leading to the nomenclature "chronic fatigue and immune dysfunction syndrome."

    Hematologic abnormalities, including complete blood count and erythrocyte sedimentation rate, are absent in FMS and variable in CFS. 

    A host of infectious agents, including EBV, measles virus, cytomegalic virus, enteroviruses, human herpesvirus 6, retroviruses, and Borrelia burgdorferi, among others, have been implicated in CFS. Antibody titers to Epstein- Barr virus were not significantly different among patients with fibromyalgia from those in matched normal controls

    Cerebral blood flow imaging by SPECT (single photon emission computerized tomography) and PET (positron emission tomography), as well as topographic brain mapping with evoked responses using BEAM (brain electrical activity mapping) have been reported to be abnormal in a large majority of patients with CFS, showing a pattern different from normal controls and those with depression.


Pathophysiological Mechanisms

    Fatigue, the overwhelming symptom in CFS, is most likely to be central in origin, although secondary changes in muscles due to deconditioning may further aggravate this symptom. (Mental or physical stress, poor sleep, depression, and infections are other aggravating factors of fatigue).  Many of the neuropsychiatric features of CFS may be explained by limbic dysfunction (I prefer the term "dysfunction" to "encephalopathy," since such a dysfunction may occur due to neurochemical aberrations, and not necessarily due to anatomic lesions or pathology), as has been suggested by Goldstein.

it is clear that neither CFS nor FMS is a psychiatric illness

Conclusion

    CFS and FMS share common characteristics, but some features are more prominent in one syndrome than the other.