Chronic Fatigue Syndrome: A Review of the Evidence

Ganiats TG. Ideas and Opinions: Redefining the Chronic Fatigue Syndrome. Ann Intern Med. 5 May 2015;162(9):653-654. doi:10.7326/M15-0357

Komaroff AL. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Real Illness. Ann Intern Med. 16 June 2015;162:871-872. doi:10.7326/M15-0647

Haney E, Smith MB, McDonagh M, et al. Diagnostic Methods for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Systematic Review for a National Institutes of Health Pathways to Prevention Workshop. Ann Intern Med. 2015;162:834-840. doi:10.7326/M15-0443

Smith MB, Haney E, McDonagh M, et al. Treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Systematic Review for a National Institutes of Health Pathways to Prevention Workshop. Ann Intern Med. 2015;162:841-850. doi:10.7326/M15-0114

Green CR, Cowan P, Elk R, et al. National Institutes of Health Pathways to Prevention Workshop: Advancing the Research on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Ann Intern Med. 2015;162:860-865. doi:10.7326/M15-0338

Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Institute of Medicine. Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness. Washington, DC: National Academies Press, 2015.

These articles in the Annals summarize the work of a committee of the Institute of Medicine (IOM), which reviewed the evidence on chronicfatiguesyndrome (CFS).

Physicians and patients have been frustrated by the difficulty of diagnosis, the overlap with other conditions, the lack of objective signs, and the absence of proven treatment.

The disease is characterized by persistent, intense exhaustion that worsens after physical, cognitive, or emotional effort. As Theodore Ganiats writes, even basic household chores can be exhausting, and grocery shopping may only be possible on a “good day.” Simple questions are hard to answer, “finding the right words” is difficult, sleep is unrefreshing. The disease is also characterized by post-exertional malaise.

These reviews filter and summarize the most rigorous evidence available.

As Anthony Komaroff explains:

-- There is a physiologic basis. There are “real” underlying biological abnormalities that can be demonstrated by objective measurements. Orthostaticintolerance can be demonstrated by objective measurements during standing or tilt testing. Neurologic abnormalities can be found during information processing, and demonstrated on PET and functional MRI. Immunologic abnormalities can be found. It often follows Epstein-Barr virus and other specific infections.

-- There is no sensitive, specific biomarker to serve as a diagnostic test.

-- There are no proven drugtreatments.

-- Counseling and gradedexercisetherapies may help in some patients, but exercise worsens symptoms in other patients.

-- We don’t understand the pathogenesis of the disease.

-- The IOM has proposed a clinical case definition which, however, needs more validation.

Under the IOMdiagnosticcriteria: Diagnosis requires that the patient have each of the following 3 symptoms:

-- A substantial reduction or impairment in the ability to engage in pre-illness levels of occupational, educational, social, or personal activities that persists for more than 6 months and is accompanied by fatigue, which is often profound, is of new or definite onset (not lifelong), is not the result of ongoing excessive exertion, and is not substantially alleviated by rest.

-- Postexertionalmalaise

-- Unrefreshingsleep

At least 1 of the following 2 manifestations is also required:

-- Cognitiveimpairment

-- Orthostaticintolerance