THE CHRONIC FATIGUE SYNDROME is a symptom complex characterized by fatigue, myalgias, arthralgias, neurologic symptoms-headaches, paresthesias, dizziness-lymph node swelling or tenderness, cognitive dysfunction, sleep disorders, and depression. The symptoms are similar to those seen in inflammatory illnesses and can be induced by the systemic administration of interferon beta. Severe fatigue is a perplexing and constant complaint in many patients with multiple sclerosis. This indicates that the perception of energy level has a sensitive physiologic basis that is dependent on the homeostasis of other body systems.
The chronic fatigue syndrome has gained popularity among the lay public and has stimulated considerable scientific debate about its existence. Many investigators and practitioners have attributed the disorder to chronic depression. Difficulty arises from the diverse symptoms associated with fatigue states; fatigue is a prominent feature of many systemic, neurologic, and psychiatric disorders. Also, fatigue is a subjective complaint without a quantifiable measure. This interweaving of many symptoms and diagnoses with disabling fatigue makes it difficult to compare patient groups. Terms applied to disorders that probably represent chronic fatigue syndrome are chronic infectious mononucleosis, myalgic encephalomyelitis, idiopathic chronic fatigue and myalgia syndrome, epidemic neuromyasthenia, postviral fatigue syndrome, and fibrositis-fibromyalgia.
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Source: Murray RS. Myth of the chronic fatigue syndrome. West J Med. 1991 Jul;155(1):68. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1002920/