Clearing Up Confusion on Fatigue Syndrome
By JANE E. BRODY
Published: December 21, 1994
IF there has been one characteristic consistently associated with chronic fatigue syndrome, it is controversy -- over its definition, its magnitude, its cause, its treatment, even its existence. To facilitate the diagnosis and study of this syndrome, an international committee of medical experts has released a refined and much-simplified definition of the condition, which has been variously attributed to everything from emotional disorders and stress to chronic viral infection and a malfunctioning immune system.
The new definition is expected to help both researchers and clinicians separate chronic fatigue syndrome from a host of other conditions that can cause prolonged fatigue and that would require more specific therapy. These other conditions include multiple sclerosis, cancer, sleep disorders, obesity, substance abuse and suicidal tendencies.
In a report in the Dec. 15 issue of The Annals of Internal Medicine, the committee did not question the existence of the syndrome but noted that a failure to apply strict criteria to define it had led many researchers to unjustifiable conclusions.
Some, for example, maintain that the syndrome does not exist independently but is, rather, a manifestation of severe emotional problems. Others, including the Chronic Fatigue and Immune Dysfunction Syndrome Association of America, maintain that an immunological disorder is the main problem in chronic fatigue. Still others have come up with wildly exaggerated estimates of how many people have the syndrome or with undocumentable claims for how to treat it.
The report emphasized that chronic fatigue syndrome, widely known as C.F.S., has as yet no known cause or effective treatment. Its hallmark is severe, disabling fatigue that persists or relapses for many months, even years. Other major symptoms may include impaired concentration and short-term memory, sleep disturbances and muscle and joint pain.
The new definition is important because there is as yet no specific test for chronic fatigue syndrome, nor is there any physical finding on which to base a diagnosis. Rather, the committee said, patients complaining of chronic fatigue should first be examined to determine if any other physical or psychiatric problems could account for their symptoms. The committee also listed specific criteria that doctors could use in making a diagnosis.
The report, based on scientific studies in several countries and input from C.F.S. patients, support-group members and doctors who treat the syndrome, was led by Dr. Keiji Fukuda of the Federal Centers for Disease Control and Prevention in Atlanta. Surveillance data from the agency, which has been conducting studies of the syndrome in four areas, indicate that 4 to 10 adults in every 100,000 suffer from it, suggesting that it syndrome afflicts 100,000 to 250,000 people nationwide.
But Dr. William Reeves, who heads the centers' C.F.S. research program, points out that these numbers reflect only those C.F.S. patients who see a doctor. Many people plagued by chronic fatigue do not seek medical help, he said. Other surveys have suggested that as many as 500,000 to 1.25 million people in this country may have it.
Symptoms very much like those of chronic fatigue syndrome are not uncommon in people suffering from serious depression, a fact that prompted the expert committee to exclude from a diagnosis of the syndrome any person who has suffered from a major depressive disorder. On the other hand, since it would not be unusual for people with symptoms characteristic of the syndrome to become depressed or anxious, the committee did not rule out the possibility that people with lesser degrees of depression or with anxiety disorders might also have C.F.S.
In a comment about the name of the syndrome, the experts suggested that available evidence did not warrant attributing C.F.S. symptoms to a particular physical problem, like immunological dysfunction. An organization that calls itself the Chronic Fatigue and Immune Dysfunction Syndrome Association of America maintains that an immunological disorder is the primary problem in chronic fatigue. Defining Chronic Fatigue: A Less Stringent Test
The new definition of chronic fatique syndrome differs from a definition issued in 1988 by substantially reducing the number of symptoms a patient must display before receiving a diagnosis of C.F.S.
The new definition states that a patient must be suffering from unexplained, persistent or relapsing chronic fatigue that is of new or definite onset, that is not the result of excessive physical activity, that is not substantially relieved by rest and that has resulted in a significant decline in previous levels of activity.
In addition, since the start of the illness, a patient must have exhibited four or more of these symptoms: problems with short-term memory or concentration severe enough to interfere with work, education or personal or social activities; sore throat or tender lymph nodes in the neck or underarm; muscle and joint pain; headaches of a new type or severity; unrefreshing sleep, and malaise lasting a day or more after physical exertion.