As a potential investigator into the mysteries of the chronic fatigue syndrome, I need some clarification of the revised case definition provided by Fukuda and colleagues [1]. If a patient relates fluently, for more than an hour, the minute details of his or her medical history, how should I assess his or her reports of defective memory, poor concentration, and difficulty in communication? If, during the interview, a patient moves easily about in a chair, walks effortlessly to the examination room, disrobes quickly, and hops (despite being 80 pounds overweight) onto the examination table, how should I assess his or her reports of disabling muscle pain and weakness? If I am exhausted after 90 minutes of clinical interaction but my patient remains lively with the energy to storm about angrily when I hesitate to order a single-photon emission computed tomographic scan, how should I assess his or her reports of overwhelming fatigue? If a patient tells me that before November he or she could run 10 miles a day but since November cannot walk a block, am I to credit the first declaration, the second, both, or neither? If his or her muscles feel "as if they were beaten for hours by a baseball bat," is that too much pain? I understand that the fever must not be too high, the lymph nodes not too large, or the throat not too red. Can subjective reports be too severe to count? Need I be concerned if a patient had echocardiography, a stress test, an upper gastrointestinal series, abdominal sonography, flexible colonoscopy, two dilatation and curettage procedures, a work-up for lupus, and treatment of hypothyroidism, all before the abrupt onset of fatigue? Finally, should my evaluation of a patient's reports be modified in any way if he or she arrives with a pamphlet from the National Institute of Allergy and Infectious Disease, fliers from the Chronic Fatigue-Immune Deficiency Syndrome Association, a report by Dr. Byron Hyde of the Nightingale Research Foundation, and a copy of Dr. Paul R. Cheney's testimony before the Food and Drug Administration Scientific Advisory Committee on 18 February 1993?

I would appreciate a prompt reply to these questions because I do want to get started on my scientific research.