Conventional and complementary treatment for cancer.
Authors: J. Cosh, K. Sikora
Journal: BMJ (1989)

Does this fatigue originate centrally in the brain or peripherally in muscle?The findings on nuclear magnetic resonance of an early and prolonged fall in muscle pH with exercise suggested peripheral lesions,"6 but later reports have been less convincing, with a schizophrenic patient showing the same changes.'7As these studies have not controlled for muscle disuse through inactivity this finding might be an effect rather than a cause.Stokes and colleagues used a twitch interpolation technique and showed that fatigue could not be explained by peripheral mechanisms-so was likely to be central in origin.'8 With what other symptoms is fatigue associated?Chen examined a large community sample and found that one in five subjects reported fatigue for over one month." Fatigue was strongly associated with self reported anxiety, depression, and "stress."General practice studies have reported similar findings.Kroenke and colleagues screened an un- selected group of 1159 consecutive patients, a quarter of whom reported fatigue as a serious problem for more than a month.2'Patients were excluded if they were currently under the care of a psychiatrist or had an obvious medical disorder, yet four fifths of the fatigued patients reported depression or somatic anxiety, or both, compared with one in eight of the controls.What proportion of patients have psychiatric or "organic" diagnoses?Morrison studied 176 patients with unexplained fatigue of recent origin and found that two fifths were later given a psychiatric diagnosis (mainly depression and anxiety).2"Organic" diagnoses were made in a further two fifths of patients, with viral illnesses being the commonest, especially in the young.Of the remaining 35 patients, 21 had mixed diagnoses and the rest were undetermined.Psychiatric diagnoses were particularly associated with a duration of symptoms longer than four months.Studies oft patients with fatigue of longer duration showed that two thirds of patients had a recognisable psychiatric disorder.Taerk and colleagues studied 24 patients with postinfectious "neuromyasthenia," 16 of whom scored more than 9 on the Beck depressive inventory.22Manu and colleagues studied 100 self referred patients with chronic fatigue of 13 years' mean duration: 66 subjects had current DSM III psychiatric disorders.23Wessely and Powell studied 47 patients with unexplained fatigue referred to the National Hospital for Nervous Diseases.24They found that 34 had psychiatric disorders even after exclusion of fatigue as a symptom.This compared with 12 of 33 controls with peripheral neuromuscular disorders.The commonest diagnosis in these last two studies was major depressive disorder in half the patients, with a further 15% having a somatisation disorder.It is difficult to assess whether these psychiatric disorders are primary or secondary to the fatigue.Three points should be noted in relation to these studies: a third of patients with fatigue had no evidence of psychiatric disorder; generalisation from selected populations may be unwise; and "organic" and "psychiatric" diagnoses may be found together in the same patients,2'25 making a simple "either/or" classification inappropriate.'025The present evi- dence suggests that a chronic fatigue syndrome does exist, certainly after particular infections.The symptoms resemble the more narrowly defined concept of neurasthenia.The reliability of the concept over time is uncertain.If symptoms persist treatable psychiatric disorders will be found in two thirds of patients.We should, however, remember what Robert Whytt wrote in 1765: that physicians diagnosed as "nervous, hypochondriac, or hysteric ... all those disorders whose nature and causes they were ignorant of."26Given our present inability to cure patients with chronic fatigue syndrome we should therefore treat what we know is treatable while keeping an open mind about aetiology.27