DETECTION OF INTRACRANIAL ABNORMALITIES IN PATIENTS WITH CHRONIC FATIGUE SYNDROME - COMPARISON OF MR-IMAGING AND SPECT

OBJECTIVE. Chronic fatigue syndrome is a recently characterized condit ion of unknown origin that is manifested by fatigue, flulike complaint s, and neurologic signs and symptoms, including persistent headache, i mpaired cognitive abilities, mood disorders, and sensorimotor disturba nces. This syndrome can be difficult to diagnose clinically or by stan dard neuroradiologic tests. We performed MR imaging and single-photon emission computed tomography (SPECT) in patients with chronic fatigue syndrome to compare the usefulness of functional and anatomic imaging in the detection of intracranial abnormalities. SUBJECTS AND METHODS. Sixteen patients who fulfilled the Centers for Disease Control, Britis h, and/or Australian criteria for chronic fatigue syndrome had MR and SPECT examinations within a 10-week period. Axial MR and SPECT scans w ere analyzed as to the number and location of focal abnormalities by u sing analysis of variance with the Student-Newman-Keuls option. MR ima ging findings in patients with chronic fatigue syndrome were compared with those in 15 age-matched control subjects, and SPECT findings in t he patients with chronic fatigue syndrome were compared with those in 14 age-matched control subjects by using Fisher's exact test. The find ings on MR and SPECT scans in the same patients were compared by using the Wilcoxon matched-pairs signed-ranks test. RESULTS. MR abnormaliti es consisted of foci of T2-bright signal in the periventricular and su bcortical white matter and in the centrum semiovale; there were 2.06 f oci per patient, vs 0.80 foci per control subject. MR abnormalities we re present in eight (50%) of 16 patients, compared with three (20%) of 15 age-matched control subjects. Neither of these differences reached significance, although the power of the study to detect differences b etween groups was small. Patients with chronic fatigue syndrome had si gnificantly more defects throughout the cerebral cortex on SPECT scans than did normal subjects (7.31 vs 0.43 defects per subject, p < .001) . SPECT abnormalities were present in 13 (81%) of 16 patients, vs thre e (21%) of 14 control subjects (p < .01). SPECT scans showed significa ntly more abnormalities than did MR scans in patients with chronic fat igue syndrome (p < .025). In the few patients who had repeat SPECT and MR studies, the number of SPECT abnormalities appeared to correlate w ith clinical status, whereas MR changes were irreversible. CONCLUSION. SPECT abnormalities occur more frequently and in greater numbers than MR abnormalities do in patients with chronic fatigue syndrome. SPECT may prove to be useful in following the clinical progress of patients with this syndrome.