OBJECTIVE: To assess cognitive function in patients with chronic
fatigue syndrome (CFS) and multiple sclerosis (MS) and to
evaluate the role of depressive symptoms in cognitive
DESIGN: Case-control. All subjects were given a
neuropsychological battery, self-report measures of depression
and fatigue, and a global cognitive impairment rating by a
neuropsychologist “blinded” to clinical diagnosis. Patients
with MS and CFS were additionally evaluated with a Structured
Clinical Interview for DSM-III-R (Diagnostic and Statistical
Manual of Mental Disorders, Revised Third Edition) disorders.
SETTING: Institutional and private neurological practices and
the community at large.
PATIENTS: Twenty patients with CFS
diagnosed in accord with the Centers for Disease Control and
Prevention-revised criteria who had cognitive complaints; 20
patients with clinically definite MS who were ambulatory and
were matched for fatigue severity, age, and education to CFS
subjects; and 20 age- and education-matched healthy controls.
RESULTS: Patients with CFS had significantly elevated
depression symptoms compared with patients with MS and healthy
controls (P < .001) and had a greater lifetime prevalence of
depression and dysthymia compared with MS subjects. Patients
with CFS, relative to controls, performed more poorly on the
Digit Symbol subtest (P = .023) and showed a trend for poorer
performance on logical memory (P = .087). Patients with MS
compared with controls had more widespread differences of
greater magnitude on the Digit Span (P < .004) and Digit
Symbol (P < .001), Trail Making parts A (P = .022) and B (P =
.037), and Controlled Oral Word Association (P = .043) tests.
Patients with MS also showed a trend of poorer performance on
the Booklet Category Test (P = .089). When patients with CFS
and MS were directly compared, MS subjects had lower scores on
all measures, but the differences reached significance only
for the Digit Span measure of attention (P = .035).
CONCLUSIONS: Patients with CFS compared with MS have more
depressive symptoms but less cognitive impairment. Relative to
controls, a subset of CFS subjects did poorly on tests of
visuomotor search and on the logical memory measure of the
Wechsler Memory Scale-revised. Poor performance of logical
memory in CFS appears to be related to depression, while
visuomotor deficits in CFS are unrelated. Cognitive deficits
in patients with MS are more widespread compared with those in
patients with CFS and are independent of depressive symptoms.
Krupp LB, Sliwinski M, Masur DM, Friedberg F, Coyle PK