The degree of neuropsychological dysfunction across multiple domains
was examined in individuals suffering from chronic fatigue syndrome
(CFS). In this descriptive study, a similar series of
neuropsychological tests was administered to a group of CFS patients
and healthy participants. More specifically, CFS patients (n =
141) who met the 1994 Case Definition criteria were compared to 76
healthy control participants on tests of memory, attention
(concentration), speed of information processing, motor speed, and
executive functioning. On the 18 measures administered, CFS patients
scored 1 standard deviation below the healthy mean on nine measures and
scored 2 standard deviations below the healthy mean on four of the
measures. Moreover, results indicated that CFS patients were more
likely than healthy controls to fail (1.6 SD below the healthy
mean) at least one test in each of the following domains: attention,
speed of information processing, and motor speed, but not on measures
of memory and executive functioning. Finally, CFS patients demonstrated
a greater total number of tests failed across domains. (JINS,
2004, 10, 278–285.)