Monday October 9 5:38 PM ET
NEW YORK (Reuters Health) - People with multiple sclerosis (MS) are far more susceptible to mental fatigue than other individuals are, researchers report.
"These findings on the mental fatigue experienced by MS patients during the course of a day should be of interest to teachers, employers, family members, and others who regularly interact with MS sufferers," said Dr. Lauren B. Krupp from State University of New York at Stony Brook, in a news release.
Krupp and associate Dr. Leigh E. Elkins put 45 patients with MS and 14 healthy individuals through a 4-hour session of mental testing that required a continuous mental effort.
At the beginning of the test session, various measures of mental function were equivalent for the two groups. But in measures of verbal memory, visual memory and conceptual planning, the MS patients worsened over the test session, while the healthy individuals improved, the authors report in the October 10th issue of Neurology.
Both groups described increases in physical fatigue during the test period, the results indicate, and at no point did their ratings differ significantly.
And the reports of fatigue and self-assessments of mental performance did not correspond to the changes in test performance for either group, the researchers note.
What processes might underlie the differences in mental fatigue between healthy individuals and patients with MS are not clear, Krupp and Elkins write. They suggest that metabolic differences may be linked to mental performance, as such abnormalities have been associated with muscle fatigue in MS patients.
SOURCE: Neurology 2000;55:934-939.