Cognition and fatigue in multiple sclerosis: Potential effects of medications with central nervous system activity

J Rehabil Res Dev. Jan-Feb 2006;43(1):83-90. doi: 10.1682/jrrd.2004.11.0148.


To evaluate the potential effects of medications with central nervous system (CNS) activity on cognitive function and fatigue in multiple sclerosis (MS), we performed a retrospective analysis of medication use among 70 subjects with MS who were participating in a clinical trial for evaluation of the effects of yoga and exercise programs on cognition and fatigue. Among these MS subjects, 74% were taking at least one potentially CNS-active medication. These 70 subjects were divided into two groups: those taking at least one CNS-active medication (n = 52) and those not on any medications with potential CNS activity (n = 18). We compared assessments of cognitive function and fatigue using an analysis of covariance. MS subjects on CNS-active medication had greater impairment on measures of processing speed, sustained attention, and fatigue than those not on these medications. While these findings do not establish a causal relationship between medication use and cognitive impairment and fatigue, the data indicate that researchers need to control for use of CNS-active medications when conducting studies of cognitive impairment and fatigue in MS subjects.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Adult
  • Age Distribution
  • Cognition Disorders / diagnosis*
  • Cognition Disorders / epidemiology*
  • Drug Therapy, Combination
  • Fatigue Syndrome, Chronic / diagnosis
  • Fatigue Syndrome, Chronic / epidemiology*
  • Female
  • Humans
  • Incidence
  • Male
  • Mental Processes / drug effects
  • Middle Aged
  • Multiple Sclerosis / drug therapy*
  • Multiple Sclerosis / epidemiology*
  • Multiple Sclerosis / psychology
  • Multivariate Analysis
  • Neuropsychological Tests
  • Probability
  • Prognosis
  • Quality of Life
  • Risk Assessment
  • Sex Distribution
  • Treatment Outcome