Cognitive impairment after three decades of multiple sclerosis

Eur J Neurol. 2010 Mar;17(3):499-505. doi: 10.1111/j.1468-1331.2009.02889.x. Epub 2009 Dec 29.


Background: Population-based studies of cognitive impairment in patients with multiple sclerosis (MS) with long disease duration are limited. The aim of this study was to evaluate long-term outcome and the predictors of cognitive impairment in a cohort of patients with MS.

Methods: Patients living in Oslo, Norway, with definite MS and onset in 1940-1980 alive on 1 May 2006 were included. Disability was assessed by Expanded Disability Status Scale (EDSS). Cognitive functioning was assessed in terms of psychomotor speed, attention, learning/memory and executive functions.

Results: A total of 123 patients was included. EDSS was < or =3.0 in 26% and > or =6.0 in 60% after mean disease duration of 34.5 years. Cognitive impairment was found in 48% of the patients eligible for neuropsychological evaluation (n = 84). Typical pattern was moderate impairment within areas of information processing, attention and memory. In the univariate analysis, younger onset age was significantly associated with cognitive impairment (P = 0.014). Younger onset age (P = 0.017) and disease course (secondary progressive vs. relapsing-remitting MS, P = 0.049) were significantly associated with cognitive impairment in the multivariate analysis.

Conclusions: After three decades of disease, half of the MS patients experienced reduced cognitive functioning; however, nearly one-third of the patients were only mildly disabled based on the EDSS. Younger onset age was associated with higher prevalence of cognitive impairment. A thorough evaluation of cognitive function in addition to EDSS is essential for evaluating long-term impairment in patients with MS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age of Onset
  • Child
  • Cognition Disorders / complications
  • Cognition Disorders / diagnosis*
  • Cohort Studies
  • Disability Evaluation
  • Female
  • Humans
  • Male
  • Middle Aged
  • Multiple Sclerosis, Chronic Progressive / complications
  • Multiple Sclerosis, Chronic Progressive / diagnosis*
  • Multiple Sclerosis, Relapsing-Remitting / complications
  • Multiple Sclerosis, Relapsing-Remitting / diagnosis*
  • Neuropsychological Tests
  • Norway
  • Prognosis
  • Time Factors
  • Young Adult