General Information


Cognitive difficulties

Just under half of people with MS say that they experience significant cognitive difficulties. When their cognition is formally assessed on psychometric tests in group studies, approximately half will have some demonstrable inefficiency. When the people with MS are recruited from the community, slightly less than half will show this effect on tests. When the people with MS are recruited from a university clinic, slightly more than half will have a demonstrable inefficiency. Test scores do not relate to how people manage in everyday life in a simple way. This is partly because of external factors influencing test performance (see contributory factors).

The types of tasks that are most likely to be affected in MS are those requiring complex attention (for example, difficult arithmetic problems done without paper and pencil) and memory for information that has just been heard or seen (e.g. remembering a list of words). Increasingly, research is pointing towards an underlying slowing in mental processing that explains all other cognitive difficulties.

Change in cognitive abilities over time is often slow or non-existent. In very long studies, which collect information over 10 years or more, it seems that there is a gradual accumulation of cognitive difficulties over time. Such studies indicate that those individuals most at risk of acquiring cognitive difficulties are those who present with them in the earliest stages of the study.

While some studies have pointed towards different cognitive profiles for the different MS subtypes (relapsing/remitting, primary progressive, secondary progressive and benign), such differences are small and subtle.

Further reading


Amato MP, Zipoli V, Portaccio E. Multiple sclerosis-related cognitive changes: a review of cross-sectional and longitudinal studies. J Neurol Sci 2006; 245(1):41-6.

Medline Abstract

Chiaravalloti ND, DeLuca J. Cognitive impairment in multiple sclerosis. Lancet Neurol 2008; 7(12):1139-51.

Medline Abstract

Langdon DW. Cognition in multiple sclerosis. Curr Opin Neurol. 2011 Jun;24(3):244-9.

Rogers JM, Panegyres PK. Cognitive impairment in multiple sclerosis: evidence-based analysis and recommendations. J Clin Neurosci 2007; 14(10):919-27.

Medline Abstract

Individual studies

Denney DR, Lynch SG, Parmenter BA et al. Cognitive impairment in relapsing and primary progressive multiple sclerosis: mostly a matter of speed. J Int Neuropsychol Soc 2004; 10:948-56.

Medline Abstract

Forn C, Belenguer A, Parcet-Ibars MA, et al. Information-processing speed is the primary deficit underlying the poor performance of multiple sclerosis patients in the Paced Auditory Serial Addition Test (PASAT). J Clin Exp Neuropsychol 2008; 30(7):789-796

Medline Abstract

Goverover Y, Genova HM, Hillary FG et al. The relationship between neuropsychological measures and the Timed Instrumental Activities of Daily Living task in multiple sclerosis. Mult Scler 2007; 13(5):636-44.

Medline Abstract

Kalmar JH, Gaudino EA, Moore NB, et al. The relationship between cognitive deficits and everyday functional activities in multiple sclerosis. Neuropsychology 2008; 22(4):442-9.

Medline Abstract

Macniven JA, Davis C, Ho MY, et al. Stroop performance in multiple sclerosis: information processing, selective attention, or executive functioning? J Int Neuropsychol Soc 2008; 14(5):805-14.

Medline Abstract

Prakash RS, Snook EM, Lewis JM, et al. Cognitive impairment in relapsing-remitting multiple sclerosis: a meta-analysis. Mult Scler 2008; 14(9):1250-61.

Medline Abstract


There are an increasing number of studies about cognitive rehabilitation in MS. Cognitive rehabilitation studies tend to take one of four approaches:

When a drug treatment is evaluated, a randomised controlled trial is carried out. Participants are randomly allocated to receive either treatment or placebo. It is relatively hard to tell a placebo tablet from a real tablet, when they have been designed to look the same. But it is much harder to devise a placebo rehabilitation programme. This means that the therapists delivering the programme and usually the participants as well, know who is receiving the “real” treatment. This can compromise the objectivity of the evaluation of the treatment.

Most rehabilitation studies rely on using neuropsychology tests of different mental skills. The scores before and after training are used to determine if positive change has occurred. Not all studies ask the participants if they found the programme useful. Very few attempt to find out if managing in daily life improved.

Further reading

Amato MP, Langdon D, Montalban X, Benedict RH, DeLuca J, Krupp LB, Thompson AJ, Comi G. Treatment of cognitive impairment in multiple sclerosis: position paper. J Neurol. 2013 Jun;260(6):1452-68.

Chiaravalloti ND, Moore NB, Nikelshpur OM, DeLuca J. An RCT to treat learning impairment in multiple sclerosis: The MEMREHAB trial. Neurology. 2013 Dec 10;81(24):2066-72.

Langdon DW. Cognitive rehabilitation. In Kesselring J, Comi G, Thompson AJ, editors. Textbook of neurorehabilitation in multiple sclerosis. Cambridge: CUP; 2009.

Pierson SH, Griffith N. Treatment of cognitive impairment in multiple sclerosis. Behav Neurol 2006; 17(1):53-67.

Medline Abstract

Rosti-Otajärvi EM, Hämäläinen PI.Neuropsychological rehabilitation for multiple sclerosis. Cochrane Database Syst Rev. 2014.

Shevil E, Finlayson M, Process evaluation of a self-management cognitive program for persons with multiple sclerosis. Patient Education and Counseling 2009;76 (1):77-83.

Medline Abstract

Solari A. Clinical trials to test rehabilitation. In Kesselring J, Comi G, Thompson AJ, editors. Textbook of neurorehabilitation in multiple sclerosis. Cambridge: CUP; 2009.

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