This review looks at how MS often affects aspects of thinking such as memory, concentration and attention span and who is more likely to experience these symptoms. Drug treatments are lacking but some success has been seen with brain training and with strategies to get round the day to day problems caused by cognitive symptoms.
About half of people with MS have difficulties with memory, concentration and attention span at some time. These aspects of thinking are together known as cognition and problems with them are known as cognitive difficulties. These symptoms can vary from day to day; they can be relatively mild or have a major impact on day to day living. They can affect someone's ability to work, to socialise and to maintain good relationships with family and friends.
Cognitive problems are often caused directly by MS although they may be the side effect of medication. Cognitive problems are not the same thing as dementia.
How this study was carried out
This article is a review of cognitive difficulties in MS including:
- what aspects of thinking are most affected
- who is more likely to experience cognitive symptoms
- what role depression or physical disability may play
- what imaging of the brain reveals
- current treatment options and the scope for better treatments
The full text is available to read online
What was found
Cognitive difficulties can have a major impact on daily living. In one study, two thirds (66%) had trouble remembering things but fewer people (one in seven /14%) had difficulties making new memories.
Difficulties can range from having trouble thinking of the right word to not being able to find the way around the local area or recall phone numbers, even though the roads and the phone numbers used to be familiar and easy to remember.
Tasks that require someone's attention for a long period of time seem to be particularly difficult for many people. This is even more the case if the task requires someone to remember information while there are distractions going on.
People with either primary or secondary progressive MS usually have more cognitive difficulties than people with relapsing remitting MS. In addition, men with MS are more likely to experience these symptoms than women and to be more severely affected. Those with depression or physical disability are more likely to experience cognitive problems.
People with a higher cognitive reserve are less likely to experience cognitive difficulties. Cognitive reserve (PDF) is the brain's ability to use its pathways more efficiently or to recruit alternative pathways if the ones usually used are damaged. Both intelligence and education contribute to improved cognitive reserve.
Cognitive difficulties are more likely if there has been nerve cell loss in the grey matter of the cerebral cortex (the thin layer of cells that makes up the outer layer of the brain) and the thalamus (the relay station between the brain and the spinal cord through which nearly all motor and sensory information travels).
Four drugs (ginkgo biloba, donepezil, rivastigmine, and memantine) have been tested in large-scale, double-blind, placebo-controlled clinical trials but none showed a significant effect.
Cognitive rehabilitation therapy (a kind of brain training) has had some success. As the brain is a dynamic organ, practicing a specific cognitive task strengthens the communication between neurons required for that task. Also, dealing with fatigue can help improve cognitive abilities.
Other strategies are problem focussed so they look for a way round the difficulty such as taking a tape recorder to a meeting to help in recalling what was said.
What does it mean?
The authors reflect on the complexities of studying cognitive difficulties as the amount of nervous system damage, the location of lesions and the kinds of difficulties experienced all vary tremendously. They suggest that it will be important to look at the many factors that seem linked to cognitive symptoms, such as fatigue, depression and physical disability, to see which comes first and how they interact.
Read information from the MS Trust on how to deal with cognitive difficulties in the blue box below.
More about cognitive difficulties in MS
You can read more about cognitive problems in the A-Z of MS.
Staying Smart is a website from the MS Trust which is designed for people who want to know more about how MS can affect thinking. It takes a practical approach and includes tips for coping with day to day problems and videos of people discussing their symptoms.
An item from a previous Research Update looks at inattentional blindness – another kind of cognitive problem
Research by topic areas...
Symptoms and symptom management
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Understanding tremor in multiple sclerosis: prevalence, pathological anatomy, and pharmacological and surgical approaches to treatment.
Tremor Other Hyperkinet Mov (N Y). 2012;2.
Berger JR, Pocoski J, Preblick R, et al.
Fatigue heralding multiple sclerosis.
Mult Scler. 2013 Feb 25. [Epub ahead of print]
Disease modifying treatments
Romeo M, Martinelli-Boneschi F, Rodegher M, et al.
Clinical and MRI predictors of response to interferon-beta and glatiramer acetate in relapsing-remitting multiple sclerosis patients.
Eur J Neurol. 2013 Feb 20. doi: 10.1111/ene.12119.[Epub ahead of print]
Lublin FD, Cofield SS, Cutter GR, et al.
Randomized study combining interferon & glatiramer acetate in multiple sclerosis.
Ann Neurol. 2013 Feb 19. doi: 10.1002/ana.23863. [Epub ahead of print]
Deiß A, Brecht I, Haarmann A, et al.
Treating multiple sclerosis with monoclonal antibodies: a 2013 update.
Expert Rev Neurother. 2013 Mar;13(3):313-35.
Evaluation of brainstem involvement in multiple sclerosis.
Expert Rev Neurother. 2013 Mar;13(3):299-311.
Drugs in development
Wolinsky JS, Narayana PA, Nelson F, et al.
Magnetic resonance imaging outcomes from a phase III trial of teriflunomide.
Mult Scler. 2013 Feb 27. [Epub ahead of print]
Amatya B, Khan F, La Mantia L, et al.
Non pharmacological interventions for spasticity in multiple sclerosis.
Cochrane Database Syst Rev. 2013 Feb 28;2:CD009974.
Luessi F, Siffrin V, Zipp F.
Neurodegeneration in multiple sclerosis: novel treatment strategies.
Expert Rev Neurother. 2012 Sep;12(9):1061-76; quiz 1077.
Grotenhermen F, Müller-Vahl K.
The therapeutic potential of cannabis and cannabinoids.
Dtsch Arztebl Int. 2012 Jul;109(29-30):495-501.
Kister I, Chamot E, Salter AR, et al.
Disability in multiple sclerosis: A reference for patients and clinicians.
Neurology. 2013 Feb 20. [Epub ahead of print]
Devy R, Lehert P, Varlan E, et al.
A short and validated multiple sclerosis-specific health-related quality of life measurement for routine medical practice.
Eur J Neurol. 2013 Feb 20. doi: 10.1111/ene.12107. [Epub ahead of print]
Causes of MS
Ramagopalan SV, Lee JD, Yee IM, et al.
Association of smoking with risk of multiple sclerosis: a population-based study.
J Neurol. 2013 Mar 2. [Epub ahead of print]
Pakpoor J, Giovannoni G, Ramagopalan SV.
Epstein-Barr virus and multiple sclerosis: association or causation?
Expert Rev Neurother. 2013 Mar;13(3)287-97.
Holmøy T, Kampman MT, Smolders J.
Vitamin D in multiple sclerosis: implications for assessment and treatment.
Expert Rev Neurother. 2012 Sep;12(9):1101-12.
Nielsen-Prohl J, Saliger J, Güldenberg V, et al.
Stress-stimulated volitional coping competencies and depression in multiple sclerosis.
J Psychosom Res. 2013 Mar;74(3):221-6.
Owens EM, Denney DR, Lynch SG.
Difficulties in planning among patients with multiple sclerosis: a relative consequence of deficits in information processing speed.
J Int Neuropsychol Soc. 2013 Feb 21:1-8. [Epub ahead of print]
Wojtowicz M, Omisade A, Fisk JD.
Indices of cognitive dysfunction in relapsing-remitting multiple sclerosis: intra-individual variability, processing speed, and attention network efficiency.
J Int Neuropsychol Soc. 2013 Feb 21:1-8. [Epub ahead of print]
Minagar A, Barnett MH, Benedict RH, et al.
The thalamus and multiple sclerosis: modern views on pathologic, imaging, and clinical aspects.
Neurology. 2013 Jan 8;80(2):210-9.
Pregnancy and childbirth
Langer-Gould A, Beaber BE.
Effects of pregnancy and breastfeeding on the multiple sclerosis disease course.
Clin Immunol. 2013 Jan 27. doi:pii:S1521-6616(13)00019-3. 10.1016/j.clim.2013.01.008. [Epub ahead of print]
Patas K, Engler JB, Friese MA, et al.
Pregnancy and multiple sclerosis: feto-maternal immune cross talk and its implications for disease activity.
J Reprod Immunol. 2013 Mar;97(1):140-6.
Lu E, Wang BW, Guimond C, et al.
Safety of disease-modifying drugs for multiple sclerosis in pregnancy: current challenges and future considerations for effective pharmacovigilance.
Expert Rev Neurother. 2013 Mar;13(3):251-61.
Sosnoff JJ, Balantrapu S, Pilutti LA, et al.
Cognitive processing speed is related to fall frequency in older adults with multiple sclerosis.
Arch Phys Med Rehabil. 2013 Feb 16. doi:pii:S0003-9993(13)00134-2. 10.1016/j.apmr.2013.02.009. [Epub ahead of print]