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MS research update - Epstein-Barr virus may explain the north-south divide in MS - 11 July 2012


The cause(s) of MS are unknown but a number of environmental factors have been implicated. The evidence for three factors is particularly strong: vitamin D deficiency, a history of smoking and exposure to the Epstein–Barr virus (EBV) which causes glandular fever (also known as infectious mononucleosis).

The vast majority of people with MS have antibodies to EBV in their blood showing that they have been exposed to the virus at some point in their life. They may have had glandular fever as a consequence or they may not have shown any symptoms.

This study

The proportion of people with MS who have antibodies to EBV (who are seropositive) has been shown, in different studies, to range from 80% to 100%. People who do not have MS, rarely have antibodies to EBV.

In addition, it has been established that MS generally occurs more frequently the further you travel from the equator. This study looked at whether the range of results for EBV seropositivity obtained in previous studies was because the studies were looking at different populations of people with MS who were living at different latitudes (distances from the equator).

The researchers collected information from 19 previous studies in the northern hemisphere where the latitude was known. They were able to confirm that having MS was strongly associated with being seropositive for EBV. However, latitude was also associated with being positive for EBV, whether someone had MS or not.

Significantly, seven of the nine studies conducted at more northern latitudes (46°–65° N), reported 100% of people with MS having antibodies to EBV. This compared with only two out of 10 studies performed at lower latitudes (29°–45° N).

Vitamin D deficiency is known to be associated with a higher risk of MS. Consequently, the studies were re-divided into those conducted above or below a latitude of 42° N as this is thought to be the cut off point for whether people can make vitamin D in the skin when exposed to sunlight. They found that above 42° N, people with MS were more likely to have antibodies to EBV. However, the same was true for people who did not have MS.

This is important as it suggests that the fact that more people have antibodies to EBV at higher latitudes is not specific to MS but is occurring in the whole population.


The researchers suggest that EBV and vitamin D may be linked together in causing MS. It is known that vitamin D helps the immune system defend the body from bacterial and viral infections and previous research has shown that lower vitamin D levels correspond to more copies of EBV in an infected individual.

They suggest that vitamin D deficiency could impair the immune response to EBV leading to increased susceptibility to the virus or to reactivation of the virus later on in life. This means that, if EBV plays a role in causing MS, then vitamin D deficiency could make MS more likely.

Disanto G, Pakpoor J, Morahan JM, et al.
Epstein-Barr virus, latitude and multiple sclerosis.
Mult Scler. 2012 Jul 5. [Epub ahead of print]

Deciding whether to have children after diagnosis with MS


MS is often diagnosed when someone is in their twenties or thirties and is about three times more common in women than men. These two factors together could mean that diagnosis with MS affects someone's decision whether to have children or not.

This study

A questionnaire was sent to over 13,000 people with MS on the NARCOMS database in North America. 5,949 people (45%) responded.

The vast majority (79%) did not become pregnant following their diagnosis.

For some people this related to their MS.

  • Almost three quarters (71%) were concerned about their symptoms interfering with parenting
  • Half (51%) were concerned about burdening their partner
  • A third (35%) were concerned about any children inheriting MS

However, there were also reasons which were not related to MS, with just over half (56%) feeling that they had already "completed" their family.

About a fifth (21%) of the people who responded to the survey, decided to become pregnant, or father a pregnancy, following a diagnosis of MS. Of these, half (50%) had two or more pregnancies.


This study suggests that diagnosis with MS does not always deter women or men from having children. The researchers expressed concern that some people with MS avoided having children because they were worried about the child inheriting MS. However, many of these couples had not sought genetic counselling, although this was often available and could have given a realistic view on the risks involved.

The researchers suggest that it is important for health professionals to discuss pregnancy with people with MS so that they are able to make informed choices about whether to start a family or not. The topics should include the effects of pregnancy on MS symptoms and disease course, the effects of MS on pregnancy outcome, possible effects of MS treatments (including DMTs) on the development of the baby, MS recurrence risks and psychosocial considerations such as having financial and family support and parenting capabilities.

Alwan S, Yee I, Dybalski M, et al.
Reproductive decision making after the diagnosis of multiple sclerosis (MS).
Mult Scler. 2012 Jul 3. [Epub ahead of print]


Research by topic areas...


Granberg T, Martola J, Kristoffersen-Wiberg M, et al.
Radiologically isolated syndrome - incidental magnetic resonance imaging findings suggestive of multiple sclerosis, a systematic review.
Mult Scler. 2012 Jul 3. [Epub ahead of print]

Symptoms and symptom management

Truini A, Barbanti P, Pozzilli C, et al.
A mechanism-based classification of pain in multiple sclerosis.
J Neurol. 2012 Jul 4. [Epub ahead of print]

Disease modifying treatments

Meyniel C, Spelman T, Jokubaitis VG, et al.
Country, sex, EDSS change and therapy choice independently predict treatment discontinuation in multiple sclerosis and clinically isolated syndrome.
PLoS One. 2012;7(6):e38661.

Bloomgren G, Sperling B, Cushing K, et al.
Assessment of malignancy risk in patients with multiple sclerosis treated with intramuscular interferon beta-1a: retrospective evaluation using a health insurance claims database and postmarketing surveillance data.
Ther Clin Risk Manag. 2012;8:313-321. Epub 2012

Klineova S, Nicholas J, Walker A.
Response to disease modifying therapies in African Americans with multiple sclerosis.
Ethn Dis. 2012 Spring;22(2):221-5.

[No authors listed]
Multiple sclerosis: Risk factors for progressive multifocal leukoencephalopathy identified in natalizumab-treated patients.
Nat Rev Neurol. 2012 May 7;8(7):358.

Drugs in development

[No authors listed]
Multiple sclerosis: teriflunomide shows efficacy as an add-on therapy to IFN-β in patients with multiple sclerosis.
Nat Rev Neurol. 2012 May 7;8(7):358.

Other treatments

Niepel G, Bibani RH, Vilisaar J, et al.
Association of a deficit of arousal with fatigue in multiple sclerosis: Effect of modafinil.
Neuropharmacology. 2012 Jul 2. [Epub ahead of print]

Pikoulas TE, Fuller MA.
A medication to improve walking in patients with multiple sclerosis
Ann Pharmacother. 2012 Jul 3. [Epub ahead of print]

Van Der Walt A, Sung S, Spelman T, et al.
A double-blind, randomized, controlled study of botulinum toxin type A in MS-related tremor.
Neurology. 2012 Jul 3;79(1):92-9.

Garcia Jalon EG, Lennon S, Peoples L, et al.
Energy conservation for fatigue management in multiple sclerosis: a pilot randomized controlled trial.
Clin Rehabil. 2012 Jul 2. [Epub ahead of print]

Di Rezze S, Frasca V, Inghilleri M, et al.
Duloxetine for the treatment of overactive bladder syndrome in multiple sclerosis: a pilot study.
Clin Neuropharmacol. 2012 Jun 29. [Epub ahead of print]


Deussing EC, Jankosky CJ, Clark LL, et al.
Estimated incidence of multiple sclerosis among United States Armed Forces personnel using the Defense Medical Surveillance System.
Mil Med. 2012 May;177(5):594-600.

Arias M, Dapena D, Arias-Rivas S, et al.
Late onset multiple sclerosis.
Neurologia. 2011 Jun;26(5):291-6.


Beer S, Khan F, Kesselring J.
Rehabilitation interventions in multiple sclerosis: an overview.
J Neurol. 2012 Jul 8. [Epub ahead of print]

Assessment tools

Akinwuntan AE, Devos H, Stepleman L, et al.
Predictors of driving in individuals with relapsing-remitting multiple sclerosis.
Mult Scler. 2012 Jul 3. [Epub ahead of print]

Kasper J, Köpke S, Fischer K, et al.
Applying the theory of planned behaviour to multiple sclerosis patients' decisions on disease modifying therapy - questionnaire concept and validation.
BMC Med Inform Decis Mak. 2012 Jul 2;12(1):60. [Epub ahead of print]

Vitamin D

Faridar A, Eskandari G, Sahraian MA, et al.
Vitamin D and multiple sclerosis: a critical review and recommendations on treatment.
Acta Neurol Belg. 2012 Jul 6. [Epub ahead of print]

Psychological aspects

Montel S, Spitz E, Bungener C.
Coping strategies in multiple sclerosis patients with frontal cognitive disorders.
Eur Neurol. 2012 Jul 3;68(2):84-88. [Epub ahead of print]

Physical activity

Sandroff BM, Motl RW, Suh Y.
Accelerometer output and its association with energy expenditure in persons with multiple sclerosis.
J Rehabil Res Dev. 2012 May;49(3):467-76.

Normann B, Sørgaard KW, Salvesen R, et al.
Contextualized perceptions of movement as a source of expanded insight: People with multiple sclerosis' experience with physiotherapy.
Physiother Theory Pract. 2012 Jul 5. [Epub ahead of print]

Cameron M, Wagner J, Zackowski K, et al.
1st international symposium on gait and balance in MS: gait and balance measures in the evaluation of people with MS.
Mult Scler Int. 2012;2012:720206.

Kjølhede T, Vissing K, Dalgas U.
Multiple sclerosis and progressive resistance training: a systematic review.
Mult Scler. 2012 Apr 24. [Epub ahead of print]

Spooren AI, Timmermans AA, Seelen HA.
Motor training programs of arm and hand in patients with MS according to different levels of the ICF: a systematic review.
BMC Neurol. 2012 Jul 2;12(1):49. [Epub ahead of print]

Steens A, Heersema DJ, Maurits NM, et al.
Mechanisms underlying muscle fatigue differ between multiple sclerosis patients and controls: a combined electrophysiological and neuroimaging study.
Neuroimage. 2012 Feb 15;59(4):3110-8.


Tomasevic L, Zito G, Pasqualetti P, et al.
Cortico-muscular coherence as an index of fatigue in multiple sclerosis.
Mult Scler. 2012 Jul 3. [Epub ahead of print]

Pregnancy and childbirth

Alwan S, Sadovnick AD.
Multiple sclerosis and pregnancy: maternal considerations.
Womens Health (Lond Engl). 2012 Jul;8(4):399-414.

Stem cells

Shevchenko JL, Kuznetsov AN, Ionova TI, et al.
Autologous haematopoietic stem cell transplantation with reduced intensity conditioning in multiple sclerosis.
Exp Hematol. 2012 Jul 4. [Epub ahead of print]

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