Multiple sclerosis is the most common potentially disabling disease of the central nervous system affecting young adults. The lifetime risk is about 1 in 500 in the UK and there is a slight excess risk in females (it affects three times more females than males).

In most patients the pattern is initially episodic but the disorder moves through characteristic phases of attacks which recover, episodes leaving persistent deficits and then slow progression; occasionally, multiple sclerosis is progressive from onset. This natural history usually evolves over many years and life expectancy is not significantly reduced. Disability relates to onset and duration of the progressive phase. Focal inflammation causes acute injury of the myelin sheath that coats many nerve fibres in the brain and spinal cord disrupting the normal rapid passage of electrical impulses (saltatory conduction). The symptoms and signs of multiple sclerosis reflect the functional anatomy of impaired saltatory conduction at the sites affected - the cerebrum, optic nerves, brain stem and cerebellum, and spinal cord - producing alterations in vision, balance and co-ordination, sensation, movement and control of the bowel and bladder. Although these effects are initially reversible, due to resolution of inflammation and (perhaps) remyelination, with time there is persistent demyelination, axonal (nerve fibre) loss and astrocytes (small star shaped cells) scarring causing the sclerosed (hardened) plaques from which the disease gets its name. The cause of the disease is unknown but epidemiological studies indicate an interplay between genetic susceptibility factors and environmental triggers.

Multiple sclerosis is usually perceived as a disorder of adulthood but children and adolescents can be affected. Although childhood and adolescent onset is not common, it is thought that two point seven to four point four per cent of people with Multiple sclerosis have onset before the age of sixteen. Of this figure, zero point two to one point six per cent are affected before the age of ten years. The relapsing remitting form of Multiple sclerosis is more common in those having childhood onset. Common features in childhood onset Multiple sclerosis are sensory problems, movement difficulties such as poor co-ordination and tremor, and visual problems.

Inheritance patterns
Multiple sclerosis is a typical complex trait and susceptibility is genetically determined. Recurrence risk amongst the relatives of probands - the affected individual through whom a family with a genetic disorder is ascertained - identify a familial recurrence rate of approximately fifteen per cent. The age-adjusted risk is highest for siblings (three per cent), then parents (two per cent) and children (two per cent) with lower rates in second and third degree relatives. Recurrence in monozygotic twins is around thirty-five per cent. The frequency of multiple sclerosis in the social relatives of adoptees is no higher than the population risk and significantly lower than expected in biological relatives of index cases. The age-adjusted risk for half-siblings is also less than for full siblings. Recurrence is higher in the children of conjugal pairs with multiple sclerosis (six per cent; age-adjusted twenty per cent) than the offspring of single affecteds (two per cent).

Prenatal diagnosis
None.

Medical text written November 2002 by Professor A Compston. Last updated June 2005 by Contact a Family and approved by Professor A Compston, Professor of Neurology, University of Cambridge, Cambridge, UK.

Further Online Resources
Medical texts in The Contact a Family Directory are designed to give a short, clear description of specific conditions and rare disorders. More extensive information on this condition can be found on a range of reliable, validated web sites and links to them are included in the CD-ROM version of this Directory. Further information on these resources can be found in our Medical Information on the Internet article.

MULTIPLE SCLEROSIS RESOURCE CENTRE

Multiple Sclerosis Resource Centre
7 Peartree Business Centre
Peartree Road
Stanway
Colchester
CO3 0JN
Tel: 0800 783 0518 (24 hour MS telephone counselling service)
Tel: 01206 505444
Fax: 01206 505449
e-mail: info@msrc.co.uk
Web: http://www.msrc.co.uk

The Centre is a National Registered Charity No. 1033731, established in 1993. It is dedicated to supporting all those affected by MS, including friends, family, work colleagues and professionals. The MSRC publishes a bi-monthly magazine New Pathways which is also available on CD. It has a wide range of information and publications, details on request. The website has extensive information about all aspects of MS and includes a message board and chat room. The MSRC works closely with the many MS Therapy Centres throughout the country. The centre has over 6,000 magazine subscribers and gives advice and information to thousands of people from all over the world.

Group details last updated August 2007.

MULTIPLE SCLEROSIS SOCIETY

Multiple Sclerosis Society
MS National Centre
372 Edgware Road
London
NW2 6ND
Tel: 0808 800 8000 Helpline (9am - 9pm, Mon-Fri)
Tel: 020 8438 0700
Fax: 020 8438 0701
e-mail: info@mssociety.org.uk
Web: http://www.mssociety.org.uk

The Society is a National Registered Charity No. 207495, established in 1953. It offers support and advice to people affected by MS, health and social care professionals. It promotes research to find the cause and a cure for MS. It offers short breaks and grants for individuals in need. It also has partnership funding for MS Nurse posts. It publishes 'MS Matters' a bi-monthly magazine for members of the Society and has a wide range of information available, details on request. Across the UK information and support is available to anyone affected by MS from a network of over 340 local branches.

Group details last confirmed February 2008.

Direct services for children and adults with Multiple Sclerosis are also provided by the National Institute of Conductive Education (see Foundation for Conductive Education, under separate entry, Cerebral Palsy)