Home > Medical Reference > Patient Education

Ask the Expert

Get answers to your Multiple Sclerosis questions.

Note: This is for informational purposes only. Doctors cannot provide a diagnosis or individual treatment advice via e-mail. Please consult your physician about your specific health care concerns.

Hospital Virtual Tour

Multiple sclerosis - Introduction

Description

An in-depth report on the causes, diagnosis, and treatment of MS.

Introduction:

Multiple sclerosis (MS) is a neurological disease that involves the central nervous system (CNS), the nerves that comprise the brain and spinal cord. It has two major features:

Destruction of myelin, a fatty insulation covering the nerve fibers, is the main characteristic of MS. The end results of this process, called demyelination, are multiple patches of hard, scarred tissue called plaques or lesions. Sclerosis comes from the Greek word skleros, which means hard.
Damage of axons, the fibers that carry electric impulses away from a nerve cell, is also a major factor in the permanent disability that occurs with MS.

Myelin is the layer that forms around nerves. Its purpose is to speed the transmission of impulses along nerve cells.

The symptoms, severity, and course of MS vary widely depending partly on the sites of the plaques and the extent of the demyelination.

Autoimmune Disease Process

Multiple sclerosis is thought to be an autoimmune disorder. In autoimmune diseases, immune factors attack the body� ' s own cells. In the case of MS, the immune system attacks the tissues that make up myelin. The damage to myelin, and nerve fibers (axon), is caused by overactivated T cells. T cells are a type of white blood cells called lymphocytes.

Types of Multiple Sclerosis

Doctors generally group multiple sclerosis into four major disease course categories:

Relapsing-Remitting MS. Relapse-remitting MS (RMSS) is the most common form of multiple sclerosis. About 85% of patients are first diagnosed with this type of MS RMSS is marked by flare-ups (also called relapses or exacerbations) of symptoms followed by periods of remission when symptoms improve or disappear.
Secondary-Progressive MS. Some patients with RMSS go on to develop secondary-progressive (SPMS). (For many patients, treatment with disease-modifying medications helps delay this progression.) In SPMS, the disease course continues to worsen with or without periods of remission or leveling off of symptom severity (plateaus).
Primary-Progressive MS. About 10% of patients are diagnosed with primary-progressive MS (PPMS). In PPMS, symptoms continue to worsen gradually from the very beginning. PPMS has no relapses or remissions. There may be periods of occasional plateaus. This type of multiple sclerosis is more resistant to the medications typically used to treat the illness.
Progressive-Relapsing MS. Progressive-relapsing MS (PRMS) is a rare form of MS, occurring in less than 5% of patients. It is progressive from the start with intermittent flare-ups of worsening symptoms along the way. There are no periods of remission.

Click the icon to see an image depicting multiple sclerosis.

Resources

www.ninds.nih.gov -- National Institute of Neurological Disorders and Stroke
www.aan.com -- American Academy of Neurology
www.msassociation.org -- Multiple Sclerosis Association of America
www.nationalmssociety.org -- National Multiple Sclerosis Society
www.msfacts.org -- Multiple Sclerosis Foundation
www.abledata.com -- National database of assistive devices and rehabilitation equipment

References

Calabresi P. Multiple sclerosis and demyelinating conditions of the central nervous system. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 436.

Correale J, Fiol M, Gilmore W. The risk of relapses in multiple sclerosis during systemic infections. Neurology. 2006 Aug 22;67(4):652-9. Epub 2006 Jul 26.

Farinotti M, Simi S, Di Pietrantonj C, McDowell N, Brait L, Lupo D, Filippini G. Dietary interventions for multiple sclerosis. Cochrane Database Syst Rev. 2007 Jan 24;(1):CD004192.

Goodin DS, Cohen BA, O'Connor P, Kappos L, Stevens JC; Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Assessment: the use of natalizumab (Tysabri) for the treatment of multiple sclerosis (an evidence-based review): report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology. 2008 Sep 2;71(10):766-73

International Multiple Sclerosis Genetics Consortium, Hafler DA, Compston A, Sawcer S,Lander ES, Daly MJ, et al. Risk alleles for multiple sclerosis identified by a genomewide study. N Engl J Med. 2007 Aug 30;357(9):851-62. Epub 2007 Jul 29.

Kappos L, Freedman MS, Polman CH, Edan G, Hartung HP, Miller DH, et al. Effect of early versus delayed interferon beta-1b treatment on disability after a first clinical event suggestive of multiple sclerosis: a 3-year follow-up analysis of the BENEFIT study. Lancet. 2007 Aug 4;370(9585):389-97.

Khan F, Ng L, Turner-Stokes L. Effectiveness of vocational rehabilitation intervention on the return to work and employment of persons with multiple sclerosis. Cochrane Database Syst Rev. 2009 Jan 21;(1):CD007256002819.

Lovera J, Bagert B, Smoot K, Morris CD, Frank R, Bogardus K, et al. Ginkgo biloba for the improvement of cognitive performance in multiple sclerosis: a randomized, placebo-controlled trial. Mult Scler. 2007 Apr;13(3):376-85. Epub 2007 Jan 29.

Multiple Sclerosis Therapy Consensus Group (MSTCG), Wiendl H, Toyka KV, Rieckmann P, Gold R, Hartung HP, et al. Basic and escalating immunomodulatory treatments in multiple sclerosis: current therapeutic recommendations. J Neurol. 2008 Oct;255(10):1449-63. Epub 2008 Oct 29.

Prakash RS, Snook EM, Lewis JM, Motl RW, Kramer AF. Cognitive impairments in relapsing-remitting multiple sclerosis: a meta-analysis. Mult Scler. 2008 Nov;14(9):1250-61. Epub 2008 Aug 13.

Ransohoff RM. Natalizumab for multiple sclerosis. N Engl J Med. 2007 Jun 21;356(25):2622-9.

Rojas JI, Romano M, Ciapponi A, Patrucco L, Cristiano E. Interferon beta for primary progressive multiple sclerosis. Cochrane Database Syst Rev. 2009 Jan 21;(1):CD006643.

Schippling S, Heesen C, Zander A, Martin R. Stem cell transplantation in multiple sclerosis. J Neurol. 2008 Dec;255 Suppl 6:43-7.

Wiendl H, Hohlfeld R. Multiple sclerosis therapeutics: unexpected outcomes clouding undisputed successes. Neurology. 2009 Mar 17;72(11):1008-15.

Reviewed last on: 6/23/2009
Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

Connect with UMMC

© 2011 University of Maryland Medical Center (UMMC). All rights reserved.
UMMC is a member of the University of Maryland Medical System,
22 S. Greene Street, Baltimore, MD 21201. TDD: 1-800-735-2258 or 1.866.408.6885