Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system (CNS) which affects mostly aged between 20 and 40 years. MS causes demyelination of the white matter of the brain with this process sometimes extending into the gray matter. The MS patients show white matter with areas of damage name plaques or lesions. The progressive loss of myelin, a lipoprotein that covers the axon of neurons, inhibits the coordinated and rapid transmission of nerve impulses causing various symptoms that characterize all demyelinating diseases in general and MS in particular.
MS is a disease not clinically well characterized since it is unpredictable. The type and severity of symptoms can vary greatly according to the affected CNS areas and the extent of the damage. Recent studies show that the biochemical aspect of the lesions may vary between the different MS forms. However, this is not the predominant reason why patients with MS differ in their symptoms.