Multiple sclerosis (abbreviated MS, formerly known as disseminated sclerosis or encephalomyelitis disseminata) is a chronic, inflammatory, demyelinating disease that affects the central nervous system (CNS). Disease onset usually occurs in young adults, is more common in women and the disease has a prevalence that ranges between 2 and 150 per 100,000 depending on the country or specific population
MS affects the neurons in the areas of the brain and spinal cord known as the white matter. These cells carry signals in between the grey matter areas, where the processing is done, and between these and the rest of the body. More specifically, MS destroys oligodendrocytes which are the cells responsible for creating and maintaining a fatty layer, known as the myelin sheath, which helps the neurons carry electrical signals. MS results in a thinning or complete loss of myelin and, less frequently, the cutting (transection) of the neuron's extensions or axons. When the myelin is lost, the neurons can no longer effectively conduct their electrical signals. The name multiple sclerosis refers to the scars (scleroses - better known as plaques or lesions) in the white matter. Loss of myelin in these lesions causes some of the symptoms that may vary widely depending upon which signals are interrupted. However, more advanced forms of imaging are now showing that much of the damage happens outside these regions. A consequence of this course of action is that almost ANY!!!!!!! neurological symptom can accompany the disease.