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). Almost all documented neurological symptoms can accompany the disease, among them, extreme fatigue, changes in sensation, visual impairment, muscle weakness, depression, difficulties with coordination and speech, cognitive dysfunction, problems with balance, urinary difficulties, constipation, sexual dysfunction, spasticity and pain. For many people with MS, a small rise in body temperature, such as caused by a hot bath or day, results in a temporary worsening of symptoms. During the relapsing-remitting phase of the disease (RRMS) most symptoms resolve to some extent, often completely, within four to six weeks. ...

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). Almost all documented neurological symptoms can accompany the disease, among them, extreme fatigue, changes in sensation, visual impairment, muscle weakness, depression, difficulties with coordination and speech, cognitive dysfunction, problems with balance, urinary difficulties, constipation, sexual dysfunction, spasticity and pain. For many people with MS, a small rise in body temperature, such as caused by a hot bath or day, results in a temporary worsening of symptoms. During the relapsing-remitting phase of the disease (RRMS) most symptoms resolve to some extent, often completely, within four to six weeks.

It is important to recognize that Multiple Sclerosis is a disease that usually lasts over several decades and that, at least in RRMS, a normal life is possible. In this form of the disease, mobility is seldom dramatically affected outside periods of attack. However, some level of permanent disability invariably accompanies progressive forms. Life-expectancy is not significantly reduced in the majority of cases, particularly in those first diagnosed with milder cases RRMS.

Multiple sclerosis affects the cells (called 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 muscles and organs in the rest of the body. More specifically, MS destroys the cells known as oligodendrocytes which are 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 (demyelination) and, less frequently, the cutting (transection) of the neuron's long thin extensions (known as axons) in patches throughout the white matter. When the myelin is lost, the neurons can no longer effectively conduct their electrical signals, and they are slowed or do not get through at all.

The name multiple sclerosis refers to the multiple scars (scleroses - better known as plaques or lesions) in the white matter. Loss of myelin in these lesions causes some of the symptoms that vary widely depending upon which signals are interrupted. Disease onset usually occurs in young adults, typically aged between 20 and 40 years, and is more common in women than in men. It affects about 400,000 Americans, and 2.5 million people worldwide.