Multiple sclerosis is a neurological disease. It is a condition in which the body's immune system attacks the myelin sheath (fatty white matter) that protects neurons and speeds up the conduction of electrical signals (action potentials). This results in interrupted functioning of the nerves, and in advanced cases, damage to the nerve itself. This may result in mobility problems and shortened lifespans — severely shortened in some cases.
The condition begins to show symptoms for people in the twenties to forties. It occurs more commonly in women and in people of Northern European descent, and tends to run in families, but not all members will contract the disease. It seems genetics may result in a higher risk, with other factors triggering the condition. The mechanism of the disorder, though, is not known. There is no specific test for MS, and a diagnosis is made by ruling out other conditions. Lesions that can be detected by brain scans sometimes disappear and the disease will spontaneously remit, only to return later; the reason for this is not known either.
There is no cure for MS, treatment consisting mainly of dealing with symptoms as they arise. Because the symptoms and severity of attacks are so variable, it can be difficult to show if a particular treatment is having the desired effect, or if the disease is simply in remission. This has led to a number of bogus treatments. Dietary supplements, vitamins, oxygen therapy, and hyperbaric chambers (among other things) have all been tried and found to have no demonstrable impact on the disease. The Quackwatch website has a page on fake MS cures, and the Multiple Sclerosis Society has a book available which shows the affect of various treatments on the disease.