MS is a chronic disease of the central nervous system, which affects mostly young people between the ages of 15 and 45. A fatty substance called myelin protects the nerve fibers and helps them conduct electrical impulses. But in MS and related disorders, the myelin can be lost in certain areas. This causes scarring and damage to the nerve fiber.
MS is thought to be an autoimmune disease. In this type of disease, the body’s immune system, which normally fights infections and protects itself, inappropriately attacks parts of the body; in the case of MS, myelin (the protective sheath around the nerves) and axons (a part of the nerve itself) are the immune systems targets.
With the current state of medical care and new treatments, the vast majority of MS patients are expected to live close to a normal life spans.
Common symptoms of MS include:
- Loss of vision
- Double or blurred vision
- Urinary frequency and/or urgency
- Heat sensitivity
Each case must be carefully evaluated; the presence of any of these symptoms does not confirm the diagnosis of MS.
Types of MS
There are two broad classes of MS:
Relapsing-Remitting Multiple Sclerosis (RRMS) is the most common type of MS (80-85%). This form of MS is characterized by relapses or attacks with periods of stability in between (or remission). This type of MS usually starts in the late twenties or early thirties and is almost three times more common in women than men. Later in the disease course, RRMS patients may stop having frequent attacks but slowly start progressing. This stage of MS is referred to as Secondary Progressive MS (SPMS). Patients with SPMS can have relapses but usually have a progressive course.
Primary-Progressive MS (PPMS) is the less common form of MS (10-15%). In this type of MS, patients do not experience relapses and progress steadily from the very beginning. This type of MS tends to occur more commonly in somewhat older people, usually in their forties or fifties. Unlike RRMS, men and women with PPMS tend to be affected equally. Rarely, patients who have had PPMS for several years may have an attack that can confuse both the patient and the neurologist regarding the type of MS. This is probably the most rare type of MS in which patients with PPMS may experience a rare attack. Such patients are referred to as Progressive Relapsing MS.