About Multiple Sclerosis

Multiple sclerosis, or MS, is a disease that affects the brain, spinal cord and/or optic nerves (collectively called the central nervous system, or CNS). Symptoms of MS vary considerably, depending on the specific location of damage in the CNS, and can include loss of muscle control, changes in sensation such as tingling and numbness, difficulties with vision, memory loss, fatigue, loss of bladder or bowel control and many more.

The cause of MS is unknown, but it is believed to involve an autoimmune process. Autoimmunity occurs when the body’s own immune system, which normally protects us against infectious agents and tumor cells, mistakenly attacks normal tissues. In MS, the immune system targets and damages myelin, a fatty substance that wraps around nerve fibers to insulate them, much like the insulation on electrical cords. Myelin is necessary for rapid and efficient conduction of electrical signals between the CNS and the rest of the body. Myelin damage, also known as demyelination, interferes with this communication and leads to the symptoms of multiple sclerosis described above.

Part of the disease process in MS involves migration of immune cells into the CNS, a phenomenon known as inflammation. When inflammation occurs repeatedly, the damage to myelin persists and leads to the formation of scars, or sclerosis in multiple regions of the CNS. This is how multiple sclerosis got its name: multiple sclerosis means multiple scars.

Although the nerves can regain myelin, this process is not fast enough to outpace the deterioration that occurs in MS. The types of symptoms, severity of symptoms, and the course of MS vary widely. This partly is due to the location of the scar tissue, the extent of demyelination and other factors, which are not yet understood.

According to the National Multiple Sclerosis Society, the condition affects approximately 400,000 Americans and is, with the exception of trauma, the most frequent cause of neurological disability beginning in early to middle-adulthood. Currently, there is no cure for multiple sclerosis, but an array of treatments is available to reduce the impact of symptoms and alter the course of the disease. The process and severity of the disease are often unpredictable and can differ widely between people.

Therefore, treatments will probably also vary between individuals.

Multiple sclerosis appears in four forms:

Relapsing-Remitting

People with this type of MS experience clear attacks of deteriorating neurologic function. The attacks — known as relapses — are followed by remissions, during which no disease progression occurs. This is the most common form of multiple sclerosis.

Primary-Progressive

People with this form of MS experience worsening neurologic function from the beginning, with no relapses or remissions. Progression rates may change, and patients may see plateaus and temporary minor improvements.

Secondary-Progressive

In this form, people first experience relapsing-remitting MS but later develop a secondary-progressive disease in which the disease worsens more steadily. They may experience occasional flare-ups, minor remissions or plateaus. Before disease-modifying medications became available, about half of people with relapsing-remitting MS developed this form of the disease within 10 years.

Progressive-Relapsing

This is the rarest form of multiple sclerosis. People experience steadily worsening disease from the beginning with additional attacks of deteriorating function. The disease continues to progress without remission.

Resources for Patients

Below are helpful resources for patients living with MS and their friends and family.

USC Multiple Sclerosis Comprehensive Care Center