Multiple Sclerosis (MS)

Multiple sclerosis (MS) is an autoimmune disease which results in loss of myelin, the insulation surrounding nerve fibers, in areas throughout the brain and spinal cord. Although MS is not a genetically inherited or transmitted disease, there appears to be genetic susceptibility to it.  Symptoms of the disease generally correspond to the specific areas of the brain and spinal cord which are affected. The most common symptoms include weakness or paralysis; tingling and numbness; poor co-ordination; visual disturbances; tremors; slurred speech; disordered bladder and bowel function; fatigue; sexual difficulties; and sensitivity to heat. These symptoms vary from person to person in severity and duration.

Multiple sclerosis most often strikes young adults between the ages of 20 and 40. More than 50,000 Canadians and 250,000 Americans suffer from MS, and nearly 200 new cases are reported each week. Forty percent of them will have to leave the workforce due to the severity of the disease.

The precise cause of MS remains unknown, but research is finding clues. Although a virus has been thought to be a causative factor, an MS virus has not yet been identified. The disease is therefore difficult to diagnose, often taking months or years of observation to confirm. However, knowledge of MS over the past 30 years has expanded at a greater rate than during the entire 100 years following the initial description of the diagnosis. This is in large part due to animal research.

Animals have been used in studies of how the body's immune system can be made allergic to brain tissue. These studies have taught us which brain substances most easily stimulate the immune system; which genetic factors influence susceptibility to allergic brain disease; and how other factors, such as the general health of the animal, influence the course of the disease.

MS research has entered a new and promising phase. New treatments that modify the immune system are beginning to show promise in their ability to affect the course of the disease. Eventually, it is hoped that a vaccine can be developed against a virus or abnormal cell in MS patients. Animal research will be essential for the development of safe and effective vaccines.