Multiple sclerosis (MS) is a common chronic disorder that usually affects people during the prime of their lives. This progressive and unpredictable disease affects the nervous system and there is currently no cure.

MS occurs when the protective sheath that surrounds the nerve fibres in the brain and spinal cord, called myelin, becomes damaged. This is known as demyelination. This process impairs the conduction of signals in the affected nerves, causing impairment in sensation, movement, cognition or other functions depending on which nerves are affected. The human brain has an estimated 100 billion neurons, all which make many connections with each other. As a result of this complexity, symptoms of MS are unpredictable and highly variable between patients. The more common symptoms include blurred vision, numbness, muscle weakness, loss of balance, extreme fatigue and hand tremors.

Our immune system normally protects us against disease by attacking foreign invaders like bacteria and viruses. However in MS, the immune system begins attacking the myelin sheath, resulting in demyelination. Although many risk factors for MS have been identified, the trigger for this immune system attack has not yet been identified. Genetics and environmental factors, such as viruses, are considered to be involved. Although MS is not considered to be a hereditary disease, genes related to susceptibility are thought to play a part, since there is a great variation in occurrence of MS in different racial groups.