MODEL RELEASED. Brain pathology. Pathologist cutting into the excised brain of a patient with multiple sclerosis (MS). The brain has been removed so that it can be studied to increase understanding of the disease. MS is an autoimmune disorder, in which the body's immune system attacks myelin, a fatty substance that surrounds nerve fibres. Without myelin the nerves cannot conduct signals correctly, leading to symptoms including tingling, speech and coordination disorders, paralysis and death. There is no cure, although some drugs, such as beta interferon, may reduce the number of attacks.