An illustration of multiple sclerosis,an autoimmune disease that damages the central nervous system,resulting in a variety of symptoms including muscle spasms,loss of balance and coordination,numbness,and muscle weakness. In multiple sclerosis,the myelin sheath which protects a neuron's axon is attacked by the immune system,due to what is thought to be a virus or defective gene. When that protective covering is damaged,nerve signals slow down or stop. This illustration depicts a neuron affect by the disease,as well as a cross-sectional view of the brain with scarring and plaque formation brought on by the body's inflammatory response |