This chapter will discuss the clinical phenomena and underlying theories of autoimmune diseases affecting the human nervous system. Examples will be drawn from diseases affecting (1) the central nervous system (CNS): brain and spinal cord, multiple sclerosis (MS); (2) a disease of the peripheral nerves, Guillain- Barré syndrome (GBS); and (3) an autoimmune disease affecting the endplate between nerve and muscle: myasthenia gravis (MG). In these diseases, the nervous system or motor endplate is the unique target of autoimmunity. Systemic lupus erythematosus (SLE), an example of a systemic autoimmune disease with nervous system involvement, will also be discussed.

Animal models for the study of pathogenesis and treatment have played a large role in the study of immunologically mediated neurological diseases. The success has been variable and not always well correlated with the human condition. Animal models will be mentioned within the context of each disease addressed, and a general discussion of this topic is included at the end of the chapter.

MULTIPLE SCLEROSIS

MS is the most prevalenat inflammatory disease of the CNS in humans, affecting 1 person per 1,000 adults. This disease affects women in a 2:1 ratio to men, and, for the most part, respects the latitudinal geographic presentation; that is, it occurs mostly in the northern European population or those of northern European descent. The incidence of MS gradually decreases as one approaches the equator. MS increases in incidence as one moves south, away from the equator.