Autoimmune autonomic ganglionopathy (AAG) is a rare autoimmune disorder in which the body's immune system mistakenly attacks and damages certain parts of the autonomic nervous system. Signs and symptoms of the condition vary but may include severe orthostatic hypotension (low blood pressure upon standing); fainting; constipation; fixed and dilated pupils; urinary retention; and/or dry mouth and eyes. The exact underlying cause of AAG is poorly understood. Treatment depends on many factors including the severity of the condition and the signs and symptoms present in each person. Due to the rarity of AAG, there are no standard treatment protocols; however, treatment with plasmapheresis, intravenous (IV) immunoglobulin, corticosteroids or immunosuppressive drugs has been reported with variable success. Approximately one third of affected people may improve spontaneously without treatment, but the recovery is often incomplete.

• Severe orthostatic hypotension (low blood pressure upon standing) that persists for weeks to years
• Fainting
• Constipation and gastrointestinal dysmotility (a condition in which the muscles and nerves of the digestive system do not move food through the digestive tract efficiently)
• Urinary retention
• Fixed and dilated pupils
• Dry mouth and eyes

Some people with autoimmune autonomic ganglionopathy present with POTS-like symptoms.

The cause of autoimmune autonomic ganglionopathy is not fully understood. An autoimmune component is presumed, as the body's own immune system damages a receptor in the autonomic ganglia (part of the peripheral autonomic nerve fiber). In one to two-thirds of affected individuals, this condition is associated with high titers of ganglionic acetylcholine receptor antibody (g-AchR antibody).. About 60% of cases follow an infection or other illness.

Since autoimmune autonomic ganglionopathy is so rare, no standard treatments have been established. Experts familiar with this condition often use plasma exchange or total plasmapheresis, intravenous immunoglobulin (IVIG), IV corticosteroids, or immunosuppressive drugs, such as Rituxan to treat the symptoms of the disease.A therapeutic trial for autoimmune autonomic ganglionopathy was recently completed by the Autonomic Disorders Consortium.