Peripheral nervous system manifestations in systemic autoimmune diseases.

The peripheral nervous system refers to parts of the nervous system outside the brain and spinal cord. Systemic autoimmune diseases can affect both the central and peripheral nervous systems in a myriad of ways and through a heterogeneous number of mechanisms leading to many different clinical manifestations. As a result, neurological complications of these disorders can result in significant morbidity and mortality. The most common complication of peripheral nervous system (PNS) involvement is peripheral neuropathy, with symptoms of numbness, sensory paresthesias, weakness, or gait imbalance. The neuropathy may be multifocal and asymmetric or, less frequently, distal and symmetric.