Chronic motor neuropathies and lower motor neurone syndromes.

Immune-mediated motor neuropathies are most often disorders manifest clinically by slowly progressive, asymmetrical, distal weakness, starting in the hands more often than the legs. In some cases, electrophysiological findings show multifocal conduction block along the length of motor axons. Other patients have findings consistent with only axonal loss. Laboratory testing is unremarkable except for high-titre serum autoantibodies to GM1 and other neural antigens. Diagnosis of immune-mediated motor neuropathies provides an opportunity for effective immunomodulating therapy that can significantly improve quality of life in affected patients. The identification of antigenic targets of serum autoantibodies in patients with motor neuropathies lends hope that immunotherapies to specifically treat the autoimmune disorder can be developed.