Chronic acquired demyelinating motor neuropathy.

A patient with chronic, acquired, demyelinating, pure or predominantly motor asymmetric neuropathy is described. Electrophysiological tests showed multifocal conduction block in motor nerves. The sensory system was intact and the first signs of slight trival involvement appeared after 4 years of disease duration. The antiganglioside antibodies were present in serum and the patient responded to immunosuppressive therapy (azathioprine). Distinction of such cases from motor neuron disease is critical since motor demyelinating neuropathy is treatable in most cases.