Polyneuropathy associated with IgM monoclonal gammapathy (MG) with anti-MAG (myelin-associated-glycoprotein) activity is a demyelinating polyneuropathy characterized clinically by sensory ataxia, tremor, paresthesia, and impaired gait.

Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course.