CNS involvement in chronic inflammatory demyelinating polyneuropathy: an electrophysiological and MRI study.

Eight consecutive patients with chronic inflammatory demyelinating polyneuropathy (CIDP) were investigated by visual evoked potential (VEP), brainstem auditory evoked response (BAER) and magnetic resonance imaging (MRI) to assess central nervous system (CNS) involvement. VEPs were abnormal in 6 patients and BAERs in 2. MRI showed changes suggestive of CNS demyelination in 2 cases. Our findings suggest the existence of a combined central and peripheral demyelinating syndrome and emphasize the possibility of a common pathogenetic mechanism for both.