ELECTROPHYSIOLOGIC FINDINGS IN MULTIFOCAL MOTOR NEUROPATHY

We performed detailed electrophysiologic studies on 16 patients with c linically defined multifocal motor neuropathy and found a wide spectru m of demyelinating features. Only five patients (31%) had conduction b lock. in one or more nerves. However, in 15 patients (94%) at least on e nerve showed other features of demyelination. We also noted a signif icant degree of superimposed axonal degeneration in 15 patients, Eight patients (50%) had individual nerves with pure axonal injury, despite the presence of demyelinating features in other nerves, Antigangliosi de antibodies were elevated in four of five patients with conduction b lock and five of II patients without conduction block. We conclude tha t multifocal motor neuropathy is characterized electrophysiologically by a wide spectrum of axonal and demyelinating features. Diagnostic cr iteria requiring conduction block may lead to underdiagnosis of this p otentially treatable neuropathy.