Pattern reversal visual evoked potentials. Studies in Charcot-Marie-Tooth hereditary neuropathy

Pattern reversal visual evoked potentials (PRVEP) were studied in 25 patients from 17 separate families with Charcot-Marie-Tooth (CMT) syndrome. Twenty patients had classic CMT with depressed tendon reflexes, slow motor nerve conduction velocities, and autosomal dominant inheritance. Four patients demonstrated typical findings of CMT, but there was no documented family history. One patient had the axonal form of hereditary motor sensory neuropathy. Abnormally delayed latencies of the PRVEP were found in four patients (16% of the total), including the only patient with clinical optic atrophy. There was no consistent correlation, of PRVEP with severity of disease. These results confirm earlier clinical reports of occasional optic nerve involvement in CMT and represent additional evidence that central pathways may be involved in this primarily peripheral nervous system disorder.