Abstract
Maximum motor nerve conduction velocities were measured in 27 epileptic patients who had been on diphenylhydantoin (phenytoin) for at least one year. These patients had no clinical features of peripheral neuropathy neither did they have clinical signs of phenytoin intoxication. Their seizures had been well controlled ona modest dose (100-300 mg daily) during the previous year before the study. Their popliteal motor nerve conduction velocities were significantly reduced compared with those of the controls mathched for age and sex (P < 0.05). Their ulnar motor nerve conduction velocities too were similarly affected. Thus subclinical peripheral neuropathy was demonstrated in this group of patients.