Somatosensory evoked potentials and peripheral nerve conduction velocities in patients on long-term carbamazepine therapy.

The motor and sensory conduction velocities were measured, and the somatosensory evoked potentials were recorded on median nerve stimulation in 20 epileptics on long-term carbamazepine therapy. The plasma drug levels were monitored and found to be consistently within therapeutic range. The electrophysiological study showed that the motor and sensory conduction velocities in the lower limbs were significantly lower than in age-and sex-matched controls, while no significant variation was found in the somato-sensory evoked potentials. There was no correlation between the neurophysiological data and any of the pharmacological data, such as duration of treatment, plasma levels and dose of drug per Kg of bodyweight per day.