Nerve conduction velocity in patients under long term treatment with antiepileptic drugs

Motor and sensory nerve conduction velocity (NCV) of median nerve and motor NCV of peroneal nerve were measured in 548 epileptic patients, aged 20 to 40 years, under long term treatment with antiepileptic drugs. Compared with a control collective of 70 healthy persons in the same age the epileptics showed a reduction of all NCVs. 19 percent of the epileptic collective had at least 1 diminished NCV. Negative correlations with total amount and average daily dose of antiepileptic drugs were found in both sexes for sensory NCV of median nerve and motor NCV of peroneal nerve, only in males also for motor NCV of median nerve. Only in females, duration of therapy correlated negative with sensory NCV of median and motor NCV of peroneal nerve. In patients under monotherapy the group with carbamazepine treatment showed the lowest NCV values, the difference being significant for motor NCV of median nerve in comparison to phenytoin and valproate sodium. It is concluded, that NCV generally is lowered under long term treatment with antiepileptic drugs and that phenytoin has no specific influence compared with the other drugs.