Cognitive and behavioral effects of antiepileptic drugs.

In managing epilepsy, drugs that offer the best seizure control to the patient should be used, but their influence on quality of life must also be considered. This must include any effects on mood and mental state, which should be minimal in order that these patients may achieve their full potential. Subtle behavioral and cognitive disadvantages may occur with anticonvulsant drug use. Behavioral changes with phenobarbital are both idiosyncratic and dose related. Carbamazepine and valproic acid can have adverse effects on mood and cognition, but do so less frequently than the other medications or combinations (Table 1). Cognitive dysfunction may relate to antiepileptic drug blood levels, but impairment of skills can occur in the nonintoxicated patient. Thus, office neurologic examinations are insufficient to detect these subtle mental impairments. Practical methods need to be developed to identify and monitor these problems so that in the future cognitive and behavioral dysfunction in epileptic patients can be minimized.