Psychosis of epilepsy, with special reference to anterior temporal lobectomy

The incidence of psychosis in patients with temporal lobe epilepsy before and after anterior temporal lobectomy, as well as that of de novo psychosis, is reviewed. Psychosis is defined as an acute confusional state, a chronic delusional state, or schizophrenialike psychosis. All three conditions have tended to decrease in recent years. In recent studies, the incidence of de novo psychosis is estimated to be similar to 4%. Early onset of de novo psychosis with decreased or diminished seizures might be an alternative psychosis related to forced normalization. In contrast, late-onset psychosis with seizure continuation might be related to synaptic changes due to aberrant reinnervation after temporal lobectomy. Right-sided temporal lobectomy might have a provoking effect on psychosis. The role of the neuropsychiatrist is important in epilepsy surgery with regard to presurgical identification and postoperative support of patients who are vulnerable to psychosis.