A prospective study of postictal psychoses with emphasis on the periictal type.

PURPOSE

To assess prospectively episodes of postictal psychosis.

METHODS

We followed 108 consecutive patients with temporal lobe epilepsy, who were divided into three groups: those without psychotic episodes (n=87, N group), those with interictal psychosis (n=13, IIP group), and those with postictal psychosis (n=8, PIP group). The first episode of postictal psychosis, which was defined as a psychotic episode that occurred within 1 week after the end or within 3 days before the beginning of seizure clusters, was assessed with the Brief Psychiatric Rating Scale (BPRS) and Social Dysfunction and Aggression Scale (SDAS) during the observation period.

RESULTS

The duration of illness was significantly different between the N and PIP groups (p=0.004) and between the N and IIP groups (p=0.039). The average initial BPRS score (obtained 3.0 days after the end of the seizure cluster) was 19.7, and then decreased to 5.8 after 1 week, and finally normalized at 1.5 after 1 month. A statistically significant decrease in BPRS scores was found between the initial assessment and those obtained after 1 week (p=0.011). Those who had psychotic episodes without a lucid interval tended to have episodes more often than monthly, and experienced additional seizure recurrence even during the psychotic episodes. Two patients exhibited a frank manic phase, and three patients showed excessively aggressive behavior, as determined by the SDAS.

CONCLUSIONS

Postictal psychosis should be subdivided into the nuclear type, with an established clinical picture as an indirect aftereffect of seizure activity, and the atypical periictal type, which is a direct manifestation of limbic discharge.