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

Abstract

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.