Relationships between pre‐, post‐, and inter‐ictal psychiatric symptoms in patients with epilepsy

Aim: Although pre- and post-ictal psychiatric symptoms (PS) in patients with epilepsy are well known, the prevalences and pathophysiologies remain unclear. We investigated the prevalences and durations of pre- and post-ictal PS, related factors, and associations between pre- and post-ictal PS. Methods: In the Neuropsychiatry Department of Kurume University Hospital, patients with epilepsy were interviewed regarding pre- and post-ictal PS. Multivariate logistic regression analyses were performed on clinical variables and pre- or post-ictal PS. McNemar analyses were performed to clarify differences in the occurrence of pre- and post-ictal PS. Results: Five percent of patients had only pre-ictal PS, 29% had only post-ictal PS, and 10% had both pre- and post-ictal PS. The most common symptoms were depressive symptoms (25%) and anxiety symptoms (16%) in the post-ictal period, and irritability symptoms (7%) and anxiety symptoms (5%) in the pre-ictal period. The duration of PS was more than 1 day but less than 1 week in many patients. Post-ictal PS showed a substantially higher ratio of a history or comorbidities of inter-ictal psychiatric disorders (IPD). In addition, post-ictal psychotic symptoms and post-ictal irritability symptoms were significantly associated with psychosis in IPD. Furthermore, while the incidence of PS was significantly higher with post-ictal PS alone than with pre-ictal PS, cases with pre-ictal PS had a significantly higher rate of post-ictal PS. Conclusion: Post-ictal PS appeared relevant to IPD, and pre-ictal PS was associated with the expression of post-ictal PS.