Incidence of Postictal Psychotic Symptoms After a Video-EEG Monitoring : Impact of Focal Epileptic Seizures

The incidence of psychotic disorders during epilepsy is eight times higher than in the general population (Clancy et al., 2014). These disorders are classified according to their chronological link to seizures. A distinction is made between (1) peri-ictal disorders: occurring before, during, or after a seizure, and (2) interictal disorders: unrelated to the occurrence of a seizure. Among the peri-ictal disorders, postictal psychosis (PIP) constitutes a complication of epilepsy, marked by the sudden occurrence of a psychotic episode in the days following a seizure. During a PIP episode, delusional, hallucinatory, and manic symptoms are observed, often accompanied by significant agitation and, in some cases, violent behavior or self-harm. A study of 77 cases of PIP found that approximately one-third of the patients had committed a self- or other-directed act of aggression (Tarrada et al., 2022).

Other studies, all retrospective, have highlighted several risk factors for PIP, such as long-standing drug-resistant focal temporal epilepsy (typically evolving over 15 to 20 years), seizure clusters, bilateral tonic-clonic generalization of seizures, and the presence of independent bilateral epileptic anomalies. The estimated prevalence of PIP is approximately 2% to 4% according to current literature. This complication appears to be more common following video-EEG hospitalizations, during which seizures may be intentionally provoked for diagnostic purposes. PIP therefore represents a significant and potentially severe complication of both epilepsy and video-EEG, underscoring the need for early detection to mitigate its consequences.

Additionally, it is very likely that patients may experience psychotic symptoms (hallucinations, delusional thoughts) in a milder form during the days following video-EEG, which could be predictive of future PIP episodes. These subthreshold postictal psychotic symptoms (PPs) are currently poorly understood, especially among non-specialist psychiatrists and neurologists, contributing to their under-recognition and underdiagnosis-particularly when symptoms do not reach the threshold of a fully developed PIP.

The hypotheses to be verified are as follows: (1) The incidence of PPs is significantly higher (at least fourfold) than the prevalence of PIP (3%) reported in the literature. (2) The incidence of PPs increases proportionally with the number of seizures induced during video-EEG monitoring.

The investigators will conduct a prospective monocentric cohort study, based on regular psychiatric assessment and interventions, at the beginning of video-EEG hospitalization, and until 2 months after discharge.