Psychotic disorders are up to eight times more prevalent in patients with epilepsy compared to the general population. Among them, postictal psychosis (PIP) is a severe complication of focal epilepsy, characterized by a brief psychotic episode emerging days after a seizure. This project investigates a potentially attenuated and under-recognized manifestation-postictal psychotic symptoms (PPs)-that may arise following hospitalization in a video-EEG monitoring unit and might serve as an early indicator for future PIP.

The investigators hypothesize that the incidence of PPs is substantially higher than the 3% PIP prevalence reported in the literature and that their occurrence correlates with the intensity of epileptic activity triggered during video-EEG monitoring. The study has three main objectives: (1) to determine the incidence of PPs in patients with drug-resistant focal epilepsy, (2) to identify predictive factors associated with PPs, and (3) to assess the validity of the PQ-16 screening tool in this clinical context.

A prospective monocentric study will be conducted in the video-EEG unit of Nancy University Hospital. One hundred and ten patients hospitalized for at least five days will be included. Psychiatric assessments will include standardized clinical interviews, Brief Psychiatric Rating Scale (BPRS) scoring, and self-report questionnaires. These evaluations will take place at three timepoints: baseline (V1), 3-5 days post-discharge (V2), and two months post-discharge (V3).

This study aims to facilitate the early identification of PPs and support the development of preventive strategies, ultimately improving psychiatric care and overall management in patients with epilepsy.

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.

Inclusion Criteria:

• confirmed diagnosis of drug-resistant focal epilepsy
• hospitalization for at least 5 days video-EEG (or SEEG) monitoring
• capable of providing informed consent, able to communicate in French, and covered by a national health insurance plan

Exclusion Criteria:

• Patients presenting with psychotic symptoms at baseline (V1), or who have had recent modifications (less than 15 days before admission) to their antiepileptic or psychotropic medications, will be excluded to reduce confounding factors in the assessment of postictal psychotic symptoms.