Abstracts

This is a Late Breaking abstract

Rationale: Postictal psychosis (PIP) is a rare manifestation of drug resistant epilepsy (DRE) with diagnostic and management challenges. PIP occurs within hours to days following a period of postictal lucidity after seizures. PIP is associated with both generalized and focal seizures. It is more frequently reported in temporal lobe epilepsy. It is typically characterized by pleomorphic symptoms including paranoid delusions, hallucinations, insomnia, and irrational behaviors.

Methods: We retrospectively investigated a series of 352 patients undergoing video-EEG (vEEG) monitoring between 2017 and 2022. Cases with history of psychogenic nonepileptic events or non-diagnostic results were excluded. Out of the remaining 214 patients, 7 patients had PIP during monitoring. Clinical data, brain imaging, vEEG findings, neuropsychology tests, and treatment outcome were reviewed.

Results: The patients (female 3, male 4) were referred to our regional tertiary epilepsy center with median 31 (27±7) years after seizure onset. The baseline seizure types were auras, complex partial seizures (CPS), and generalized tonic/clonic seizures. The patients were on more than 2 antiseizure medications (ASMs) with weekly seizures.  All patients had pre-existing symptoms of anxiety, depression, or aggression.  Only one patient had a prior history of psychosis. The patients experienced 4.5±1.6 CPS before developing PIP, with a median lucid interval of 24 (47±32) hours. Four patients were noted with temporal onset CPS. Delusions, hallucination, violent behaviors, hyperactivity were common PIP phenomenology. Three of the patients experienced insomnia, and only 1 patient presented with negative symptoms. No ictal pattern was observed on vEEG during the PIP episodes, but normal or slow background with interictal epileptiform features were noted. PIP episodes lasted a median of 72 hours in duration (range, 1-20 days). Five patients required treatment with antipsychotics in addition to resuming ASMs. During the follow up (median, 3 years), all patients experienced significant improvement in seizure control after ASMs adjustment (maintaining 2-6 months seizure freedom, or reduced seizure frequency and severity); and never experienced psychosis after the EMU stay. Ictal EEG data did not provide sufficient information for seizure onset lateralization or localization; however, it was revealed that all the patients had wide epilepsy networks instead of single seizure focus. On neuroimaging, two had left mesial temporal sclerosis (MTLS), one had bilateral MTLS, one had left temporal gyrus atrophy without MTLS, and two had unremarkable MRIs. Neuropsychology results did not correlate with the PIP presentations.

Conclusions: Our study reiterates that PIP is rare. Timely recognition of PIP can avoid unnecessary diagnostic studies and treatment delay. History of DRE, and new onset bizarre behaviors should warrant consideration of PIP. Improved seizure treatment prevents recurrent PIP.

Funding: None