Perampanel-associated exacerbation of de novo psychosis and lateralized rhythmic delta activity: A case report

Perampanel (PER) may instigate psychiatric phenomena encompassing irritability and aggression. This study elucidates an epileptic patient in whom PER appeared to exacerbate preexisting psychosis, concomitant with lateralized rhythmic delta activity (LRDA).

A 30-year-old right-handed female initially exhibited focal aware seizures and focal to bilateral tonic-clonic seizures at 21 years of age. Despite administration of multiple antiseizure medications (ASM), she continued to experience weekly seizure episodes. At the age of 26 years, she underwent right selective amygdalohippocampectomy (SeAH) concurrent with vagus nerve stimulation (VNS) implantation. Following this intervention, the seizure frequency diminished from weekly to monthly, albeit not entirely eliminated. Five months postoperatively, the patient displayed paranoid delusions and auditory hallucinations. Her psychotic symptoms were assessed as de novo psychosis. In July of year Y-1, PER was coadministered with Valproic acid, Lacosamide, and Levetiracetam to optimize seizure control, with the dosage escalated to 6 mg by December of year Y-1. Simultaneously, in July of year Y, heightened irritability, aggression, and psychomotor agitation became prominent, necessitating hospitalization in August of year Y. An electroencephalogram (EEG) upon admission revealed LRDA over the right posterior quadrant. Subsequent cessation of PER administration culminated in the resolution of both exacerbated psychiatric symptoms and LRDA within approximately a week.

The observed LRDA in this case may represent cerebral dysregulation, possibly induced by PER, concurrent with the worsening of psychiatric sequelae. Psychosis during PER treatment could signify underlying brain dysfunction, highlighting the potential utility of EEG monitoring in managing these patients.