Perampanel in post-stroke epilepsy: Clinical practice data from the PERampanel as Only Concomitant antiseizure medication (PEROC) study

Introduction: Post-stroke epilepsy (PSE) is one of the most common causes of acquired epilepsy. Nevertheless, there is limited evidence regarding the clinical profile of antiseizure medications (ASMs) in PSE. This study aims to evaluate the 12-month effectiveness and tolerability of perampanel (PER) used as only add-on treatment in patients with PSE in a real-world setting. Methods: We performed a subgroup analysis of PSE patients included in a previous retrospective, longitudinal, multicentre observational study on adults. Treatment discontinuation, seizure frequency and adverse events were collected at 3, 6 and 12 months. Sub-analyses by early (≤1 previous ASM) or late PER add-on were also conducted. Results: Our analysis included 56 individuals with PSE, characterized by varying initial treatment modalities and timeframes relative to disease onset. We found notable retention rates (92.8%, 83.7%, and 69% at 3, 6, and 12 months), with treatment withdrawal mainly due to poor tolerability. One year after PER introduction, seizure frequency significantly reduced, with a responder rate (≥50% reduction) of 83.9% and a seizure-free rate of 51.6%. Adverse events occurred in 25 (46.3%) patients, mainly dizziness, irritability, and behavioural disorders. No major statistical differences were found between early (30 patients, 53.6%) and late add-on groups, except for a higher 6-month responder rate in the early add-on group. Conclusion: Adjunctive PER was effective and well-tolerated in patients with PSE in a real-world setting. Perampanel demonstrated good efficacy and safety as both early and late add-on treatment, making it a compelling option for this unique patient population.