ABSTRACT NUMBER: ESOC2026A864 IMPACT OF REPERFUSION TIMING ON INTERICTAL EPILEPTIFORM DISCHARGES AFTER ISCHEMIC STROKE

Abstract Background and aims Interictal epileptiform discharges (IEDs) on EEG in the early phase of acute ischemic stroke (AIS) are associated with an increased risk of post-stroke epilepsy and unfavorable outcome. Whether timely reperfusion can prevent IEDs and their clinical impact remains unknown. Methods We performed a retrospective observational study of consecutive patients with AIS admitted to our Stroke Unit between January 2021 and May 2023. Patients with wake-up stroke or unknown symptoms onset were excluded. All patients underwent routine EEG within 72 h from symptoms onset and were treated with acute reperfusion therapy, including intravenous thrombolysis (IVT) and/or mechanical thrombectomy (MT). Patients were stratified by the presence of interictal epileptiform discharges (IEDs). Reperfusion timing metrics (onset-to-needle, onset-to-groin, and onset-to-reperfusion) were compared between groups. Results Among 221 included patients, 60 (27%) showed interictal epileptiform discharges (IEDs) on subacute EEG, while 161 (73%) did not. Onset-to-needle times were similar in patients with and without IEDs (159 [112-225] vs 156 [118-206] min). In contrast, onset-to-groin (210 [150-300] vs 161 [139-244] min) and onset-to-reperfusion times (275 [225-350] vs 233 [195-316] min) were longer in patients with IEDs. Overall, IVT timing showed a limited association with IEDs, whereas earlier MT-related reperfusion more consistently indicated a lower IEDs probability. Conclusions Earlier MT or bridging therapy may reduce IEDs occurrence, supporting the role of early reperfusion in lowering the risk of post-stroke epilepsy and poor outcome. Further studies are needed to clarify the impact of reperfusion timing on the incidence of IEDs. Conflict of interest All the authors have nothing to disclose