Epileptiform Abnormalities in Acute Ischemic Stroke: Impact on Clinical Management and Outcomes.

Purpose: Studies examining seizures (Szs) and epileptiform abnormalities (EAs) using continuous EEG in acute ischemic stroke (AIS) are limited. Therefore, we aimed to describe the prevalence of Sz and EA in AIS, its impact on anti-Sz drug management, and association with discharge outcomes.
Methods: The study included 132 patients with AIS who underwent continuous EEG monitoring >6 hours. Continuous EEG was reviewed for background, Sz and EA (lateralized periodic discharges [LPD], generalized periodic discharges, lateralized rhythmic delta activity, and sporadic epileptiform discharges). Relevant clinical, demographic, and imaging factors were abstracted to identify risk factors for Sz and EA. Outcomes included all-cause mortality, functional outcome at discharge (good outcome as modified Rankin scale of 0-2 and poor outcome as modified Rankin scale of 3-6) and changes to anti-Sz drugs (escalation or de-escalation).
Results: The frequency of Sz was 7.6%, and EA was 37.9%. Patients with Sz or EA were more likely to have cortical involvement (84.6% vs. 67.5% P = 0.028). Among the EAs, the presence of LPD was associated with an increased risk of Sz (25.9% in LPD vs. 2.9% without LPD, P = 0.001). Overall, 21.2% patients had anti-Sz drug changes because of continuous EEG findings, 16.7% escalation and 4.5% de-escalation. The presence of EA or Sz was not associated with in-hospital mortality or discharge functional outcomes.
Conclusions: Despite the high incidence of EA, the rate of Sz in AIS is relatively lower and is associated with the presence of LPDs. These continuous EEG findings resulted in anti-Sz drug changes in one-fifth of the cohort. Epileptiform abnormality and Sz did not affect mortality or discharge functional outcomes.
Competing Interests: M. B. Dhakar received research support for clinical trials from UCB Pharma and Marinus Pharmaceuticals; in the past, she received an honorarium for a consultancy from Adamas Pharmaceuticals; she also receives salary support from NIH. Z. Sheikh received travel reimbursements from Medtronic for attending meetings on deep brain stimulation in epilepsy. A. Rodriguez has participated in an education symposium sponsored by Neuropace, Inc. H. A. Haider receives consultant support from Ceribell, Inc, author royalties from UpToDate, Inc and Springer Publishing, and serves on the advisory board of Esai, Inc. The remaining authors have no funding or conflicts of interest to disclose.
(Copyright © 2020 by the American Clinical Neurophysiology Society.)