Clinical Implications of Various Electroencephalographic Patterns in Post-Stroke Seizures. The Utility of Routine Electroencephalogram

Objective: Post-stroke seizures (PSS) are one of the major stroke-related complications. Early therapeutic interventions are critical therefore using electroencephalography (EEG) as a predictive tool for future recurrence may be helpful. We aimed to assess frequencies of different EEG patterns in patients with PSS and their association with seizure recurrence and functional outcomes. Methods: All patients admitted with PSS were included and underwent interictal EEG recording during their admission and monitored for seizure recurrence for 24 months. Results: PSS was reported in 106 patients. Generalized slow wave activity (GSWA) was the most frequent EEG pattern observed (n = 62, 58.5%), followed by Focal sharp wave discharges (FSWDs) (n = 57, 55.8%), focal slow wave activity (FSWA) (n = 56, 52.8%), periodic discharges (PDs) (n = 13, 12.3%), and ictal epileptiform abnormalities (n = 6, 5.7%). FSWA and ictal EAs were positively associated with seizure recurrence (p < .001 and p = .015 respectively) and it remained significant even after adjusting for age, sex, stroke severity, stroke subtype, or use of anti-seizure medications (ASMs). Other positive associations were status epilepticus (SE) (p = .015), and use of older ASM (p < .001). FSWA and GSWA in EEG were positively associated with severe functional disability (p = .055, p = .015 respectively). Other associations were; Diabetes Mellitus (p = .034), Chronic Kidney Disease (p = .002), use of older ASMs (p = .037), presence of late PSS (p = .021), and those with Ischemic stroke (p = .010). Conclusions: Recognition and documentation of PSS-related EEG characteristics are important, as certain EEG patterns may help to identify the patients who are at risk of developing recurrence or worse functional outcomes.