Outpatient EEG in Routine Clinical Care of Patients With Stroke-Related Acute Symptomatic Seizure Concerns.

Purpose: Acute symptomatic seizures (ASyS) after stroke contribute the highest risk to poststroke epilepsy (PSE) development. We investigated the use of outpatient EEG (oEEG) among stroke patients with ASyS concerns.

Methods: Adults with acute stroke, ASyS concerns (underwent cEEG), and outpatient clinical follow-up were included (study population). Patients with oEEG (oEEG cohort) were analyzed for electrographic findings. Univariable and multivariable analyses helped identify predictors of oEEG use in routine clinical care.

Results: Among 507 patients, 83 (16.4%) underwent oEEG. The independent predictors of oEEG utilization included age (OR = 1.03 [1.01 to 1.05, P = 0.01]), electrographic ASyS on cEEG (OR 3.9 [1.77 to 8.9], P < 0.001), ASMs at discharge (OR 3.6 [1.9 to 6.6], P < 0.001), PSE development (OR 6.6 [3.5 to 12.6], P < 0.001), and follow-up duration (OR = 1.01 [1.002 to 1.02], P = 0.016). Almost 40% of oEEG cohort developed PSE, but only 12% had epileptiform abnormalities. Close to a quarter (23%) of oEEGs were within normal limits.

Conclusions: One in six patients with ASyS concern after stroke undergoes oEEG. Electrographic ASyS, PSE development, and ASM at discharge are primary drivers of oEEG use. While PSE drives oEEG use, we need systematic, prospective investigation of outpatient EEG's role as prognostic tool for PSE development.