Stroke is a common cause of epilepsy in older adults. Electroencephalography (EEG) assists with the diagnosis of seizures, however its diagnostic yield when seizure is suspected in the setting of acute ischemic stroke is unknown. This study examines the diagnostic yield of EEG monitoring during hospitalization for acute ischemic strokes.

Estimated rate of early post-ischemic stroke seizures is 3%. Although seizures are common after stroke, indications for if, and when, to obtain EEG monitoring remain unclear. Cost of a routine awake EEG (CPT 95816) and a 24-hour continuous EEG (CPT 95951) monitoring in the inpatient setting is $370.12 and $329.40, respectively based on the CY 2019 Medicare Physician Fee Schedule. Identifying unnecessary testing and utilization of healthcare resources is paramount in the effort to contain costs.

We conducted a retrospective chart review of patients admitted to a single academic tertiary care center in the United States between September 1, 2015 - November 30, 2019 with a primary diagnosis of acute ischemic stroke and who were monitored on EEG for suspected seizures. The primary outcome was how often EEG monitoring changed clinical management defined as starting, stopping, or changing the dose of an anti-epileptic drug. Secondary analysis was estimating the cost of EEG monitoring per change in management.

We identified 126 patients admitted with acute ischemic stroke who underwent EEG of which 70 met all inclusion and exclusion criteria. EEG monitoring resulted in a change in management in 22 patients (31%). Predictors associated with EEG monitoring resulting in a change in management were admission to the ICU, pre-existing atrial fibrillation, and symptomatic hemorrhagic transformation. Estimated cost of EEG per change in management was $1374.96 USD.

EEG monitoring resulted in a changed management in nearly one third of patients admitted with acute ischemic stroke suspected of having seizures.