To delineate the electroencephalographic (EEG) findings of patients undergoing ECMO and to determine if they differ by type of ECMO or by the patient outcome.

Neurologic adverse events are common amongst patients undergoing ECMO. EEG may have a role in monitoring the neurologic status of these patients though the EEG findings amongst this patient cohort has not been readily reported in the literature.

We prospectively followed patients undergoing ECMO at our institution from 1/2017-2/2019. 93 patients were followed (VA ECMO-84 vs VV ECMO-9). EEG monitoring was performed as part of multi-modality monitoring.

Amongst our patient cohort clinical seizures were seen in 2% of the patients while an electrographic seizure was captured in only 1% of the patients. Epileptiform discharges were present in 2% of the patients while 6% of the patients had focal asymmetry, 11% had generalized periodic discharges and 6% had presence of sharp waves. A posterior dominant rhythm (PDR) was present in 8% of the patients while 4% had presence of sleep architecture and 3% had periods of discontinuity.

EEG characteristics were grossly similar in VA and VV ECMO patients except for the presence of sleep architecture which was more common in VA ECMO (28.6% vs 3%, P-Value=0.044).

There were no differences amongst EEG characteristics between patients who had a neurologic adverse event (defined as significant CTH findings) and those that had a poor overall outcome (defined as death at the time of discharge).

In our patient cohort the incidence of clinical seizures amongst patients undergoing ECMO was estimated to be around 2%. Patients undergoing VA ECMO were more likely to have presence of sleep architecture whereas no differences were seen in patients having an adverse neurologic event or poor outcome.