To assess the incidence of electrographic seizures (ES) and describe EEG background features in children with brain tumors admitted to the pediatric intensive care unit (PICU).

Electrographic seizures are common in critically-ill children; the incidence of ES ranges from 10-50%. Continuous EEG (cEEG) is commonly indicated in children with brain tumors due to altered mental status or concern for seizures.  Despite this, little is known about the incidence of ES, EEG background features, or the impact of EEG on clinical management in this population.

This is a prospective single-center study of critically ill children with brain tumors admitted to the PICU from July 2021 to May 2023. Patients diagnosed with brain tumors and cEEG completed during their admission were included. We excluded patients with non-intracranial tumors and/or planned admissions for EEG. Clinical variables included age, sex, oncologic diagnosis, tumor grade and location, indication for EEG, EEG findings, and changes in management (i.e. EEG findings prompted neuroimaging).

132 patients with brain tumors were screened and 27 met the inclusion criteria. 15 patients were female. The median age was 13.3 years (interquartile range 6.3-14.9 years). The most common indication for EEG was encephalopathy (44%) followed by characterization of events concerning for seizure. ES were captured in 19% (5/27), most subclinical; in patients with new encephalopathy, ES were captured in 33% (4/12). 96% of cases had an abnormal EEG background. The most common EEG background was slow disorganized with background asymmetry seen in 82%. EEG background features met criteria for the ictal-interictal continuum in 19%. Finally, EEG led to a change in management in 33% of patients.

ES are common in critically-ill children with brain tumors and go undetected without cEEG. EEG findings often led to a change in clinical management, making EEG a vital tool for the evaluation of this population.