Point-of-Care EEG Enables Rapid Management of Non-Convulsive Seizures in the Emergency Department

Abstract

Background: Non-convulsive seizures (NCS) are increasingly recognized as a cause of persistent encephalopathy in the emergency department (ED) and are diagnosed using electroencephalography (EEG). However, EEG is often delayed or unavailable, especially in the ED, resulting in significant uncertainty in clinically diagnosing NCS and leading to delayed or inappropriate treatment with anti-seizure medications (ASMs), unnecessary intubation, and increased morbidity. Point-of-care EEG (pocEEG) could fill this critical gap in the ED, as it has in inpatient and intensive care unit (ICU) settings. In this study, we describe the impact of pocEEG on the management of ED patients with suspected NCS. Methods: We retrospectively identified patients who underwent pocEEG monitoring in the ED at Mission Hospital (1/1/2020-12/31/2020). We extracted pocEEG findings (categorized as seizure, highly epileptiform patterns [HEP], and slow/normal activity; excluding repeat studies for the same patient) and ASM treatment information (pre-hospital, pre-pocEEG, post-pocEEG) to determine whether pocEEG led to appropriate ASM escalation or avoidance of inappropriate ASM escalation. Statistical significance was assessed using chi-square tests with Bonferroni correction. Results: Of 157 ED patients (mean age 57.7±22.4 years, 49% female), pocEEG revealed seizures in 22 (14%), HEP in 33 (21%), and slow/normal activity in 102 (65%). Most studies (53%) were performed after-hours (5p-8a), and most patients were admitted (54% ICU, 41% floor). Five patients (3%) were treated with ASMs prior to ED arrival, but 93 (59%) were treated in the ED prior to pocEEG monitoring and 80 (51%) were treated after pocEEG monitoring. By reviewing each patient’s ED course and the relationship between pocEEG monitoring and ASM treatment, we found a significant association between pocEEG findings and changes in management (p<0.001). Patients with seizures were significantly more likely to be treated than patients with slow/normal activity (59% vs. 25%, p=0.002) and patients with slow/normal activity were significantly more likely to not have treatment escalation (28% vs. 0% for seizure/HEP patterns, p<0.001). Conclusion: By guiding bedside diagnosis and treatment decision-making, pocEEG can empower ED physicians and consulting neurologists to evaluate and manage patients with suspected NCS and can positively and substantially impact the care of patients with neurological emergencies.