Abstracts

Rationale: Continuous long-term video-EEG monitoring is the ‘gold-standard’ diagnostic test to assess whether epilepsy is the etiology of a seizure-like event. We evaluate the outcome of ambulatory (in-home) diagnostic video-EEG performed on a nationwide cohort of patients over one calendar year. We compare our findings with outcomes of inpatient adult and pediatric video-EEG monitoring performed during the same year at academic epilepsy centers. We assess prevalence of seven phenomenological features in clinical history and during video-EEG events. Finally, we estimate interrater-reliability of neurologist ambulatory video-EEG interpretation. Methods: This is a retrospective cohort study. We obtained ambulatory video-EEG outcome data from the Alliance Family of Companies, an independent diagnostic ambulatory-EEG testing facility. Inpatient video-EEG data from a 4-bed adult epilepsy center and an 8-bed pediatric epilepsy center were also included.  Primary outcome measure was composite percentage of video-EEG records with epileptiform activity on EEG tracings or at least one video-recorded pushbutton event. Results: Of 9,221 ambulatory video-EEG recordings performed across 28 states, 62.5% attained primary outcome. Ambulatory video-EEG efficacy was similar as compared to inpatient video-EEG monitoring in adults (61.7%, VAEEG; 54.4%, inpatient; p=0.201), and higher in the inpatient setting in the pediatric population (72.5%, VAEEG; 86.3% inpatient; p<0.001)Of note, pediatric patients had more events than adults in ambulatory and inpatient settings. Altered sensorium/awareness was the most prevalent feature in ambulatory sample, whereas focal motor feature was most prevalent in inpatient sample. Interrater-reliability of four electroencephalographers’ interpretation of 25 ambulatory video-EEG recordings was ‘excellent’ (?=0.81). Conclusions: Ambulatory video-EEG may be an effective first-line assessment for evaluation of seizure-like events in adult patients. Selected pediatric patients may benefit from inpatient video-EEG monitoring. Funding: None