Abstracts

Rationale: Electroencephalograms (EEG) can be helpful in evaluating patients presenting to the emergency department (ED) with a suspicion of new onset seizures, recurrent seizures, altered mental status, suspicion of subclinical seizures, or any other neurological problem.^1,2 Our study is a retrospective analysis of the utility of EEGs done in the ED in terms of ascertaining a diagnosis and facilitating discharge of the patient from the ED. We also examined whether a video EEG , if performed during the same encounter, added any additional information.

Methods: We reviewed the charts of patients who had an EEG done in the ED at Dayton Children’s hospital, Dayton, Ohio, from 2010-2017. We divided the indication for EEG into 6 groups, 1) suspected new onset seizures, 2) recurrent seizures, 3) altered mental status, 4) death, 5) non-convulsive status epilepticus, and 6) psychogenic seizures. We collected data on age, gender, suspected diagnosis, EEG result, outcome of the visit in terms of discharge versus inpatient admission, medications administered in the ED, CT scan done in the ED, follow up of the patient with respect to a) diagnosis, b) medication, c) recurrent visit to the ED, and d) clinical outcome over a 2-year follow up. We also collected data on the results of the video EEG in patients who had an EEG in the ED and determined whether the video EEG had the same results and/or added any additional information

Results: We studied 163 patients (mean age 7.7 years, 42.9% females) with routine EEG in the ED from 2010-2017. In 142 patients (87.1%), the EEG was helpful in confirming or ruling out the suspected diagnosis. For the indications of new onset seizures (n=90), recurrent seizures (n=49), acute mental status change (n=22), and psychogenic seizures (n=5), the EEG was useful in 91.1%, 79.6%, 81.8%, and 100% respectively. We did not have any EEGs done for the indication of confirming death or non-convulsive status epilepticus in our cohort. Of the 163 patients, 59 were discharged and 104 were admitted. For the 142 patients in whom the routine EEG was diagnostically useful, 59.2% were admitted, compared to 95.2% of the 21 patients in whom the EEG did not help in clarifying the diagnosis. (p = 0.001). In 33 of the admitted patients, a video EEG was done. In the 33 patients who obtained video EEG, it did not add any additional information in 23 patients while in 10 patients the video EEG provided additional information that was useful for diagnosis and management. In these 10 patients, 8 patients belonged to the group where the diagnosis was uncertain despite obtaining a routine EEG in the ED.

Conclusions: EEG done in the ED is a useful diagnostic tool that may prevent admission to the hospital. Video EEGs should be considered in patients where the diagnosis is uncertain despite obtaining a routine EEG in the ED.

Funding: Please list any funding that was received in support of this abstract.: We did not receive any funding.