Determining Utility of Additional Days in the Epilepsy Monitoring Unit (EMU) for Patients without Events in First 5 Days of Admission (P3.5-026)

Objective: To identify characteristics predictive of non-diagnostic admission for differential diagnosis/classification EMU patients who have not had events in the first 5 days of admission. Background: There is limited evidence-based guidance regarding appropriate timing of discharge from the EMU. In particular, it is unknown which patients without successful diagnosis early in their admission are likely to benefit from continued monitoring. Design/Methods: We performed a retrospective chart review of patients admitted to the EMU at the Hospital of the University of Pennsylvania between 1/2012 and 7/2017. Chi-squared tests and logistic regression modelling were used to investigate whether a variety of patient, EEG, and imaging characteristics could independently or in combination predict if a patient would go on to have a non-diagnostic stay. Results: We identified 198 patients with EMU length of stay >5 days without events in first five days of admission out of a total of approximately 1400 EMU admissions over a five year period. Absence of interictal discharges in the first 5 days was associated with non-diagnostic stay (p =.0009, OR = 2.90). Lack of motor semiology was also associated with non-diagnostic stay (p =.0267, OR = 2.36). The absence of both interictal discharges and major motor semiology had a positive predictive value of 82.8% for non-diagnostic admission. Demographic factors, lesional MRI, and number and type of AEDs did not influence likelihood of diagnostic or non-diagnostic stay. Conclusions: Non-motor semiology and the absence of interictal discharges predict non-diagnostic admission in patients admitted to the EMU for >5 days. These criteria may identify patients unlikely to benefit from prolonged EMU admission and thereby facilitate earlier discharge and improved EMU utilization. Disclosure: Dr. Cherayil has nothing to disclose. Dr. Khankhanian has nothing to disclose. Dr. Gelfand has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Guidepoint. Dr. Gelfand has received research support from Aquestive, Biogen Idec, Eisai Inc., Epilepsy Foundation, Engage Therapeutics, Pfizer Inc., SK, and UCB Pharma.