Abstracts

Rationale: The Epilepsy Monitoring Unit (EMU) is a specialized inpatient unit designated to the identification and characterization of refractory seizures. Patients are commonly tapered off their antiepileptic drugs (AED) to induce seizures during hospitalization. Withdrawing of AEDs in patients with epilepsy can lead to adverse events and injury due to the occurrence of more frequent and more violent seizure episodes.Methods: A retrospective review of noninvasive EMU admissions of adult intractable epilepsy patients over the course of 6 months (February to August of 2014) was completed. Prior to EMU admission, the ordering physician specifies medication taper based on clinical acumen. The patient can be admitted 1) ON medication – the patient is instructed to take medication regularly and decision to continue or taper medication is made by one of three rotating epileptolgist; or 2) OFF medication – the patient is instructed to take 50% of dose one day prior to admission and no medications on the morning of admission. Patients were admitted on a Monday and stayed no longer than Friday, unless deemed medically necessary. Patient demographics, seizure history, taper type, duration to first seizure, total number of seizures, the presence of generalized tonic-clonic seizures, and the presence of 4 hour and 24 hour clusters (> 2 seizures) were recorded in a systemic fashion. In addition, falls and injuries, utilization of additional diagnostic studies such as x-rays and CT scans, as well as the occurrences of status epilepticus and postictal pyschosis were noted.Results: 77 patients were admitted for noninvasive EMU monitoring. 49 (64%) had diagnostic events during admission with a total of 134 recorded seizures (42 of which were GTCs from 13 patients). Three patients had preadmission seizures and of those none resulted in early admission. Mean time to first seizure was 24 hours (1 to 91 hours), with a mean Length of Stay of 80 hours (23 to 192 hours). There was a total of 1 occurrence of postictal psychosis and 1 occurrence of status epilepticus. 4-hour clusters occurred in 9 patients (11.7%) and additional 17 patients (22.1%) suffered 24 hour clusters. Eight patients did not have pre-admission taper (10.4%). One of these patients had a 4 hour cluster (12.5%) and three had 24 hour clusters (37.5%), with average time to first seizure of 27 hours.Conclusions: Pre-admission fast AED taper resulted in relatively shorter time to first seizure (24 hours) than previously reported in the literature (2 to 3.3 days). This was done safely with no increase rate of 4-hour and 24-hour clusters which is reported to be 11-18% and 39-64% respectively and with a rare single occurrence of status epilepticus. This taper however did not greatly improve diagnostic yield with only 64% of admissions resulting in a diagnostic event. This may have been limited by shorter length of stay of 3.3 days, likely influenced by epilepsy center’s protocol of discharging patients on Friday.