S92. Outcome of prolonged EEG-video monitoring in a new V.A. monitoring unit

Abstract

Introduction For patients with refractory seizures or seizure-like activity, prolonged inpatient video-EEG (v-EEG) monitoring is standard of care to guide diagnosis and management. With the advent of the “Epilepsy Centers of Excellence (ECOE)” in the VA system, many V.A. hospitals have developed an epilepsy monitoring unit (EMU). The purpose of this study was to describe the outcome of v-EEG monitoring in a new VA EMU. Methods In this retrospective study, we reviewed the diagnoses of all prolonged (>24 h) inpatient v-EEGs performed in our EMU at the James A Haley VA in Tampa, Florida. A total of 195 prolonged inpatient v-EEGs were performed over a four-year period (11/2013–10/2017). The patient population consisted of adult veterans (171 males, 24 females) ranging of 22–84 years old. The duration of monitoring ranged from 24 h to 7 days (mean 3 days). The outcomes of monitoring were then categorized as epileptic seizures (ES) (generalized versus focal ), interictal epileptiform abnormalities without a clinical event (IIAE), psychogenic nonepileptic seizures (PNES), other non-epileptic seizures (NES), non-diagnostic events (event captured was not the event in question or milder form of the typical event), and lastly those which were inconclusive (no event captured and no IIAE). Results Of the 195 studies, 44 (23%) had exclusively epileptic seizures (ES). Of these, 42 (95%) had focal seizures, and 2 (5%) had generalized seizures. Of the 42 cases with focal seizures, all but 2 had clear ictal changes on EEG. Both of the generalized seizures had clear ictal correlates on EEG. Twenty-two (11%) EEG studies revealed interictal epileptiform abnormalities without a clinical event. Fifty-three (27%) of the v-EEGs had exclusively non-epileptic events. Of these, 21 (∼11%) were psychogenic non-epileptic seizures (PNES) and 32 (16%) were other non-epileptic seizures (NES) such as syncope, hypnic jerks or subjective non-motor symptoms such as head pain or dizziness. There was only one case of mixed ES and PNES. Seventy-five (38%) of the studies were inconclusive, either due to lack of events captured (52) or because the events recorded were not the patient’s typical episodes (23). Conclusion A significant portion of the prolonged inpatient v-EEGs done during this time period was inconclusive. A possible explanation is that patients with infrequent events were often referred for v-EEG, and a longer monitoring period may be needed. The criteria of selecting patients for video-EEG may have to be better defined. There were less PNES than expected even within the NES group. This could be a result of the sample population, which consisted predominantly of males, whereas PNES occur more commonly in females. Another possible explanation is that at our center PNES are often captured during outpatient v-EEGs performed prior to EMU admission. The main limitation is that this study represents a single center. Future studies compiling data from all 16 VA ECOEs may help to better refine this data.