Abstracts

Rationale: This study aimed to evaluate the diagnostic outcomes of Epilepsy Monitoring Unit admissions, with particular interest in determining the prevalence of recorded seizure types and epilepsy diagnoses, as well as psychogenic nonepileptic spells (PNES).

Methods: In preparation for a multicenter study, titled “Retrospective SUDEP at Epilepsy Centers: A Case-Control Study,” we performed a comprehensive review of adult and pediatric EMU records from University Health System (UHS, San Antonio, Texas) between January 2012 and December 2013. Age, sex, occurrence of seizures or nonepileptic events, as well as seizure types and characterization of interictal epileptiform discharges (IEDs) were tabulated. Intracranial evaluations were not included. In our academic practice, antiseizure medications (ASMs) were discontinued or rapidly tapered after admission. This study was approved by the Institutional Review Boards of University of Texas Health Science Center at San Antonio and UHS.

Results: In total, 609 patients with a median age of 32 (range 8 months-86) years were included with 150 (25%) patients under the age of < 18 years; 395 (65%) were females. Seizures were recorded in 273 (45%) patients and were predominantly focal onset (85%). Bilateral convulsive seizures were recorded in 23 (10%) patients with focal epilepsy and generalized tonic clonic-seizures (GTCS) were recorded in 26 (39%) patients with generalized epilepsy. IEDs were present in 343 (56%): 288 (84%) were focal, 101 (29%) generalized, and 45 (13%) had both. Among 154 (25%) patients with PNES, 10 (6%) also had epileptic seizures while 33 (21%) patients had IEDs. Other nonepileptic events, which included myoclonus, movement or sleep disorders, and autonomic irregularities, were recorded in 29 (5%) patients. No seizures, spells or IEDs were recorded in 115 (18.4%) patients.

Conclusions: Preliminary categorization of EMU findings in a South Texas population confirm the expected predominance of focal epilepsies, which tend to be more refractory than generalized epilepsies, as well as female predominance. Surprisingly, despite rapid weaning of ASMs, convulsive seizures were rarely recorded, and were more predominant in people with generalized epilepsies. It will be of interest to see whether the patients exhibiting convulsions in the EMU setting are at higher risk for SUDEP. The rate of PNES is also comparable to other EMU-based studies in the U.S., with a substantial subgroup also exhibiting epileptic seizures or interictal markers of epilepsy.

Funding: Please list any funding that was received in support of this abstract.: None.