Abstracts

Rationale: Epilepsy monitoring unit (EMU) study has been widely utilized to make a definitive diagnosis of epileptic seizures (ES) vs. non-epileptic seizures (NES). Since 20-30% of patients may have both ES and NES, sufficient number of events should be captured during EMU if clinically indicated. In outpatient setting, NES has higher frequency of reported events compare to ES. However, it is not clear if patients with NES have more captured events during EMU. The primary goal of the study was to investigate if the number of recorded events during EMU was significantly different between ES and NES. Methods: We reviewed EMU admission records at the Barrow Neurological Institute from 2006 to 2013 in both pediatric and adult patients. We reviewed the number of events captured during the EMU admission, the gender, and diagnosis of the EMU admission. Final diagnosis was classified either as ES or NES. For the purpose of this study, NES included both non-epileptic seizures and non-epileptic events. Patients with ambiguous events, no captured event, and both ES and NES events in a single admission were excluded from the study. The primary study group was divided to ES and NES. In order to capture the potential gender differences, study subjects were further categorized in four groups: female with ES (f-ES), male with ES (m-ES), female with NES (f-NES), and male with NES (m-NES). One-tailed t-test was used to compare the number of recorded events between the NES and ES groups. Two-tailed t-test was used to compare the gender difference in the number of recorded events within the NES and ES groups. Results: This study included 1,526 cases. ES group consisted of 687 patients: 400 f-ES and 287 m-ES. The mean number of captured events (i.e. seizures) for the ES group was 7.50 (SD =10.31). The mean for f-ES group was 7.54 (SD = 10.58), and for m-ES group, 7.44 (SD = 9.94). There were 839 patients in NES group: 606 f-NES and 233 m-NES. The mean number of events for the NES group was 4.33 (SD = 4.39). The mean for f-NES was 4.41 (SD =4.33), and for m-NES, 4.12 (SD = 4.57). The number of captured events for ES patients was significantly higher than NES patients (p < 0.05). No significantly different gender difference was seen in regards to number of captured events. Conclusions: Even though patients with NES tend to report higher frequency of seizures than ES, lower number of events was captured during the actual diagnostic evaluation such as EMU. Future study may clarify if the intra-patient difference exists in reported versus captured events in NES population.