Abstracts

Rationale: The main purpose of this study is to explore the effect of serotonin reuptake inhibitors (SSRIs) on proposed EEG correlates of sudden unexpected death in epilepsy (SUDEP). In previously published studies, mouse models of SUDEP were shown to have abnormal serotonin receptors in the brainstem1,2. Sudden death in these animals could be prevented by SSRI treatment3. The severity of ictal hypoxemia may be linked to post ictal EEG suppression(PGES)4, and SSRI use may reduce the severity of ictal hypoxemia5. Since ictal hypoxemia may contribute to PGES, and the tonic phase of seizures is associated with apnea, we evaluated the tonic phase duration (TPD) and PGES in patients either on or off SSRI. We hypothesized that TPD and PGES would be shorter in patients taking an SSRI.Methods: We examined 46 patients with generalized tonic-clonic seizures using a retrospective control of video electroencephalographic (EEG)-confirmed epilepsy patients at Thomas Jefferson University Hospital between 2010 and 2014. We determined the total seizure duration, TPD, clonic phase duration, and the duration of PGES via retrospective review of EEG data.Results: 10 of 46 (22%) were taking a therapeutic SSRI at time of video EEG monitoring. 2 of 10 SSRI+ patients had post ictal periods obscured by artifact and could not be used for PGES analysis, but were included in the TDP analysis. The mean duration of PGES in the SSRI+ group was 30.15 seconds (SD =28.9 seconds, range 0 – 73.5 seconds) compared to 34.62 seconds (SD = 26.0 seconds, range 0 – 110 seconds) in the SSRI- control group (p=0.67), and the ratio of average PGES to total seizure duration was 0.326 (SD = 0.38, range 0 – 1.0) in the SSRI+ group and 0.568 (SD = 0.25, range 0.037 – 0.64) in the SSRI- control group (p=0.056). Mean tonic phase and the ratio of tonic phase to total seizure duration were similar in SSRI+ and SSRI- patients. There was a trend towards decreased ratio of PGES to total seizure duration in the SSRI+ group.Conclusions: There was a trend towards a shorter ratio of PGES to total seizure duration in the SSRI+ study group compared to the SSRI- control group. This finding supports prior studies suggesting that SSRI use may reduce PGES duration. This may be related to reduction in ictal hypoxemia or may be due to alteration of brainstem function and post-ictal cortical recovery related to SSRI use. Further prospective studies are needed to explore the electrophysiologic response to SSRI use.