Graham M Winston1, Sergio Guadix2, Miguel Tusa Lavieri2, Rafael Uribe-Cardenas2, Gary Kocharian2, Nicholas Williams3, Evan Sholle4, Zachary Grinspan5, Caitlin E Hoffman2. 1. Department of Neurological Surgery, Weill-Cornell Medicine/NewYork-Presbyterian Hospital, 525 East 68th Street, Box 99, New York, NY, USA. Electronic address: gmw2002@nyp.org. 2. Department of Neurological Surgery, Weill-Cornell Medicine/NewYork-Presbyterian Hospital, 525 East 68th Street, Box 99, New York, NY, USA. 3. Department of Healthcare Policy and Research, Weill Cornell Medicine, New York, USA. 4. Information Technologies & Services Department, Weill Cornell Medicine, New York, USA. 5. Department of Population Health Sciences and Pediatrics, Weill Cornell Medicine/NewYork-Presbyterian Hospital, New York, USA.
Abstract
PURPOSE: A new class of heart-rate sensing, closed-loop vagal nerve stimulator (VNS) devices for refractory epilepsy may improve seizure control by using pre-ictal autonomic changes as an indicator for stimulation. We compared our experience with closed- versus open-loop stimulator implantation at a single institution. METHODS: We conducted a retrospective chart review of consecutive VNS implantations performed from 2004 to 2018. Bivariate and multivariable analyses were performed to compare changes in seizure frequency and clinical outcomes (Engel score) with closed- versus open-loop devices. Covariates included age, duration of seizure history, prior epilepsy surgery, depression, Lennox Gastaut Syndrome (LGS), tonic seizures, multiple seizure types, genetic etiology, and VNS settings. We examined early (9-month) and late (24-month) outcomes. RESULTS: Seventy subjects received open-loop devices, and thirty-one received closed-loop devices. At a median of 8.5 months, there was a greater reduction of seizure frequency after use of closed-loop devices (median 75% [IQR 10-89%]) versus open-loop (50% [0-78%], p < 0.05), confirmed in multivariable analysis (odds ratio 2.72 [95% CI 1.02 - 7.4]). Similarly, Engel outcomes were better after closed-loop compared to open-loop confirmed in the multivariable analysis at the early timepoint (OR 0.26 [95% CI 0.09 - 0.69]). These differences did not persist at a median of 24.5 months. CONCLUSIONS: This retrospective single-center study suggests the use of closed-loop VNS devices is associated with greater seizure reduction and more favorable clinical outcomes than open-loop devices at 9-months though not at 24-months. Expansion of this study to other centers is warranted to increase the generalizability of our study.
PURPOSE: A new class of heart-rate sensing, closed-loop vagal nerve stimulator (VNS) devices for refractory epilepsy may improve seizure control by using pre-ictal autonomic changes as an indicator for stimulation. We compared our experience with closed- versus open-loop stimulator implantation at a single institution. METHODS: We conducted a retrospective chart review of consecutive VNS implantations performed from 2004 to 2018. Bivariate and multivariable analyses were performed to compare changes in seizure frequency and clinical outcomes (Engel score) with closed- versus open-loop devices. Covariates included age, duration of seizure history, prior epilepsy surgery, depression, Lennox Gastaut Syndrome (LGS), tonic seizures, multiple seizure types, genetic etiology, and VNS settings. We examined early (9-month) and late (24-month) outcomes. RESULTS: Seventy subjects received open-loop devices, and thirty-one received closed-loop devices. At a median of 8.5 months, there was a greater reduction of seizure frequency after use of closed-loop devices (median 75% [IQR 10-89%]) versus open-loop (50% [0-78%], p < 0.05), confirmed in multivariable analysis (odds ratio 2.72 [95% CI 1.02 - 7.4]). Similarly, Engel outcomes were better after closed-loop compared to open-loop confirmed in the multivariable analysis at the early timepoint (OR 0.26 [95% CI 0.09 - 0.69]). These differences did not persist at a median of 24.5 months. CONCLUSIONS: This retrospective single-center study suggests the use of closed-loop VNS devices is associated with greater seizure reduction and more favorable clinical outcomes than open-loop devices at 9-months though not at 24-months. Expansion of this study to other centers is warranted to increase the generalizability of our study.