gms | German Medical Science

Objective: The most widely used neuro-stimulation treatment for drug-resistant epilepsy is Vagus Nerve Stimulation (VNS) Therapy^®. Ictal tachycardia can be an indicator of a seizure, and if monitored, can be used to trigger an additional on-demand stimulation, which may positively influence seizure severity or duration. A new VNS Therapy generator model, AspireSR^® was introduced and approved for CE mark in February 2014. In enhancement to former models, the AspireSR has incorporated a Cardiac-Based-Seizure-Detection (CBSD) algorithm that can detect ictal tachycardia and automatically trigger a defined auto-stimulation. To evaluate differences in pre, intra- and postoperative handling, we compared the AspireSR to a conventional generator model (Demipulse^®).

Method: Between February and September 2014 seven patients with drug-resistant epilepsy and ictal tachycardia were implanted with an AspireSR. Between November 2013 and September 2014 seven patients were implanted with a Demipulse and served as control group. Operation time, skin incision length and position, and complications were recorded. Handling of the new device was critically evaluated.

Results: The intraoperative handling was comparable and did not lead to a significant increase in operation time. In our fourteen operations, we had no significant short-term complications. Due to its larger size, patients with the AspireSR had significantly larger skin incisions. For optimal heart rate detection the AspireSR had to be placed significantly more medial in the décolleté area than the Demipulse. The pre-operative testing is a unique addition to the implantation procedure of the AspireSR, which may provide minor difficulties, and for which we provide several recommendations and tips. The price of the device is higher than of all other models.

Conclusions: The new AspireSR generator offers a unique technical improvement over the previous Demipulse. Whether the highly interesting CBSD feature will provide an additional benefit for the patients, and will rectify the additional costs, respectively, cannot be answered in the short-term. The pre-operative handling is straight forward, provided that certain recommendations are taken into consideration. The intraoperative handling is equivalent to former models – except for the placement of the generator. We recommend the consideration of the AspireSR in patients with documented ictal tachycardia to provide a substantial number of patients for later seizure outcome analysis.