June 14, 2022

Practical Considerations in Epilepsy Neurostimulation

Abstract found on Wiley Online Library

Neuromodulation is a key therapeutic tool for clinicians managing patients with drug-resistant epilepsy. Multiple devices are available with long-term follow-up and real-world experience. The aim of this review is to give a practical summary of available neuromodulation techniques to guide selection of modalities, focusing on patient selection for devices, common approaches and techniques for initiation of programming, and outpatient management issues.

Vagus nerve stimulation (VNS), deep brain stimulation of the anterior nucleus of the thalamus (DBS-ANT), and responsive neurostimulation (RNS) are all supported by randomized controlled trials that show safety and a significant impact on seizure reduction, as well as a suggestion of reduction in the risk of sudden unexplained death from epilepsy (SUDEP). Significant seizure reductions are observed after 3 months for DBS, RNS, and VNS in randomized controlled trials, and efficacy appears to improve with time out to 7-10?years of follow-up for all modalities, albeit in uncontrolled follow-up or retrospective studies. A significant number of patients experience seizure-free intervals of 6 months or more with all three modalities. Number and location of epileptogenic foci are important factors affecting efficacy, and together with co-morbidities such as severe mood or sleep disorders, may influence choice of modality. Programming has evolved – DBS is typically initiated at lower current/voltage than used in the pivotal trial while charge density is lower with RNS, but generalizable optimal parameters are yet to be defined. Non-invasive brain stimulation is an emerging stimulation modality, although currently not widely used.

Clinical practice has evolved from those established in pivotal trials. Guidance is available for clinicians wishing to expand their approach, and choice of neuromodulation technique may be tailored to individual patients based on their epilepsy characteristics, risk tolerance, and preferences.