Rapid titration of VNS therapy reduces time-to-response in epilepsy
Tzadok M, Verner R, Kann L, Tungala D, Gordon C, El Tahry R, Fahoum F.
Epilepsy Behav. 2022 Sep;134:108861.
https://doi.org/10.1016/j.yebeh.2022.108861
Traditional dose titration for vagus nerve stimulation (#VNS) Therapy in drug-resistant epilepsy (#DRE) is generally performed in small increments over an extended period (usually months). While this allows for close assessments of VNS tolerability, it may also substantially delay target dosing and some patients may not reach target dosing before the common efficacy follow-up 12 months post-implantation.
This new publication by Tzadok ๐ฆ๐ต ๐ข๐ญ. 2022 retrospectively analyzed the relationship between time to the target dose* (fast: <3 months, medium: 3-6 months, or slow: >6 months) and the time to VNS response (โฅ50% reduction in seizure frequency) based on data from 12 clinical studies (N= 651 adults and 344 children). The study further examined patient #tolerability and safety based on the different titration regimens.
๐๐ข๐ ๐ก๐ฅ๐ข๐ ๐ก๐ญ๐ฌ
- ๐๐๐ฉ๐ข๐ ๐ญ๐ข๐ญ๐ซ๐๐ญ๐ข๐จ๐ง ๐จ๐ ๐๐๐ ๐ฉ๐๐ซ๐๐ฆ๐๐ญ๐๐ซ ๐ฌ๐๐ญ๐ญ๐ข๐ง๐ ๐ฌ ๐ซ๐๐ฌ๐ฎ๐ฅ๐ญ๐ฌ ๐ข๐ง ๐ ๐๐๐ฌ๐ญ๐๐ซ ๐จ๐ง๐ฌ๐๐ญ ๐จ๐ ๐๐ฅ๐ข๐ง๐ข๐๐๐ฅ ๐ซ๐๐ฌ๐ฉ๐จ๐ง๐ฌ๐
- ๐๐ฎ๐ฆ๐ฎ๐ฅ๐๐ญ๐ข๐ฏ๐ ๐ฆ๐๐๐ง ๐๐๐ฏ๐๐ซ๐ฌ๐ ๐๐ฏ๐๐ง๐ญ๐ฌ ๐๐จ ๐ง๐จ๐ญ ๐๐จ๐ซ๐ซ๐๐ฅ๐๐ญ๐ ๐ฐ๐ข๐ญ๐ก ๐ญ๐ข๐ญ๐ซ๐๐ญ๐ข๐จ๐ง ๐ญ๐ข๐ฆ๐ ๐ข๐ง ๐ฉ๐๐๐ข๐๐ญ๐ซ๐ข๐ ๐ฉ๐๐ญ๐ข๐๐ง๐ญ๐ฌ
- ๐๐ก๐ ๐ฌ๐ข๐๐ ๐๐๐๐๐๐ญ ๐ฉ๐ซ๐จ๐๐ข๐ฅ๐ ๐๐ฉ๐ฉ๐๐๐ซ๐ฌ ๐ญ๐จ ๐๐ ๐๐จ๐ฆ๐ฉ๐๐ซ๐๐๐ฅ๐ ๐๐๐ญ๐ฐ๐๐๐ง ๐๐ข๐๐๐๐ซ๐๐ง๐ญ ๐ญ๐ข๐ญ๐ซ๐๐ญ๐ข๐จ๐ง ๐ฌ๐ฉ๐๐๐๐ฌ
Cox weighted regression analysis revealed a significant relation between titration time and time to response. Furthermore, adverse events appeared to be more common in adults undergoing rapid titration, whereas adverse events were comparable between different titration regimens in children.
Despite limitations, such as the influence of possible antiepileptic drug (#AED) changes during follow-up, the current data suggest that rapid titration of VNS parameters results in a faster response onset and should be considered when deciding on a titration strategy. Especially in pediatric patients where the side effect profile is comparable between titration regimens.
*The target dose was empirically defined as 1.625 mA, 250 ยตs, and 20 Hz.
