Long-term results of vagus nerve stimulation in children with Dravet syndrome: Time-dependent, delayed antiepileptic effect
Youn SE, Jung DE, Kang HC, Kim HD.
Epilepsy Res. 2021 Aug;174:106665.
https://doi.org/10.1016/j.eplepsyres.2021.106665.
Continuing on the theme of vagus nerve stimulation (#VNS) in Dravet syndrome (#DS). This retrospective study by Youn et al. (May. 2021) examined the long-term outcomes of VNS in pediatric patients with DS.
The study enrolled 22 patients who underwent VNS implantation at a single center. The median follow-up post-VNS implantation was 4.3 years (range: 3.0-6.5y). The median age at seizure onset and at VNS implantation was 6 months (4-8m) and 10.0 years (7.7-13.3y), respectively. Generalized tonic-clonic seizures were the predominant seizure type (present in 17 out of 22 patients, 77.3%).
𝐈𝐦𝐩𝐫𝐨𝐯𝐞𝐝 𝐬𝐞𝐢𝐳𝐮𝐫𝐞 𝐜𝐨𝐧𝐭𝐫𝐨𝐥 𝐨𝐯𝐞𝐫 𝐭𝐢𝐦𝐞
VNS resulted in progressively increased seizure control for DS patients during the follow-up. The responder rates at 12, 24, and 36 months were 36.4% (8/22), 54.5% (12/22), and 63.2% (12/19), respectively. Three patients (13.6%) became seizure-free for more than one year. Furthermore, 5 VNS responders were able to reduce the number of antiseizure medications (#ASMs).
𝐌𝐚𝐠𝐧𝐞𝐭𝐢𝐜 𝐞𝐟𝐟𝐞𝐜𝐭𝐬
27.3% of the patients reported a benefit of using the magnet for seizure control. However, the author highlights the challenges of using the patient magnet in patients with intellectual disabilities due to the potential difficulties in identifying an epileptic aura or seizure onset.
According to the current results, VNS appears to provide sustainable, progressively increased seizure control for patients with DS. However, to achieve a better understanding of VNS treatment effects in this rare syndrome, further multicenter, prospective studies are needed.