Vagus nerve stimulation in children with drug-resistant epilepsy of monogenic etiology
Xie H, Ma J, Ji T, Liu Q, Cai L, Wu Y.
Front Neurol. 2022 Sep 1;13:951850.
https://doi.org/10.3389/fneur.2022.951850
Publications on the outcome of vagus nerve stimulation (#VNS) in patients with drug-resistant epilepsy (#DRE) of monogenic #etiologies are rarely reported in the literature.
This single-center study by Xie et al. (Sep. 2022) analyzed the outcome of VNS Therapy in 20 patients who were diagnosed with monogenic epilepsy (follow-up duration: 1-2.9 years). The most common pathogenic genes were SCN1A (n=4) and DNM1 (n=2). The median age of #seizure onset and VNS implantation were 5.5 months and 55 months, respectively.
➤ 𝐒𝐞𝐢𝐳𝐮𝐫𝐞-𝐫𝐞𝐥𝐚𝐭𝐞𝐝 𝐨𝐮𝐭𝐜𝐨𝐦𝐞𝐬 𝐢𝐧 𝐝𝐢𝐟𝐟𝐞𝐫𝐞𝐧𝐭 𝐦𝐨𝐧𝐨𝐠𝐞𝐧𝐢𝐜 𝐞𝐭𝐢𝐨𝐥𝐨𝐠𝐢𝐞𝐬
The overall responder rates at 6, 12, 18, and 24 months of follow-up were 40%, 55%, 58.3%, and 62.5%, respectively. The rate of seizure freedom at the last visit was 10.0% (2/20). 75% (3/4) of patients with SCN1A variants were responders. Patients with SLC35A2 (1/1), CIC (1/1), DNM1(1/2), MBD5 (1/1), TUBGCP6 (1/1), EEF1A2 (1/1), and CHD2 (1/1) or MECP2 gene (1/1) were responders at the last visit.
➤ 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭𝐚𝐥 𝐨𝐮𝐭𝐜𝐨𝐦𝐞
75% of the patients had a severe developmental delay or intellectual disability. Even though no improvements were observed by developmental/intelligence scales at 6 and 12 months post-VNS implantation, 5 VNS responders reached new milestones or acquired new skills following the improved seizure control.
Further studies with a larger sample size for each monogenic etiology of DRE are needed to fully unravel the effects of VNS implantation in these specific groups of patients.