Vagus nerve stimulation for drug-resistant epilepsy induced by tuberous sclerosis complex
Tong X, Wang X, Qin L, Zhou J, Guan Y, Teng P, Wang J, Yang Y, Li T, Luan G.
Epilepsy Behav. 2022 Jan;126:108431.
https://doi.org/10.1016/j.yebeh.2021.108431.
By the end of our current theme - vagus nerve stimulation (#VNS) in tuberous sclerosis complex (#TSC), we would like to share a retrospective study by Tong et al. (2022) reporting the dynamic and long-term efficiency of VNS in drug-resistant epilepsy (#DRE) induced by TSC. This study included a relatively large cohort of patients (n=17) with a follow-up duration ranging between 0.5-10 years. 70.6% of the patients were VNS responders and achieved ≥50% seizure frequency reduction.
The mean age at #seizure onset and at VNS implantation, respectively, was 3.7 years (range: 0.25-11 years) and 11.4 years (range: 0.9-30 years). The mean monthly seizure frequency before VNS treatment was 154.4 (range: 0.33-600). 4 patients had infantile spasms. 4 patients failed epilepsy surgery before VNS treatment. The mean number of failed antiseizure medications (#ASMs) was 3.8 (range: 3-6).
The monthly seizure frequency was significantly decreased from 3 months to 4 years after VNS treatment (p<0.05), with a 70.6% responder rate. At the last follow-up, 3 patients became seizure-free. Furthermore, a subgroup of pediatric patients who performed the Wechsler Intelligence Scale test (N=6), showed improved full-scale intelligence quotient (p=0.078), processing speed (p=0.025), working memory (p=0.82), perceptual reasoning (p=0.79), and verbal comprehension (p=0.83) after 1-year of VNS treatment. Prior to VNS implantation, 4 patients had anxiety problems, and 3 patients had mild depression symptoms. Noteworthy, following VNS implantation, the anxiety and depression levels decreased in those patients (p=0.083, p=0.003, respectively).
Despite the relatively small number of patients in the subgroup analysis for neuropsychological assessments, the current results indicate that VNS treatment might result in promising improvements in cognition and depressive mood for patients with TSC. However, further studies with larger sample sizes should be conducted to validate the findings.
Link to the article:
https://www.epilepsybehavior.com/article/S1525-5050(21)00692-2/fulltext
