Efficacy and potential predictors of vagus nerve stimulation therapy in refractory postencephalitic epilepsy
Liu S, Xiong Z, Wang J, Tang C, Deng J, Zhang J, Guo M, Guan Y, Zhou J, Zhai F, Luan G, Li T.
Ther Adv Chronic Dis 2022, Vol. 13: 1–13
https://doi.org/10.1177/20406223211066738
Vagus nerve stimulation (#VNS) is a valuable treatment option for patients with drug resistant epilepsy (#DRE). However, the effectiveness of VNS in refractory postencephalitic epilepsy (#PEE) has not yet been fully established.
This #retrospective study by Liu et al., 2022, aimed to examine the effectiveness of VNS in patients with refractory PEE. Furthermore, plausible #predictors of effect were identified by multivariate analysis of presurgical data.
Highlights
• The responder rate (≥50% reduction in #seizure frequency) for patients with PEE was 64.29%.• 7.14% of the subjects became seizure free.
• The efficacy of VNS Therapy increased over time.
• Focal interictal epileptic discharges (#IEDs) and a high seizure frequency prior to VNS implantation were possible predictors of VNS effectiveness.
42 patients with intractable PEE, treated with VNS Therapy, were included in the analysis. Mean age at VNS implantation was 18.05 ± 10.08 years and the median #follow-up duration was 2.71 years (range: 1-11.83 years). Seizure frequency reduction was categorized based on the McHugh and modified Engel seizure outcome classification.
At the last follow-up, 64.29% of patients were VNS responders and three patients (7.14%) were seizure free. Furthermore, responder rates increased over time from 40.5% at the 6 month follow-up to 50.05% at the 12 month follow-up. A further increase, to 57.1%, was observed at the 24 month follow-up.
Multivariate regression analysis of presurgical data revealed a high seizure frequency and focal IEDs to be significantly correlated with VNS efficacy.
Based on the current results, VNS Therapy may be an effective treatment option for patients with refractory PEE. Furthermore, focal IEDs and a high seizure frequency appear to be plausible predictors of VNS efficacy.