Subgroup analysis of seizure and cognitive outcome after vagal nerve stimulator implantation in children

Pediatric

May 19

Knorr C, Greuter L, Constantini S, Fried I, Kremer U, Datta AN, Guzman R, Soleman J.
Child's Nervous System volume 37, pages243–252 (2021)
http://ow.ly/YvUm50JbW9a

Continuing our monthly theme, “Early use of vagus nerve stimulation (#VNS),” this publication by Soleman et al. 2021 aimed to identify potential #predictors for #seizure control, cognitive outcomes, and improvements in quality of life (#QoL) following VNS implantation in pediatric patients with drug-resistant epilepsy (#DRE), thus optimizing patient selection. The study provides a subanalysis of data presented in Soleman et al. 2018.

Underlying cause

The patients with encephalitis had significantly better responder rates (defined as ≥50% reduction in seizure frequency; P = 0.013) and better seizure control, as measured by the McHugh and Engel classification scales (P = 0.049, P = 0.022, respectively), as compared to the patients with other underlying causes (P = 0.013). However, the complication rate for patients with encephalitis (71.4%, n = 5) was higher compared to other groups (idiopathic: 20.8%, n = 5; stroke: 12.5% n = 1; syndromic: 33.3% n = 2; P = 0.045).

Frequency of preoperative seizures

The patients with higher preoperative seizure frequencies also had a shorter duration of preoperative seizures (<89 months). This led to more extensive improvements in QoL (based on the total Pediatric Quality of Life, #PEDSQL™, questionnaire; P = 0.038).

Duration of preoperative seizures

The patients with a shorter duration of preoperative seizures (<89 months) were more likely to be rated as “very much improved” on the caregiver impression (#CGI) scale (P = 0.02) and showed better total scores on the PEDSQL™ questionnaire (P = 0.013).

Age

Patients under the age of two showed significantly better developmental and #cognitive outcomes than other age groups.

The current result suggests a shorter preoperative seizure duration and a younger age at VNS implantation to be significantly associated with improved QoL, cognition, and development. Furthermore, despite the limited number of patients younger than two years old (n = 4, 8.9%), the results demonstrate the safety and possibility for implantation of VNS in very young children. Considering that cognition, development, and QoL are as vital as the seizure-related outcomes, especially in young patients, implantation of VNS should be considered at an earlier stage in patients with specific epilepsy etiologies.