Responsive neurostimulation for pediatric patients with drug-resistant epilepsy: a case series and review of the literature

Abstract

OBJECTIVE Responsive neurostimulation (RNS) is a promising treatment for pediatric patients with drug-resistant epilepsy for whom resective surgery is not an option. The relative indications and risk for pediatric patients undergoing RNS therapy require further investigation. Here, the authors report their experience with RNS implantation and therapy in pediatric patients. METHODS The authors performed a retrospective chart review to identify patients implanted with RNS depth or strip electrodes for the treatment of drug-resistant epilepsy at their institution between 2020 and 2022. Patient demographics, surgical variables, and patient seizure outcomes (Engel class and International League Against Epilepsy [ILAE] reporting) were evaluated. RESULTS The authors identified 20 pediatric patients ranging in age from 8 to 21 years (mean 15 [SD 4] years), who underwent RNS implantation, including depth electrodes (n = 15), strip electrodes (n = 2), or both (n = 3). Patient seizure semiology, onset, and implantation strategy were heterogeneous, including bilateral centromedian nucleus (n = 5), mesial temporal lobe (n = 4), motor cortex or supplementary motor area (n = 7), or within an extratemporal epileptogenic zone (n = 4). There were no acute complications of RNS implantation (hemorrhage or stroke) or device malfunctions. One patient required rehospitalization for postoperative infection. At the longest follow-up (mean 10 [SD 7] months), 13% patients had Engel class IIB, 38% had Engel class IIIA, 6% had Engel class IIIB, 19% had Engel class IVA, 19% had Engel class IVB, and 6% had Engel class IVC outcomes. Using ILAE metrics, 6% were ILAE class 3, 25% were ILAE class 4, and 69% were ILAE class 5. CONCLUSIONS This case series supports current literature suggesting that RNS is a safe and potentially effective surgical intervention for pediatric patients with drug-resistant epilepsy. The authors report comparable rates of serious adverse events to current RNS literature in pediatric and adult populations. Seizure outcomes may continue to improve with follow-up as stimulation strategy is refined and the chronic neuromodulatory effect evolves, as previously described in patients with RNS. Further large-scale, multicenter case series of RNS in pediatric patients with drug-resistant epilepsy are required to determine long-term pediatric safety and effectiveness.

Neurostimulation for childhood epilepsy

“…Recently, several small retrospective studies investigated the efficacy and safety of RNS in paediatric patients with various epilepsy aetiologies and seizure types. Results were promising, with responder rates between 31% and 100% 19–24 . Importantly, no increases in seizure frequency were reported.…”

“…Results were promising, with responder rates between 31% and 100%. [19][20][21][22][23][24] Importantly, no increases in seizure frequency were reported. An overview of these studies is given in Table 1.…”

“…Reported adverse events with RNS in children were rare and mainly concerned postoperative infections or device malfunction. [19][20][21][22][23][24][25] A potential concern with RNS in children is the implantation of a device in a thinner and still growing skull. However, it has been demonstrated that the RNS device does not alter skull shape or growth.…”

“…A median seizure frequency reduction of 75% was seen, with a responder rate of 80% after a median follow‐up of 22 months. Reported adverse events with RNS in children were rare and mainly concerned postoperative infections or device malfunction 19–25 . A potential concern with RNS in children is the implantation of a device in a thinner and still growing skull.…”

Predictors of therapeutic response following thalamic neuromodulation for drug‐resistant pediatric epilepsy: A systematic review and individual patient data meta‐analysis

“…Of 417 citations, 21 articles reporting on 88 participants were eligible for inclusion. 6,21,[28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] The PRISMA flow chart is depicted in Figure 1. Sixteen studies were published from institutions located in high-income countries, and five studies originated from high-middle-income countries.…”