Citations

Abstract Objectives Pivotal trials have established the effectiveness of the Responsive Neurostimulation System (RNS® System) in treating focal epilepsy. In clinical trials, depth leads were primarily used to treat mesial temporal seizure onsets while cortical strip leads were used to treat neocortical seizure onsets. Here, we systematically analyze the safety and efficacy of stereoelectroencephalography (sEEG)‐guided depth leads to provide responsive stimulation to neocortical gray matter. Methods Patients were stratified as strong responders (>median cohort seizure reduction %), weak responders (>0% and ≤median cohort seizure reduction %), and anti‐responders (≤0%) based on percent seizure reduction at 1 year post‐implant (1‐Y). Pre‐operative T1‐weighted magnetic resonance imaging and post‐operative computed tomography images were merged, and the Euclidean distance between the sEEG epileptic focus (sEEG‐EF) and the nearest RNS System depth lead contacts was calculated. Results A total of 87 depth leads were implanted in 55 patients across neocortical brain regions. The median reduction in clinical seizures improved from 66.7% at 1‐Y to 77.5% at long‐term follow‐up (LTFU: 2.35 ± 0.95 years), with 10 patients (18.2%) achieving complete seizure freedom. Seven patients (12.7%) experienced six serious adverse events. At 1‐Y, shorter Euclidean distance between the sEEG‐EF and RNS System depth leads predicted improved seizure outcome in strong responders ( β = −0.84, p = 0.008) but not in weak responders ( β = 0.21, p = 0.9) or anti‐responders ( β = −20.34, p = 0.11). At LTFU, there was no significant relationship between Euclidean distance and seizure reduction in strong responders ( β = 0.77, p = 0.18), weak responders ( β = 2.05, p = 0.54), or anti‐responders ( β = 0.24, p = 0.99). Exploratory analyses at 1‐Y showed nominal associations between older age ( ρ = 0.32), longer epilepsy duration ( ρ = 0.27), and non‐mesial temporal sEEG‐EFs and greater seizure reduction; however, none survived Bonferroni correction (adjusted α = 0.0027; all post‐correction p > 0.0027), and no associations were observed at LTFU. Significance In this series, neocortical depth leads for RNS therapy had favorable safety and efficacy and proximity to the sEEG‐EF drove initial outcomes for strong responders to RNS therapy. Plain Language Summary In this multi‐center study, patients with difficult‐to‐treat seizures received brain‐responsive stimulation using a device called responsive neurostimulation (RNS), which delivers small electrical pulses to reduce seizures. We focused on patients treated with electrodes placed in the brain's outer regions (the neocortex) and guided by a mapping procedure called sEEG. On average, patients had their seizures cut by two‐thirds after one year and by more than three‐quarters with longer follow‐up, with about one in five becoming seizure‐free. The treatment was safe, and closer electrode placement to the seizure source helped explain early—but not long‐term—improvements.

BACKGROUND AND OBJECTIVES: The Risk Analysis Index (RAI) is a comprehensive assessment of frailty for predicting neurosurgical outcomes. The aim of this study was to assess whether frailty, measured by a modified RAI (mRAI), was an independent predictor of adverse events (AEs), nonroutine discharge (NRD), and in-hospital mortality for patients with acute cervical spinal cord injuries (SCIs). METHODS: A retrospective cohort study was performed using the American College of Surgeons Trauma Quality Programs database. Adult patients with acute cervical SCI from 2016 to 2022 were stratified by mRAI score into 3 groups: Robust (mRAI 0-10), Frail (mRAI 11-20), and Very Frail (mRAI ≥21). Patient demographics, comorbidities, injury type, diagnostic and treatment modality, AEs, and in-hospital mortality were assessed. A multivariate logistic regression analysis was used to identify independent predictors of AEs, NRD, and in-hospital mortality. RESULTS: 71 048 patients were stratified by mRAI score: 59 796 Robust (84.2%), 9558 Frail (13.5%), and 1694 Very Frail (2.4%). The proportion of SCIs secondary to a fall (Robust: 44.1% vs Frail: 70.2% vs Very Frail: 82.3%; P < .001) and AEs (Robust: 21.5% vs Frail: 24.4% vs Very Frail: 25.0%; P < .001) significantly increased with frailty. Very Frail patients experienced higher NRDs (Robust: 72.3% vs Frail: 85.2% vs Very Frail: 91.0%; P < .001) and in-hospital mortality (Robust: 10.9% vs Frail: 18.3% vs Very Frail: 29.2%; P < .001). On multivariate regression analysis, both Frail (odds ratio [OR]: 1.42; 95% CI: 1.25-1.61; P < .001) and Very Frail (OR: 2.09; 95% CI: 1.46-2.99; P < .001) mRAI scores predicted NRD, but only Frail mRAI score (OR: 1.12; 95% CI: 1.05-1.21; P = .001) was significantly associated with AEs. In addition, Frail (OR: 1.50; 95% CI: 1.36-1.65; P < .001) and Very Frail (OR: 2.79; 95% CI: 2.36-3.29; P < .001) mRAI scores were independent predictors of in-hospital mortality. CONCLUSION: Our study suggests that mRAI may be used to assess morbidity and mortality in patients presenting with spinal cord injury.