Safa, Adrian

BACKGROUND The authors aimed to evaluate the feasibility/safety of stereo-electroencephalography (SEEG) and SEEG-guided radiofrequency thermocoagulation (RFTC) in patients with drug-resistant epilepsy previously implanted with neuromodulation devices, using a retrospective cohort design evaluating patients treated at the Mayo Clinic Florida Epilepsy Center. OBSERVATIONS Nine patients (mean age 36.3 ± 10.9 years, 33% female) with prior implantation of neuromodulation devices were included. A vagus nerve stimulator was present in 8 of 9 patients, and 4 patients had undergone previous intracranial neuromodulation. Five patients underwent SEEG-RFTC. The mean SEEG monitoring duration was 6.5 ± 2.9 days. No intraoperative or procedural complications occurred, including hardware-related issues. No permanent or significant neurological/cognitive deficits occurred. One patient experienced transient postoperative neurological symptoms attributed to perilesional edema. Seizure reduction ranged from 50% to 75% following SEEG-RFTC. LESSONS SEEG and SEEG-RFTC are feasible in patients who have implanted neuromodulation devices, including intracranial implants. These procedures may be performed without interference with existing hardware and provide meaningful seizure reduction in highly refractory populations. Further studies with larger cohorts and longer follow-up are needed to better define efficacy and patient selection. https://thejns.org/doi/10.3171/CASE26376

Purpose: Subcortical functional brain mapping is a valuable technique, especially involving lesions within or near white matter tracts. Motor and language deficits caused by intraoperative damage to these subcortical fibers are associated with worse outcomes. However, there are variable approaches to performing subcortical functional brain mapping. This systematic review was performed to better understand indications and optimal stimulation parameters. Methods: A systematic review was performed by PRISMA guidelines, using PubMed, Scopus, and Medline databases. Search dates ranged from inception to November 30th, 2024. Studies included adults who underwent subcortical electrical stimulation for functional brain mapping. Results: A total of 55 articles (249 patients, mean age 44.8 years, 114 female) were included. The most common pathology was brain tumor (96.3%), primarily gliomas and metastases, and 24.4% of all cases had a history of epilepsy. The most frequently mapped white matter tracts were the arcuate fasciculus, corticospinal/pyramidal tract, and inferior fronto-occipital fasciculus, involving motor, language, and cognitive functions. Bipolar stimulation (50–60 Hz, 0.5–1 millisecond, 1–10 mA) was preferred over monopolar stimulation. Among 147 patients with outcome data, 89.1% did not suffer permanent adverse outcomes including neurologic deficits, although long-term outcomes were inconsistently reported. Conclusions: The methodologic variability of subcortical functional brain mapping and lack of long-term follow-up reported limits determination of optimal parameter selection for electrical stimulation although common trends are reported. Functional brain mapping approaches may be guided by the tract and network involved. Further studies are needed to develop a standardized approach and more definitive guideline to its performance.

OBJECTIVE The aim of this study was to compare 3 electrode designs—a novel 22-contact circular grid, standard 6-contact strip, and high-density (HD) grid between 32 and 64 contacts—for the detection of epileptiform activity during awake craniotomy. METHODS This study included patients who underwent functional brain mapping with and without direct electrical stimulation during awake craniotomy. Demographic, clinical, and electrocorticography (ECoG) data were collected. RESULTS A total of 194 patients were included, with 264 instances of electrode use: 113 circular grid, 96 strip electrode, and 55 HD grid. The HD grid (15%) was used less to record ECoG during direct electrical stimulation than the circular grid (80%, p < 0.001) and strip electrodes (69%, p < 0.001). Sporadic interictal epileptiform activity was better detected with circular (45%, p < 0.001) and HD (40%, p = 0.006) grids compared with strip electrodes (16%). Spontaneous seizures were recorded more frequently with the circular grid (16%, p = 0.018) compared with the strip electrode (9.4%) and HD grid (1.8%). Afterdischarges were more frequently detected by the circular grid (69%, p = 0.031) and with circular and HD grids (combined) compared with strip electrodes (67% vs 48%, p = 0.024), at lower median intensity (3 mA vs 5 mA, p < 0.001). Multivariable analyses demonstrated circular grids (p < 0.001) to be more sensitive in detecting spontaneous epileptiform activity than strip and HD grid electrodes, and grids (circular and HD) to be better in recording stimulus-induced epileptiform activity (p = 0.01). CONCLUSIONS This study demonstrates a higher rate of detection of epileptiform activity with circular and standard grids when compared with strip electrodes. The standard HD grid was used less during electrical stimulation, demonstrating the importance of both the number of contacts and design array when considering optimal conditions for ECoG and functional brain mapping.

OBJECTIVE The implementation of robotics and spinal anesthesia (SA) in spine surgery is rapidly expanding, offering significant benefits for an increasingly complex and aging patient population with degenerative spinal disease. Here, the authors present the largest cohort to date evaluating the combined use of these two techniques in minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF). METHODS The authors retrospectively analyzed surgical outcomes of a series of patients who underwent robot-assisted (RA)–MIS TLIF under SA and general anesthesia (GA) at their institution from 2018 to 2024. Primary outcomes included operative times and postoperative pain intensity. Secondary outcomes included estimated blood loss, intraoperative complications, postoperative functional status, length of stay (LOS), and discharge status. To address potential confounders, a 1:1 propensity score–matching and regression analysis was implemented. Statistical analyses were conducted using Python. RESULTS A total of 209 patients underwent RA-MIS TLIF, with 31 (14.83%) receiving SA and 178 (85.17%) GA. After propensity score matching, the SA cohort demonstrated significantly shorter median total operating room (OR) time, total procedure time, time from entering the OR to skin incision, and time from closure to leaving the OR (all p < 0.01). Additionally, postoperative pain scores were significantly lower (p < 0.01), and LOS was significantly shorter (p < 0.01) in the SA cohort. Regression analysis, adjusting for potential confounders, further supported these findings. CONCLUSIONS RA-MIS TLIF fusion under SA is a safe and effective approach that significantly reduces operative time, postoperative pain, and hospital LOS in patients undergoing surgery for degenerative lumbar spine disease.

Abstract Purpose Cenobamate is approved for treating focal epilepsy and has potential for treating tumor‐related epilepsy (TRE) based on potential anti‐tumor effects, though there is little data on efficacy and safety in this patient population. Methods This was a retrospective, multi‐center study of patients with TRE who were prescribed cenobamate as adjunctive treatment between January 2020 and November 2024 at Mayo Clinic in Florida, Minnesota, and Arizona. Drug efficacy was assessed, and factors that were predictive of response to treatment were analyzed. Results A total of 17 patients were included, with 12 being drug resistant. The median seizure frequency for the entire group before starting cenobamate treatment was 12 (IQR = 4–64) per month, and after treatment at last follow‐up was 3 (IQR = 1–15) per month, with an overall 56.3% reduction. Four patients (23.5%) were seizure‐free, and 7 (41.1%) patients were responders (at least 50% seizure reduction). No adverse events were reported for patients on concurrent chemotherapy. Responders had significantly fewer seizures per month compared to non‐responders (5.72 ± 10.29 vs. 27.33 ± 30.17; p = .030). No clinical factors were predictive of responsiveness (or lack thereof) to cenobamate. Conclusions This study demonstrates that adjunctive therapy with cenobamate treatment for TRE is a feasible and potentially effective option. Clinical history, including drug resistance, did not predict drug efficacy. No adverse effects were reported in those treated with chemotherapy. Further studies are needed to validate treatment response and safety.