Intraoperative neuromonitoring potentials and evidence of preserved neuronal circuitry below the anatomical and functional level in patients with complex spinal dysraphism undergoing detethering reoperations.

OBJECTIVE: Spina bifida represents one of the most common birth defects, occurring in approximately 1-2 children per 1000 live births worldwide. The functional level of patients with spina bifida is highly variable and believed to be correlated with the anatomical level of the lesion. The variable clinical picture is well established, but the correlation with anatomical level and intraoperative neuromonitoring (IONM) data has not been investigated. Furthermore, the potential for preserving function beyond the apparent clinical level has also not been investigated. The objective of this research was to determine the presence and level of intraoperative transcranial motor evoked potential (tcMEP) and triggered electromyography (tEMG) responses, and the association of these responses with preoperative clinical function and radiographic data in pediatric cases of complex tethered cord release reoperations. METHODS: A single-center retrospective review of pediatric patients with complex spinal dysraphism undergoing detethering reoperations was conducted. Preoperative demographic and clinical data, including the radiographic and clinical level of dysraphism, were collected. IONM, including tcMEPs and tEMG responses, were obtained and compared with preoperative clinical data. Descriptive analysis was performed, by patient for demographics and by case for surgeries performed. RESULTS: In 100% of 21 cases of complex detethering reoperations, representing 20 patients, intraoperative tcMEPs could be generated at (4.8%) or below (95.2%) the level of clinical function. Compared with the preoperative clinical examination, 5 cases (23.8%) demonstrated tcMEP responses that were 1 level below the clinical function level, 11 cases (52.4%) were 2 levels below, and 4 cases (19.0%) were 3 levels below. Overall, 18 of 21 cases showed tEMG responses at or below the level of clinical function; of these, 7 cases (33%) were 1 level below and 3 (14%) were ≥ 2 levels below the clinical function level. CONCLUSIONS: The presence of positive stimulation potentials below the level of clinical function in patients with complex spinal dysraphism undergoing detethering reoperations indicates a degree of preserved neuronal connectivity. These findings suggest novel future treatment approaches for these patients, including using devices targeted to stimulation of these neurological pathways.

Deep Brain Stimulation of Bilateral Centromedian Thalamic Nuclei in Pediatric Patients with Lennox-Gastaut Syndrome: An Institutional Experience.

BACKGROUND: Surgical management of pediatric patients with nonlesional, drug-resistant epilepsy, including patients with Lennox-Gastaut syndrome (LGS), remains a challenge given the lack of resective targets in most patients and shows seizure freedom rates <50% at 5 years. The efficacy of deep brain stimulation (DBS) is less certain in children than in adults. This study examined clinical and seizure outcomes for pediatric patients with LGS undergoing DBS targeting of the centromedian thalamic nuclei (CMTN). METHODS: An institutional review board-approved retrospective analysis was performed of patients aged ≤19 years with clinical diagnosis of LGS undergoing bilateral DBS placement to the CMTN from 2020 to 2021 by a single surgeon. RESULTS: Four females and 2 males aged 6-19 years were identified. Before surgery, each child experienced at least 6 years of refractory seizures; 4 children had experienced seizures since infancy. All took antiseizure medications at the time of surgery. Five children had previous placement of a vagus nerve stimulator and 2 had a previous corpus callosotomy. The mean length of stay after DBS was 2 days. No children experienced adverse neurologic effects from implantation; the mean follow-up time was 16.3 months. Four patients had >60% reduction in seizure frequency after surgery, 1 patient experienced 10% reduction, and 1 patient showed no change. No children reported worsening seizure symptoms after surgery. CONCLUSIONS: Our study contributes to the sparse literature describing CMTN DBS for children with drug-resistant epilepsy from LGS. Our results suggest that CMTN DBS is a safe and effective therapeutic modality that should be considered as an alternative or adjuvant therapy for this challenging patient population. Further studies with larger patient populations are warranted.

A comparison of computed tomography angiography and digital subtraction angiography for the diagnosis of penetrating cerebrovascular injury: a prospective multicenter study.

OBJECTIVE: In this research, the authors sought to characterize the incidence and extent of cerebrovascular lesions after penetrating brain injury in a civilian population and to compare the diagnostic value of head computed tomography angiography (CTA) and digital subtraction angiography (DSA) in their diagnosis. METHODS: This was a prospective multicenter cohort study of patients with penetrating brain injury due to any mechanism presenting at two academic medical centers over a 3-year period (May 2020 to May 2023). All patients underwent both CTA and DSA. The sensitivity and specificity of CTA was calculated, with DSA considered the gold standard. The number of DSA studies needed to identify a lesion requiring treatment that had not been identified on CTA was also calculated. RESULTS: A total of 73 patients were included in the study, 33 of whom had at least 1 penetrating cerebrovascular injury, for an incidence of 45.2%. The injuries included 13 pseudoaneurysms, 11 major arterial occlusions, 9 dural venous sinus occlusions, 8 dural arteriovenous fistulas, and 6 carotid cavernous fistulas. The sensitivity of CTA was 36.4%, and the specificity was 85.0%. Overall, 5.6 DSA studies were needed to identify a lesion requiring treatment that had not been identified with CTA. CONCLUSIONS: Cerebrovascular injury is common after penetrating brain injury, and CTA alone is insufficient to diagnosis these injuries. Patients with penetrating brain injuries should routinely undergo DSA.