Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Adult biomechanical studies suggest a significant reduction in flexion-extension motion after occipitocervical and atlantoaxial fusion. Anecdotal experience in children suggests a lower magnitude of reduction in motion after these procedures, but high-quality quantitative assessments of this motion have not yet been performed. As such, the aim of this study was to determine the magnitude of reduction in cervical spine flexion-extension after O-C2 and C1-2 fusion in pediatric patients. METHODS:The Pediatric Spine Study Group international registry was queried for patients aged 21 years or younger who underwent O-C2 or C1-2 instrumentation and fusion. Patients with cervical spine flexion-extension radiographs preoperatively and ≥6 months postoperatively were included. Flexion, extension, and overall range of motion (ROM) of the cervical spine were measured on radiographs using McGregor line and the inferior endplate of C7. RESULTS:In total, 34 patients were included, with 19 undergoing index O-C2 and 15 undergoing index C1-2 stabilization. The mean age was 9.3 ± 4.5 years with average follow-up of 3.5 ± 2.6 years. The most common etiologies were syndromic (n = 20) and congenital (n = 9). Patients undergoing O-C2 fusion had reduced neck extension (80° vs 69.6°, P = .003) and overall ROM (92.9° vs 80°, P = .002) after stabilization, but no significant reduction in flexion (-12.9° vs -10.4°, P = .324). After C1-2 fusion, there was no significant reduction in overall ROM (85.0° vs 77.5°, P = .079), extension (70.5° vs 63.4°, P = .120), or flexion (-14.6° vs -14.0°, P = .831). CONCLUSION/CONCLUSIONS:In this cohort, children undergoing O-C2 stabilization had a 13.9% reduction in flexion-extension motion of the cervical spine, primarily due to a reduction in extension. There may be a smaller reduction in flexion-extension motion after stabilization in children when compared with adult studies. Further studies with video analysis including axial rotation and lateral bending will be necessary to comprehensively quantify cervical spine motion after fusion across the occipitocervical and atlantoaxial junctions.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Neurosurgical clinical research depends on medical data collection and evaluation that is often laborious, time consuming, and inefficient. The goal of this work was to implement and evaluate a novel departmental data infrastructure (Neuro Data Hub) designed to provide specialized data services for neurosurgical research. Data acquisition would become available purely by request. METHODS:through collaboration between Department Leadership and Medical Center Information Technology, integrating it with Institutional Review Board workflows and an existing Epic electronic health record Datalake infrastructure. The system implementation included monthly departmental meetings and an asynchronous Research Electronic Data Capture-based request system. Data requests submitted between August 2023 and November 2024 were analyzed and categorized as basic, complex, or Natural Language Processing (NLP)-augmented, with optional visualization and database creation services. Request volumes, types, and execution times were assessed. RESULTS:The Hub processed 39 research data requests (2.6/month), comprising 3 basic, 22 complex, and 14 NLP-augmented requests. Two complex requests included visualization services, and one NLP request included database creation. Average request execution time was 36.5 days, with NLP-augmented requests showing increasing adoption over time. CONCLUSION/CONCLUSIONS:The Neuro Data Hub represents a paradigm shift from centralized to department-level data services, providing specialized support for neurosurgical research and democratizing access to institutional data. While effective, implementation may be limited by institutional information technology infrastructure requirements. This model could serve as a template for any form of medical-clinical research program seeking to improve data accessibility and research capabilities.

This position statement provides updated member guidance from the American Academy of Neurology (AAN) regarding (1) communication with surrogate decision makers about brain death/death by neurologic criteria (BD/DNC), (2) management of surrogate decision-maker objections to BD/DNC, (3) the ethical considerations associated with BD/DNC determination in a pregnant person, and (4) enhancing public trust in BD/DNC. This position statement is intended to complement recommendations in the 2023 "Pediatric and Adult Brain Death/Death by Neurologic Criteria Consensus Guideline" published by the AAN, American Academy of Pediatrics, Child Neurology Society, and Society of Critical Care Medicine, as well as the 2021 AAN Code of Professional Conduct. It replaces the 2019 AAN position statement, "Brain death, the determination of brain death, and member guidance for brain death accommodation requests."

OBJECTIVE:While health-related quality of life (HRQOL) measures have been extensively quantified in cervical deformity (CD), this clinical dimension has not yet been fully integrated into understanding CD radiographic subtypes prior to surgery. The aim of this study was to identify distinct patterns of HRQOL deficits among patients with CD by focusing on clinical scores and to examine the association of these patterns with radiographic morphotypes of CD. METHODS:This was a retrospective analysis of a prospective multicenter database of patients with CD aged 18 years or older. Patient-reported outcome measures consisted of the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) scale, and Swallowing Quality of Life (SWAL-QOL) questionnaire. After performing a principal component analysis on the individual questions of the NDI, mJOA, and SWAL-QOL, 4 factors with eigenvalues > 1 were retained and included in a cluster analysis to assign patients into homogeneous groups of outcomes. Moreover, a subgroup of patients with severe deformity was described and analyzed. RESULTS:Overall, 134 patients (59% female, mean age ± SD 60.9 ± 10.8 years) were included in this analysis. The mean HRQOL scores were NDI, 49.1 ± 17.6; mJOA, 13.5 ± 2.7; and EQ-5D, 0.7 ± 0.1). The factor analysis involving NDI, SWAL-QOL, and mJOA revealed 4 clusters. Cluster A represented patients with a predominant sleep problem. Cluster B was patients with the lowest neck disability. Cluster C represented the most disabled patients in terms of dysphagia and neck disability. Cluster D represented patients with myelopathy. Among the 71 patients with severe deformity, the distribution of cervical morphotypes significantly differed across the 4 clusters of disability (p = 0.009). Cluster C mainly consisted of patients with cervicothoracic deformity (66.7%, p = 0.002). Cluster D had a large proportion of patients (66.7%) with focal deformity (p = 0.007). In clusters A and B, 57.9% and 46.4% of patients, respectively, presented with "flat neck" deformity (p = 0.02). CONCLUSIONS:Distinct patterns of HRQOL deficits were observed across a heterogeneous population of patients with CD, and these patterns were associated with specific radiographic morphotypes. These findings provide a framework for the next generation of CD classification, wherein HRQOL measures are combined with radiographic parameters.

OBJECTIVE:To characterize patient outcomes after primary stereotactic radiosurgery (SRS) for the management of sporadic facial nerve schwannoma. STUDY DESIGN/METHODS:Retrospective cohort study. SETTING/METHODS:Six tertiary referral centers across the United States and United Kingdom. PATIENTS/METHODS:Adults undergoing SRS from 2000 through 2023 for sporadic facial nerve schwannoma along any segment of the facial nerve were included. Patients with NF2-related schwannomatosis were excluded. INTERVENTION/METHODS:Stereotactic radiosurgery. MAIN OUTCOME MEASURE/METHODS:Long-term tumor control. RESULTS:Among 60 patients meeting inclusion, the median age at SRS was 52 years (IQR: 41 to 64) with a median tumor size of 19.5 mm (IQR: 14.7 to 22.8). Tumors commonly involved the internal auditory canal (73%), cisternal (49%), geniculate/labyrinthine (47%), and tympanic segments (22%). Two patients experienced SRS failure and underwent salvage treatment; salvage-free survival rates (95% CI; number still at risk) at 1, 3, 5, and 10 years after SRS were 100% (100 to 100; 55), 100% (100 to 100; 36), 100% (100 to 100; 18), and 87% (72 to 100; 9), respectively. Among 31 (52%) patients with House-Brackmann (HB) grade I facial function at presentation, only 6 demonstrated worse facial function at a median of 3.2 years (IQR: 1.7 to 6.6) after SRS. Of 18 patients with serviceable hearing (AAO-HNS class A/B) at SRS, 13 maintained serviceable hearing at a median of 1.0 years (IQR: 0.5 to 4.9) of post-SRS audiometric follow-up. CONCLUSIONS:Durable tumor control after primary SRS for sporadic facial nerve schwannoma is achieved in most patients. Among those with HB grade I facial function at presentation, treatment with SRS harbors limited additional risk of facial paresis beyond observation alone.

The management of drug-resistant epilepsy (DRE) in the pediatric population using neurostimulation of the centromedian (CM) nucleus of the thalamus (CMN) has been reported to be effective and safe. We present a case series of pediatric patients treated with responsive neurostimulation (RNS) and report on contact localization in relation to preliminary outcomes, specifically seizure reduction rates. Thirteen pediatric patients treated with RNS underwent direct targeting of the CMN based on Magnetization-Prepared 2 Rapid Gradient-Echo (MP2RAGE) scans, using ClearPoint neuronavigation. The implanted electrodes were co-registered to a probabilistic anatomical model of the thalamic nuclei (Freesurfer) for secondary confirmation of contact localization. Ten out of the 12 patients with extra-temporal multifocal or generalized DRE (83.3%) had over 50% reduction in seizures, benefiting from an 80.4% seizure reduction rate. The average follow-up interval was 25.2 months, with no patients experiencing stimulation-related side effects. The analysis of post-operative images revealed that out of the 24 CM-processed electrodes, 23 (95.8%) had at least two contacts in the nucleus, based on patient-specific segmentation of the thalamus. The preliminary outcomes suggest a robust response to central neurostimulation and no stimulation-related side effects in pediatric patients suffering from multifocal or generalized DRE when implementing high-accuracy direct targeting. PLAIN LANGUAGE SUMMARY: We are reporting our experience in the management of the most challenging types of pediatric epilepsy, involving seizures originating from multiple and/or poorly defined brain areas. We surgically implanted a responsive neurostimulation device (RNS) in central areas of the brain that function as connection hubs between different brain regions. These devices are designed to detect early signs of abnormal brain activity, and respond with electrical pulses to prevent progression to clinical seizures. Using our approach, we reduced the seizure rates by an average of 80% in 83% of the pediatric patients who received this treatment.

In children undergoing craniotomy, the impact of postoperative pain on recovery is receiving growing recognition. While opioids are often the primary treatment, their administration requires a delicate balance between achieving sufficient analgesia and mitigating side effects like sedation, nausea, vomiting, and respiratory depression. We review the emerging adjunct treatment modality regional scalp block (RSB) infiltration for post-craniotomy pain. Postoperative pain after pediatric craniotomy can be challenging to manage and may contribute to unnecessary suffering as well as the development of long-term neurocognitive and psychological sequelae. Pain during the PICU stay is also a major risk factor for post-PICU syndrome, which involves persistent impairments in children's physical, cognitive, or mental health persisting beyond acute hospitalization. Despite increasing awareness and treatment strategies for post-craniotomy pain in adults, significant gaps remain in understanding its assessment and management in children. This review examines the current literature surrounding post-craniotomy pain management in children with a special emphasis on RSB, a treatment option increasingly used in adults and children. RSB has been shown in randomized trials to reduce postoperative pain and opioid use. However, while pediatric perioperative trials support its safety and feasibility, robust clinical evidence supporting RSB's efficacy for post-craniotomy pain in children remains limited, hindering wider translation into clinical standard. RSB infiltration is an emerging and promising technique for pediatric post-craniotomy pain management. Early evidence suggests it is both safe and effective, with potential to enhance postoperative recovery and to be integrated into clinical practice. Further research is critical to validate initial findings and better define the benefits across diverse pediatric populations.

STUDY DESIGN/METHODS:Retrospective cohort. OBJECTIVE:The ISSG-AO Spinal Deformity Complication Classification System (SDCCS) predicts Diagnosis Related Group (DRG) coding and cost. BACKGROUND:Inconsistent definitions of complications contribute to variation in reported surgical complication rates. Incorrect complication reporting can lead to over or under DRG reimbursement. The ISSG-AO SDCCS provides improved complication reporting reproducibility and may help predict complication costs. METHODS:ASD patients were grouped into: DRG without complication or comorbidity (CC) or Major CC (MCC) (DRGs 455 & 458), with CC (DRGs 454 & 457), and with MCC (DRGs 453 & 456). Complications were graded by intervention severity per ISSG-AO system: grade 0 (none), 1 (mild-e.g., med change), 2 (moderate-e.g., ICU), 3 (severe-e.g., reoperation). Cost were based on Medicare inpatient prospective payment system (IPSS, Medicare Allowable rate). A multinomial logistic model identified key predictors of DRG assignment by complication grades. RESULTS:Of the 675 patients, 14% were in DRGs without CC/MCC, 71% in DRGs with CC, and 15% were DRGs with MCC. Patients with complications requiring intervention mostly fell into the higher DRG categories (97%). Patients who received an intervention are approximately 6.75 (2.01-22.75, P<.0021) times more likely to be classified under DRG with CC and 15.72 (95% CI, 4.23-58.45, P<.0001) times more likely to be classified with DRG with MCC compared to those who did not receive an intervention. Each unit increase in Edmonton Frailty Score raises the odds of being in DRG with MCC by 1.24 (95% CI 1.04-1.48, P 0.017). Similar trends were seen for OR time and LOS. Reimbursement showed incremental increase from $49.5K to $56K to $70K across DRG categories. CONCLUSIONS:Patients with elevated ISSG-AO scores are more likely to be categorized into higher DRGs, experience extended lengths of stay and generate greater healthcare expenditures. The ISSG-AO SDCCS predicts DRG thereby helping standardize complication reporting.

PURPOSE/OBJECTIVE:Histopathological grading of IDH-mutant astrocytomas demonstrates limited prognostic accuracy. However, DNA methylation subclassification has demonstrated improved prognostication beyond histological grading. This study aimed to investigate the associations between imaging features, tumor volumetric data, and DNA methylation grade in IDH-mutant astrocytomas. METHODS:We analyzed imaging features and volumetric data for 72 patients diagnosed with IDH-mutant astrocytomas, who underwent preoperative MRI and DNA methylation profiling. VASARI features and multicompartmental volumetrics were evaluated. Logistic regression was used to identify imaging predictors of methylation subclass, WHO histologic grade, copy number variation (CNV), and CDKN2A/B homozygous deletion. Univariable and multivariable Cox proportional hazard models were also developed to assess these variables' influence on overall survival and progression-free survival. RESULTS:Patients were classified into 27 methylation high-grade (A_IDH_HG) and 45 methylation low-grade (A_IDH_LG) tumors. Tumor volumes and proportions varied by methylation grade, CNV status, and WHO histologic grade, but not by CDKN2A/B status. Imaging features distinguished methylation subclasses with 75% accuracy (AUC = 0.77). Methylation high-grade subclass was associated with imaging features such as midline crossing, ependymal extension, and poorly defined enhancing margins. Predictive performance for WHO histologic grade, CNV status, and CDKN2A/B deletion was moderate (AUC = 0.67, 0.69, and 0.65, respectively). Methylation grade, CDKN2A/B status, VASARI features, and proportions of edema and non-contrast enhancing tumor were significantly associated with survival. CONCLUSION/CONCLUSIONS:MRI-derived imaging features facilitate noninvasive prediction of DNA methylation subclass in IDH-mutant astrocytomas.