Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Severe hypoxemia after generalized convulsive seizures (GCSs) can trigger neural injury and is a potential biomarker for sudden unexpected death in epilepsy (SUDEP). Some degree of variability in interbreath interval is normal, but increased variability may suggest dysfunctional breathing control and may be associated with severe postictal hypoxemia. We evaluated the relationship between interictal breathing variability and severity and duration of hypoxemia after GCS. METHODS:nadir), and secondary outcome: occurrence of combined prolonged and pronounced hypoxemia. Univariable and multivariable models were created for primary outcomes, but only univariable analyses were performed for the secondary outcome. RESULTS:= 0.002) was the only variable significantly associated with hypoxemia severity after controlling for duration of postictal generalized EEG suppression, SD-2 of the awake interbreath interval, and body mass index. Univariable analyses for combined prolonged and pronounced hypoxemia showed SD-2 of the awake interbreath interval, temporal lobe epilepsy, ictal central apnea, and a shorter tonic phase duration were significantly associated. DISCUSSION/CONCLUSIONS:Measures of interictal respiratory variability are associated with severe and prolonged hypoxemia after GCS. Increased interictal respiratory variability suggests baseline respiratory dysregulation in some PWE and may be a surrogate for SUDEP risk.

PURPOSE OF REVIEW/UNASSIGNED:Alzheimer disease (AD) and epilepsy are major causes of neurologic disability and are reciprocally related: epileptiform discharges, subclinical seizures, and epilepsy are more prevalent in patients with AD compared with controls; progressive cognitive impairment commonly afflicts epilepsy patients; and late-onset epilepsy patients have higher rates of new-onset dementia. RECENT FINDINGS/UNASSIGNED:Epidemiologic studies support shared risk factors (e.g., genetic variants, vascular disease, sleep disorders, microbiome) with notable divergences. AD and epilepsy have some overlapping anatomic (e.g., hippocampus, entorhinal, and association cortex), clinical (e.g., memory, attentional, and executive) impairments, and neuropathologic (e.g., amyloid, tau, neurofibrillary tangles) features. Shared clinical and translational challenges include underlying mechanisms (e.g., genetic variants, neuroinflammation, metabolic and mitochondrial dysfunction, excitatory/inhibitory imbalance, microbiome, and sociodemographic factors) and identifying valid and reliable biomarkers (e.g., total tau and phosphorylated tau (p-tau), amyloid deposition, Aβ42/Aβ40 ratio) to assess disease progression, predict outcomes, and assess potentially disease-modifying interventions. SUMMARY/UNASSIGNED:Identifying convergences and divergences between epilepsy and AD may inform our understanding. The clinical, neurophysiologic, neuropathologic, and molecular pathologic changes in AD and epilepsy may reveal pathophysiologic insights and therapeutic opportunities.

Despite the increasing prevalence of micromobility vehicles, including bicycles, e-bikes, and e-scooters, the burden of neurocranial trauma sustained by pedestrians struck remains understudied. This retrospective observational cohort study compared injury patterns, management, and outcomes between vehicle riders and pedestrians admitted to a level 1 trauma center from 2020 to 2024 for neurocranial trauma. Presence of traumatic brain injury, intracranial hemorrhage, neurocranial fracture, surgical intervention, intensive care unit admission, intensive care unit length of stay, hospital length of stay, 30-day readmission, mortality, and focal neurological deficits on discharge were assessed. χ2 tests and independent-samples t tests were used for comparison between vehicle riders and pedestrians struck. Of the 250 total patients, 70 were pedestrians struck. Pedestrians exhibited significantly greater rates of moderate or severe traumatic brain injury (71.4% versus 56.7%, P=0.032), subdural hematoma (58.6% versus 37.8%, P=0.003), and frontal bone fracture (24.3% versus 13.9%, P=0.048), and were more likely to undergo burr hole evacuation (4.3% versus 0.6%, P=0.035), intracranial pressure monitor placement (5.7% versus 0.6%, P=0.009), and intensive care unit admission (82.9% versus 59.4%, P<0.001). The overall incidence of micromobility-related neurocranial trauma more than doubled (25 in 2020 and 59 in 2024), whereas pedestrian admissions tripled (6 in 2020 and 18 in 2024) during the study period. Pedestrians struck by micromobility vehicles exhibit a growing, underappreciated, and more severe burden of neurocranial trauma than vehicle riders, underscoring the need for targeted prevention strategies.

Spinal tumor surgery requires rapid tissue diagnosis to guide surgical decisions and further treatment strategies, yet current intraoperative methods are time-intensive and require specialized expertise. No AI systems exist for real-time spinal tumor classification during surgery. We developed SpineXtract, the first AI-powered system for rapid intraoperative spinal tumor diagnosis using stimulated Raman histology (SRH) - a label-free Raman spectromics imaging technique without tissue processing available during surgery. We created a transformer-based classifier optimized for spinal tissue characteristics to identify common tumor types: meningioma, schwannoma, ependymoma, and metastasis. The system was tested in an international, multicenter, simulated, single-arm study using existing SRH datasets (44 patients, 142 slide-images) from three international institutions, with final pathological diagnosis as reference standard. SpineXtract achieved a 92.9% macro-average balanced accuracy (95% CI: 85.5-98.2) within 5 minutes (tumor-specific accuracy range, 84.2-98.6%), while providing quantitative microscopic feedback for granular tissue analysis. Performance remained consistent across institutions (macro balanced accuracy 91.4-92.0%) and outperformed existing brain tumor classifiers by 15.6%. Our results demonstrate clinical applicability, enabling rapid intraoperative diagnosis with performance exceeding current methods, potentially transforming intraoperative diagnostic workflows in spinal tumor surgery.

STUDY DESIGN/METHODS:Retrospective review of multicenter data. OBJECTIVE:To compare long-term neurologic recovery in patients with and without incidental durotomy (hereafter, "durotomy") after adult spinal deformity surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:Durotomy is a common complication of adult spinal deformity surgery and is typically associated with technical challenges during the procedure. METHODS:Using a prospectively collected database, we included 1452 patients (73% female; mean age, 60±14 y) who underwent adult spinal deformity surgery from 2008-2020 at 22 US centers. We compared patients with and without durotomy with respect to demographic characteristics, surgical variables, and neurologic outcomes at baseline and at 1 and 2 years postoperatively. Multivariate analysis compared neurologic complications and length of stay (LOS) between the groups. P<.05 was considered significant. RESULTS:Durotomy occurred in 121 patients (8.3%). Patients with durotomy were more likely to have undergone revision surgery (P<.001) and had higher Charlson Comorbidity Index values (P=.029) than those who did not. Patients with durotomy had higher estimated blood loss, longer operative time, more frequent 3-column osteotomies, and longer LOS (all, P<.001). Lower-extremity motor scores did not differ between patients with durotomy and those without at 1 and 2 years postoperatively. The incidence of neurologic, medical, and surgical complications did not differ significantly between the 2 groups. Patients with durotomy had a higher rate of inpatient return to the operating room (5.0%) than those without (2.0%) (P=.04). On multivariate analysis, there were no differences between groups in lower-extremity motor scores, neurologic complications, or LOS. CONCLUSIONS:Incidental durotomy during adult spinal deformity surgery was associated with greater intraoperative complexity and transient sensory symptoms but did not adversely affect long-term motor recovery, neurologic complications, or patient-reported outcomes. These findings suggest durotomy is a manageable complication without lasting functional consequences.

STUDY DESIGN/METHODS:Retrospective review of prospectively collected, multicenter data. OBJECTIVE:To assess associations between patient height and weight independently and interactively with the incidence of proximal junctional kyphosis (PJK) after surgical treatment of adult spine deformity. SUMMARY OF BACKGROUND DATA/BACKGROUND:Body mass index has traditionally been used to assess the influence of body composition on surgical outcomes, but the individual effects of height and weight have not been studied in relation to PJK. METHODS:We compared baseline demographic characteristics, radiographic measurements, and perioperative variables between patients who developed PJK after adult spinal deformity surgery between 2008 and 2020 and those who did not. Using a generalized additive model with a logistic link function, we modeled height and weight and their interaction as smooth terms to capture potential nonlinear effects on PJK risk. Multivariate analysis was adjusted for age, history of osteoporosis, upper instrumented vertebra, number of levels fused, and postoperative pelvic incidence minus lumbar lordosis and T1 pelvic angle. RESULTS:Of 904 included patients, the median age was 65 years (interquartile range: 58-71), and 76% were female. PJK developed in 131 patients (14%). Baseline characteristics, including frailty, comorbidities, and radiographic measures, did not differ significantly between the PJK and non-PJK groups. Taller height was a predictor of PJK (P=.03). In contrast, weight was not an independent predictor, and there was no significant interaction between height and weight. The incidence of PJK peaked at a height of approximately 179 cm before plateauing. CONCLUSIONS:Taller height, but not weight, was associated with developing PJK after adult spinal deformity surgery. These findings underscore the importance of considering patient height during surgical planning.

BACKGROUND:Many survivors of hemorrhagic stroke have impaired communication. We aimed to identify preadmission, admission, and post-discharge factors associated with self-reported impaired communication after hemorrhagic stroke. DESIGN/METHODS:Patients with intracerebral or subarachnoid hemorrhage (ICH or SAH) admitted at an urban academic medical center were assessed 3-months post-bleed using the communication Quality of Life in Neurological Disorders (Neuro-QoL) short form inventory. Multivariate analysis was performed to evaluate the relationship between impaired communication (Neuro-QoL scaled score < 100) and preadmission, admission, and post-discharge factors. RESULTS:Of 108 patients (68 ICH and 40 SAH), 59 (54.6%) had impaired communication 3-months post-bleed. On multivariate analysis of the full cohort, when controlling for NIHSS score on admission, impaired communication was associated with: retirement prior to admission (OR: 8.18, 95% CI 1.95-40.5, p = 0.005), hospital length-of-stay (OR: 1.11, 95% CI 1.03-1.22, p = 0.012), and cognitive impairment post-bleed (OR: 32.1, 95% CI 8.93-146, p < 0.001). There were 43 (63.2%) ICH patients with impaired communication 3-months post-bleed. On multivariate analysis, impaired communication was associated with: retirement prior to admission (OR: 9.46, 95% CI 1.76-71.8, p = 0.014), supratentorial location (OR: 8.93, 95% CI 1.22-93.6, p = 0.043), hospital length-of-stay (OR: 1.21, 95% CI 1.01-1.45, p = 0.018), and cognitive impairment post-bleed (OR: 16.3, 95% CI 3.58-102, p < 0.001). CONCLUSIONS:Impaired communication after hemorrhagic stroke is more common in patients who were retired prior to admission and who have post-bleed comorbid cognitive impairment. Increased surveillance is recommended for retired and cognitively impaired patients. Additional investigation into the relationship between communication and both retirement status and cognitive impairment is needed.

PURPOSE/OBJECTIVE:We sought to characterize outcomes from a large institutional database of patients treated with 3-fraction spine stereotactic body radiation therapy (SBRT) after prior overlapping RT. MATERIALS AND METHODS/METHODS:The primary outcome of interest was local failure (LF) in the treated lesion, defined based on MRI. We also characterized toxicities such as vertebral compression fracture (VCF) and radiation myelitis (RM). RESULTS:There were 83 patients treated to 87 spinal lesions between 2014-2023. Median follow-up was 14.2 (interquartile range (IQR) 6-29.4) months and median overall survival was 20.5 (95% confidence interval (CI) 16.5-29.9) months. Most lesions were treated with 27 Gy in 3 fractions (n=78; 90%). Most lesions had been treated with prior conventionally fractionated RT (59%), and the most common histology was prostate cancer (n=15; 17%). The 1- and 2-year LF rate was 8.4% (95% CI 3.7-16%) and 15% (95% CI 8.1-24%), respectively. On univariable analysis, lower minimum dose (DMin) to the planning target volume (PTV) (HR 0.85, 95% CI 0.74-0.99, p=0.03) and colorectal, cholangio-, or hepatocellular carcinoma histology (HR 5.6, 95% CI 1.11-28.4, p=0.037) were associated with risk of LF. There was 1 case of RM (1.3%) and 5 cases (5.5%) of VCF. CONCLUSION/CONCLUSIONS:Re-irradiation with spine SBRT in 3 fractions appears safe and is associated with a 2-year local control rate of 85%. Lower PTV DMin and gastrointestinal histology were associated with increased risk of LF. Further work is needed to identify the optimal dose-fractionation regimen for re-irradiation with spine SBRT.