bluuebunny/crossref_metadata_2025_split huggingface dataset:
383 Artificial Neural Network Modeling of Outcomes in Subarachnoid Hemorrhage
Authors: Steed Tyler , Hsu Alice , Akbik Feras , Luu Kevin , Samuels Owen B. , Sadan Ofer , Grossberg Jonathan Andrew 
Published: March 2023

INTRODUCTION:
Aneurysmal subarachnoid hemorrhage is a devastating neurological condition which requires complex neurocritical care and neurosurgical decision-making yet results in remarkably variable outcomes. Robust methods of identifying patients who may need operative and critical care interventions, such as those who develop hydrocephalus requiring long-term shunting or cerebral vasospasm, or predicting patients who may go on to have long-term disability or worsened neurological outcomes are lacking.

METHODS:
Data used to train our models included demographic data (gender, age and race), history of medical conditions (hypertension, diabetes, coronary artery disease, hyperlipidemia, tobacco use), Hunt and Hess scale, ventriculostomy data (external ventricular drain (EVD) output, EVD level, EVD age), and cerebrospinal fluid (CSF) lab values (CSF protein and glucose levels). The models were trained on a subpopulation of 85% of subjects and then individually validated in a training-naive subset of 15% of subjects with high accuracy.

RESULTS:
Using this data, we have generated artificial neural network classifiers with hyperparameter tuning which predict the need for long-term cerebrospinal fluid (CSF) diversion via placement of a shunt (receiver operating characteristic area under the curve) (ROC AUC) = 0.8312), vasospasm (ROC AUC = 0.8058), and the categorical outcome of patient disposition (model accuracy = 0.7786).

CONCLUSIONS:
We hope the use of artificial intelligence and machine learning techniques will continue to demonstrate power in predicting complex medical outcomes and ultimately help neurosurgeons and neuro-critical care personnel prognosticate and provide appropriate and timely treatment.
386 Stereotactic Implantation of Autologous Mesenchymal Stem Cells Improves Neurological Outcomes in a Rat Model of Chronic Middle Cerebral Artery Stroke
Authors: Hines Kevin , Myers Max , Spagnuolo Gabrielle , Gray Andrew , Galvez Yolanda Gomez , Cai Jingli , Tjoumakaris Stavropoula I. , Rosenwasser Robert H. , Iacovitti Lorraine 
Published: March 2023

INTRODUCTION:
Limited treatment options exist for patients with chronic infarcts. Multipotent adult mesenchymal stem cells (MSC) show promise as a treatment for chronic stroke. Allogeneic MSCs have been implanted successfully in chronic stroke1,2. However, no literature evaluates the use of autologous MSCs delivered via stereotactic implantation. Autologous MSCs provide safety and accessibility benefits.

METHODS:
Male Sprague-Dawley rats underwent transient right MCAO for 120 minutes. Brain MRI and sensorimotor behavior were used to evaluate stroke. Sixteen days post stroke, tibial bone marrow was aspirated and MSCs were grown in a closed bioreactor. At 28 days post stroke, 3 trajectories of MSCs were implanted in the peri-infarct zone using a stereotactic robot. The treatments consisted of group 1 (5 x 106 cell dose, N = 6), group 2 (1 x 106 cell dose, N = 6) and a control group (saline injection, N = 9). In a second cohort of animals, Q-dot labeled autologous MSCs were tracked in the brain for 7 or 30 days.

RESULTS:
Behavior as determined by the modified neurological severity score (0-16) significantly improved in both groups. Stroke volume did not decrease. Histological analysis confirmed increased astrocyte and microglia presence in the affected hemisphere. Quantum dot analysis of injections showed presence of MSCs along trajectory as well as targeting perilesional brain tissue at 7 and 30 days post-implantation.

CONCLUSIONS:
Stereotactic injection of autologous MSCs represent an effective treatment for chronic stroke. Cells were effective at the lowest dose studied, with no added benefit at higher cell dosages. Unlike allogeneic MSCs which disappear over days to weeks3, autologous MSCs persist long term in the brain, potentially providing continued benefit. This treatment warrants human trials to study its effectiveness.
394 R2* and QSM Reliability for Measuring Brain Tissue Iron Concentrations
Authors: Fliegner Max , Lin Leanne , Chaudhary Neeraj , Pandey Aditya S. , Keep Richard , Xi Guohua , Troost Jonathan , Chenevert Tom 
Published: March 2023

INTRODUCTION:
Pathologic levels of iron have been implicated in various neurological disease states, such as Parkinson’s, Multiple Sclerosis, Amyotrophic Lateral Sclerosis, and Stroke (hemorrhagic & ischemic). Using brain tissue iron concentration as a biomarker for disease progression has great potential for clinical translation; however, measuring iron concentrations non-invasively remains challenging. MRI based R2* and quantitative susceptibility mapping (QSM) values have been shown to correlate with iron levels in previous cadaveric studies.

METHODS:
Ten normal human subjects (ages 35-73) underwent test and retest MRI scans approximately 10 minutes apart. T1 and gradient-echo images were used to segment 7 regions of the brain bilaterally. The gradient-echo sequences were used to calculate the R2* and QSM for each region of interest. Iron concentrations were calculated from the R2* values based on R2* calibrated with a phantom.

RESULTS:
R2* values ranged from 19.45 Hz in the hand homunculus to 38.81 Hz in the substantia nigra and were consistent across 8-echo and 6-echo sequences. Mean QSM values ranged from -0.041 in the internal capsule to 0.046 in the globus pallidus. Calculated iron concentrations ranged from 52.1 mg/kg in the centrum semiovale to 104.6 mg/kg in the substantia nigra. Test and retest values showed consistency across brain regions for R2* with weighted coefficient variation percent of 3.9-9.6%. White matter iron concentrations ranged from 52.1-59.5 mg/kg, while deep grey nuclei iron concentrations ranged from 72.5-104.6 mg/kg.

CONCLUSIONS:
Our study demonstrates the ability of gradient-echo MRI to reliably measure tissue iron levels in non-disease states in healthy human subjects. Further research is needed to validate the ability of specific MRI sequences to be a surrogate biomarker in disease states.
399 Role of Plaque Inflammation in Symptomatic Carotid Stenosis
Authors: Zheng Yilong , Rui Jun Rui Lim Mervyn Jun , Tan Benjamin , Chan Bernard , Paliwal Prakash , Ong Jonathan , Bharatendu Chandra , Chan Amanda , Yeo Leonard , Vijayan Joy , Chee Young Heng , Wong Lily , Chen Jintao , Chong Yao Feng , Dong Yanhong , Tan Chi Hsien , Sunny Sibi , Teoh Hock Luen , Sinha Arvind Kumar , Sharma Vijay 
Published: March 2023

INTRODUCTION:
Prior studies have shown that plaque inflammation on FDG-PET and the SCAIL score were associated with recurrent ischemic events. However, the findings have thus far not been widely validated.

METHODS:
This was a single-center prospective cohort study that included patients with (1) recent TIA or ischemic stroke within the past 30 days, (2) ipsilateral carotid artery stenosis of ≥50%, and (3) not considered for early carotid revascularization. The (1) maximum standardized uptake value (SUVmax) of the symptomatic carotid plaque, (2) stenosis severity of the symptomatic carotid artery, and (3) the SCAIL score (a composite score consisting of the degree of plaque inflammation and stenosis severity) were measured for all patients. The outcomes were (1) a 90-day ipsilateral ischemic stroke and (2) a 90-day ipsilateral symptomatic TIA or major adverse cardiovascular event (MACE).

RESULTS:
Of 131 included patients, 21 (16.0%) patients had a 90-day ischemic stroke, and 41 (31.3%) patients had a 90-day TIA or MACE. Symptomatic plaque SUVmax (AUC = 0.92; 95% CI = 0.82–1.00) was superior to the SCAIL score (AUC = 0.79; 95% CI = 0.65, 0.92) in predicting 90-day ischemic stroke. Symptomatic plaque SUVmax (AUC = 0.84; 95% CI = 0.76, 0.92) was also superior to the SCAIL score (AUC = 0.76; 95% CI = 0.66, 0.85) in predicting 90-day TIA or MACE.

CONCLUSIONS:
Plaque inflammation may serve as a reliable biomarker for risk stratification and selection of patients for carotid revascularization and/or anti-inflammatory therapy.
404 Identification of Persistent Racial Inequities in Recommendations for Resection of Primary Brain Tumors Using a Harmonized Dual Registry Analysis
Authors: Butterfield Jack , Golzarian Sina , Johnson Reid Alexander , Fellows Emily , Dhawan Sanjay , Chen Clark C C. , Marcotte Erin , Venteicher Andrew Sean 
Published: March 2023

INTRODUCTION:
Disparities in outcomes disproportionately affect minority populations in many surgical fields. In contrast, racial disparities in surgical decision-making remains an enigma due to the difficulty in capturing surgeon recommendations during initial patient workup.

METHODS:
The odds of recommendation against surgical resection at initial diagnosis of primary brain neoplasms was determined using multivariable logistic regression with clinical, demographic, and socioeconomic factors. A dual registry analysis was designed using two national databases (NCDB and SEER), with independent analyses that were harmonized to ensure robustness of conclusions. Adults with the six most common intracranial neoplasms were included in the analysis.

RESULTS:
Two registries were queried to identify adults with meningioma (n = 63674, n = 222673), glioblastoma (n = 35258, n = 104047), pituitary adenoma (n = 27506, n = 87772), vestibular schwannoma (n = 11525, n = 30745), astrocytoma (n = 5402, n = 10631), and oligodendroglioma (n = 3977, n = 9187) in SEER and NCDB databases, respectively. Multivariable analysis in SEER demonstrated that, independent of clinical, demographic, and socioeconomic factors, Black patients had significantly higher odds of recommendation against surgical resection of meningioma (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.06-1.21, p < 0.001), glioblastoma (OR 1.14, 95% CI 1.01-1.28, p = 0.038), pituitary adenoma (OR 1.13, 95% CI 1.05-1.22, p < 0.001), and vestibular schwannoma (OR 1.48, 95% CI 1.19-1.84, p < 0.001) when compared to White patients in the SEER dataset. Performing a parallel analysis in NCDB confirmed these results in meningioma (OR 1.26, 95% CI 1.22-1.30, p < 0.001), glioblastoma (OR 1.20, 95% CI 1.13-1.29, p < 0.001), pituitary adenoma (OR 1.26, 95% CI 1.22-1.31), p < 0.001), and vestibular schwannoma (OR 1.30, 95% CI 1.15-1.48, p < 0.001). These findings persisted independent of both patient comorbidities and potential overlap between the databases.

CONCLUSIONS:
Racial disparities in surgery recommendations for patients with primary brain tumors independent of multiple potential confounders including clinical, demographic, and socioeconomic factors.
405 Cost and Cost-Effectiveness in the Development of Brain Tumor Clinical Trials
Authors: Koester Stefan Wolfgang , Chinard Stephen , Ani Chinonso , Liles David Campbell , Dambrino Robert J. , Feldman Michael , Chambless Lola Blackwell 
Published: March 2023

INTRODUCTION:
New approaches to brain tumor treatment are constantly evolving, as evidenced by the high number of completed and ongoing clinical trials. While treatment outcomes are the primary focus of such work, allocation of resources is also an important consideration in a constrained healthcare environment.

METHODS:
The Clinical.Trials.gov website was queried for all studies involving brain tumors that mention cost. Data on trial characteristics were analyzed to generate an overview of how cost was discussed in these studies. Data collected pertained to start date, enrollment size, study funding/sponsors, country of origin, and cost as a primary, secondary, or tertiary outcome.

RESULTS:
2,572 studies were identified. Our search yielded 42 (1.63%) results that discussed cost. 27 of 42 (64.3%) studies discussed cost as being a part of the study. Of those, 2 (7.4%) has cost as a primary outcome, 19 (70.4%) has cost as a secondary outcome, and 6 (22.2%) has cost as an additional outcome. Of the 27 studies, 11 (40.7%) studies utilized a cost-effectiveness analysis as part of their design study. 11 (40.7%) studies came from drug or device trials and 7 (26.0%) studies came from procedural intervention trials. Considering evolution of cost consideration over time, 10 (37.0%) of the studies were within the last 5-year time period from 2017 - 2022, and 10 (37%) from the prior 5-year period from 2012-2017.

CONCLUSIONS:
Less than 1% of clinical trials pertaining to brain tumors report cost as any endpoint, despite cost being a major future consideration to implementation and use within the healthcare system. This metric has not changed within recent years, and we implore more investigators to consider and discuss cost openly to gain a more insightful economic perspective to juxtapose their proposed shift in brain tumor technologies.
421 Quantifying the Opportunity Cost of Neurosurgical Resident Education
Authors: Venkatraman Vishal , Suarez Alexander , Kirsch Elayna , Heo Helen , Wu Kevin , McDaniel Kate , Yang Zidanyue , Dharmapurikar Rajeev , Lad Nandan P. , Haglund Michael M. 
Published: March 2023

INTRODUCTION:
Education is at the core of neurosurgical residency, but little research has been done on the opportunity cost of surgical education.

METHODS:
SAP structures cases into zones of proximal development (opening, exposure, key section, and closing) and is used to evaluate resident mastery. All 1-4 level ACDF non-reoperative cases between March 2014 and March 2022 from one attending surgeon at Duke University were divided into three groups: cases without residents, cases with residents prior to implementation of SAP (before June 2018) and cases with residents after implementation with SAP (after June 2018). Surgical times for all cases were collected via electronic record review. Times were compared within levels of surgery between groups.

RESULTS:
There were 2140 ACDF cases identified, of which 1758 were done independently, 223 with residents prior to SAP, and 159 with residents and SAP. Across 1, 2, 3, and 4 level ACDF surgeries, cases with residents took longer to complete than when done independently, with SAP adding additional time. For 2-level ACDF cases, the average surgical time was 72.0 ± 18.2 min independently, 121.7 ± 33.7 min pre-SAP, and 143.4 ± 34.9 min post-SAP, with t-tests showing significant differences between all three groups.

CONCLUSIONS:
There is a significant time cost for neurosurgeons to educate residents, but with some additional time, more structured education can be implemented. There is also a significant monetary cost to educating residents compared to operating independently, since it is expensive to run an operating room. Since attending neurosurgeons lose opportunities to perform more surgeries when working with residents, there is a need to incentivize and compensate surgeons who dedicate time to education.
429 Intramedullary Spinal Arteriovenous Malformations—Definition of Two Distinct Subtypes
Authors: Srinivasan Visish M. , Scherschinski Lea , Rhodenhiser Emmajane , Karahalios Katherine , Garcia Joseph , Catapano Joshua , Labib Mohamed , Graffeo Christopher Salvatore , Spetzler Robert F. , Lawton Michael T. 
Published: March 2023

INTRODUCTION:
Intramedullary spinal arteriovenous malformations (SpiAVM) are complex lesions. Due to their rarity, reports of their management and outcomes are limited.

METHODS:
Our neurovascular database was reviewed SpiAVMs between January 1986 and December 2021. Demographic, clinical, radiographic, and outcome data were obtained. Eccentric SpiAVMs were defined as those with a significant portion presenting through the pia mater into the subarachnoid space, with large vessels coursing outside the parenchyma. Concentric SpiAVMs were defined as those embedded within the spinal cord parenchyma, not presenting to pia mater, and well circumscribed.

RESULTS:
Fifty-nine patients (mean [SD] age, 34 [15] years; female sex, 34) were identified. Patients exhibited myelopathy (88%), including pain (51%), paresis (88%), sensory deficits (46%), and bowel and bladder dysfunction (46%). Twenty-seven patients (46%) presented with hemorrhage. Forty-nine percent of lesions were located in the cervical spine and 51% in the thoracic spine. Thirty-five lesions (59%) were previously embolized. Twenty-eight patients (51%) were classified as eccentric and 27 (49%) as concentric SpiAVMs. Postoperative outcomes were similar with no significant differences (improved, 8/18 [44%] vs. 9/17 [53%]; unchanged, 8/18 [44%] vs. 7/17 [41%]; worse, 2/18 [11%] vs. 1/17 [6%]). Retreatment rates were not significantly different between both subtypes (eccentric, 9/28 [32%]; concentric, 6/27 [22%]). Eccentric and concentric SpiAVMs were associated with similar rates of complete resection (eccentric, 14/26 [54%], concentric, 18/26 [69%]). Of 55 classifiable lesions, 4 (7%) were determined to have a mixed phenotype, harboring characteristics of eccentric and concentric SpiAVMs.

CONCLUSIONS:
Intramedullary AVMs may cause significant symptoms. The eccentric and concentric subtypes have different angioarchitecture and outcomes. While complete resection is usually the preferred surgical objective, eccentric SpiAVMs are amenable to the pial resection that may achieve angiographic obliteration without complete resection.
430 Cranially Directed Upper Instrumented Vertebrae Screw Angles are Associated with Proximal Junctional Kyphosis in Adult Spinal Deformity Surgery
Authors: Chen Jeffrey , Longo Michael , Chanbour Hani , LaBarge Matthew , Abtahi Amir , Stephens Byron , Zuckerman Scott L. 
Published: March 2023

INTRODUCTION:
The effect of the upper instrumented vertebral (UIV) screw angle in adult spinal deformity (ASD) surgery on surgical complications and patient outcomes remains understudied.

METHODS:
A single-institution, retrospective cohort study was undertaken from 2011-17. UIV screw angle was trichotomized into: 1) Positive: cranially-directed screws relative to the UIV superior endplate (2° ≤ Θ); 2) Neutral: screws parallel to the UIV superior endplate (-2° <Θ <2°); and 3) Negative: caudally-directed screws relative to the UIV superior endplate (-2° ≥ Θ). The primary outcome was PJK/F. Secondary outcomes included remaining mechanical complications, reoperation, and PROMs: Oswestry Disability Index (ODI), Numeric Rating Scale (NRS) back/leg, and EuroQol (EQ-5D). Regression controlled for age, BMI, postoperative sagittal vertical axis, and pelvic-incidence to lumbar-lordosis mismatch.

RESULTS:
Among 145 patients undergoing ASD surgery, UIV screw angles were: 35(24.1%) cranially directed, 24(16.6%) neutral, and 86(59.3%) caudally directed. PJK occurred in 47(32.4%) patients. The incidence of PJK was highest for patients with cranially-directed screws (51.43%, p = 0.022). Cranially-directed screws were independently associated with PJK (OR = 4.88, 95%CI = 1.85-13.5, p = 0.002) and PJF (OR = 3.06, 95%CI = 1.32-12.30, p = 0.015), with a threshold value of -8.9° on ROC analysis (AUC = 0.64, 95%CI = 0.55-0.74, p<0.001). There was no association between UIV screw angle and remaining mechanical complications, reoperations, or PROMs. In addition, cranially directed screw angle was associated with increased risk of PJK (OR = 5.56, 95%CI = 1.86-17.90, p = 0.003) in lower thoracic cohort (T8 or below, N = 37), but not in the upper thoracic group (T7 or above, N = 37).

CONCLUSIONS:
Positive, cranially-directed UIV screw angles significantly increased the odds of PJK/F but not other mechanical complications, reoperation, or PROMs. Meticulous attention should be paid to UIV screw angle to reduce PJK/F.
446 Accurate Localization of Back Pain by Radiomic Assessment of Sigma-1 Receptor Expression
Authors: Haider Ghani , Schonfeld Ethan , Biswal Sandip , Veeravagu Anand 
Published: March 2023

INTRODUCTION:
The current diagnostic tools that we have for back pain have low sensitivity and poor accuracy which leads to ineffective and unnecessary treatments, resulting in high health care costs and unwanted outcomes. Sigma-1 receptor (s1R) is broadly implicated in nociceptive signaling and peripheral pain sensation.

METHODS:
Specific patient selection for full body ([18F]FTC-146) PET/MRI scan was done after clinical and radiological review by a neurosurgeon specializing in spinal surgery. Six patients with various etiologies of back pain were included. For all the study participants, we recorded all relevant clinical details and reviewed prior diagnostic tests. All PET/MRI scans were completed at our institution’s facilities and images were reviewed and correlated by a musculoskeletal radiologist to identify lesions that may be causing patient’s symptoms.

RESULTS:
Our study results strongly support the likelihood of achieving enhanced diagnostic sensitivity to sources of back pain with the proposed s1r imaging approach. PET/MRI imaging matched the clinical diagnosis in all cases, including disc herniation, nerve compression, stenosis, and arthropathy. Additionally, it offered benefit over traditional MRI by identifying additional “functional” findings both within and outside the spine. This additional functional detail, was useful for patients with either no or multiple structural abnormalities on MRI to pinpoint the true cause of pain demonstrating the synergistic utility of this imaging modality. Such functional detail guided successful interventions including surgery, therapy, and injections in our patient cohort that successfully addressed the pain.

CONCLUSIONS:
Early results show promise for improved confidence and sensitivity in detecting sources of pain using full body ([18F]FTC-146) PET/MRI scan which can potentially improve patient management and outcomes.
449 Stereoencephalography of Centromedian Thalamus Reveals Distinct Patterns of Thalamocortical Synchrony Across Seizure Onset Zones
Authors: Gadot Ron , Reddy Sandesh , Devara Ethan , Dang Huy , Shofty Ben , Gavvala Jay R. , Sheth Sameer A. 
Published: March 2023

INTRODUCTION:
Thalamic nuclei are increasingly used targets for study and therapeutic modulation in drug-resistant epilepsy (DRE). Centromedian nucleus of thalamus (CMN) is relatively understudied despite known widespread connectivity and previous reports suggesting a role in both generalized and multifocal epilepsies.

METHODS:
The clinical and electrographic data of 13 consecutive patients who had at least one sEEG electrode sampling CMN were included. Electrographic seizures were visually analyzed for thalamic activity changes at seizure onset (SO), maintenance (SM), and end (SE) periods. Recordings were quantitatively assessed using a measure of sEEG signal interdependency (non-linear regression coefficient, h2) to compare thalamocortical synchrony at SO and SE periods. All analyses were performed using AnyWave software.

RESULTS:
Eighty focal-onset seizures (median 4, range 1-19 per patient) were captured and included in analysis. SOZs were mesial temporal (33%), neocortical temporal (23%), frontal (29%), and non-frontal extratemporal (15%). Median seizure length was 78 (IQR 25-133) seconds. In 74% of seizures, a change in thalamic activity was visually perceptible during the seizure with a median latency of 5 (IQR 2-9) seconds. A low voltage fast activity pattern predominantly in the alpha band was most commonly seen during SO. When thalamic activity changed during SM, a rhythmic spike-wave pattern was most often seen. Rhythmic waves predominantly in the delta band were the most common pattern of activity at SE. Average thalamocortical h2 values in the SE period were significantly higher than the SO period (Kruskal-Wallis p < 0.0001). Mesial temporal, temporal, and frontal seizures demonstrated significant increases in thalamocortical synchronization while non-frontal extratemporal seizures did not.

CONCLUSIONS:
Consistent dynamic ictal patterns can be visualized within CMN thalamus using sEEG recordings. Bidirectional signal synchronization peaks during the SE period and may be involved in seizure termination.