bluuebunny/crossref_metadata_2025_split huggingface dataset:
479 Validation and Comparison of Pupillary Reflex Indices in TBI and Matched Healthy Controls Using PupilScreen, a Smartphone-based Pupillometer
Authors: Gulek Bernice G. , Maxin Anthony , Lim Do , Lee Chungeun (Chloe) , Buzytsky Ilya , Coppess Steve , Alfieri Robin , Law Anthony , Levitt Michael R. , Bly Randy , Kelly Cory , McGrath Lynn 
Published: March 2022

INTRODUCTION:
Pupillary light reflex (PLR) is one of the earliest biomarkers used to assess, diagnose, and treat neurological conditions, particularly traumatic brain injury (TBI). PLR indices have been examined as an indicator for specific neurological conditions using a pupillometer. We developed an alternative, mathematically driven stand-alone app to increase precision, to provide broader accessibility, and utilization of automated pupillometry.

METHODS:
The second-generation PupilScreen app was developed using a fully convolutional neural network (FCNN) model, using the standard iPhone light source and camera without any external environmental controls. We examined n=21 TBI subjects with n=21healthy controls matched to primary eye color. We analyzed known pupillary biomarkers for TBI and compared the metrics in both cohorts. Additionally, we examined age, gender, ethnicity, GCS, eye color, and primary lesion.

RESULTS:
Distribution of eye color was 38% brown eyes, 29% blue eyes, and 33% mixed eyes in both cohorts. Mean age was 54 vs 35 in TBI and healthy controls, respectively. Female sex was 19% versus 62% TBI and healthy controls sequentially. Ethnicities included White (TBI 67%, healthy controls 76%), African American (TBI 9%, healthy controls 10%), Asian (TBI 9%, healthy controls14%), Native American/Indian (TBI 5%, healthy controls 0%). Lesions consisted of subdural hematoma (61%), intraparenchymal hemorrhage (24%), contusions (10%), traumatic subarachnoid hemorrhage (5%), and 38% of lesions were multifocal. Mean GCS was 8, and 52% were classified as severe TBI. PupilScreen measurements included mean latency of 0.45s(L)/0.31s(R) in TBI and 0.17s (L/R) (p<0.05) healthy controls; mean % diameter change was 21%(L)/17%(R) in TBI, 39%(L/R) (p<0.05) in healthy controls; mean constriction velocity was 3.7px/s(L)/3.6px/s(R)in TBI and 11.4px/s(L)/11.1px/s(R) (p<0.05) n healthy controls; and the mean dilation velocity was 2.4px/s(L/R) and 4.1px/s(L)/4.5px/s(R) (p<0.05) in TBI and healthy cohorts respectively.

CONCLUSION:
The preliminary PupilScreen results demonstrated capability in identification of PLR biomarkers in TBI population compared to healthy cohort without the need for external environmental controls. Further development of PupilScreen app is warranted.
509 Microenvironmental Characteristics of Growing and Static Vestibular Schwannomata
Authors: Hannan Cathal , Lewis Daniel , MacArthur Joshua , Cooper Christopher , Hammerbeck-Ward Charlotte , Rutherford Scott A. , Lloyd Simon K. , Freeman Simon R. M. , Coope David J. , Pathmanaban Omar N. , Roncaroli Federico , King Andrew 
Published: March 2022

INTRODUCTION:
Vestibular schwannomas (VS) display a wide variation in their natural history, with ∼60% exhibiting progressive growth, while the remainder do not grow. There is emerging evidence that the tumor microenvironment (TME) plays a central role in driving tumour growth. Previous studies in this area have been limited by small sample sizes, a shortcoming we addressed in the present study.

METHODS:
We identified 120 patients with sporadic VS from a prospectively maintained database. 100 consecutive growing cases and 20 consecutive static cases were included. Tumour volumes and growth rates were established by analysis of MR imaging using Brainlab ElementsTM. Tumour tissue was analysed using immunohistochemistry to assess for macrophage infiltrates (Iba1), microvessel surface area (CD31) and vascular permeability (Fibrinogen). Immunostains were quantified using ImageJ (www.imagej.nih.gov). Statistical analysis was performed using the appropriate non-parametric tests.

RESULTS:
The mean Iba1+ macrophages was significantly higher in growing VS when compared to static VS (591 vs. 317/x20 HPF, p=0.02). Growing VS also had a significantly higher microvessel surface area than static VS (2.16% vs. 1.37%, p=0.032), as well as higher vascular permeability as assessed by optical density of fibrinogen staining (0.64 vs. 0.45, p=0.038). There was a statistically significant correlation between tumour macrophage infiltration and tumour vascularity (rs=0.4189, p=<0.001).

CONCLUSION:
We documented marked differences in the TME of growing and static VS, validating our previous observation. Growing VS exhibited higher macrophage density, increased vascularity and higher vascular permeability. Targeting these processes may yield therapeutic benefit for patients with sporadic and neurofibromatosis type 2 related VS.
510 Artificial Intelligence Tutoring Compared with Expert Instruction in Neurosurgical Simulation Training: A Randomized Controlled Trial
Authors: Fazlollahi Ali , Bakhaidar Mohamad , Alsayegh Ahmad , Yilmaz Recai , Winkler-Schwartz Alexander , Langleben Ian , Mirchi Nykan , Ledwos Nicole , Harley Jason , Del Maestro Rolando 
Published: March 2022

INTRODUCTION:
Resection of subpial tumors adjacent to critical brain areas is one of the most high-stakes surgical procedures that lacks opportunities for safe deliberate practice. Furthermore, performance-based assessment in neurosurgical apprenticeship is inefficient and vulnerable to subjectivity. Utilizing Artificial Intelligence (AI) to classify neurosurgical psychomotor expertise, we developed the first AI-powered tutor in neurosurgical simulation training, known as the Virtual Operative Assistant (VOA), to augment technical skills acquisition training by providing intelligent feedback.

METHODS:
A multi-institutional randomized controlled trial compared VOA’s automated audiovisual metric-based feedback vs remote verbal debriefing with expert instruction and no-feedback controls. Medical students performed six simulated subpial brain tumor resections: five practice attempts followed with feedback and one complex realistic attempt evaluated skill retention and transfer. A deep learning model, Intelligent Continuous Expertise Monitoring System (ICEMS Expertise Score), and blinded Objective Structured Assessment of Technical Skills (OSATS) evaluated performance. Participants reported emotions before, during and after training and completed a cognitive load questionnaire following training.

RESULTS:
Seventy medical students from four institutions were randomly assigned to VOA (n=23), Instructor (n=24), and Control (n=23) Groups. 350 practice attempts were assessed by ICEMS, and 70 realistic attempts were evaluated by ICEMS and OSATS. During practice, VOA training resulted in a significant improvement of participants’ Expertise Scores that was on average 0.66 (95% CI 0.55-0.77) and 0.65 (95% CI 0.54-0.77) points higher than Instructor and Control Groups (p<.001). Realistic attempt’s average Expertise Score was significantly higher in the VOA Group compared to Instructor and Control Groups (mean difference 0.53; 0.49, respectively, p<.001). VOA and Instructor Group’s realistic attempt OSATS ratings were not significantly different. OSATS ratings demonstrated that VOA feedback resulted in significantly higher Respect for Tissue and Economy of Movement compared to Control while expert instruction significantly improved Instrument Handling compared to Control. There was no significant between-groups difference in cognitive load, positive-, and negative-activating emotions.

CONCLUSION:
VOA’s quantitative automated benchmark feedback demonstrated superior performance outcome, improved skill transfer, with equivalent OSATS ratings and similar cognitive and affective responses compared to remote expert instruction.
515 Serious Illness Communication Practices in Glioblastoma Care: An Institutional Perspective
Authors: Miranda Stephen , Reed-Guy Lauren , Alexander Tyler , Biggiani Gregory , Grady M. Sean , Jones Joshua , Bagley Stephen , Kumar Pallavi , O'Connor Nina 
Published: March 2022

INTRODUCTION:
Serious illness (SI) communication about goals, prognosis, and advance care planning is essential for supporting goal-concordant care among glioblastoma patients, however clinicians may fail to elicit patients’ preferences while they have decision-making capacity.

METHODS:
The electronic medical records of 240 glioblastoma patients who died between 2017 and 2019 were systematically reviewed for documented SI conversations about four domains (prognosis, goals, end-of-life planning, and code status) using published criteria. Patient outcomes and SI conversation characteristics were analyzed using descriptive statistics. Standardized interviews about glioblastoma care were held with five clinicians. Interview transcripts were analyzed using grounded-theory coding to identify emergent themes.

RESULTS:
Nearly all patients (96%) had at least one documented SI conversation (median: 4; interquartile range: 2-7), mostly outpatient with oncology physicians. Median timing of first SI conversation was 360 days before death. Prognosis (92% of patients) and goals (89%) were the domains discussed most frequently. SI conversations were not significantly associated with patient outcomes, including inpatient death and hospice enrollment. Seven themes emerged from clinician interviews: balancing hope and reality, anticipatory guidance, neglect of the “big picture,” need for earlier conversations, care coordination, the role of clinical expertise, and communication training.

CONCLUSION:
SI conversations were documented earlier and more often in our sample than has been previously reported, but their quality was difficult to assess. Contrary to chart review findings, interviewees reported that SI conversations were late, infrequent, and fragmented across specialties, failing to explore issues such as functional prognosis and anticipatory guidance.
516 Artificial Neural Networks Predict the Need for Permanent CSF Diversion After Posterior Fossa Tumor Surgery
Authors: Bray David P. , Saad Hassan , Douglas James A. M. , Grogan Dayton , Dawoud Reem , Nduom Edjah K. , Pradilla Gustavo , Olson Jeffrey , Alawieh Ali M. , Hoang Kimberly B. 
Published: March 2022

INTRODUCTION:
Resection of posterior fossa tumors (PFTs) can result in hydrocephalus that requires permanent CSF diversion. Clinicians need a durable method to predict occurrence of CSF diversion in this population.

METHODS:
We collected pre-operative and post-operative variables on 510 patients that underwent PFT surgery at our center in a retrospective fashion to train several statistical classifiers to predict the need for permanent CSF diversion as a binary class. A total of 62 classifiers relevant to our data structure were surveyed including regression models, decision trees, Bayesian models, and multilayer perceptron artificial neural networks (ANN). Models were trained using the (N=510) retrospective data using 10-fold cross validation to obtain accuracy metrics. Given the low incidence of our positive outcome (12%), we used the true positive rate along with the area under the receiver operating characteristic curve (AUC) to compare models. The best performing model was then prospectively validated on a set of 90 patients.

RESULTS:
12% of patients in our dataset required permanent CSF diversion after PFT surgery. Of the trained models, 8 classifiers had an AUC greater than 0.5 on prospective testing. Artificial neural networks (ANN) demonstrated the highest AUC of 0.902 with a true positive rate of 83.3%. Despite comparable AUC, the remaining classifiers had a true positive rate below 35% (compared to ANN, P<0.0001). The negative predictive value of the ANN model was 98.8%.

CONCLUSION:
ANN-based models can reliably predict the need for ventriculoperitoneal shunt after PFT surgery.
800 Patient Frailty Predicts Cerebral Arteriovenous Malformation Microsurgical Outcomes: An Analysis of 16,721 Nationwide Admissions
Authors: Tang Oliver Young , Bajaj Ankush , Zhao Kevin , Liu James K. 
Published: March 2022

INTRODUCTION:
Earlier research has demonstrated that patient frailty is associated with higher morbidity and mortality for several neurosurgical procedures. However, the comparative accuracy between different frailty metrics for cerebral arteriovenous malformation (AVM) outcomes is poorly understood.

METHODS:
We identified all adult AVM admissions undergoing microsurgery in the National Inpatient Sample from 2002-2017. Three frailty measures were analyzed: mFI-5 (range=0-5), mFI-11 (range=0-11), and Charlson Comorbidity Index (CCI) (range=0-29). We generated receiver operating characteristic (ROC) curves to compare accuracy and determine the optimal cutoff of “high frailty” for each score (=2 for all three scores). Analyzed endpoints included in-hospital mortality, routine discharge, complications, length of stay (LOS), and hospitalization costs. We used survey-weighted multivariate regression to analyze the associations between frailty and outcomes, adjusting for twelve confounding variables, including patient demographics, hospital characteristics, ruptured status, hydrocephalus or epilepsy on admission, and treatment modality. Statistical significance was maintained at P<0.05.

RESULTS:
We analyzed 16,271 total AVM admissions nationwide. 3,515 patients (21.0%) presented with ruptured AVMs. Patients were treated via microsurgery alone (81.7%) or combined microsurgical and endovascular management (18.3%). High frailty status in the mFI-5, mFI-11, and CCI were all predictive of lower rates of routine discharge disposition (CCI: odds ratio [OR]=0.25, P=0.001), increased perioperative complications (CCI: OR=2.35, P=0.001), and elevated postoperative (CCI: +60%, P=0.001) and total LOS (CCI: +56%, P=0.001). The mFI-11 (+8%, P=0.001) and CCI (+30%, P=0.001) also predicted higher hospital costs. However, only the CCI remained significantly associated with all of the aforementioned outcomes following stratification by ruptured status (unruptured vs. ruptured) and treatment modality (microsurgery vs. combined). On ROC analysis, the CCI significantly outperformed age, mFI-5, and mFI-11 in predicting routine discharge for microsurgical, combined, and unruptured AVM admissions (all P<0.01). However, the CCI had comparable predictive ability to age for ruptured AVMs (P=0.449).

CONCLUSIONS:
Patient frailty was predictive of lower routine hospital discharge rates and higher complications, LOS, and costs for AVM admissions undergoing microsurgery, with the CCI outperforming the mFI-5 and mFFI-11.
803 Extracorporeal Filtration of Blood and Blood Breakdown Products from CSF via Spinal Catheter (PILLAR-XT) Following Aneurysmal Subarachnoid Hemorrhage
Authors: Blackburn Spiros L. , Babi Marc , Grande Andrew W. , Choudhri Omar , Hauck Erik F. , Kellner Christopher P. 
Published: March 2022

INTRODUCTION:
Delayed cerebral ischemia (DCI) is a secondary injury of aneurysmal subarachnoid hemorrhage (aSAH), and is considered to be related to blood and blood breakdown products (BBPs) in the CSF. Previously, bulk drainage of CSF post-aSAH via lumbar drain appeared to result in decreased DCI. If inflammation related to BBPs plays a role in DCI, accelerating removal of BBPs following aSAH could be of significant therapeutic benefit. This study evaluated a system designed to accelerate removal by rapidly filtering BBPs from CSF while returning filtered CSF to the patient via a dual lumen catheter and extracorporeal filtration system (Neurapheresis™ System).

METHODS:
Patients with aSAH had a dual lumen lumbar, intrathecal catheter placed after aneurysm securement and received up to 72±4 hours Neurapheresis therapy. The catheter aspirated blood-contaminated CSF from the lumbar cistern and returned filtered CSF to the thoracic subarachnoid space, routing BBPs to a waste bag.

RESULTS:
Of 7 males (24.1%) and 22 females (75.9%), a catheter was successfully placed in 27 subjects out of 29 attempts (93.1% success rate. The mean duration of treatment was 34:18 hrs [3:39 – 62:17] (n=27), and the system maintained its expected, controlled, safe drainage rate, mean 6.5 ml/hr [2.1 – 12.5] (n=27). Mean paired RBC values in CSF (106/mm3) declined by 84.5±22.3% (n=21) by the end of treatment. Mean paired total protein (mg/dL) declined by 85.3±8.3% (n=21) to within normal range. Paired Hijdra Sum Scores (sum of ten cistern blood fullness scores - maximum score: 30) declined by 60.1±24.1% (n=25); the largest decline was noted between catheter placement and catheter removal.

CONCLUSIONS:
In this feasibility study, Neurapheresis was associated with a decline in RBC and protein concentration in CSF, and improvement in blood clearance as measured by Hijdra Sum Scores. The procedure was safe and well tolerated in this study.
806 Do Robotic Procedures Have Improved Perioperative Outcomes After a Learning Curve Period?
Authors: Passias Peter G. , Krol Oscar , Ahmad Salman , Passfall Lara , Kummer Nicholas , Imbo Bailey , Tretiakov Peter S. , Joujon-Roche Rachel , Moattari Kevin , Williamson Tyler , Vira Shaleen 
Published: March 2022

INTRODUCTION:
Robot-assisted surgical techniques are being increasingly implemented to increase surgeon accuracy and stamina; however, the effects of surgeon learning curve on outcomes have not been well studied.

METHODS:
Robotic cases were isolated from single center multi surgeon database. Single surgeon cases were ranked by DOS into 3 quartiles. 1st Quartile (Group I) was analyzed against the 3rd Quartile (Group II). Univariate analysis was used to assess differences between quartiles. A propensity score matched (PSM) cohort of patients undergoing identical surgical procedures was included as a control group.

RESULTS:
281 patients undergoing robotic surgery met inclusion criteria (Age: 56±12.5, BMI: 30±6, 42% female) with an average of 1.6 levels fused. Group I had 95 patients and Group II had 94. Group II had a lower EBL (314 vs 492, p<0.05), shorter LOS (3.8 vs 4.7, p=.1), greater amount of levels fused (2 vs 1.4, p=.021), greater amount of decompressions (2.5 vs 1, p=.003), with less return to the OR within 30 days (7% vs 14%, p=.2), and a lower rate of overall post-operative complications (34% vs 54%, p=.04). In a PSM cohort, the mean EBL was 411±790, LOS 3.7±2.7, overall post-operative complication rate 58%, and rate to return to OR within 30 days was 8%.

CONCLUSIONS:
There is a substantial learning curve that exists in order to capture the potential benefits of robotic surgery. Performing more robotic cases over time can potentially result in a surgeon lowering length of stay, EBL, and complication rate. Furthermore, this study shows that progressing through this learning curve allows a surgeon to become more comfortable performing larger surgeries in the form of greater levels of decompression.
808 Metastatic Breast Cancer to the Spine: Outcomes After the Introduction of Small Molecule Inhibitors
Authors: Rabah Nicholas M. , Khan Hammad A. , Jarmula Jakub , Hamza Omar , Chakravarthy Vikram , Wright Christina , Wright James Monroe , Steinmetz Michael P. , Krishnaney Ajit A. 
Published: March 2022

INTRODUCTION:
Over the past decade, with the development of small molecule inhibitors and immunotherapies, expanded attention is being paid to the somatic mutations expressed within a patient’s individual breast tumor, especially in the case of advanced or metastatic disease. A number of mutations have been found to occur most commonly in patients with metastatic breast cancer, including TP53, PI3K, CDH1, and MAP3K. Specifically, with regards to patients with metastases to bone, PIK3 mutations have been found to increase in frequency.

METHODS:
This is a retrospective study of patients who underwent treatment (surgery/radiation) at a tertiary care center for their diagnosis of breast cancer metastatic to the spine between 2010 and 2020. Review of peripheral sample gene sequencing reports was conducted to calculate the prevalence of different somatic gene mutations within our population. The use of small molecule inhibitors in the post-treatment period was determined and patient post-treatment mortality was calculated in order to elucidate the effect of systemic therapy on overall survival.

RESULTS:
77 patients were included in our final analysis. Within our population of spine metastases patients, 44 (57%) were found to have a PI3K mutation, followed by 20 (26%) with a TP53 mutation. Furthermore, those patients given targeted molecular therapies in the post-treatment period were found to have a median overall survival of 1356 days. In comparison, those who did not receive targeted molecular therapies were found to have a median overall survival of 503 days (p<0.001).

CONCLUSIONS:
The results of the present study demonstrate that not only is there an increased prevalence of PI3K mutations within spine metastases in comparison to the general metastatic breast cancer population, there is also a significant mortality benefit with adding targeted molecular therapies to the patient’s post-operative treatment plan.
809 Comparison of Intraoperative Indocyanine Green Videoangiography Versus Postoperative Catheter Angiography to Confirm Microsurgical Occlusion of Dorsal Intradural Arteriovenous Fistulas
Authors: Karahalios Katherine , Srinivasan Visish M. , Scherschinski Lea , DiDomenico Joseph D. , Catapano Joshua , Safaee Michael , Lawton Michael T. 
Published: March 2022

INTRODUCTION:
Dorsal intradural arteriovenous fistulas (DI-AVFs) represent 70% of all spinal vascular malformations and 80% of all spinal AVFs. Microsurgical clip occlusion is a durable treatment for DI-AVFs and includes pre- and postoperative digital subtraction angiography (DSA) as the standard practice. Intraoperative indocyanine green videoangiography (ICG-VA) has become a valuable intraoperative adjunct in these cases. Results with intraoperative ICG-VA have not been compared to postoperative DSA.

METHODS:
A multi-institutional database of vascular malformations was queried for all surgically managed cases of DI-AVFs. Patients with both intraoperative ICG-VA and postoperative DSA were included. Demographic, radiologic, intraoperative findings, and surgical outcomes data were obtained and retrospectively analyzed.

RESULTS:
Forty-five cases of DI-AVFs were identified. Patients had a mean age of 61.9 years old (range 26-85), including 32 males and 13 females. Except for one asymptomatic patient, all other patients presented with leg numbness and weakness, gait instability, bowel and/or bladder incontinence, back pain, paresthesias, paraplegia, upper extremity discoordination, erectile dysfunction, and/or general weakness. The majority of lesions were diagnosed in the thoracic spine (72%). All DI-AVFs were treated with interruption of the fistula with clip occlusion of the draining vein. Intraoperative ICG-VA confirmed complete obliteration in all patients. Postoperative spinal angiography was performed on 40 patients confirming complete obliteration in all patients. More patients had clinical improvement compared to their preoperative state than stayed the same (47.4% vs. 42.1%).

CONCLUSIONS:
ICG-VA is useful for both intraoperative identification of DI-AVFs and confirmation of complete microsurgical occlusion. Perfect correlation between intraoperative ICG-VA and postoperative DSA demonstrates the diagnostic power of the former. This finding suggests that postoperative DSA is not necessary when intraoperative ICG-VA confirms complete occlusion of the DI-AVF, which will spare patients the procedural risk and cost of this invasive procedure.