bluuebunny/crossref_metadata_2025 huggingface dataset:
402 Disparities in Traumatic Brain Injury Patients’ Length of Stay: An Analysis of NTDB Data
Authors: Tantry Evelyne Kezia , Yue John K. , Krishnan Nishanth , Strelko Oleksandr , Spiro Ergi , Tarapore Phiroz E. , Haddad Alexander F. , Huang Michael C. , Manley Geoffrey T. , DiGiorgio Anthony Michael
Published: March 2023

INTRODUCTION:

Traumatic brain injury (TBI) presents a disproportionate biopsychosocial and economic burden on certain patient populations compared to others. Inpatient length of stay (LOS) emerges as a proxy measure of injury severity, resource utilization, and access to post-acute care. Identifying determinants of prolonged LOS following TBI admission allows for the evaluation of disparities in care.

METHODS:

The NTDB compiles trauma registry data across various U.S. trauma centers. Our study’s inclusion criteria were adult patients who were admitted after a TBI. xLOS was defined as 99th percentile or greater LOS. Patients with xLOS were compared to patients below the xLOS threshold (sLOS). A generalized losgistic regression analysis was performed to assess the effect of covariates on xLOS.

RESULTS:

257,836 patients were included and the mean, median and IQR LOS were 7.1 days, 4.0d and 1-7d, resepectively. The xLOS threshold was ≥49d (range: 49–357d). xLOS patients, compared to sLOS, were more often associated with Medicaid insurance (32.5% vs. 13.5%.; p<0.001), a lower age quintile (29–46 years: 30.3% vs. 20.3%; 47–60 years: 29.9% vs. 20.5%; p<0.001), and greater injury severity (moderate :19.8% vs. 4.7%; severe: 47.6% vs. 5.2%; p<0.001). The xLOS were also more commonly Black (22.2% vs. 13.5%; p< 0.001) and hispanic (8.8% vs. 5.4%; p < 0.001). Fewer xLOS patients were discharged home (17.4% vs. 61.8%; p< 0.001). Multivariate analysis showed that xLOS is associated with younger age, greater injury severity, discharge to post-acute facillities, and, Medicaid or self-pay insurance. Relative to non-hispanic whites, Black(OR: 1.45; p< 0.001), Hispanic (OR: 1.54; p < 0.001), and Asian(OR: 1.32; p = 0.02) patients are more likely have xLOS.

CONCLUSIONS:

There are multiple socioeconomic factors that dispose patients to xLOS after TBI, even when adjusting for injury severity. Examining the heterogeneity of LOS within demographic categories provides one avenue to evaluate disparities in TBI care.
403 Inferior Clinical Outcomes for Patients with Medicaid Insurance Following Surgery for Degenerative Lumbar Spondylolisthesis: A Prospective Registry Analysis of 608 Patients
Authors: Chan Andrew K. , Letchuman Vijay , Mummaneni Praveen V. , Burke John Frederick , Agarwal Nitin , Randy Bisson Erica Fay , Bydon Mohamad , Foley Kevin T. , Shaffrey Christopher I. , Glassman Steven D. , Wang Michael Y. , Park Paul , Potts Eric A. , Shaffrey Mark Edwin , Coric Domagoj , Knightly John J. , Fu Kai-Ming G. , Slotkin Jonathan , Asher Anthony L. , Virk Michael S. , Kerezoudis Panagiotis , Alvi Mohammed , Guan Jian , Haid Regis W. , DiGiorgio Anthony Michael
Published: March 2023

INTRODUCTION:

It remains unclear how type of insurance coverage impacts long-term, spine-specific patient-reported outcomes (PROs).

METHODS:

The prospective Quality Outcomes Database registry was queried for patients with grade 1 degenerative lumbar spondylolisthesis who underwent single-segment surgery. 24-month PROs compared included Oswestry Disability Index (ODI), Numeric Rating Scale Back Pain (NRS-BP), NRS Leg Pain (NRS-LP), EuroQol-5D (EQ-5D), and North American Spine Society (NASS) Satisfaction.

RESULTS:

608 patients undergoing surgery for grade 1 degenerative lumbar spondylolisthesis (mean age 62.5 ± 11.5 years and 59.2% women) were selected. Insurance types included private insurance (n = 319, 52.5%), Medicare (n = 235, 38.7%), Medicaid (n = 36, 5.9%), and VA/government (n =17, 2.8%). 1 patient (0.2%) was uninsured and was removed from the analyses. In adjusted multivariable analyses, when compared to patients with private insurance, Medicaid was associated with worse 24-month postoperative ODI β = 10.2, 95% CI 3.9 - 16.5) and NRS-LP β = 1.3, 95% CI 0.3 - 2.4). Medicaid was associated with worse EQ-5D scores compared to private insurance (β = -0.07, 95% CI -0.01 - -0.14), but not when compared to Medicare and VA/government insurance (p > 0.05). Medicaid was associated with lower odds of reaching ODI minimal clinically important difference (OR = 0.2, 95% CI 0.03 - 0.7) compared to VA/government insurance. NRS-BP and NASS satisfaction did not differ by insurance coverage (p > 0.05).

CONCLUSIONS:

Despite adjusting for potential confounding variables, Medicaid coverage was independently associated with worse 24-month PROs following lumbar spondylolisthesis surgery compared to other payer types. While all improved postoperatively, those with Medicaid coverage had relatively inferior improvements.
413 Addressing Healthcare Disparities in Patients Undergoing Cervical Spine Surgery
Authors: Gonzalez Glenn A. , Mitchell Dwight , Wang Victor , Leibold Adam T. , Harrop James S. , Schmidt Richard
Published: March 2023

INTRODUCTION:

Health disparities may be observed across pre and post-operative hospital courses amongst patients undergoing cervical spine surgery across racial minorities and their white counterparts.

METHODS:

Retrospective data analysis of the Thomas Jefferson University Center City Department of Neurosurgery undergoing cervical spine surgeries (based on select CPT codes) between January 1, 2018, and January 6, 2021, was conducted to evaluate healthcare disparities across the post-operative management of cervical myelopathy cases as part of a quality improvement initiative. Outcomes evaluated included: hospital length of stay, the 30-day hospital readmission rate, and discharge disposition (home vs non-home). Normality was assessed using Kolmogorov-Smirnov test. Readmission rates, length of stay (LOS) in days, and discharge disposition (DD) (home vs. non-home) were analyzed using the Student's T-test, ANOVA, and Mann-Whitney test.

RESULTS:

Two thousand twenty-five patients were identified that met inclusion criteria, of which 298 (15%) were readmitted within 30 days to the Emergency Department at Thomas Jefferson University Hospital. Of the 15% readmitted, 74% (223/298) were white, while 25% (75/298) were non-white. Non-white LOS was higher compared to the white population (5.7 days vs 4.3 days, p < 0.0001. Non-white readmission rate was higher compared to the white population (22.3% vs 16%) p < 0.001. Non-white DD was higher compared to the white population (61.9% vs 50%) p < 0.001.

CONCLUSIONS:

Significant disparities exist in the post-operative management of patients with cervical myelopathy, particularly affecting the non-white population. Health disparities exist across multiple aspects of the discharge process for post-cervical spine surgery cases. Future investigations and interventions are required to address this quality gap.
416 On-Call Junior Neurosurgery Residents Spend 9 Hours of Their On-Call Shift Actively Using the Electronic Health Record
Authors: Patel Arati , Zheng Jeff , Rosner Benjamin , Thombley Robert , Sorour Omar , Theodosopoulos Philip V. , Aghi Manish Kumar , Berger Mitchel , Chang Edward , Chou Dean , Manley Geoffrey , Mummaneni Praveen V. , DiGiorgio Anthony Michael
Published: March 2023

INTRODUCTION:

The Electronic Health Record (EHR) is central to clinical workflow, yet few studies to date have explored EHR usage patterns among neurosurgery trainees.

METHODS:

We utilized the EHR audit logs, time-stamped records of user activities, to review EHR usage of PGY-2 and 3 neurosurgery residents scheduled for 1 or more on-call days across 2 calendar years at the University of California San Francisco. We focused on the PGY-2 and 3 years, which in our training program represent the primary participants in the in-house on-call pool.

RESULTS:

Over 723 call days, 12 different residents took at least one on-call shift. The median (IQR) number of minutes that residents spent per on-call shift actively using the EHR was 536.8 (203.5), while interacting with an average (SD) of 68.1 (14.7) patient charts. There was no significant difference between active EHR time between residents as PGY-2 and PGY-3 on paired t-tests. Residents spent the most time on the following EHR activities: patient reports, notes, order management, patient list, and chart review.

CONCLUSIONS:

Residents spent, on average, 9 hours of their on-call shift actively using the EHR, and there was no improved efficiency as residents gained experience. We noted several areas of administrative EHR burden which could be reduced.
417 An Athlete-Oriented Holistic Coaching Program Targeting Performance and Wellbeing in Neurosurgery Residents
Authors: Schupper Alexander J. , Carr Matthew , Philbrick Brandon , Chennareddy Susmita , Kalagara Roshini , Turner Dan , Kellner Christopher P.
Published: March 2023

INTRODUCTION:

Neurosurgery residency is a demanding environment, requiring high levels of performance endured over long periods of time. As a result, neurosurgery residency has been associated with significant rates of fatigue, depression, and physician burnout. To address this, the authors instituted a program within the residency, entitled the “Performance Protection Program,” consisting of a personalized program based on principles used with world-class extreme sports athletes designed for residents to achieve sustainably high levels of performance.

METHODS:

A 12-month coaching program was instituted by a performance coach within a single neurosurgery residency program. Residents attended individual and team-based monthly meetings, engaged in offsite team outings, and completed interactive reflective questions. The program focused on several pillars of performance excellence including mental, emotional, social, physical and physiological domains.

RESULTS:

Residents engaged in a total of 19 team sessions, 3 team outings, and over 87 individual sessions by mobile device or in-person during which they strategized with the coach on topics including: productivity, communication, regulating emotions under pressure, in-hospital nutrition, meal preparation, efficiency, accountability, posture and strength, job interviewing, confidence, visualization skills, and team leadership dynamics. By demand, a bi-weekly posture and mobility session was incorporated into the program. Early feedback demonstrated a need for adaptive strategies personalized to the resident’s stage of training and life. Most residents expressed need for improvement in nutrition, physical wellness, and communication under fatigue.

CONCLUSIONS:

Neurosurgery residency is stress-provoking and arduous for trainees. To optimize resident performance while minimizing burnout, a curriculum based on principles in extreme sports was successfully enacted over a 12-month period. Other training programs may utilize similar interventions to promote resident well-being and improve mental and physiological states.
424 Evaluating the Impact of Effective Neurosurgical Educators on Resident Operative Progression Using the Surgical Autonomy Program
Authors: Suarez Alexander , Venkatraman Vishal , Kirsch Elayna P. , McDaniel Kate , Dharmapurikar Rajeev , Lad Nandan P. , Haglund Michael M.
Published: March 2023

INTRODUCTION:

Surgical education remains a core goal of all neurosurgical programs, however limited research exists on the impact of highly effective educators vs. less effective educators on trainee progression1.

METHODS:

The SAP breaks a surgical case into four zones of proximal development (ZPD). For each ZPD, residents are evaluated on a 4-tier autonomy scale (“stages) (TAGS scale: T: Teach/Demonstrate, A: Advise/Scaffold, G: Guide/Monitor, S: Solo/Observe) in a surgical case. All neurosurgery residents at Duke University Hospital from July 2017-July 2021 participated in this study. Trainee autonomy was rated by both attendings and residents, and resident progression was defined as the difference in a resident’s autonomy for a case compared to the resident’s prior comparable case. Relative Value Units (RVUs) were utilized to correct for difficulty of an index case. Faculty were divided into performance quartiles (top – “strong educators”, bottom – “poor educators”).

RESULTS:

There were a total of 3993 cases logged by 28 different residents and 27 attendings. Resident progression was significantly higher with strong educators compared to poor educators, both when evaluated by the attending (+1 stage vs. -1 stage, p = .002) and by the resident (+1 vs. -0.5 stage, p = .001). Resident regression was noted in the poor educator cohort. Differences in resident progression remained when accounting for difficulty of cases (resident self-evaluation, p < .0001; attending evaluation, p = .002).

CONCLUSIONS:

Differences exist in the quality of neurosurgical educators. Strong educators compared to poor educators make a demonstrable difference in resident surgical progression. Poor educators are associated with resident autonomy regression. Moving forward, the SAP will be used to provide faculty feedback on the quality of their surgical instruction.
433 Trajectory-based Classification of Recovery Potential in Mild Degenerative Cervical Myelopathy: Analysis of a Prospective Multicentre Dataset of 1047 Patients
Authors: Moghaddamjou Ali , Bak Alex , Badhiwala Jetan H. , Wilson Jefferson R. , Fehlings Michael G.
Published: March 2023

INTRODUCTION:

Degenerative Cervical Myelopathy (DCM) is the leading cause of disability secondary to a spinal pathology in adults. There exists clinical equipoise between surgery and conservative management with monitoring for patients with mild DCM.

METHODS:

A harmonized dataset was developed from the AOSpine North America, AOSpine International datasets as well as the CSM-Protect trial (N:1047). DCM patients (mJOA ≥15) were selected from the harmonized dataset. Latent class trajectory modeling was applied to classify patients into distinct trajectories. The optimal number of trajectories were chosen based on i) least Bayesian Information Criterion; ii) posterior probability >0.70; iii) odds of correct classification >5; and concordance between the estimated and actual proportion of patients assigned to a class. Predictors of recovery trajectories were identified using descriptive statistics and logistic regression on baseline variables.

RESULTS:

Two distinct recovery trajectories were revealed from our analysis. Good recovery trajectory had patients that improved to near-maximal mJOA scores within 12 months. Functional decline trajectory was characterized by a decline in more than two mJOA points over 12 months. There were 33 patients (15.6%) that followed functional decline and 179 that showed good recovery (84.4%). Demographic factors associated with following a functional decline trajectory included older age, hypertension, and higher baseline Nurick score. Posterior laminectomy and fusion was associated with functional decline compared to anterior fixation.

CONCLUSIONS:

Mild DCM can be classified into one of two distinct subpopulations with different recovery trajectories. This study lends support to the heterogeneity of mild DCM and classifying the clinical course of mild DCM based on defined clinical phenotypes rather than baseline severity of myelopathy alone. We also discovered that anterior surgery is associated with better neurological recovery in the context of mild DCM patients.
435 Non-smokers and Smokers Undergoing Decompression for Lumbar Spinal Stenosis and Lumbar Disc Herniation Experience Similar Clinical Improvement at 12 Months
Authors: Owens Kirk , Carreon Leah , Gum Jeffrey Lynn , Randy Bisson Erica Fay , Djurasovic Mladen , Bydon Mohamad , Glassman Steven D.
Published: March 2023

INTRODUCTION:

Smoking has been shown to be detrimental on patient reported outcomes (PROs) and fusion with lumbar arthrodesis. Evidence is unclear whether smoking affects PROs in patients undergoing decompression only.

METHODS:

Patients who underwent 1 or 2-level decompression only for LDH or LSS enrolled in QOD were identified. Demographics, surgical variables, smoking status and PROs at baseline and 12 months postoperatively were collected.

RESULTS:

3038 Smokers and 14,233 Nonsmokers met inclusion criteria. Smokers were younger (50.3 vs 56.7, p<0.000), had worse ASA grades (2.3 vs 2.2, p<0.000) and had more males (1663, 55% vs 7130, 50%, p<0.000) compared to Nonsmokers. Number of surgical levels was similar between groups (1.7, p = 0.169). For all PROs, both Smokers and Nonsmokers improved following surgery. Preoperative PROs in Smokers were worse (p<0.000) for BP (7.0 vs 6.1), LP (7.4 vs 6.9), ODI (52.2 vs 45.9) and EQ-5D (0.5 vs 0.6). PRO improvement in Smokers was less than in Nonsmokers at 12-months (p<0.001), but may be clinically irrelevant: BP (3.2 vs 3.3), LP (4.3 vs 4.6), ODI (25.0 vs 26.8) and EQ-5D (0.24 vs 0.26). Only 60 LSS and 38 LDH cases could be propensity matched, with no significant differences in improvements in PROs in the LSS group (ΔBP:3.2 vs 3.5, p = 0.577; ΔLP:3.3 vs 4.5, p = 0.097; ΔODI:18.1 vs 23.5, p = 0.155; ΔEQ5D: 0.2 vs 0.2, p = 0.948) or in the LDH group (ΔBP:3.1 vs 3.7, p = 0.530; ΔLP:3.7 vs 5.3, p = 0.050; ΔODI:24.6 vs 28.6, p = 0.463; ΔEQ5D: 0.2 vs 0.3, p = 0.301).

CONCLUSIONS:

Although Nonsmokers demonstrated greater improvement in all PROs, these differences were small and less evident in a propensity-matched sub-analysis. Compared to fusion surgery, both smokers and non-smokers treated with decompression only for LDH or LSS exhibit significant clinical improvement in PROs.
445 Evaluation of Low Dose Intrathecal Morphine Delivery in the Treatment of Chronic Pain
Authors: Jalal Muhammad Ibrahim , Jalal Muhammad , Jalaluddin Muhammad
Published: March 2023

INTRODUCTION:

The use of low-dose intrathecal morphine via a morphine drug delivery system is an alternative to oral analgesics in the treatment of chronic pain.

METHODS:

This was a retrospective chart-review. Patients were enrolled from June 2016 to April 2019. An out-patient intrathecal morphine trial was performed by injecting a single dose of 0.1-0.2 mg of preservative-free morphine in the lumbar intrathecal space. Following at least 60% reduction in pain, patients were weaned off oral analgesics completely over several weeks, and a permanent intrathecal catheter and morphine pump was implanted. Follow-up data was included at 3 and 6 months and 1 and 3 years.

RESULTS:

20 patients were enrolled (median age 59, 60% female). 10 patients were diagnosed with CPS and 10 were diagnosed with PLS. Pain was significantly controlled and reduced at each time point post-implantation compared to baseline. (p < 0.05). Intrathecal dosing did increase over the 3-year period on average, but the increase in dose was moderate. (p < 0.01) (median increase: 0.09 mg/day over 3 years).All patients were on oral medication for their pain prior to implantation as summarized: Remarkably, no patients previously taking oral opiates/analgesics restarted oral opiate/analgesic therapy following implantation up to and including the 3 years follow-up. There were no infections or complications present in the study.

CONCLUSIONS:

Low dose intrathecal drug delivery was shown to significantly reduce pain following treatment at each follow-up time point. This study further characterizes the efficacy of the use of low-dose intrathecal drug delivery in the treatment of chronic pain. A future multi-center study is desired.
448 Analysis of Bipolar Re-Referencing on Spectral Composition and Spike Detection in Human Electrocorticography
Authors: Caldwell David , Krish Devon , Chang Edward , Kleen Jonathan
Published: March 2023

INTRODUCTION:

Electrocorticography (ECoG) enables the localization of epileptic seizure foci prior to surgical resection. Improving the signal-to-noise ratio is paramount, and can be accomplished with bipolar re-referencing.

METHODS:

Intracranial recordings for drug-resistant epilepsy were performed at UCSF using high-density ECoG grid (4 mm inter-electrode pitch), strip (10 mm), and penetrating depth (5 mm) electrodes. Raw voltages for each participant (n = 11) were systematically re-referenced (bipolar subtraction) at increasing scales (4 mm-50 mm) and a multi-taper power spectrum (2-200 Hz) was generated around spike-free baseline windows. Cluster based permutation tests (p < 0.05) were used to compare spectral composition features after z-scoring log power features by frequency and binning by bipolar distance. High-density and low-density (4mm vs 8mm) re-referencing schemes were used for spike localization by applying a line length transform to highlight epileptiform features in peri-spike windows and comparing to baseline windows using cluster-based permutation tests.

RESULTS:

Bipolar pair distances <10 mm decreased low-frequency (<30 Hz) power, whereas both low and high frequency (30-200 Hz) power increased by longer bipolar distances. These findings were consistent across different components (grids, strips, depths). The detection of high gamma (50-200 Hz) neural activity in the STG related to an audio stimulus was enhanced at bipolar distances of <45 mm but attenuated at higher distances. Similar spike detection (duration and number of channels involved) was seen between high- vs. low-density bipolar re-referencing.

CONCLUSIONS:

Re-referencing at <10 mm bipolar distance preferentially attenuated low-frequency signal while standard clinical and larger distances systematically augmented broadband (2-200 Hz) signals. Shorter distances, especially high-density, augmented spatial delineation of neural activity when compared to more widely spaced arrays, however, standard clinical arrays capture the general spatio-temporal extent of spike waveforms.
452 Booting Up the Brain: Intracranial Electroencephalography Reveals Cognitive Network Dynamics During Anesthesia Emergence
Authors: Purger David Arnold , Eagleman Sarah , Arikan Lara , Reid Brandon , Kaboodvand Neda , Halpern Casey H. , Drover David , Razavi Babak , Meador Kimford , Buch Vivek
Published: March 2023

INTRODUCTION:

The dynamic interplay between several large-scale brain networks is thought to underlie human consciousness. The default mode network (DMN) governs internal thought during rest, the central executive network (CEN) drives goal-directed problem solving, and the salience network (SN) detects and integrates new stimuli during the transition between resting and cognitively active states. While scalp electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) have elucidated much about these networks in steady states, intracranial EEG (iEEG) dynamics during state transitions remain largely unclear.

METHODS:

Seven patients with medically refractory epilepsy underwent robot-assisted stereotactic placement of depth electrodes for epileptic focus localization. Recordings from 422 total iEEG contacts representing 49 distinct cognitive network nodes were obtained during anesthesia emergence. Local-field dynamics and Observer’s Assessment of Alertness/Sedation (OAAS) scale state were analyzed in 20s clips for complexity, functional connectivity (FC), and graph communicability metrics.

RESULTS:

Signal complexity as represented by mean multiscale sample entropy (MSE) of SN and DMN nodes increases significantly during emergence from anesthesia (P < 0.05), driven by a shift from low- to mid-frequency power in key nodes. Intermediate consciousness states demonstrated higher mean MSE and participation coefficient, representing early integrative network behavior, before reaching an optimal balance of segregation and integration at wakefulness. During emergence, between-network FC increased most strongly between SN and CEN nodes. Communicability of SN nodes increased during emergence, driven predominately by increasing communicability of right anterior insula.

CONCLUSIONS:

Intracranial electroencephalographic recording of brain activity during anesthesia emergence demonstrates a complex but quantifiable interplay of default mode, central executive, and salience network hubs. There may be a greater than previously understood role of right anterior insula in gating transitions in consciousness states.
454 Effects of Human Brain Organoid Age on Post-Transplant Growth in the Rat Motor Cortex
Authors: Blue Rachel , Fu Marissa , Harary Paul , Jgamadze Dennis , Rahaman Imon , Singh Shikha , Ming Guo-Li , Song Hongjun , Chen H. Isaac
Published: March 2023

INTRODUCTION:

Human brain organoids have potential to be used as a substrate for brain repair following injury, however the factors affecting survival and integration of transplanted organoids are unknown. We hypothesized that organoids transplanted at an earlier time point would result in improved survival and integration into the motor cortex because of their greater growth potential.

METHODS:

Human forebrain organoids at two timepoints (d20-25, d55-60) were transplanted into the motor cortex of adult rats following an aspiration injury. The first cohort was survived for 1 month post transplantation (MPT, n = 6); the second cohort was survived for 2 MPT (n = 16). Quantification of organoid volume and immunohistochemistry were performed.

RESULTS:

Survival of organoids post-transplantation was >90%. Pre-transplantation organoid size at d20-25 was significantly smaller than d55-60 (p < 0.0001). Average organoid volume 2 MPT was 1.04E + 10 µm3, significantly increased from 1435.4 µm3 pre-transplant (p = 0.0156). 2 MPT was correlated with more growth than 1MPT, though not statistically significant (p = 0.2672). Younger organoids trended toward a larger end-volume with the mean d20-25 volume being 3.1x larger than d55-60 at 1MPT (p = 0.3211) and 1.74x larger at 2MPT (p = 0.5090). Axon projections were seen in the adjacent host cortex at both timepoints. Both organoid age groups contained neural progenitors (PAX6, Sox2) with d20-25 retaining areas reminiscent of neural progenitor zones at 1MPT.

CONCLUSIONS:

Survival of transplanted organoids following injury was successful with a vast majority of organoids experiencing rapid growth within the injury cavity. Both age cohorts demonstrated adjacent axon projection and the presence of neural progenitors. Though further investigation is needed to clarify the influence of organoid maturity on integration, the survival rate and degree of post-transplant growth is a promising first step.
470 Robotic Transcranial Doppler With Artificial Intelligence for Real-Time Intraoperative Neuromonitoring During Endovascular Carotid Revascularization – A Novel and Autonomous Neuromonitoring Tool
Authors: Baig Ammad , Cappuzzo Justin Mark , Monteiro Andre , Khawar Wasiq , Waqas Muhammad , Donnelly Brianna , Davies Jason , Levy Elad I. , Siddiqui Adnan Hussain
Published: March 2023

INTRODUCTION:

Real-time intraoperative neuromonitoring is crucial to account for cerebral blood flow and embolic protection offered by proximal and distal cerebral protection devices during carotid revascularization procedures.

METHODS:

All patients diagnosed with high-grade carotid stenosis were prospectively enrolled between October 2021 thru February 2022. The TCD Robot head-brace system was used to secure the patients head, and the robot calibrated to automatically identify ipsilateral MCA or the terminal ICA. Patient demographics and procedural characteristics relevant to the robotic system such as signal strength, time to find signal, intracranial depth of the relevant vessel, cerebral waveform, and emboli count were recorded for the 4 critical phases: i- Access to crossing the lesion, ii- Filter and balloon deployment, iii- Stent placement and implantation, and iv- Removal of delivery system.

RESULTS:

Eight patients were included in our study (6 males [75%]; mean age 71.5 ± 3.9). Six out of 8 patients were symptomatic with a mean diameter stenosis of 83.5 ± 4.1. Average time taken to find a stable signal was 62 seconds (Range: 10-122). Terminal ICA was the vessel identified in all cases with a mean depth of 64mm (Range: 59-71). Flow arrest was demonstrated in all cases with flow reversal demonstrated in 2. Mean duration for the TCD Robotic surveillance was 23.6 ± 0.9 minutes with an average of 117 distal emboli (Range: 45-143) recorded by the device. Linear regression model identified stent placement and implantation as statistically significant (P = 0.0419) contributor to the final emboli count.

CONCLUSIONS:

To our knowledge, this is the first case series of real-time comprehensive neuromonitoring using a Robotic Transcranial Doppler system with Artificial Intelligence demonstrating various cerebral blood flow parameters including flow arrest and distal embolic incidence intra-operatively.
474 Incidence and Risk Factors for Perioperative Stroke Following Resection of Intracranial Tumors: A Nationwide Analysis of 30,951 Cases
Authors: Kassicieh Alex , Varela Samantha , Rumalla Kavelin NA , Kazim Syed Faraz , Bowers Christian Andrew
Published: March 2023

INTRODUCTION:

Perioperative cerebrovascular accidents (CVA) in neurosurgical patients is a serious complication that may result in permanent neurological deficits. Establishment of associated risk factors allows for mitigation of CVA risk and sequelae.

METHODS:

The National Surgical Quality Improvement Program (NSQIP) database was queried for cranial tumor excision cases (2015-2019, N = 30,951). Univariate and multivariable analysis of demographic data and comorbidities was used to assess predictive strength of these factors on postoperative CVA.

RESULTS:

CVA occurred in 1.7% of cases (N = 532). Patients with CVA, on average, were older, frailer, with increased rates of diabetes mellitus, hypertension, and weight loss. In multivariable analysis, predictors of CVA included advanced age (≥75th percentile in cohort)(OR: 1.9, 95% CI: 1.4-2.5), diabetes mellitus (OR: 1.4, 95% CI: 1.1-1.8), hypertension (OR: 1.4, 95% CI: 1.1-1.7), and weight loss (OR: 1.9, 95% CI: 1.1-3.2). Increased proportions of CVA were found among patients with primary malignant brain tumors (46.1%) and meningiomas (32.9%) when compared to all other benign brain tumors (6.6%) and secondary metastatic brain tumors (14.5%)(all p < .001). Elective surgery status was associated with decreased likelihood of CVA (OR: .74, 95% CI: .60-.91). In multivariable analysis, increasing frailty (as measured by mFI-5 and RAI-revised) was associated with increasing likelihood of CVA.

CONCLUSIONS:

The current study was the largest to identify preoperative risk factors for perioperative stroke after resection of intracranial tumors. Patients with advanced age, multiple comorbidities, and higher frailty scores were significantly more likely to suffer CVA. Frailty (as measured by mFI- and RAI-revised) is a valuable tool for preoperative risk stratification.
491 Durability of Short Segment Instrumentation With Vertebrectomy in the Setting of Metastatic Disease to the Thoracic Spine
Authors: Fahim Daniel K. , Vanood Aimen , Chieng Lee Onn , Ragheb Andrew
Published: March 2023

INTRODUCTION:

Current treatment of spinal metastases in the thoracic spine requiring vertebrectomy entails pedicle screw fixation at least two levels above and below the level of reconstruction.

METHODS:

We reviewed a series of 30 patients treated for single-level, non-junctional (T2 to T11) thoracic spinal metastasis via single level vertebrectomy with posterior short segment instrumentation. The primary outcome was need for reoperation due to construct failure. Secondary outcomes included local tumor recurrence, pain scores, neurological function, estimated blood loss, operative time, length of hospital stay, and post-operative wound complications.

RESULTS:

The most common primary tumor origin was non-small cell lung carcinoma (n = 9). All patients had a SINS score of at least 10 and Bilsky Grade of 2 or 3. Mean intraoperative blood loss was 605 mL (range 50 – 1200 mL) and mean operative time was 260.73 minutes (range 169 to 442 minutes). Two patients suffered perioperative complications but there was no construct failure or need for revision surgery at any time during the follow-up period. Mean length of follow-up was 24 months (range 1-65 months). An overall improvement in pain was seen postoperatively (7.67 versus 2.77, p < 0.001) and no patient experienced worsening neurological function. Average length of stay was six days. Three patients in this cohort had local tumor recurrence, although two of these patients suffered from a radioresistant tumor pathology.

CONCLUSIONS:

Our results encourage consideration of this less invasive technique in the management of patients suffering from metastatic disease requiring vertebrectomy and reconstruction in the non-junctional thoracic spine.
506 Fingerprinting the Epileptogenic Zone in RAVE
Authors: Nikitenko O'Leary Sean Mikhail , Musa Ibrahim , Zhou Oliver , Husain Adam , Price Anthony , Magnotti John F. , Wang Zhengjia , Beauchamp Michael S. , Gadot Ron , Sheth Sameer A. , Rodriguez Liliana Camarillo , Karas Patrick J.
Published: March 2023

INTRODUCTION:

The treatment of drug-resistant epilepsy remains a significant challenge. Surgical resection of the epileptogenic zone (EZ) often offers the highest chance of seizure freedom. Grinenko et al. [Brain. 2018; 141(1):117–131] demonstrated that intracranial EEG (iEEG) data analysis can be used to identify a time-frequency pattern or “fingerprint” to help identify the EZ. Complex algorithmic techniques, lack of standardization, and inaccessibility pose a hurdle to surgical programs that may consider fingerprinting as a tool to aid resection. R Analysis and Visualization of Intracranial EEG (RAVE) is a powerful, free, open-source, NIH-funded software designed to analyze iEEG data through a web browser on an internet-connected device. Here we present an accessible implementation of a fingerprinting algorithm with RAVE.

METHODS:

Our fingerprint module consists of three steps, following closely the work of Grinenko et al. First, iEEG seizure data is pre-processed with Morlet wavelet transform and bipolar normalization. Second, each electrode's time-frequency map is run through an image processing algorithm to extract the EZ fingerprint biomarkers: (1) pre-ictal spikes, (2) multiband fast activity, and (3) low-frequency suppression. Each electrode is ranked by biomarker and combined “fingerprint” score based on work by Woolfe et al. [J Neurosci Methods. 2019; 325:108347]. Data is then displayed via time-frequency plot for each electrode and the fingerprint score is projected across the brain with a 3D brain map viewer,

RESULTS:

Our fingerprint module in RAVE significantly streamlines EZ isolation. Time-consuming calculations are built-in, allowing users with no coding, image processing, or statistical experience to explore and share EZ fingerprinting data.

CONCLUSIONS:

We incorporated an algorithm to detect the epileptogenic zone fingerprint into RAVE, allowing free distribution and use of this research algorithm to surgical epilepsy programs.
510 Prospective, Multicenter, International Outcomes Study of Deep Brain Stimulation for Essential Tremor
Authors: Deuschl Günther , Loret Griet , Kovacs Norbert , Estrada Marta Blázquez , Clement Frederik , Lee Jung Il , Schuurman P.R. , Chen Lilly , Jain Roshini
Published: March 2023

INTRODUCTION:

Essential Tremor (ET) treatment is focused on medical management of motor symptoms and includes pharmacotherapy and ventral intermediate nucleus (VIM) thalamotomy, which is being largely replaced by thalamic Deep Brain Stimulation (DBS) as the surgical treatment of choice. DBS of the VIM thalamus is recommended as a therapeutic option for appropriate subjects with ET (Elble RJ., et al. Expert Rev Neurother. 2018).

METHODS:

This is a prospective, on-label, multi-center, international DBS outcomes study conducted at up to 50 implanting centers. All participants are implanted with a multiple-source, constant-current directional DBS system (Vercise, Boston Scientific). Subjects are followed for up to 3-years post implantation where their overall improvement in quality of life and ET symptoms are evaluated. Clinical endpoints evaluated at baseline and follow-up timepoints include: The Essential Tremor Rating Assessment Scale (TETRAS), Quality of Life in Essential Tremor Questionnaire (QUEST), Fahn-Tolosa-Marin Rating Scale (TRS), and Global Impression of Change. Adverse events also collected.

RESULTS:

To date, 18-implanted subjects with a mean disease duration of 15.1 ± 14.6-years and a baseline QUEST Summary Index score of 35.0 ± 12.4. At 6-months post-DBS, a clinically significant improvement in quality of life (∆ = 19.5-point change in QUEST SI score) was reported. In addition, a mean 9-hours of tremor reduction was noted (14-hours at Baseline, 6.9-hours at 6-months) in a typical day at 6-months. All subjects (100%) reported mild disability, and no subject reported moderate or marked disability (89% at baseline) as reported by TRS at 6 months.

CONCLUSIONS:

This work represents the first comprehensive, large scale collection of real-world outcomes and evaluation of safety and effectiveness of a multiple-source, constant-current DBS system capable of providing directionality for use in treatment of Essential Tremor.
524 Cytodifferentiation of Pituitary Tumors Influences Pathogenesis and Cavernous Sinus Invasion
Authors: Asmaro Karam Paul , Zhang Michael , Rodrigues Adrian , Mohyeldin Ahmed , Vigo Vera , Vogel Hannes , Born Donald , Katznelson Laurence , Fernandez-Miranda Juan Carlos
Published: March 2023

INTRODUCTION:

Pituitary neuroendocrine tumors (PitNET) continue to offer unique challenges given their proximity to the cavernous sinus, whereby invasive behavior can dictate extent of resection and surgical outcome, especially in neuroendocrine-active tumors. Recent advances in surgical techniques have resulted in the development of transcavernous endonasal surgery for invasive tumors.

METHODS:

169 consecutive primary PitNET were analyzed, of which 45% were neuroendocrine-active. There were 64 PIT-1, 62 SF-1, 38 TPIT, and 5 none-staining PitNets. The gold standard for cavernous sinus invasion was based on histopathological examination of the cavernous sinus medial wall and intraoperative exploration of cavernous sinus compartments.

RESULTS:

Cavernous sinus disease was present in 33% of patients. PIT-1 tumors had a significantly higher predilection for cavernous sinus invasion, 53% versus 24% and 18% for TPIT and SF-1 tumors, respectively (OR 6.13, 95% CI 1.08-2.58; p<0.001). For Knosp 0-2 tumors, 44% of PIT-1 tumors had cavernous sinus invasion compared to 7% and 13% for TPIT and SF-1 tumors, respectively (p < 0.01). Utilizing the transcavernous approach, surgical biochemical remission rates for patients with acromegaly, hyperprolactinemia, and Cushing’s disease were 88%, 87%, and 94%, respectively. Granulation pattern of PIT-1 tumors, corticotroph functional status, and Crooke’s cell corticotroph morphology did not influence cavernous sinus invasion.

CONCLUSIONS:

Likelihood of cavernous sinus invasion differed by transcription factor expression; PIT-1 expressing somatotroph and lactotroph tumors had a higher predilection for invading the cavernous sinus compared to other tumor subtypes. This elucidates a unique cavernoinvasive behavior absent in cells from other lineages. Innovative surgical techniques, however, can mitigate tumor behavior and achieve robust, reproducible biochemical remission and gross total resection rates. These findings can have considerable implications on the surgical management and study of PitNET biology and behavior.
525 Diffuse Microglia Inflammation is Associated with Anti-Tumor Efficacy in Polio Virotherapy for Glioblastoma
Authors: Yang Yuanfan , Brown Michael , Zhang Gao , Stevenson Kevin , Mohme Malte , Kornahrens Reb , Bigner Darrell , Lopez Giselle , Gromeier Matthias
Published: March 2023

INTRODUCTION:

Glioblastomas (GBM) harbor abundant inflammatory infiltrates with glioma-associated macrophages and microglia (GAMM) actively promoting tumor progression. Intratumor virotherapy with the highly attenuated rhino:poliovirus chimera, PVSRIPO, causes sublethal infection and activation of GAMM via the constitutively expressed human poliovirus receptor, CD155.

METHODS:

We optimized immune-competent CT2A murine glioblastoma models for blinded neuropathological analysis of therapy responses. Samples (n = 55) were collected in a time series after PVSRIPO or mock intratumor infusion for systemic review of histological features related to therapy. Immune cells were defined both by morphology and immunohistochemical (IHC) staining patterns. Multiplex IHC and RNA sequencing were performed to study the immune infiltrate and PD1/PD-L1 immune checkpoint expression. The role of the PD1:PD-L1 axis in restricting the antitumor efficacy of PVSRIPO was tested using survival studies.

RESULTS:

PVSRIPO treatment caused substantial, but transient tumor regression with intense engagement of the GAMM infiltrate. This was accompanied by diffuse microglia activation and inflammtion in the CNS surrounding the tumor, extending to the ipsilateral and even the contralateral hemispheres. PVSRIPO-instigated pervasive microglia activation occurred against a backdrop of sustained innate antiviral inflammation, associated with induction of the PD-L1 immune checkpoint on GAMM. Combining PVSRIPO with PD1/PD-L1 blockade led to more durable remissions in CT2A model.

CONCLUSIONS:

Our work implicates GAMM as active drivers of PVSRIPO induced antitumor inflammation and reveals profound and widespread neuroinflammatory activation of the CNS-resident myeloid compartment by PVSRIPO, which is closely associated with tumor regression.
551 Middle Meningeal Artery Embolization Embolic Agents – A Systematic Review & Meta-Analysis
Authors: Ellens Nathaniel R. , Schartz Derrek , Kohli Gurkirat S. , Rahmani Redi , Medha Akkipeddi Sajal , Mattingly Thomas , Bhalla Tarun , Bender Matthew T.
Published: March 2023

INTRODUCTION:

Middle meningeal artery (MMA) embolization is increasing in popularity and is thought to lower the rate of subdural hematoma recurrence and need for surgical rescue. Multiple embolic agents have been utilized, but the most effective agent has not been identified.

METHODS:

Clinical outcomes of embolization using polyvinyl alcohol (PVA) with or without (+/-) coils, N-butyl cyanoacrylate (n-BCA) +/- coils, and Onyx alone were separately evaluated. Outcome measures were the need for surgical rescue and in hospital periprocedural complications.

RESULTS:

30 studies were identified with a total of 646 patients, with 449 receiving PVA +/- coils, 134 receiving n-BCA +/- coils, and 60 patients receiving onyx alone. Composite rates for need for surgical rescue following embolization were 4.6% (95% Confidence Interval: 2.5% to 6.7%) for PVA +/- coils, 3.7% (CI: 0.6% to 6.8%) for n-BCA +/- coils, and 9.0% (CI: 1.9% to 5.4%) for Onyx alone. However, meta-regression revealed no significant difference between n-BCA and PVA based embolization (P = 0.728), between n-BCA and Onyx alone (P = 0.177), nor between PVA based and Onyx (P = 0.323) concerning need for surgical rescue. In regard to periprocedural complication rates, there was a pooled composite rate of 1.5% (CI: 0.3% to 2.7%) for PVA +/- coils, 3.1% (CI: 0.2% to 6.1%) for n-BCA +/- coils, and 2.7% (CI: 0% to 6.7%) for Onyx embolization. Similarly, meta-regression indicated no significant difference between PVA and n-BCA based therapy (P = 0.318), between n-BCA and Onyx embolization (P = 0.869), nor between PVA based and Onyx (P = 0.574).

CONCLUSIONS:

Rates of periprocedural complications and need for surgical rescue following MMA embolization are not influenced by the type of embolic agent utilized.
557 Results of Microsurgical Clipping of Unruptured Anterior Communicating Artery Aneurysms (ACOMa) Using the Pretemporal Minimal Durotomy Approach
Authors: Adepoju Adedamola , Krisht Ali F.
Published: March 2023

INTRODUCTION:

Recent reports suggest the superiority of microsurgical clipping of ACOMa compared to endovascular treatments. We present our experience with the pretemporal minimal durotomy (minimal brain exposure) approach in 168 patients.

METHODS:

Data of 168 patients were prospectively collected and retrospectively reviewed. The pretemporal approach with the removal of the posterior roof of the orbit and the anterior clinoid process with a minimized subfrontal durotomy allowed broad exposure to the ACOMa complex and minimal exposure to the surrounding brain. The technique allowed early proximal control and 360-degree visualization of the aneurysm and its surroundings.

RESULTS:

The average aneurysm size was 6.4 mm. Total clip occlusion was achieved in 100%, confirmed by intraoperative indocyanine green videography and post-operative computer tomography angiography/cerebral angiography. At discharge, 93.5% were modified Rankin Scale (mRS) 0-2, and 99.0% were mRS 0-2 at 1 year follow up. There was zero mortality, and one patient with a giant aneurysm had a stable residual on follow-up.

CONCLUSIONS:

Microsurgical clipping of ACOM aneurysms using the pretemporal minimal durotomy approach results in more durable outcomes than endovascular technique with excellent functional outcomes and should be strongly considered as a first treatment option, especially in aneurysms that have anatomic endovascular disadvantages that have a high likelihood of recurrence.
565 Delayed Rupture Risk of Persistently Filling Saccular ICA Aneurysms Following Flow Diversion with the Pipeline Embolization Device
Authors: Lee Ryan P. , Bhimreddy Meghana , Kim Jennifer E. , Wicks Robert Thomas , Xu Risheng , Bender Matthew T. , Jackson Christopher Mitchell , Gonzalez L. Fernando , Tamargo Rafael Jesus , Caplan Justin M.
Published: March 2023

INTRODUCTION:

Flow diversion of intracranial aneurysms results in high occlusion rates. However, 10-20% of aneurysms remain persistently filling on one year angiography. Often, these are retreated, but risks and benefits of retreatment are not well established. Calculating benefit requires a better understanding of rupture risk of persistently filling flow diverted aneurysms, which is not sufficiently established.

METHODS:

Our single institution database of 1000 flow diversion cases was queried for persistently filling saccular aneurysms of the clinoidal, ophthalmic, and communicating segments of the internal carotid artery treated with Pipeline Embolization Device or Pipeline Flex. Persistent filling was defined as continued contrast flow into the aneurysm on catheter angiogram one year after treatment. The clinical record was queried for occurrences of retreatment and delayed subarachnoid hemorrhage. Only cases with at least two years of follow up were included.

RESULTS:

Ninety-four persistent aneurysms were identified. The average size was 6 mm. The branch vessel originated separately from the aneurysm in 55% of cases, from the body of the aneurysm in 10.6% of cases, and from the neck in 34% of cases. Eighteen percent of aneurysms demonstrated >95% filling at one year and 61% were filling 5-95% of their original size. Average follow up time was 4.9 years, including 23 cases with >5 years follow up. No retreatment was undertaken in 91.5% of aneurysms. There were no cases of delayed subarachnoid hemorrhage.

CONCLUSIONS:

In our cohort of saccular ICA aneurysms treated with Pipeline flow diversion that demonstrated persistent aneurysm filling at one year, there were no instances of delayed rupture during the study period. This data suggests that observation may be appropriate for continued aneurysm filling at least in the first several years following Pipeline placement.