bluuebunny/crossref_metadata_2025_split huggingface dataset:
171 Neurosurgical Utilization, Charges, and Reimbursement Following the Affordable Care Act: Trends from 2011 to 2019
Authors: Hersh Andrew , Dedrickson Tara , Gong Jung Ho , Jimenez Adrian , Materi Joshua , Veeravagu Anand , Ratliff John K. , Azad Tej D. 
Published: March 2023

INTRODUCTION:
An estimated fifty million Americans receive Medicare healthcare coverage, a number expected to increase with an aging population. Despite rising costs, prior studies have established a downward trend in Medicare reimbursement rates adjusted for inflation for commonly billed surgical procedures. However, it is unclear if these trends hold true across all neurosurgical procedures.

METHODS:
We review the yearly Physician/Supplier Procedure Summary datasets from the Centers for Medicare and Medicaid Services for all procedures billed by neurosurgeons to Medicare Part B between 2011 and 2019. Procedural coding was categorized into cranial, spine, vascular, peripheral nerve, and radiosurgery cases. Weighted averages for charges and reimbursements adjusted for inflation were calculated each year. The ratio of the weighted mean reimbursement to weighted mean charge was calculated as the reimbursement-to-charge ratio (RCR), representing the proportion of charges reimbursed by Medicare.

RESULTS:
Overall enrollment-adjusted utilization of neurosurgical procedures decreased by 12%, with utilization in the inpatient setting decreasing by 24%. However, we identified a large increase in procedures at ambulatory surgery centers (639%) and in the outpatient setting (80%). Over the study period, inflation-adjusted, weighted mean charges decreased by 4.0% while reimbursement decreased by 4.6%, resulting in a decrease in the RCR of 0.6%. Procedure groups that saw increases in reimbursement included anterior and posterior cervical spine surgery, cranial functional and epilepsy procedures, cranial pain procedures, and endovascular procedures. Ambulatory surgery centers saw the greatest increase in charges and reimbursements.

CONCLUSIONS:
Overall reimbursement declined over the study period; however, significant variations emerged across procedural categories. We further find a significant shift in utilization and reimbursement for neurosurgical procedures outside of inpatient care settings.
174 Magnitude and Origins of Gender Differences in Medicare Payments to Neurosurgeons
Authors: Oshinowo Temitope Oladoyin , Rallo Michael Stephen , Chambless Lola Blackwell 
Published: March 2023

INTRODUCTION:
Gender pay disparities have been described across numerous specialties but have been relatively unexplored in neurosurgery.

METHODS:
We analyzed public data summarizing services provided to Medicare beneficiaries from 2013-2019. Practice metrics were compared between male and female neurosurgeons via Students’ T-test, Wilcoxon Rank-Sum, multiple linear regression.

RESULTS:
Women accounted for 8.3% of the 5,846 neurosurgeons serving the Medicare population. Females were reimbursed 41.8% ($59,163.20) less compared to their male colleagues (p < 0.001). Additionally, females billed for fewer services (288 vs. 474, p < 0.001), beneficiaries treated (128 vs. 193, p < 0.01), and unique codes (38.0 vs. 50.0, p < 0.001). However, the disparity persisted even when controlling for differences in years of practice, number of beneficiaries, and total services ($25,444.76, p < 0.001). There was no difference in geographic practice cost indices. The average payment-per-service was $78.15 (95%-CI, $73.14-$83.17, p < 0.001) less than that of males. This was influenced, in part, by women submitting for fewer services within the top quartile of payment (6.26% vs. 11.21%, p < 0.001). However, even when matching procedures by code, females were reimbursed $177.80 (95%-CI, $153.28-$202.31) less than males (p < 0.001).

CONCLUSIONS:
Female neurosurgeons are reimbursed 18% less when controlling for metrics of practice volume including number of services and beneficiaries treated. Importantly, the disparity exists even for individual procedures, which may represent more limited use of enhancement modifiers. Identifying origins of this disparity will aid in designing interventions that promote more equitable compensation for the work of female neurosurgeons. It is important to note that this database describes a primarily adult patient population and, therefore, discrepancies in reimbursement for pediatric neurosurgery, a field in which women represent a larger proportion, cannot be extrapolated from this study.
176 Use of Computed Assisted Neuronavigation During Spine Fusions and Long-term Health Care Utilization: An Exact Matched Analysis of National Administrative Database
Authors: Sharma Mayur , Ugiliweneza Beatrice , Boakye Maxwell , Drazin Doniel 
Published: March 2023

INTRODUCTION:
Computer assisted neuronavigation (CAN) during spine fusions has increasing being utilized in the United States. The impact of CAN on long-term health care utilization is not well defined.

METHODS:
MarketScan database were queried using the ICD-9/10 and CPT 4th edition, from 2003 to 2019. We included patients ≥ 18 of age who underwent spine fusions with at least 2 years follow-up. Outcomes were repeat fusions or new fusions, length of stay (LOS), discharge disposition, hospital re-admissions, outpatient services, and medication refills for up to 24 months following the index procedure.

RESULTS:
Of 183,620 patients who underwent spine fusions during the study years, 5046 (2.75%) were identified to have CAN used for the fusions. Exact matching was successful for 4861/5046 (96%) in the CAN group. CAN had no effect on LOS, home discharge, or complications at index hospitalization and 30-days post discharge. However, CAN was associated with a $7667 difference in median payments ($60501 vs $52834, p < .0001). CAN was associated with lower rates of repeat fusions at 6-months (3% vs. 4%), 12 months (2% vs. 3%) and 24 months (5% vs. 6%) following the index procedure, p < 0.05. Patients who underwent CAN had lower payments at 6 months ($5186 vs $5527, p: 0.0159), 12 months ($10267 vs $11262, p: 0.0207) and 24 months ($21453 vs $24355, p: 0.0021).

CONCLUSIONS:
CAN is increasing being used for spine fusions primarily for thoraco-lumbar procedures. No difference in complications, discharge disposition and LOS were noted across the cohorts at index hospitalization, with higher index payments with CAN use. CAN was associated with lower rates of repeat fusions and corresponding health care utilization for up-to 24 months following the index procedures compared to non-CAN cohort.
177 International Authorship Trends in Academic Neurosurgery and Effect of Double-Blind Review
Authors: Chalif Eric , Yue John K. , Chillakuru Yeshwant , Badani Aarav , Aghi Manish Kumar 
Published: March 2023

INTRODUCTION:
There is a lack of data on international publication rates and whether reviewer biases exist that may affect diversity of authorship.

METHODS:
Articles published within Neurosurgery, Journal of Neurosurgery (JNS), and World Neurosurgery (WNS) were collected from 2000-2019. Country affiliation data was assigned and analyzed with respect to journal, year of publication, neurosurgical subspeciality, and relative impact.

RESULTS:
Across 23,325 articles, lead authorship consisted of United States (42.9%, N = 10,005), Japan (9.9%, N = 2,305), China (9.3%, N = 2,167), Germany (5.1%, N = 1,187), South Korea (3.3%, N = 773), Italy (3.3%, N = 773), Canada (3.3%, N = 769), and other nations (22.9%, N = 5,346). Rates of publications did not differ across United States, Asian countries, South/Latin American countries, or African countries pre- and post-initiation of double-blind review in Neurosurgery (p > 0.05). Annual percentage of publications showed highest relative decrease for the United States (-0.48% per year, r2 = 0.194) and increase for China (0.87% per year, r2 = 0.761). WNS published fewer articles from the United States compared to Neurosurgery or JNS (Mean difference [MD] -20.6%, p < 0.001), and more articles from Asian (MD +23.5%, p < 0.001), Latin/South American (MD +1.4%, p < 0.001), and African countries (MD +0.8%, p < 0.001). Unbiased co-authorship clustering by country demonstrated that certain countries were more likely to publish together based on geopolitical characteristics.

CONCLUSIONS:
There is a higher relative contribution to neurosurgery publications from authors in the United States compared to other countries. This effect is not due to potential biases in single-blind review, as evidenced by a natural experiment comparing authorship rates at Neurosurgery pre- and post-initiation of double-blind review in 2011. Additional research is needed to determine whether other biases contribute to differences in publication rates across countries.
181 Costs of Surgery in Adult Spinal Deformity: Do Higher Cost Surgeries Lead to Better Outcomes?
Authors: Passias Peter G. , Joujon-Roche Rachel , Williamson Tyler K. , Tretiakov Peter S. , Imbo Bailey , Krol Oscar , Lebovic Jordan , Diebo Bassel G. , Vira Shaleen 
Published: March 2023

INTRODUCTION:
With increased focus on delivering cost effective healthcare, interventions associated with high resource utilization, such as adult spinal deformity (ASD) surgery, have received greater scrutiny.

METHODS:
A retrospective analysis of a single-center ASD database. ASD patients ≥18 years with baseline (BL) and 2-year (2Y) data were included. Surgical costs were calculated based on 2021 average Medicare reimbursement by CPT code. Costs of complications and reoperations were intentionally excluded. Patients were ranked into tertiles by surgical cost. The tertile with the highest surgical costs (HC) and lowest surgical costs (LC) were propensity score matched (PSM’d) to account for differences in baseline age and deformity. Multivariable logistic regressions assessed odds of achieving outcomes of interest in PSM’d groups.

RESULTS:
421 patients met inclusion (139 LC; 127 HC). After PSM, 102 patients remained in each cost group with an average reimbursement of LC: $11,279 vs. HC: $29,274. PSM’d groups had similar demographics and baseline deformity (all p >.05). Compared to LC patients, HC had higher odds of meeting SCB in SRS-22-Total (OR: 2.461, [1.321, 4.586], p = .005) and higher odds of meeting SCB in NRS Back (OR:1.961, [1.032, 3.723], p = .040). With respect to deformity, HC patients were more likely to have “0” Schwab modifier at 2Y in SVA (OR: 5.736, [2.798, 11.761], p<.001), PI-LL (OR: 2.239, [1.100, 4.559], p = .026), and PT (OR: 2.456, [1.335, 4.518], p = .004).

CONCLUSIONS:
While patient presentation impacts surgical planning and costs, we sought to control for such variations to assess association between surgical costs and outcomes. Although higher cost did not guarantee an ideal outcome, high cost patients generally experienced superior patient reported outcomes and realignment at 2-years. Thus, isolating cost reduction as a public health priority may compromise outcomes in ASD patients.
183 Proposed Classification System of Radiographic Bone Changes After Cervical Disc Replacement
Authors: Khachatryan Armen , Phillips Frank M. , Lanman Todd Hopkins , Andersson Gunnar B. J. , Jacobs Joshua , Kurtz Steven , Pratt Stuart 
Published: March 2023

INTRODUCTION:
Cervical Disc Replacement (CDR) is an increasingly utilized procedure to address cervical degenerative conditions, as an alternative to discectomy and fusion, for the purpose of preserving natural segmental motion.

METHODS:
Using serial radiographs from patients, a panel of experts assembled for the purpose of creating a classification system to aid in reproducibly and consistently identifying boney changes and assessing CDR device radiographic appearance. Subdividing the superior and inferior vertebral bodies into 3 equal sections, observed bone loss such as endplate rounding, cystic erosion adjacent to the endplate, and cystic erosion not adjacent to the endplate, is recorded. Determining if bone loss is progressive and estimating severity of bone loss (measured by the percentage of end plate involved) is recorded. Additional relevant boney changes and device observations include radiolucent lines, heterotopic ossification, loss of core implant height, and presence of device migration, subsidence, and olisthesis.

RESULTS:
Serial radiographs from 26 patients implanted with a variety of CDR products were assessed by 6 investigators including clinicians and scientists experienced in CDR or appendicular skeleton joint replacement. After several iterations, a classification system emerged that had improved concordance among the participating investigators. Next steps include assessing reliability with a broad group of clinicians, using serial radiographs from a significant number of patients, to confirm the proposed classification scheme.

CONCLUSIONS:
A standardized nomenclature for boney changes following CDR will facilitate accurate and reproducible scientific communications regarding the clinical outcomes of this procedure. The novel system proposed demonstrated good concordance among experienced investigators in this field and represents an important advancement.
185 Cannabis Dependence and Health Care Utilization Following Cervical and Lumbar Spine Fusions: National Database Analysis
Authors: Alkin Victoria , Dietz Nicholas , Sharma Mayur , Drazin Doniel 
Published: March 2023

INTRODUCTION:
Recent increases in cannabis use have been associated with broader legalization and social acceptance. Smoking tobacco leads to a higher incidence of pseudoarthrosis and complications following spinal fusion. However, little research has been done regarding the impact of cannabis on outcomes following spine fusions.

METHODS:
The IBM MarketScan Database (2009-2019) was used to identify patients who underwent single or multilevel cervical or lumbar fusions. Patients were categorized based on cannabis abuse disorder. Inpatient hospitalization outcomes (length of stay, discharge disposition, complications, payments), post-discharge outcomes (reoperation, readmission, outpatient services, medication refills, payments), and complications were analyzed at 6- and 12- months following index procedure. Exact match was used to control for unbalanced demographics. SAS 9.4 was used for data analysis.

RESULTS:
The exact match cohort had 2958 cervical fusion patients (1479 with a cannabis-related disorder) and 3204 lumbar fusion patients (1602 with a cannabis-related disorder). For cervical fusion, no significant difference between patients with and without cannabis-related disorder was found for most peri- and postoperative complications, overall complications, or discharge home. Users had significantly higher occurrence of sepsis (1.1% vs 0.3%, P = 0.0073) and significantly lower hospitalization payments ($18541 vs. $21137, P=0.0019). For lumbar fusion, no difference was found for overall complications or specific peri- and postoperative complications. Users had significantly lower hospitalization payments ($22612 vs. $29013, P = 0.0002). In both the cervical and lumbar groups, no differences were found in reoperation. Opioid use was lower for users directly post-operation, but higher 3-12 months post-operation.

CONCLUSIONS:
Cannabis dependence and abuse disorders are not associated with worsened perioperative outcomes in patients undergoing single or multilevel cervical or lumbar fusions.
189 Novel Wireless Battery-Free Fully Passive Flexible Brain/Spine Implant for Improved Recovery of Function Through Epidural Stimulation
Authors: Garcia Diogo P. , Gullick Daniel , Benbuk Ahmed , Liu Shiyi , Esmaeli Hamid , Nikkhah Medhi , Christen Jennifer , Quinones-Hinojosa Alfredo 
Published: March 2023

INTRODUCTION:
Acquired motor impairment from diseases such as stroke, trauma, epilepsy, and cancer remains an important cause of disability. Current treatments provide insufficient brain/spine recovery, with most patients failing to recover adequate motor function with rehabilitation alone. Brain stimulation can lead to enhanced synaptic density and synaptic response after long-term stimulation and enhanced motor function recovery. However, non-invasive options remain inadequate and invasive approaches are associated with unacceptable risks.

METHODS:
A flexible and transparent silicone elastomer substrate was used through microfabrication processes, with an external antenna near the implant to control the stimulation. In vitro validation was accomplished by wireless stimulation of human-induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs). In vivo validation was performed by motor cortex stimulation on an anesthetized rat. The corresponding hindlimb motion was captured by video. To separate implant-evoked movement from spontaneous movement, we compared the peak hindlimb velocity during 0.5 sec post-stimulation periods vs. the 0.5 sec pre-stimulation periods, across a continuous series of N = 43 stimulation pulses.

RESULTS:
Cultured hiPSC-CMs cells demonstrated well-controlled beating behavior under 0.5, 1, and 2Hz wireless stimulation. Statistical analysis further confirmed the change in beating rate corresponded with stimulation frequency (p < 0.001). The recorded hindlimb movement under wireless motor cortex stimulation demonstrated synchronization with the delivered voltage pulse trains. Average peak hindlimb velocity during pre-stimulation periods was 0.8 ± 0.4 mm/sec (± S.D.); during post-stimulation periods, 47 ± 13 mm/sec. A two-sample t-test confirmed the applied wireless power directly evoked movement, (p < 0.001).

CONCLUSIONS:
We have developed a wireless, battery-less implant with demonstrated efficacy in vitro and in vivo. Efforts at long-term safety evaluation are ongoing in a smaller and larger animal model as a bridge to phase 0/1 clinical trials.
199 Rates of Upper Extremity Compression Neuropathies Among Obese Patients Compared to Non-Obese Controls and Obese Patients Who Underwent Bariatric Surgery
Authors: Khalid Syed Ibad , Maasarani Samantha , Thomson Kyle , Pires Giovanna , Becerra Adan , Adogwa Owoicho , Mehta Ankit Indravadan , Noland Shelley , Torquati Alfonso 
Published: March 2023

INTRODUCTION:
Upper extremity compression neuropathies(UECN) are increasingly prevalent and decrease the quality of life of affected individuals. Studies suggest obesity as a risk factor for carpal tunnel syndrome, the most common type of UECN.

METHODS:
A retrospective cohort study was conducted using the PearlDiver Mariner Database, an all-payor claims database containing claims for over 53 million patients from 2010 to 2019 in all 50 US states. Rates and odds of all types of UECN were compared between 1:1:1 exact matched cohorts of obese patients who were medically managed, obese patients who underwent bariatric surgery, and nonobese patients (111,967 patients in each cohort).

RESULTS:
Compared with nonobese patients, patients with obesity were significantly more likely to develop any UECN (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.09–1.18), carpal tunnel syndrome (OR, 1.15; 95% CI, 1.10–1.30), and 2 or more UECN (OR, 1.34; 95% CI, 1.20–1.48). Compared with obese patients who were managed medically, obese patients who underwent bariatric surgery were significantly less likely to develop any UECN (OR, 0.87; 95% CI, 0.84–0.91) and carpal tunnel syndrome (OR, 0.85; 95% CI, 0.81–0.89).

CONCLUSIONS:
Obese patients have higher odds of both single and concomitant UECN, specifically carpal tunnel syndrome, compared with nonobese patients. Bariatric surgery decreases the odds of developing UECN compared with obese patients not undergoing surgical intervention.
207 An Investigation Into the Characteristics of Peri-Lead Edema After Deep Brain Stimulation Surgery
Authors: Devara Ethan , Dang Huy , Shofty Ben , Sheth Sameer A. 
Published: March 2023

INTRODUCTION:
Peri-lead edema (PLE) is an increasingly recognized effect of deep brain stimulation (DBS) surgery. Despite this, PLE remains poorly characterized, with reports of the phenomenon’s incidence and clinical meaning differing widely among studies.

METHODS:
We regularly obtained 2 CT scans at each stage of routine DBS surgery (lead implantation and implantable pulse generator implantation) in 55 consecutive patients. Both image sets (early and late postoperative CTs) were inspected for PLE, and edema volume was manually segmented. Clinical characteristics were procured by chart review. Edema volume was assessed quantitatively and compared with clinical postoperative course to investigate any possible correlations.

RESULTS:
Zero (0%) and 24 (43.6%) patients were found to have PLE at stage one and stage two imaging, respectively. Nineteen of the edema patients were treated for Parkinson’s Disease and 5 for essential tremor. DBS targets were STN (12), VIM (6), and GPi (6). Mean edema volume was 8.10 ± 5.66 mL, with a median of 8.91 mL and ranging from 1.60 to 26.90 mL. Closer inspection of volume into left- and right-hemispheric PLE ascertained no discernible difference between each or to the total (ANOVA F < 0.0005, p = 0.99), nor did an analogous partition into volume by target (ANOVA F = 0.19, p = 0.90). Three patients experienced symptomatic PLE, all of whom had DBS targeting VIM. One patient had experienced seizure, another with altered mental status and gait instability, and the last had dizziness and weakness. All fully recovered following antiepileptic medication for the patient with seizure, and the other two following steroid administration.

CONCLUSIONS:
PLE occurs in about half of the patients undergoing DBS and is usually asymptomatic. Symptomatic PLE may be managed to resolution in an outpatient setting with steroid administration.
208 DBS-Induced Improvement in Cognitive Control is Mediated by Theta Oscillations in Human Intracranial Recordings
Authors: Allawala Anusha , Vartany Stephanie , Mathura Raissa , Ritz Harrison , Adkinson Joshua , Gadot Ron , Oswalt Denise , Shenhav Amitai , Goodman Wayne , Pouratian Nader , Bijanki Kelly R. , Borton David , Sheth Sameer A. 
Published: March 2023

INTRODUCTION:
Deficits in cognitive control, defined as the ability to adjust response or attention in the face of competing or changing demands, are thought to be responsible for inflexible behaviors in neuropsychiatric diseases. Here, we seek to understand frontotemporal networks underlying dysfunctional cognitive function using sEEG recordings and deep brain stimulation (DBS) in human subjects with treatment-resistant depression (TRD).

METHODS:
We employed a forced two-choice cognitive control task where the strength in the target and the distractor interference of a visual stimulus was parametrically and independently varied, resulting in granular variation in response congruence. This task was performed in 13 total subjects, 10 of whom underwent sEEG implants for epilepsy monitoring, whereas 3 subjects were participating in a clinical trial of DBS for TRD and were additionally implanted with DBS leads in the ventral capsule/ventral striatum and subcallosal cingulate.

RESULTS:
Reaction time (RT) and accuracy worsened with increasing levels of conflict across all subjects (Cohen’s d-accuracy = 0.7, Cohen’s d-RT = 0.2) prior to stimulation. Single-trial regression analyses revealed a parametric effect of task conflict with theta-band (4-7 Hz) power across the dorsolateral PFC (dlPFC), dorsal anterior cingulate cortex, orbitofrontal cortex (OFC) as well as the insula. DBS significantly improved behavioral performance, demonstrated by reduced RT (1080 土 10 ms to 840 土 50 ms), and improved accuracy(70 土 9.8% to 90 土 5%). While we observed an overall increase in theta power across the PFC and ACC in TRD participants following DBS, the effect of conflict in theta power was reversed (theta power decreased with increasing conflict in dlPFC and OFC).

CONCLUSIONS:
Leveraging this unique behavioral paradigm with concurrent distributed intracranial recordings and causal manipulation broadens our understanding of neural substrates of decision-making as well as the mechanisms of therapeutic action of DBS for TRD and other psychiatric disorders.