bluuebunny/crossref_metadata_2025_split huggingface dataset:
201 Tractography Analysis of Deep Brain Stimulation for Obsessive-Compulsive Disorder
Authors: Avecillas-Chasin Josue M. , Choi Ki S. , Mayberg Helen S. , Figee Martijn , Kopell Brian H. 
Published: March 2022

INTRODUCTION:
Deep brain stimulation of the anterior limb of the internal capsule (ALIC-DBS) is an effective treatment for refractory obsessive-compulsive disorder (OCD). Animal tracing studies and human tractography suggest that the putative ALIC target for OCD impacts brain circuits for reward, affect and inhibitory control, including projections to orbitofrontal (OFC) and ventromedial (vmPFC) cortex, ventrolateral cortex (vlPFC), dorsal anterior cingulate cortex (dACC), dorsal medial cortex (dmPFC) and dorsolateral prefrontal cortex (dlPFC). The recent development of directional segmented DBS leads may allow for selective stimulation of these ALIC-projections.

METHODS:
We generated structural connectivity maps of therapeutic stimulation using probabilistic tractography in OCD patients treated with ALIC-DBS. Response was defined as = 35% improvement in YBOCS after routine clinical parameter optimization. We also generated the volume of tissue activation (VTA) based on the stimulation parameters at the last follow-up. We estimated probability of connections between the VTA and each projection to the prefrontal regions (vmPFC/OFC, vlPFC, dlPFC, dmPFC, and dACC) in responders and non-responders. To further explore how connectivity would explain clinical improvement, we correlated connectivity values from stimulation sites to cortical regions to the percentage of change in YBOCS using Spearman correlation. Finally, we developed directional tractography activation models and explored personalized circuit-specific targeting and stimulation for patients with directional DBS-leads.

RESULTS:
All patients with ALIC DBS displayed stimulation of OFC/vmPFC and dmPFC connections. However, non-responders had incomplete stimulation of vlPFC, dACC and dlPFC compared to responders. Correlation analysis revealed that fibers from the dorsolateral ALIC to vlPFC were positively associated with improvement in Y-BOCS scores, while connections from ventral ALIC to vmPFC were negatively associated. We were able to successfully construct a stimulation tractography model of directional segmented lead configurations along the medial-lateral axis, which we used for personalized DBS targeting and programming in our most recent patients. Early observations suggest that this directional precision-strategy allows for fast improvement in patient-specific symptom domains for reward, affect and inhibitory control.

CONCLUSION:
Our findings suggest that the therapeutic benefit of ALIC DBS for OCD is associated with stimulation of a subset of specific ALIC WM pathways, which can be selectively targeted using directional DBS-systems.
202 Overlapping Functional and Stereotactic Surgery: A Retrospective Cohort Study of 1-Year Complications
Authors: Greven Alex C. M. , Douglas James A. M. , Malcolm James G. , Campbell Melissa , Lamanna Jason J. , Bray David P. , Howard Brian M. , Willie Jon T. , Boulis Nicholas M. , Gross Robert E. 
Published: March 2022

INTRODUCTION:
Overlapping surgery, when one attending surgeon manages two overlapping operating rooms and is present for all of the critical portions of each procedure, is an important policy that improves healthcare access for patients and case volumes for surgeons and surgical trainees. Despite several studies demonstrating the safety and efficacy of overlapping neurosurgical operations, the practice of overlapping surgery remains controversial. To date, there are no studies that investigate long term complication rates of overlapping functional and stereotactic neurosurgical procedures.

METHODS:
851 functional neurosurgical cases were divided into two cohorts: non-overlapping (n = 374) and overlapping (n = 477). The Anesthesia Society of America (ASA) score was used to compare the pre-operative risk for both cohorts. A complication was any surgically related reason that required readmission, reoperation, or an unplanned emergency department or clinic visit that required intervention. Complications were stratified into infectious and non-infectious. Chi-square and independent samples t-tests were used to determine significance.

RESULTS:
The mean ASA score was the same for both cohorts (2.7 +/- 0.6). There were no statistically significant differences in total complication rates (12% vs. 13%, p=0.74) or infectious complication rates (4% vs. 6%, p=0.27) between non-overlapping and overlapping cases. Infections accounted for the highest percentage of complications in both cohorts (33% vs. 44%, p = 0.26). There were no statistically significant differences between mean in-OR time (204 minutes vs. 206 minutes, p = 0.44) or mean skin-to-skin time (127 minutes vs. 129 minutes, p = 0.75) between non-overlapping and overlapping cases.

CONCLUSION:
There is no increased risk of 1-year complications or increased OR time for overlapping functional and stereotactic neurosurgical procedures compared to non-overlapping procedures.
205 Optimization of DBS Electrode Position With Multisite Microelectrode Recordings, Macrostimulation, and Atlas-Based Prediction Maps Visualized in 3D
Authors: Paulo Danika L. , Narasimhan Saramati , Gonzalez Hernan F. J. , Rodriguez William , Li Rui , Konrad Peter , Neimat Joseph S. , Shah Hamid M. , Bick Sarah K. B. , D'Haese Pierre , Dawant Benoit M. , Englot Dario J. 
Published: March 2022

INTRODUCTION:
Deep brain stimulation (DBS) at our institution is performed with a custom-made miniature stereotactic frame (STarFix, FHC) with the patient kept awake during electrode implantation to perform microelectrode recordings (MER) and macrostimulation testing. Pre-operative targets are selected with guidance from atlas-based efficacy prediction maps. Multisite intraoperative microelectrode recordings (MER) and macrostimulation data are collected, visualized in 3D in real-time, and integrated into selection of a final target.

METHODS:
A sample of 490 patients treated with DBS at Vanderbilt from 2011-2021 with 892 individual leads were included. During surgery, FHC microelectrodes are implanted in 2-3 test tracks on each side and microelectrode recordings are collected. Atlas-based prediction maps based on position and efficacy of previous cases help guide targeting. Macrostimulation data is collected at multiple depths along the same tracks, with efficacy quantified in quartiles and side effects noted. Preoperative maps and intraoperative data are visualized in 3D with color and integrated in real time to guide optimal FEP selection. Basic statistics were used to calculate percentages and means.

RESULTS:
Of 892 individual leads, 467 (52%) had FEP in the center track and 225 of those had FEP within 1mm of planned target depth. MER was collected in 435 (49%) of test tracks with 380 (43%) recordings collected in the FEP track. Stimulation data was collected for all leads and 867 (97%) of FEP tracks.

CONCLUSION:
Although planned targets were carefully selected preoperatively based on anatomy, coordinates, and guidance from atlas-based efficacy maps, FEP differed from anticipated target in 75% of cases. This discrepancy supports use of multisite MER and stimulation testing and the value of keeping patients awake to complete testing, optimizing their FEP in real-time based on maximal efficacy and minimal side effects. Finally, atlas-based prediction maps help guide initial targeting.
213 5-Aminolevulinic Acid for Enhanced Surgical Visualization of High-Grade Gliomas: A Prospective, Multicenter Study
Authors: Schupper Alexander J. , Baron Rebecca , Cheung William , Rodriguez Jessica , Kalkanis Steven N. , Chohan Mohammad , Nahed Brian V. , Zacharia Brad E. , Jensen Randy L. , Olsen Jeffrey , Sherman Jonathan , Prince Gabrielle , Carter Bob S. , Germano Isabelle M. , Hadjipanayis Constantinos G. , Yong Raymund L. 
Published: March 2022

INTRODUCTION:
Greater extent of resection is associated with longer overall survival in patients with high grade gliomas (HGG). 5-aminolevulinic acid (5-ALA) can increase EOR by improving intraoperative visualization of contrast-enhancing tumor during fluorescence-guided surgery (FGS). 5-ALA is converted by glioma cells into protoporphyrin IX (PPIX), which fluoresces under blue light. 5-ALA has been available for use in Europe since 2010, but only recently gained FDA approval as an intraoperative agent for HGG tissue.

METHODS:
This single-arm, prospective study included adults aged 18-80 with Karnofsky performance status (KPS)>60 and an MRI diagnosis of suspected new or recurrent resectable HGG. Intraoperatively, 3-5 samples per tumor were taken and their fluorescence status recorded by the surgeon. Patients were followed for six weeks postoperatively for adverse events, changes in the neurological exam, and KPS. We performed multivariate analyses of the outcomes of KPS decline, EOR, and residual enhancing tumor volume to identify predictive patient and intraoperative variables.

RESULTS:
Sixty-nine patients underwent 5-ALA FGS, providing 275 tumor samples for analysis. PPIX fluorescence had a sensitivity of 96.5%, specificity of 29.4%, positive predictive value (PPV) for HGG of 95.4%, and diagnostic accuracy of 92.4%. Drug-related adverse events occurred at a rate of 22%. Serious adverse events occurred at a rate of 4.3%. There were 2 unrelated deaths. KPS was significantly lower at 48 hours and 2 weeks, but was not different at 6 weeks postoperatively. Complete resection of enhancing tumor occurred in 51.9% of patients. Smaller preoperative tumor volume and use of intraoperative MRI predicted lower residual tumor volume.

CONCLUSION:
PPIX fluorescence, as judged by the surgeon, has a high sensitivity and PPV for HGG. 5-ALA was well-tolerated, and its application by trained surgeons in FGS for HGGs was not associated with any excess neurological morbidity.
307 The Hospital Frailty Risk Score Independently Predicts Increased Complication Rates and Healthcare Resource Utilization After Endovascular Treatment of Ruptured Aneurysms
Authors: Koo Andrew B. , Elsamadicy Aladine A. , Sarkozy Margot , Sherman Josiah , Reeves Benjamin , Freedman Isaac G. , Antonios Joseph P. , Sujijantarat Nanthiya , Renado Daniela , Hebert Ryan M. , Malhotra Ajay , Matouk Charles C. 
Published: March 2022

INTRODUCTION:
Frailty has emerged as an important indicator of patients who are at greater risk of adverse healthcare outcomes. The Hospital Frailty Risk Score (HFRS) was recently developed utilizing ICD-10 diagnostic codes to identify frailty using routine administrative hospital data but has not been applied to the evaluation of patients with ruptured intracranial aneurysms (IAs).

METHODS:
A retrospective cohort study was performed using the 2016-2017 National Inpatient Sample (NIS) database. All adult patients (=18 years) undergoing endovascular treatment for IAs after subarachnoid hemorrhage were identified using ICD-10-CM diagnostic and procedural codes. Patients were categorized into three HFRS-based frailty cohorts: Low (HFRS<5), Intermediate (HFRS=5 and <15), and High (HFRS=15). Patient demographics, comorbidities, treatment modality, perioperative complications, LOS, discharge disposition, and total cost of hospital admission were assessed. A multivariate logistic regression analyses were used to identify independent predictors of prolonged LOS, increased cost and non-routine discharge.

RESULTS:
Of the 16,290 patients identified, 4,200 (25.8%) were found to be Low frailty, 9,505 (58.3%) were Intermediate, and 2,585 (15.9%) were High by HFRS criteria. A greater proportion of patients in the Intermediate and High frailty cohorts experienced greater than one perioperative complication than Low frailty (Low: 16.4% vs Intermediate: 61.7% vs High: 87.6%, p < 0.001). There is a step-wise increase in mean LOS (Low: 12.2 ± 9.4 days vs Intermediate: 19.0 ± 14.8 days vs High: 26.9 ± 19.3 days, p < 0.001), mean total hospital cost (Low: $62,642 ± 39,552 vs Intermediate:$98,415 ± 63,042 vs High: $132,087 ± 75,263, p < 0.001), and non-routine discharge (Low: 20.0% vs Intermediate: 46.5% vs High: 73.9%, p < 0.001) with increasing frailty. On multivariate regression analysis, similar step-wise impact was found with increasing frailty in prolonged LOS [Intermediate: OR 1.56 (p = 0.02) and High: OR 2.82 (p < 0.001)], hospital cost [High: OR 2.01 (p = 0.001)], and non-routine discharge [Intermediate:OR 1.59 (p < 0.001) and High: OR 3.12 (p < 0.001)].

CONCLUSION:
Our study is the first to use the HFRS to assess the impact of frailty on patients undergoing endovascular treatment of ruptured IAs. We found that greater frailty was associated with increased complications, prolonged LOS, higher costs, and non-routine discharge.
309 Oscillating Between Gratitude and Fear: Lived Experience of Aneurysmal Subarachnoid Hemorrhage Survivors
Authors: Gulek Bernice G. , Haberman Mel , Oneal Gail , James Lois 
Published: March 2022

INTRODUCTION:
Aneurysmal subarachnoid hemorrhage (ASAH) is a devastating stroke that affects young adults at a mean age of 55 and mortality rate of 32%. Those who survive are subjected to short- and long-term consequences and the description of self-accounts of experiences are lacking.

METHODS:
This qualitative study utilized Husserl’s descriptive phenomenology methodology. Participants were recruited from an academic medical center outpatient neurosurgery clinic. A semi-structured interview guide and biodemographic background questionnaire guided data collection. Verbatim texts were analyzed according to Giorgi five-step method. The City of Hope Health-Related Quality of Life Theoretical Model gave structure to open-ended interviews, literature review, and for synthesis of results.

RESULTS:
Characteristics of the 16 participants included a median age of 56 years, predominantly female (81%), and six weeks to nine years since aneurysm rupture. Three major qualitative themes were uncovered that explained the structure of the general experience. The salient experiences reported by participants included psychological trauma, difficulty of symptom management, uncertainty, change in social relationships, and being unprepared for life after discharge. Other experiences discovered were difficulty in finding resources, fear of recurrence, social support as critical, and spirituality as a protective factor for wellbeing.

CONCLUSION:
Dimensions of the City of Hope Health-Related Quality of Life Model surfaced as essential, describing life after ASAH, when compared to the study’s conceptual model. The results highlight the need for multidisciplinary comprehensive post discharge support services, programs acknowledging the salience of all dimensions of health-related quality of life, and matching data-based standardized interventions to core sets of patient-reported short- and long-term outcomes.
316 Optimizing Safety in Robotic Lumbar Instrumented Fusions: A Risk Factor Analysis of Robotic Failures
Authors: Ashayeri Kimberly , Norris Zoe , Mottole Nicole , Patel Hershil , Balouch Eaman , O’Malley Nicholas , Frempong-Boadu Anthony , Eisen Leon , Buckland Aaron , Protopsaltis Themistocles 
Published: March 2022

INTRODUCTION:
There may be early complications with robot-guided lumbar fusions (RGLF). This study determines risk factors for robot-related complications and suggests optimal OR workflow.

METHODS:
Single-institution retrospective review of 525 RGLFs. Univariate analysis (independent samples t-tests, chi-squared analysis) assessed demographics, Hounsfield units (HU), procedural characteristics, and OR workflow as risk factors for robot registration failures and pedicle screw malpositioning. Multivariate logistic regression of significant factors was conducted. Subanalysis of Anterior Lumbar Interbody Fusion (ALIF) with RGLF was conducted. Receiver operating characteristic (ROC) curve determined thresholds for independent risk factors.

RESULTS:
All RGLF: Lower L1-HU and L5-S1 inclusion were significant risk factors for registration failure on univariate analysis. Placing pedicle screws directly after CT acquisition (PS after CT) and before interbody placement showed fewer registration failures. On multivariate analysis, L1-HU (Odds Ratio (OR): 1.012; p = 0.006), L5-S1 inclusion (OR: 2.795; p = 0.033) were independent risk factors. PS after CT improved registration (OR: 0.145; p = 0.004). Age and female gender were risk factors for pedicle screw malpositioning on univariate analysis. PS after CT showed fewer pedicle screw malpositions on univariate and multivariate (OR: 0.146; p = 0.006) analysis. ALIF with RGLF: PS after CT had fewer registration failures. Low L1-HU units was a risk for registration failure on univariate and multivariate (OR: 1.022; p = 0.001) analysis. ROC analysis of L1-HU showed a 145.85 cutoff. Age and hyperlordotic interbody use were risk factors for pedicle screw malposition on univariate analysis.

CONCLUSION:
Early robot-related complications may be avoided by recognizing risks. PS after CT, before interbody placement may avoid complications including pedicle screw malpositioning. Poor bone quality can lead to registration failures.
321 Mesenchymal Stem Cell-derived Exosomes Improve Functional Recovery in Rats After Traumatic Brain Injury with a Broad Therapeutic Window
Authors: Mahmood Asim , Zhang Yanlu , Zhang Yi , Zhang Zhenggang , Chopp Michael , Xiong Ye 
Published: March 2022

INTRODUCTION:
Mesenchymal stem cell (MSC)-derived exosomes are emerging as an important therapy in regenerative medicine with broad applications.

METHODS:
Male rats were injured with controlled cortical impact. In the dose-response study, a single intravenous injection of exosomes (50, 100, 200 µg/rat) or vehicle (n = 8/group) was administered 1 day after TBI. In the therapeutic window study, an intravenous injection of 100 µg exosomes or vehicle was administered on days 1, 4, or 7 after injury (n = 8/group). Neurological function was assessed using Neurological Severity Scores (NSSs), Footfault and Morris Water Maze (MWM) tests. Animals were sacrificed 35 days after TBI and tissues were analyzed using immunohistological studies.

RESULTS:
Compared to the vehicle, regardless of the dose and delay in treatment, exosome treatment significantly improved sensorimotor and cognitive function (NSS, MWM & Footfault tests), reduced hippocampal cell loss, promoted angiogenesis and neurogenesis, and reduced neuroinflammation. Maximum therapeutic benefit was seen with 100 µg dose. The time-dependent treatment data demonstrated that although 1-day post TBI treatment provided greatest improvement, significant functional and histological benefit was also seen with the other two delayed treatments (4 & 7 days post TBI).

CONCLUSION:
These results indicate that exosomes have a wide range of effective doses for treatment of TBI with a therapeutic window of at least 7 days post-injury. This efficacy of delayed treatment enhances the promise of exosome treatment as a potential therapeutic intervention for TBI.
328 Induced Spreading Depolarizations Produce Exaggerated Electrophysiologic Pathology in a Rat Model of Traumatic Brain Injury
Authors: Best Faith , Hopkins Tracy , Hartings Jed , Ngwenya Laura B. 
Published: March 2022

INTRODUCTION:
Spreading depolarizations (SDs) are waves of cortical depolarization that cause loss of ion homeostasis, brain silencing, and are prognostic of worse functional outcome in traumatic brain injury (TBI) patients. SDs occur in ∼50% of surgical TBI patients and have potential to spread from areas of injured brain into less-injured or “uninjured” cortex. Understanding differences in how injured versus uninjured cortex responds to SD waves can provide insight for therapeutic targets.

METHODS:
Adult Long Evans rats were subjected to either a moderate lateral fluid percussion injury (LFPI) or a sham injury. Beginning 103.4 ± 28.4 minutes after injury or sham, an electrode was placed at the site of injury (or sham) and electrocorticographic activity was recorded for two hours. SDs were induced every 15 minutes using 1M potassium chloride (KCl) soaked cotton balls placed on a frontal craniectomy separate from the recording site. Saline soaked cotton balls were used as a control.

RESULTS:
A total of 37 SDs were induced in the uninjured group and 32 SDs were induced in the injured group. No SDs were recorded in saline controls. There was no difference in the average time from KCl application to the start of the SD between groups (sham = 136.2, LFPI = 113.9, p = 0.4219). There was also no difference in average amplitude of the direct current (DC) shift (sham = 10.33, LFPI = 13.26, p = 0.1402). However, the injured group had longer average duration of DC shifts (sham = 53.54, LFPI = 99.22, p < 0.0001), longer average depression durations (sham = 206.6, LFPI = 265.8, p = 0.001), and larger average depth of depression (sham = 0.6824, LFPI = 0.8399, p = 0.0018).

CONCLUSION:
Our study revealed electrophysiologic differences between SDs induced in injured versus uninjured animals. Further studies are needed to determine the impact of these differences on neuronal damage and functional outcome.
334 Phase Synchrony within the Right Prefrontal Cortex Predicts Severity of Major Depression
Authors: Xiao Jiayang , Myers John , Metzger Brian , Pirtle Victoria , Mathura Raissa , Allawala Anusha , Adkinson Joshua , Rey Hernan , Goodman Wayne , Pouratian Nader , Bijanki Kelly R. , Sheth Sameer A. 
Published: March 2022

INTRODUCTION:
Widespread alteration of brain networks has been observed in people with major depression. Although many conventional treatments are available, nearly one-third of patients could become treatment-resistant. Therefore, a clearer understanding of brain networks in depression is needed in order to develop more effective treatments. As part of an ongoing trial utilizing stereo-EEG (sEEG) intracranial recordings to inform deep brain stimulation (DBS) for treatment-resistant depression (TRD), we measured neural activity in the dorsolateral prefrontal cortex (dlPFC) and orbitofrontal cortex (OFC).

METHODS:
Treatment-resistant depression patients (n = 2) were implanted with frontotemporal sEEG electrodes and DBS leads in the ventral capsule/ventral striatum and sub-callosal cingulate. We acquired several measurements of depression severity throughout a 9-day inpatient monitoring period using the computerized adaptive test for depression inventory (CAT-DI). We measured connectivity using the phase locking value (PLV) between oscillations in the right dlPFC and OFC during resting state. Then we examined the relationship between depression severity and peak PLV within alpha band (8-12 Hz).

RESULTS:
We examined the connectivity between the deepest grey matter contact in the right dlPFC and in the right OFC. Peak PLV in alpha band was correlated with CAT-DI score under eyes-open condition in patient 1 and patient 2.

CONCLUSION:
Phase synchrony between right dlPFC and right OFC is involved in the severity of major depression. Increased dlPFC-OFC phase synchrony may relate to increased mood control or management.