bluuebunny/crossref_metadata_2025_split huggingface dataset:
144 Sports Participation and Sports-Related Neurologic Injuries in Pediatric Patients With Chiari I Malformation
Authors: Wieland Clare , Holste Katherine , Garton Hugh , Muraszko Karin M. , Maher Cormac O. 
Published: March 2023

INTRODUCTION:
Currently, there is no consensus recommendation regarding the safety of sports participation for pediatric patients with Chiari I malformation (CM-I).

METHODS:
A prospectively administered survey was given to 744 pediatric neurosurgery clinic patients at the University of Michigan between December 2010 and December 2021. Data were recorded on demographic information, imaging characteristics, treatment, sports participation, and presence of sports-related neurologic injury. Patients with incomplete survey data were called. Two hundred and seven patients completed at least 1 subsequent survey and were prospectively followed for a mean of 1.56 years. A season was defined as 3 months of sports play.

RESULTS:
Of the 744 patients with completed surveys, 462 patients participated in sports. Patients who participated in sports were more likely to be older at presentation (p < 0.001) and have rounded cerebellar tonsil morphology (p < 0.001). A cumulative total of 6,854.67 seasons of sports were played (5,918.67 prior to CM-I decompression (CMD) and 936 after). There were 84 sports-related concussions among 55 patients; 79 prior to CMD and 5 after CMD. The concussion rate was 12.25 per 1,000 seasons of all sports, 9.16 per 1,000 seasons of limited-contact sports and 13.76 per 1,000 of contact sports. The concussion rate after CMD was 5.34 per 1,000 seasons of all sports, 9.19 per 1,000 seasons of limited-contact sports and 7.09 per 1,000 seasons of contact sports. There were no reports of long-lasting neurologic issues post-concussion or of permanent spinal cord injury.

CONCLUSIONS:
There were no permanent or catastrophic sports-associated neurologic injuries reported in this study. The concussion rate in CM-1 patients before and after CMD were low and therefore sports participation in this population should not be counseled against.
145 Incorporating Intraoperative Mechanomyography to Peripheral Nerve Decompression Surgery
Authors: Taghlabi Khaled , Guerrero Jaime , Cruz-Garza Jesus , Javeed Saad , Dibble Christopher , Ray Wilson Zachary , Faraji Amir H. 
Published: March 2023

INTRODUCTION:
Considerable progress has been made in the development of novel intraoperative nerve monitoring technologies. Recent studies demonstrated the high sensitivity of mechanomyography (MMG) in detecting nerve function as compared to traditional electromyographic recording. MMG reflects the mechanical vibrations of single motor units detected via accelerometer sensors and is therefore indicative of underlying axonal integrity.

METHODS:
A total of 20 consecutive patients undergoing decompression procedures for ulnar nerve (8 patients) or common peroneal nerve (12 patients) neuropathies were included. Four patients did not have MMG signals elicited: 1 ulnar and 3 common peroneal nerve patients. Intraoperatively, the nerves were stimulated via MMG ball tip electrode probe starting at 0.1 mA threshold and increasing by 0.1 mA increments until target muscle activity was noted. The lowest threshold current required to elicit a muscle response was recorded prior to decompression and following proximal and distal decompression.

RESULTS:
Of the patients, 80% (16/20) had MMG signals detected and recorded. The mean pre-decompression stimulus threshold was 1.59 ± 0.77 mA. Following surgical decompression, a statistically significant improvement in mean MMG stimulus threshold was noted (0.47 mA ± 0.13, p < 0.0001). The average stimulus threshold change for the common peroneal nerve patients was -0.80 mA (p = 0.001), and -1.48 mA (p = 0.002) for ulnar nerve patients. Post-operatively, all patients endorsed symptomatic improvement with no complications.

CONCLUSIONS:
MMG is an established technique that may provide objective intraoperative guidance in determining the extent of surgical nerve decompression. Lower stimulus thresholds likely represent increased sparing of axonal tissue, which may correlate with improved functional recovery. Future work should focus on validating normative values of MMG stimulus thresholds in various nerves and establishing clinical associations with functional outcomes.
149 Quantitative Performance Assessment of a Wirelessly Powered Vagus Nerve Stimulator in a Porcine Model
Authors: Habibagahi Iman , Omidbeigi Mahmoud , Hadaya Joseph , Lyu Hongming , Jang Jaeeun , Ardell Jeff , Bari Ausaf A. , Babakhani Aydin 
Published: March 2023

INTRODUCTION:
Electrophysiological stimulation has been widely used in the management of various disorders, including neurological and cardiac disorders. The dependence on an implantable pulse generator (IPG) increases the risk of surgical complications, patient discomfort, and need for IPG replacement surgery in stimulation methods. Wireless and batteryless stimulators offer important capabilities such reduced need for reoperation, and shorter surgical time compared to their wired counterparts. However, stable quantitative functionality assessment of wireless systems is an essential requirement for their practical usage.

METHODS:
In vivo studies were performed in three anesthetized male pigs. Conventional wired stimulation using bipolar electrodes and a wireless stimulator using the circular wireless receiver (ø 13 mm, 483 mg) with cuff electrodes were implanted around the right Vagus nerve of all animals. Stimulation was performed at varying frequencies (1–20 Hz), and pulse widths (0.1–1 ms) using both systems. Heart rate, left ventricle pressure, and EKG were monitored during VNS. A paired t-test was used to compare physiological responses to different VNS systems.

RESULTS:
A total of 84 stimulations by the wireless device and 36 stimulations by the conventional system were performed. 72% of wireless device stimulations and 75% of the conventional VNS stimulations led to significant heart rate reduction (P < 0.05, paired t-test). There was no significant difference between conventional and wireless systems when comparing physiological markers in response to different pulse widths and stimulation frequencies.

CONCLUSIONS:
This study quantitatively compared functionality of a novel wireless and batteryless VNS system to a conventional VNS, and can serve as a basis for future wirelessly powered implants in the field of neurosurgery to assess functionality and perform close loop stimulation using physiological markers.
150 Genetic Markers of Peripheral Nerve Tumors: Results From the UCSF500 Cancer Gene Panel
Authors: Vargas Enrique , Haddad Alexander F. , Vasudevan Harish , Jacques Line G. , Mummaneni Praveen V. 
Published: March 2023

INTRODUCTION:
The purpose of the UCSF 500 test is to identify genetic mutations in the DNA of a patient’s cancer. The UCSF 500 test results also provide information on genetic changes that are inherited and increase the risk of developing cancer for a patient or a patient’s family. We report an institutional experience of UCSF500 results from peripheral nerve tumor samples.

METHODS:
The UCSF 500 Cancer Gene Test uses capture-based next-generation sequencing to target and analyze the coding regions (exons) of 529 cancer genes, as well as select introns of 47 genes. This test can be ordered on solid tumors, hematopoietic malignancies, or lesional tissue specimens. A retrospective analysis of patients with schwannoma, malignant peripheral nerve sheath tumors (MPNST), neurofibroma, and other types of peripheral nerve tumors was performed.

RESULTS:
178 samples from 163 patients with peripheral nerve tumors undergoing genetic testing met inclusion criteria. The top 5 mutated genes and their frequency for Neuroblastoma includes PIK3C2G (1.0), IGF1R (0.2), NOTCH2 (0.2), CIC (0.2), ATR (0.2). The 5 genes with the highest frequency copy number alteration (CNA) include SOX9, SRSF2, PRKAR1A, PRKCA, PPM1D. Schwannoma: NF2 (0.58), LZTR1 (0.21), MSH2 (0.14), FAT3 (.13), SMARCB1 (0.1). The top 5 CNA genes were all deletions on chromosome 22. MPNST: TYK2 (1.0), MRE11 (1.0), NF1 (0.65), SUZ12 (0.33), TP53 (0.32). Neurofibroma: TNFAIP3 (1.0), ADGRA2 (1.0), FLT4 (1.0), NF1 (0.61), PRKCH (0.11). Other: TERT (0.39), DDR1 (0.25), KMT2C (0.25), FAT1 (0.15), NRG1 (0.13).

CONCLUSIONS:
We describe an institutional experience with UCSF500 genetic test results on all peripheral nerve tumors sent for analysis from 2015 to 2022. Using these data to guide the development of understudied genes of interest could lead to increased understanding of the genetic mechanism of these tumors.
151 Intracranial Magnetic Resonance Guided Laser Interstitial Thermal Therapy for Epilepsy: A Single Institution’s Experience of 226 Cases
Authors: Philbrick Brandon , Blanpain Lou T. , Gross Robert E. , Willie Jon Timothy 
Published: March 2023

INTRODUCTION:
Magnetic resonance guided laser interstitial thermal therapy (MRg-LITT) is a minimally invasive alternative to open surgical resection for epilepsy. Patient and technical factors associated with outcomes remain unclear.

METHODS:
We performed a retrospective review of consecutive patients undergoing MRg-LITT surgery at a single high-volume epilepsy center. Medical and surgical history, trajectory number per patient, adverse events, and outcomes up to 24 months were obtained and statistically analyzed.

RESULTS:
203 patients underwent a total of 226 MRg-LITT procedures for epilepsy between 2011-2020. 52% and 55% of patients experienced seizure freedom at 12 and 24 months after ablation, respectively. Overall, patients with lesional epileptogenic foci were more likely to have better seizure control at 12- and 24-months after surgery (p < 0.05). Of cases performed with curative intent, patients with mesial temporal sclerosis (MTS) were most likely to maintain long-term seizure freedom. Ablations performed for disconnection (corpus callosotomy) or palliation of multifocal epilepsy were unlikely to provide complete seizure freedom. 6 cases (2.7%) were complicated by intra- or post-operative hemorrhage. 3 patients (1.5%) experienced persistent post-operative complaints including cranial nerve palsy and headaches. The odds of complication (minor or major vs none) were multiplied by 1.43 for each additional trajectory (95% CI [1.16, 1.76]), and by 1.04 for each additional 1cm3 of volume ablated (95% CI [1.008, 1.076]).

CONCLUSIONS:
MRg-LITT, a safe and effective approach to distinct epilepsy types, appears most persistently beneficial for lesional epilepsy, particularly MTS. Although serious complications were infrequent, adverse events were statistically correlated with multiple stereotaxic trajectories and larger ablation volumes. Our results provide additional guidance for patient counseling and surgical planning.
152 Caudate and Dorsolateral Prefrontal Cortex Beta Bursts During Working Memory Encoding Correlate with Memory Impairment in Parkinson’s Disease
Authors: Qian Helen , Paulo Danika Lea , Subramanian Deeptha , Dhima Kaltra , Bick Sarah KB 
Published: March 2023

INTRODUCTION:
Cognitive dysfunction is a common nonmotor symptom of Parkinson’s disease (PD), with memory impairment being a primary cause of disability. Decreased dopamine in PD elevates beta power in cortico-striato-thalamo-cortico (CSTC) motor circuits and is the basis of closed-loop deep brain stimulation (DBS) strategies. Analogous dysfunction of parallel CSTC cognitive circuitry including caudate and dorsolateral prefrontal cortex (DLPFC) may mediate PD cognitive impairment and be a neuromodulation target for cognitive symptoms. We have previously shown caudate and DLPFC beta power contributes to working memory updating, and suppression of prefrontal cortex beta bursts during working memory encoding has been linked with improved performance. However, how PD affects beta bursting in relation to memory function remains unknown.

METHODS:
Fourteen PD patients undergoing awake DBS surgery with electrode trajectories traversing the caudate, DLPFC, or both participated in this study. Subjects completed a 2-back working memory task where they identified whether a presented word matched the word presented two trials prior. Bursts were defined as epochs where power exceeded a Z-score of two for at least three oscillatory cycles. We correlated change in caudate and DLPFC beta burst rates during working memory encoding with subjects’ composite memory scores, which were calculated from preoperative neuropsychological assessments.

RESULTS:
Caudate and DLPFC beta burst rates decreased significantly during working memory encoding for correct trials. In both structures, change in beta burst rate was significantly correlated with subjects’ composite memory scores, with greater decreases in beta bursting corresponding with better memory function.

CONCLUSIONS:
Beta bursts are suppressed in caudate and DLPFC during working memory encoding. Reduced beta burst suppression during encoding correlated with greater memory impairment in PD patients, indicating that altered caudate and DLPFC beta bursting dynamics may contribute to PD memory impairment.
154 Comparison of Chronic and Intraoperative LFP and ECoG Recordings in Humans With Parkinson’s Disease
Authors: Caldwell David , Olaru Maria , de Hemptinne Coralie , Starr Philip A. 
Published: March 2023

INTRODUCTION:
Advances in implantable neurotechnologies have enabled chronic invasive long-term recordings of field potentials from depth leads or paddle-type electrocorticography (ECoG) leads. The relationship between these long-term recordings and those obtained acutely in the operating room has not been studied.

METHODS:
Human subjects (n=6) with movement disorders (Parkinson’s disease, dystonia) were permanently implanted with quadripolar DBS leads, and quadripolar ECoG leads over primary motor and sensory cortices, attached to a Medtronic Summit RC+S investigational device in the chest. Recordings were acquired intraoperatively using a NeuroOmega (Alpha Omega, Inc) recording system customized for research use. RC+S recordings were acquired between 1 and 345 days post implantation. The same processing pipeline was applied to both data sets, and average power spectra in canonical frequency bands (delta, theta, alpha, beta, gamma) were compared using rank sum tests within each subject.

RESULTS:
Power spectra show similar power law scaling phenomena between intraoperative and chronic recordings. Disease specific frequency band characteristics such as beta peaks could be seen in both chronic and intraoperative recordings, however, within subjects these were not always consistently seen.

CONCLUSIONS:
We present within-patient comparisons of signal characteristics (power spectra) of intraoperative recordings from a research grade recording system, with wirelessly streamed data from a chronic implantable device, using the same brain leads. Power spectra have similar characteristics between the intraoperative and long term recordings, however, there are distinct differences between the intraoperative and longer term clinic recordings, reinforcing the utility of tracking neural signals over time after the effects of lead insertion on the motor circuit have diminished.
156 Major Depression is Linked to Increased Information Flow From the Orbitofrontal Cortex
Authors: Myers John , Xiao Jiayang , Metzger Brian , Adkinson Joshua , Allawala Anusha , Pirtle Victoria , Mathura Raissa , Anand Adrish , Gadot Ron , Najera Ricardo Andres , Rey Hernan Gonzalo , Shofty Ben , Provenza Nicole , Goodman Wayne , Mathew Sanjay , Pouratian Nader , Bijanki Kelly R. , Sheth Sameer A. 
Published: March 2023

INTRODUCTION:
Major depression is associated with widespread dysfunction throughout the limbic system and neocortical regions such as the orbitofrontal cortex (OFC) and the dorsolateral prefrontal cortex (dlPFC) (4–7). The brain regions comprising the limbic system, including the amygdala, ventral striatum, and anterior cingulate cortex (ACC), show altered connectivity in MDD patients (5, 7). As part of an ongoing NIH-funded trial of DBS for depression, we implanted 3 patients with both DBS leads and stereo-EEG (sEEG) electrodes to measure neural oscillations in the dlPFC, OFC, and ACC.

METHODS:
Three depression patients were implanted with sEEG electrodes in areas including OFC, dlPFC, and ACC. We frequently measured depression severity throughout a 9-day inpatient monitoring period using a validated adaptive severity scale (8). We measured directed connectivity using multivariate vector autoregressive models that measure information flow between the right dlPFC, OFC, and ACC during resting state). Then we examined the relationship between depression severity and GC within the delta band (1-3 Hz).

RESULTS:
Information flow within the delta band was positively correlated with depression severity in each patient. Each showed distinct patterns of pathophysiological connectivity. Across all patients, directed connectivity from the OFC to the ACC predicted depression severity (p < 0.05).

CONCLUSIONS:
Information flow within the prefrontal cortex correlates closely with depression severity. Increased OFC -> ACC connectivity may relate to increased self-appraisals of mood and diminished control of emotional state during depressive episodes.
160 The Neurosurgical Anatomy of Deficits in Speech Production
Authors: Andrews John P. , Cahn Nathan , Speidel Benjamin , Chung Jason , Levy Deborah , Wilson Stephen , Berger Mitchel S. , Chang Edward 
Published: March 2023

INTRODUCTION:
Why do similar neurosurgical lesions cause a range of deficits in speech production? We investigated Broca’s aphasia as a disorder of fluency and apraxia of speech (AOS) as a disorder of articulatory coordination to dissociate the anatomy and lesional etiology of these syndromes.

METHODS:
Patients were prospectively tested with a standardized speech paradigm. Resections were outlined into 3D regions of interest and transformed into a common brainspace (MNI brain). Recordings of speech were retrospectively review by speech language experts to assess apraxia of speech. A voxel-based lesion-mapping (VLSM) algorithm was used to associate resection areas with acute postoperative aphasia or apraxia of speech. Averages of white-matter tracts were overlaid onto MNI reconstructions for analyses of white-matter tract involvement. Pre-operative diffusion tensor imaging reconstructions were created using peri-lesional regions of interest for seeds to investigate perilesional white matter tracts in these cohorts.

RESULTS:
Of 289 patients with left sided craniotomies and prospective language evaluation, 19 had Broca’s aphasia. 255 of these patients had recordings available for expert review, of whom 28 had apraxia of speech. VLSM analysis found Broca’s aphasia and fluency deficits were not associated with classic anatomic Broca’s area (pars opercularis and triangularis). Rather, they were associated with ventral sensorimotor cortex (SMC) and supramarginal gyrus (P < 0.001). Apraxia of speech was associated the most ventral aspects of SMC (P < 0.001). SLF III reconstructions terminated in the areas associated with Broca’s aphasia and fluency deficits, but had more limited overlap with the VLSM regions associated with apraxia of speech.

CONCLUSIONS:
Lesions leading to AOS and Broca’s aphasia after neurosurgical resection do not correlate with Broca's area. Rather, they cluster in ventral sensorimotor cortex. Subcortical white-matter tract injury may explain disparate non-fluent aphasia subtypes in patients with anatomically similar lesions.
161 Single-Cell RNA-seq Highlights Immune-Driven Gender Differences in Glioblastoma
Authors: Wang Elaina , Young Jacob , Chen Jia-Shu , Aghi Manish Kumar 
Published: March 2023

INTRODUCTION:
Glioblastoma (GBM) is the most common primary malignant brain tumor and has a 1.6-fold higher incidence and shorter survival in men versus women. Gene expression differences may contribute to gender-specific differences.

METHODS:
Single cell RNA-sequencing (scRNA-seq) was conducted on 19,642 cells from primary IDH-wild type GBM patients of both sexes (n = 11 total, 5 men and 6 women). A two-sample t-test was conducted on average age between sexes. Kaplan-Meier curves were used to evaluate survival between sexes. Bulk RNA-sequencing data was accessed via The Cancer Genome Atlas GBM dataset. Functional enrichment analyses were conducted on both scRNA and bulk RNA-seq data to determine relevant pathways from upregulated genes and visualized as gene concept networks via R.

RESULTS:
There was no difference in age (63.8 versus 53.8 years in men and women respectively) and survival (24 versus 26 months in men and women respectively). scRNA-seq functional enrichment analysis revealed myeloid cell upregulation in men and increased expression of angiogenesis genes such as ADM in women. There was no difference in T cell gene expression between sexes. Bulk RNA-seq analysis of 90 men and 50 women revealed marked elevation of immunoglobulin genes in men and innate genes such as M1 marker NOS2 in women.

CONCLUSIONS:
Innate myeloid and adaptive humoral components are highly upregulated in men with GBM compared to women, with no differences seen in T cell expression between sexes. This may contribute to higher incidences and shorter survival in men versus women, which should be accounted for in clinical trial evaluation.
168 Elevated Intracranial Pressure is Associated With Memory Dysfunction in Intraventricular Hemorrhage Animal Model
Authors: Peterson Catherine , Puglisi Chloe , Hawk Cameron , Waldau Ben 
Published: March 2023

INTRODUCTION:
Survivors of nontraumatic intraventricular hemorrhage are often left with memory impairment, however, underlying mechanisms of this dysfunction remain to be elucidated.

METHODS:
The experimental design included two groups of Sprague Dawley rats (n=30): intraventricular hemorrhage (control) and intraventricular hemorrhage with sustained high intracranial pressures (experimental). The autologous intraventricular blood injection model was used. In the experimental group the intracranial pressure was artificially elevated. Ten days following surgery, each rat underwent Morris water maze. T test was used with a p value of < 0.05 considered statistically significant.

RESULTS:
The average maximum intracranial pressure in the experimental group was 75.6 ± 17.5 mmHg compared to 66.5 ± 17.3 mmHg in the control group (p = 0.260). The experimental group experienced elevated intracranial pressure for two hours following induction of intraventricular hemorrhage, whereas the intracranial pressure normalized within minutes in the control group. The mean cerebral perfusion pressure tended to be lower in the experimental group (20 ± 25.6 mmHg) compared to the control group (30 ± 19.4 mmHg) (p = 0.302). In Morris water maze, the experimental group needed more time to reach the platform (37.3 ± 21.8 seconds) compared to the control group (19.7 ± 14.3 seconds) (p = 0.041). The experimental group also spent less time in 5% and 10% target quadrants, 2.4 ± 1.8 and 5.7 ± 3.9 seconds, respectively (p = 0.004) compared to the control group, 5.3 ± 2.2 and 10 ± 3 seconds, respectively (p < 0.001).

CONCLUSIONS:
Animals who have prolonged elevated intracranial pressures following intraventricular hemorrhage perform poorly in spatial memory and learning. The authors suggest that a rise in intracranial pressure might be the driver for activating pathways responsible for subsequent memory dysfunction.