bluuebunny/crossref_metadata_2025_split huggingface dataset:
170 Disc Space Height in Relation to Neural Foraminal Dimensions and Patient Characteristics: A Morphometric Analysis From L1-S1 Using Computed Tomography
Authors: Razzouk Jacob Anees , Vyhmeister Ethan , Carter Mei , Kagabo Whitney , Harianja Gideon Galatoba , Ramos Omar , Wycliffe Nathaniel D. , Douglas Clifford Carl , Cheng Wayne K. , Danisa Olumide A. 
Published: March 2024

INTRODUCTION:
The normative relationship between lumbar intervertebral disc space height (DSH) and neuroforaminal dimensions (NFD) has yet to be defined.

METHODS:
Anterior, middle, and posterior DSH were measured on 350 female and 350 male patients between 18 and 35 years of age without spinal pathology. NFD were defined as sagittal anterior-to-posterior (AP) width, axial AP width, foraminal height, and area. Statistical analyses were performed to assess associations among DSH, NFD, and patient height, weight, body mass index, sex, and ethnicity.

RESULTS:
DSH measurements demonstrated increasing, linear trends moving caudally from L1-L2 to L5-S1, while NFD demonstrated a unimodal distribution pattern with largest NFD at L3-L4 and smallest NFD at L1-2 and L5-S1. Accounting for confounding due to height, weight, and ethnicity, male patients demonstrated larger DSH compared to female patients across all levels L1-S1 (p < .001). Asian patients demonstrated taller DSH compared to Caucasian, Hispanic, and African-American patients across all levels L1-S1 (p = .014). Zero moderate or strong correlations were observed between DSH and NFD measurements or patient characteristics for all levels L1-S1, though weight and foraminal height were weakly (r = .3) associated with increased DSH (p < .001).

CONCLUSIONS:
This study describes 38,500 CT-based L1-S1 disc space height and neuroforaminal measurements in young patients without spinal pathology. Among these patients, disc space height follows an increasing trend moving caudally from L1-S1, while foraminal dimensions demonstrate a unimodal distribution clustered at L3-L4. Neuroforaminal dimensions, including foraminal height, are not moderately or strongly associated with disc space height. Disc space height is influenced by sex and ethnicity but is not moderately or strongly influenced by patient height, weight, and BMI.
171 Not Just a Matter of Retained Embryonic Spinal Cord: Histopathology of the Filum Terminale in Tethered Cord Syndrome
Authors: Abdulrazeq Hael , Tang Oliver Young , Leary Owen P. , Ayala Cameron , Najib Hebah , Gokaslan Ziya L. , Donahue John , Klinge Petra Margarete 
Published: March 2024

INTRODUCTION:
We present a large consecutive series of patients with tethered cord syndrome who underwent resection of the filum terminale (FT) and the histopathologic findings as analyzed by the neuropathologists.

METHODS:
FT specimens obtained from a consecutive series of 288 pediatric and adult patients that underwent spinal cord releases performed at a single academic institution from 2013-2021 were analyzed retrospectively (IRB #787945). Hematoxylin and eosin (HE) and immunohistochemistry staining was performed to study the spectrum of cells known to reside in connective tissues.

RESULTS:
The most common structures included peripheral nerves (97.6%), ependymal cells (70.8%), ganglion cells (38.5%), and neuropil (15.3%). Cases with excess ependymal cells were associated with ependymal canals (5.9%), ependymal cysts (3.1%), and one case with extensive ependymal “proliferation” (0.3%). With regards to the inflammatory cellular findings, eleven specimens (3.8%) contained scattered or accumulated lymphocytes, macrophages, mast cells, macrophage-derived giant cells, and a secondary lymph follicle in one patient. 36 patients (12.5%) had increased vascularity with enlarged capillaries. Nine patients (3.1%) had an associated type of vascular malformation. A group of specimens included dystrophic calcification within the FT (7.6%).

CONCLUSIONS:
Both vascular and inflammatory changes along with calcifications have been overlooked as possible associated histologic secondary to mechanical stress on the FT. Additionally, vascular anomalies could alter the filum’s mechanical properties due to venous congestion.
177 So the Bone Flap Hit the Floor, Now What?
Authors: Marion Alexis , Lévesque Simon , Touchette Charles , Villeneuve Samuelle-Arianne , Huppé-Gignac Béatrice , Mathieu David , Martin Philippe , Arsenault Christine , Lorio-Morin Christian 
Published: March 2024

INTRODUCTION:
Dropping the free bone flap on the operating room floor during a neurosurgical procedure is a rare and poorly documented accident. In fact, it has been reported in up to 3 out of 1000 operations involving craniotomies. The literature guiding its management is insufficient: to date, there is no protocol for sterilization of an accidentally contaminated flap in order to reposition it safely on the patient's skull.

METHODS:
Cadaveric human bone flaps were collected and intentionally dropped onto the floor of a neurosurgical operating room. Bacterial contamination from these flaps was quantified in colony forming units (CFU) counted on culture plates inoculated with the fragments. Identified species were included in a mixed preparation of microorganisms used to artificially contaminate fragments from 29 other individual flaps in a standardized manner. All 29 contaminated flaps were previously cut into five pieces and the following five sterilization protocols were completed on a fragment per flap each: rinsing with saline, mechanical debridement with sterile gauze, rinsing with antibiotics, rinsing with alcoholic chlorhexidine and flash sterilization by autoclave. Decontamination was measured by inoculation onto culture plates and CFU count.

RESULTS:
The observed contamination from a flap dropped on an operating room floor can be significant (up to 120 CFU cultured per flap). All protocols tested decreased bacterial load of the bone flaps to different degrees: saline by 95.7%, mechanical debridement by 97.6%, antibiotic bath by 99.5%, alcoholic chlorhexidine by 99.9% and flash sterilization by 100.0%.

CONCLUSIONS:
In the event of the accidental fall of a bone flap, decontamination by rinsing in an alcohol-chlorhexidine solution, which seems to represent the best combination of effectiveness versus the risks and the complexity of the method, could be considered.
183 Earlier Surgery is Associated With Improved Post-operative Language Development in Children With Tuberous Sclerosis Complex (TSC)
Authors: Sadeghzadeh Sina , Peters Jurriaan , Porter Brenda , Ihnen S. Katie 
Published: March 2024

INTRODUCTION:
Early life epilepsy in TSC has been strongly associated with lifelong intellectual disability. While improved seizure control correlates with improvements in quality of life and cognition, the importance of surgery timing in young children has not been well-studied.

METHODS:
Changes in patients’ preoperative (0-12 months) to postoperative (36 months) scores in neuropsychologic tests—including the Mullen Scales of Early Learning (MSEL), Vineland Adaptive Behavior Scales, Second Edition (VABS-II), and the Preschool Language Scales, 5th addition (PLS-5)—were calculated. Pearson correlation and multivariate linear regression models were used to correlate changes in test scores with age at surgery and separately with duration of epilepsy prior to surgery. Analysis was limited to those patients who demonstrated improved seizure control post-operatively (n = 18).

RESULTS:
Age at surgery had a statistically significant negative correlation with changes in the combined verbal sub-tests of the MSEL (R = -0.41, p = 0.04) and predicted the change in that measure outcome in a multivariate linear regression model (β: -0.09, p = 0.03). Similar trends were seen for the change in the total language score of the PLS-5 (R = -0.38, p = 0.06; β: -0.21, p = 0.07). Results were similar when the duration of epilepsy prior to surgery was assessed as the independent variable. However there were no clear trends with the VABS-II questionnaires, even in language domains.

CONCLUSIONS:
Our data shows that successful earlier surgery and shorter epilepsy duration prior to surgery are both associated with improved post-operative language development in a small cohort of patients with TSC. Prospective clinical trials are necessary to further elucidate this relationship.
184 PTEN Mutations Portend Cerebral Ventriculomegaly With Autism-Like Deficits in Cortical Circuitry
Authors: DeSpenza Tyrone , Kizlitug Emre , Allington Garrett , Barson Daniel , O'Connor David , Robert Stephanie , Mekbib Kedous Y. , Singh Amrita , Phan Duy , Nanda Pranav , Mandino Francesca , Constable Todd , Lake Evelyn , Carter Bob S. , Gunel Murat , Lifton Richard , Luikart Bryan , Kahle Kristopher Thomas 
Published: March 2024

INTRODUCTION:
Fetal ventriculomegaly, the most common antenatally-diagnosed brain abnormality, is the defining feature of congenital hydrocephalus (CH). Fetal ventriculomegaly is also an overlooked associated finding in neuropsychiatric disorders, including autism spectrum disorder (ASD), which is diagnosed at a 10-fold higher rate in CH patients than in the general population.

METHODS:
We subjected 2,978 parent-trio probands with primary ventriculomegaly, including shunted, sporadic CH, to whole exome sequencing (WES). Using mouse molecular genetics, we generated a novel CH mutant mouse model via prenatal, genetic deletion of a WES-identified CH gene. MRI, measurement of CSF secretion, and cortex-wide, mesoscopic Ca2+ imaging were performed in mice.

RESULTS:
We identify phosphatase and tensin homolog (PTEN) to be the most frequently mutated gene in primary human ventriculomegaly. Integrative analysis of the human fetal brain revealed PTEN was most highly expressed in NKX2.1+ neuroprogenitor cells (NPCs) and their post-natal interneuron descendants. Pten mutant mice with Nkx2.1-specific Pten deletion exhibited neonatal-onset obstructive hydrocephalus, resulting from aqueductal stenosis due to mTor-activated hyperproliferation of NPCs, and CSF hypersecretion due to inflammation-driven choroid plexus hyperplasia. Hydrocephalic Pten mutants also exhibit autism-like hypersynchronization of the somatosensory cortices due to impaired activity of interneurons. Strikingly, genetic or pharmacologic mTORC1 inhibition (everolimus) corrects ventriculomegaly and rescues cortical pathology of Pten mutants.

CONCLUSIONS:
Our data demonstrate that PTEN, a commonly mutated ASD gene, is also the most frequently mutated gene in primary ventriculomegaly. To attenuate the pathologically entangled enlargement of the ventricular system and intrinsic neuronal deficits within the surrounding cortical mantle, the use of rapamycin analogs has high translational potential as an adjunct therapy to neurosurgical CSF diversion in ventriculomegalic patients harboring PTEN mutations. Ventriculomegaly may also be a useful radiographic biomarker for early referral for exome sequencing and formal neurodevelopmental assessments.
185 Deuterium MRI for CSF Studies in Normal and Hydrocephalic Rats
Authors: Hunt Rachel Joy , Nagaraja Tavarekere , Knight Robert , Lee Ian Yu , Ewing James , Penning Donald Henry 
Published: March 2024

INTRODUCTION:
The recent characterization of the glymphatic system has revived interest in the interaction of cerebrospinal fluid (CSF) with brain tissue via perivascular spaces. Traditional CSF tracers, such as gadolinium and iohexal, are large molecules that do not cross the blood brain barrier (BBB). The primary component of CSF, however, is water, which is BBB permeable.

METHODS:
Eight adult male rats underwent cisterna magna catheterization for intrathecal infusion. Brain MR images were obtained in a 7 tesla small-animal MRI system. Temporal T1-weighted images (T1WI) were obtained before, during, and after intrathecal infusion of D2O. Five rats then underwent ventricular kaolin injection for induction of hydrocephalus, after which repeat imaging with intrathecal D2O infusion was performed.

RESULTS:
Intrathecal deuterium infusion produced consistent changes on MRI imaging. Because conventional MRI does not sense deuterium, the T1WI showed a loss in proton signal with D2O infusion. Rapid D2O uptake of <2.5 minutes was noted in CSF spaces, brain tissue, and saggital and straight venous sinuses.

CONCLUSIONS:
Use of deuterium as an intrathecal contrast agent provides a physiologically realistic model of CSF behavior. Efforts are ongoing to quantify the relationship between MRI signal loss and deuterium tissue concentration for comparative analysis between healthy and hydrocephalic rats. The loss of MRI signal in the straight sinus after intrathecal infusion implicates the deep venous system in the clearance of CSF, suggesting that CSF is reabsorbed into the venous system via the brain tissue itself. Because traditional CSF tracers do not cross the BBB, the role of the brain tissue in the reabsorption of CSF has been overlooked.
186 Outbreak of Bacterial Subdural Empyema in Pediatric Patients After Relaxation of COVID-19 Non-pharmaceutical Interventions (NPIs)
Authors: Garcia David Matthew , Yekzaman Bailey R. 
Published: March 2024

INTRODUCTION:
Non-pharmaceutical interventions (NPIs), in response to the COVID-19 viral pandemic altered viral transmission. In addition, endemic viral strains (influenza, RSV, etc) also experienced unprecedentedly low infection rates. Endemic viral infections typically followed seasonal outbreak spikes, but these spikes were noticeably absent in the COVID-19 control period. After many COVID-19 restrictions were ceased, there was an unusually high spike in endemic viral infections. Many COVID-19 measures were relaxed in the early/middle part of 2021, and we noted a sharp increase in post-viral, complicated sinusitis/subdural empyema cases.

METHODS:
Data collection was via retrospective chart review of subdural empyema cases at our institution. “Post-viral” was defined as positive viral test or VURI symptoms within 30 days.

RESULTS:
Our group previously published our case series on the management of subdural empyema. That served as an historical cohort of 16 patients and 23 procedures over an 8 year period (July 2013-June 2021). During the previous academic year, July 2021 to June 2022, there were a total of 14 patients and 19 surgeries, which nearly doubles the previous 8 years combined. The current academic year (to date) has had 9 empyema patients and 12 surgical cases. 100% of patients in the previous 2 years has had historical symptoms of viral URI symptoms or positive viral URI testing within 30 days. None were documented positive for COVID-19. In less than 2 years since many NPIs were lifted, post-viral, bacterial empyema cases have increased dramatically by a fold of 2.56.

CONCLUSIONS:
NPIs may have created an endemic viral “immunity gap” and an immunologically susceptible population, and thereby could have contributed to a sharp increase in bacterial subdural empyema.
188 Timing of Nerve Reconstruction Surgery to Optimize Long-Term Recovery at the Elbow and Forearm in Neonatal Brachial Plexus Palsy
Authors: Muhlestein Whitney , Chang Kate , Justice Denise , Nelson Virginia , Saadeh Yamaan S. , Smith Brandon W 
Published: March 2024

INTRODUCTION:
Restoration of elbow flexion is highly prioritized in nerve reconstruction for neonatal brachial plexus palsy (NBPP). Elbow extension and forearm supination are also frequently impacted in NBPP. Timing of surgical reconstruction for optimal outcomes at the elbow and forearm remains unknown.

METHODS:
We interrogated a prospectively collected database of all children with NBPP who underwent nerve reconstruction at a single center between 2005-2020. AROM was collected for elbow flexion and extension and forearm supination at every clinic visit and normalized between 0 and 1. The cohort was divided into those with surgery =6 months old, 6-9 months old, and >9 months old. We compared elbow and forearm AROM in local age windows between the groups using a regression model expressing the expected AROM as a linear function. Significant differences between the groups were identified using a Wald test.

RESULTS:
Of 99 included children 28 had surgery =6 months old, 46 had surgery between 6-9 months, and 25 had surgery >9 months. At ∼13 years follow up, there was no difference in recovery of AROM for elbow flexion between the groups. For elbow extension, mean normalized AROM was significantly worse when comparing the >9 month and =6 month group (0.41 vs 0.84, p < 0.001). For forearm supination, the =6 month group had significantly better AROM than the 6-9 month (0.57 vs 0.77, p = 0.02) and >9 month (0.46 vs 0.77, p < 0.001) groups. Children who presented earlier had surgery at a younger age.

CONCLUSIONS:
Earlier surgery may result in better long-term recovery of elbow extension and surgery =6 months of age may yield the best outcomes for forearm supination. Early referral may help optimize timing of nerve surgery.
196 Quantifying Cholinergic Cortical Response to Deep Brain Stimulation in Murine Models
Authors: Oliver Tucker , Shanazz Khadijah , Pennington Kendyl , Blake David , Vale Fernando L. 
Published: March 2024

INTRODUCTION:
Deep brain stimulation has become a potential treatment for mental disorders. We have previously documented that chronic, one-hour daily, intermittent stimulation of the basal forebrain causes increases in cortical levels of acetylcholine and demonstrates improvement in working memory behavior in monkeys and mice. Continuous stimulation, in contrast, appears to deplete releasable acetylcholine in roughly one minute (Blake et al., Brain Stimulation, 2023; 16(1): 364). This study serves as the first quantification of cortical acetylcholine response to stimulation.

METHODS:
Viral vectors encoding cell surface receptors fluorescent to acetylcholine are injected into superficial cortex in mice through a small craniotomy. After three weeks, the craniotomy is enlarged for glass window affixation above the injection site. Electrodes are implanted posteriorly and angled to contact the basal forebrain. Cortical expression of acetylcholine in response to stimulation is visualized via two-photon microscopy through the window and quantified over time.

RESULTS:
Preliminary data suggest that the physiologic half-life of acetylcholine in the cerebral cortex is 10-12 seconds. Also, the system expressed acetylcholine at normal levels after 20 minutes following 100 seconds of 60Hz stimulation (6000 total pulses). Based on these observations, each second of 60 Hz stimulation of the basal forebrain requires 12 seconds of recovery time.

CONCLUSIONS:
These data are foundational for future explorations in developing treatments for pathology involving cholinergic exchange and recycling, with implications in optimizing deep brain stimulation and tailoring pharmaceuticals that augment acetylcholine reuptake. These data also suggest that high-frequency stimulation decreases neurotransmitter output through depletion. Additional experimentation in the future will incorporate acetylcholinesterase inhibitors and additional stimulation patterns to assess clinical response.
197 Pre-clinical Ex-vivo Study of a 3D Neuronavigation With a Neurosurgical Microrobot
Authors: Andre Arthur , Garvayo Marta , Oulmas Ali , Francois Quentin , Chalivoy Lucas , Zarader Pierre , Ibrahim Souha , Gallardo Oscar , Daher Georges , Nascimento Leandro , Duplat Bertrand 
Published: March 2024

INTRODUCTION:
Access to deep brain structures for diagnostic and therapeutic purposes remains a challenge for neurosurgeons. To solve this obstacle, we are developing a micro-robot with the technology to navigate the brain with 3D curved trajectories that will open a new range of possibilities in the neurosurgical world (tumor identification, treatment of epileptic foci, DBS, targeted therapies, fenestration of membranes). The microrobot is tracked and navigated with a transcranial ultrasound system.

METHODS:
10 cadaveric studies were performed using 4 adult swine and 6 human subjects using micro-robot models with diameters of 4.5 mm and 2.9 mm. The microrobotic base for injection and ultrasound tracking of the microrobot (CAP) was placed on the skull at the insertion hole. The micro-robot was remotely controlled, and the surgeries were performed in a hybrid operating room with 3D fluoroscopy, allowing us to validate the surgery feasibility and evaluate the accuracy of the transcranial tracking.

RESULTS:
20 burr holes were performed with holes ranging from 4-9 mm in diameter. The microrobot was inserted successfully infall cases. The navigation was effective with straight or curved trajectories in 18 cases and the targeted points were reached in 16 cases. We observed a mean 3D tracking accuracy of 1.49mm with a S.D. of 0.58 mm, demonstrating a millimetric tracking accuracy, similar to the best stereotaxy performance.

CONCLUSIONS:
These results are a world first, proving the feasibility of intracerebral parenchymal microrobotic neuro-navigation with a millimetric ultrasound transcranial tracking. Future tests will allow testing new prototypes of 1.8mm diameter enabling clinical translation.
198 Human Focal Seizures Induce Wavelike States in Bursts of Neuronal Activity
Authors: Diamond Joshua M. , Inati Sara , Zaghloul Kareem A. 
Published: March 2024

INTRODUCTION:
Recent advances in high-density microelectrode arrays (MEAs) have allowed clinicians to record from individual neurons (single-unit activity) or from ensembles of neurons (multi-unit activity, MUA) in the human brain. These recordings have yielded fundamental advances both in epilepsy and in normal brain function. However, the properties of bursts of neuronal activity during seizures have not been characterized.

METHODS:
Five patients at our institution were implanted with microelectrode arrays and met inclusion criteria. Bursts were captured using custom code (MATLAB). We used statistical techniques to compute the rate similarity or sequence similarity between any two sequences.

RESULTS:
We found strong internal consistency within groups of pathological discharges -- that is, IED and seizure related bursts -- for both rate and sequence similarity. We found that baseline, IED, and seizure-related bursts all reside in particular subspaces, after dimensionality reduction using UMAP. During seizures, the LFP exhibits strong wavelike properties. Interestingly, the MUA direction echoes that of the LFP in this patient. However, MUA discharges are only partially wavelike. In IEDs, while the LFP is quite wavelike, the MUA does not exhibit wavelike properties. We found that LFP wave directions, for both seizures and IEDs, tend to arise from the seizure source, as determined using the ECoG. The relationship between the ECoG source and the MUA wave direction is less consistent. Seizure sequences start near the baseline subspace. Over time, seizure bursts are recruited to a distinct subspace, at which time they develop wavelike properties.

CONCLUSIONS:
Seizure events induce wavelike states in neuronal bursts. These findings may help explain why seizures alter cognition.