bluuebunny/crossref_metadata_2025 huggingface dataset:
132 A Novel Mechanism of Periventricular Strain Observed in Post-Mortem Human Brains for Mild Traumatic Brain Injury
Authors: Poon Katherine , Post Andrew , Brien Susan , Rovt Jennifer , Dutrisac Scott , Cusimano Michael , Jalali Alireza , Goodwin Shannon , Petel Oren , Karton Clara , Hoshizaki Thomas
Published: March 2023

INTRODUCTION:

Mild traumatic brain injury (mTBI) can result in a myriad of long-term functional deficits reflecting diffuse axonal disruption. While microstructural anomalies in the periventricular regions of the brain have been identified through immunohistochemical analyses, diffusion tensor imaging and animal models, and contribute to a range of symptoms observed in mTBI, the mechanism of injury is not fully described.

METHODS:

Post-mortem human brains without space-occupying lesions and significant atrophy were included in this study. Using MRI and anatomical surface landmark localisation, cortical and subcortical markers were implanted along a sagittal plane in anterior, posterior and inferior periventricular regions as well as in the frontal, parietal, occipital and cerebellar lobes. A high-speed, high-resolution, two-dimensional imaging system was employed to measure brain displacement from direct low-velocity frontal impacts. Impact kinematics of the skull were measured using a DTS 6DX SLICE sensor array. Marker displacement in the anterior, inferior and posterior periventricular regions were calculated and individual frame position time-histories for markers' centre of gravity were recorded.

RESULTS:

Upon impact, the frontal horns of the lateral ventricles were observed to immediately collapse, followed by posterior fluid motion and occipital horn dilation not previously described in the literature. Substantial deformation was recorded in the periventricular areas, resulting in a significantly higher magnitude of strain relative to more superficial subcortical and cortical structures. In comparison, the posterior periventricular region of the brain recorded the highest magnitude of strain.

CONCLUSIONS:

This study describes the generation of unique high magnitude strain in the periventricular regions from ventricular fluid flow upon low-velocity frontal head impacts. While the clinical significance of the ventricular deformation remains to be elucidated, this represents an important association between the mechanism of injury and diffuse symptomatology observed in mTBI.
135 Real-World Data of Microvascular Decompression in Trigeminal Neuralgia: Analysis of 26 Tertiary Care Centers of the European Continent
Authors: Sommer Björn , Shiban Ehab , Schatlo Bawarjan , Rohde Veit , Thomé Claudius , Brito Silva Barbosa Marcos Daniel , Jödicke Andreas , Gandía González Maria Luisa , Blasco Guillermo , Demetriades Andreas K. , Sure Ulrich , Vanaclocha Vincente , Mastronardi Luciano , Ringel Florian , Gonzalez-Lopez; Peter Vajkoczy Pablo , Ruiz-Juretschke Fernando , Stummer Walter , Sames Martin , Fedirko Volodymyr , Bijlenga Philippe A. , Seifert Volker , Meyer Bernhard , Lehmberg Jens
Published: March 2023

INTRODUCTION:

Patients with classic trigeminal neuralgia (TN) usually receive first-line treatment with carbamazapine. The known effect of wearing-off is hold against the result of expert single-center series of microvascular decompression (MVD) as a successful treatment option. However, real-world data regarding MVD is lacking.

METHODS:

A multicenter retrospective data analysis was performed in 26 European hospitals. Inclusion criteria were a) age >18 to 85 years, b) patients with classical TN, c) patients who underwent microvascular decompression (MVD) and d) minimum follow-up of 12 months. Primary outcome is pain-freedom at last follow up. Secondary outcome parameters were duration of symptoms prior to MVD, neurovascular conflict in MRI, time to pain recurrence, complications, and a tailored questionnaire.

RESULTS:

1140 patients from 26 European institutions were analysed. Of those, 591 (346 female, 245 male, age (mean±SD) 60.1 ± 13.4 years) fulfilled the inclusion criteria. Mean duration of symptoms prior to surgery was 73.3 ± 67.0 months (6.1 ± 5.6 years). 73.3% of patients had a visible neurovascular conflict in MRI. After a follow-up 49.9 ± 36.8 months, 68.7% of patients were pain free or had occasional pain (BNI score 1 and 2). There was no correlation between symptom duration and time to pain recurrence. Involvement of SCA (61%) was associated with a high probability of pain freedom (p<0.01). Complications occurred in 31.6% of all cases, with hypoesthesia of the facial nerve being the most common event. Three out of four patients (74%) were satisfied with the treatment, and 72% would choose MVD as the preferred treatment option again.

CONCLUSIONS:

Microvascular decompression for trigeminal neuralgia is an effective treatment modality with excellent pain control. Two-third of patients were satisfied with the treatment.
140 Diffuse Midline Glioma Harbors Alterations That are Attenuated by MEK Inhibitors and 5-Aminolevulinic Acid-Photodynamic Therapy
Authors: Price Gabrielle , Anastasiadou Maria , Bouras Alexandros , Hadjipanayis Constantinos G.
Published: March 2023

INTRODUCTION:

Diffuse midline glioma (DMG) is the leading cause of brain cancer-related mortality in children. There is a desperate need for therapeutic models that abrogate tumor cell invasion processes since standard radiation therapy is associated with transitory benefit and therapeutic resistance. 5-aminolevulinic acid-photodynamic therapy (5-ALA-PDT) is a photo-therapy that preferentially ablates tumor cells when 5-ALA is delivered with 635 nm light by metabolizing to protoporphyrin IX (5-ALA metabolite). The RAS/MEK signaling pathway has been implicated in tumorigenesis and been shown to synergize with 5-ALA-PDT in various carcinoma models.

METHODS:

Five DMG lines were treated with 5-ALA-PDT and MEKi trametinib to evaluate effects on proliferation, invasion, live cell dynamics, and cell death in vitro. Apoptotic effects and changes in the tumor microenvironment were evaluated in vivo using a patient-derived xenograft model

RESULTS:

Functional screens demonstrate sensitivity to 5-ALA-PDT and trametinib (5-ALA-PDT IC50 = 0.25-0.41 µM; trametinib IC50 = 0.03 µM-0.03 mM). An increase in cleaved-caspase3 (p = 0.0006) and reactive oxygen species concentration (p < 0.0001) was characteristic in DMG cell lines post-treatment. Immunofluorescence stainings showed a decrease in PDGFRa (p = 0.007) and increase in Hsp70 (p < 0.0001) expression. Trametinib and 5-ALA-PDT dampened cell invasion (invasive/total cells: 1.30, 0.20, 0.26, 0.05 for control, trametinib, 5-ALA-PDT, and combination, respectively). For in vivo studies, there were changes in cleaved-caspase3 (>4-fold difference) and glioma-associated neovascularization in tumor bearing mice.

CONCLUSIONS:

This study proposes a promising, novel combinatorial strategy involving the use of 5-ALA-PDT and MEKi for DMG treatment and can be implemented for other CNS tumors.
142 Pediatric Epilepsy Outcomes After Laser Ablation: An Institutional Cohort Analysis
Authors: Li Daphne , Barros Guinle Maria Isabel , Johnstone Thomas , Kaur Harsheen , Porter Brenda , Grant Gerald A.
Published: March 2023

INTRODUCTION:

Laser interstitial thermotherapy (LiTT) is a minimally invasive technique for targeting epileptogenic foci but there is limited data on outcomes in pediatric epilepsy.

METHODS:

A retrospective review of consecutive pediatric epilepsy patients at Stanford who underwent invasive stereoelectroencephalography between May 2017 to August 2021 and LiTT ablation of epileptogenic foci. Patient demographic, medication usage, seizure, prior surgical interventions, procedural details, and pre- and post-operative seizure history were analyzed.

RESULTS:

Thirty-five patients (24 male, 11 female) identified with average seizure onset 2.8 ± 2.8 years (range 0.25-12)) and average age 9.3 ± 5 years at the time of LiTT (range 2.4-17.9). Etiologies include 21 lesional patients (16 tuberous sclerosis, 4 focal cortical dysplasia, 1 gliosis), and 14 non-lesional (5 insular, 2 frontal, 5 temporal lobe, 2 had multiple foci). Eighteen patients had prior interventions including open resections n = 13 (singular n = 11, multiple n = 2), LiTT (n = 4) or a combination (n = 1), of which LiTT targeted a nearby area in 5. The median number of lasers placed in each procedure was 3 (range 1-5). Complications occurred in 13 cases (37%): 1 venous hemorrhage requiring evacuation intraoperatively, 1 aseptic meningitis, 2 immediate post-operative seizures, and 9 neurologic deficits (6 improving with therapy, 3 stable). Average post-operative length of stay is 2.11 ± 2.11 days (median 1, range: 1-9). Postoperatively, 18 patients (51.43%) were seizure free and median Engel score was 1 (Engel 1 n = 18, Engel 2 n = 6, Engel 3 n = 4, and Engel 4, n = 7) at last follow-up (average follow-up: 13.040 ± 11.37 months; range: 0.43-47.83). 15 (42.86%) patients were reported to experience neurocognitive or behavioral improvement, but this was not found to correlate with lower engel score (p = 0.777).

CONCLUSIONS:

LiTT is a safe and effective method of treatment for pediatric patients with medically refractory epilepsy of various etiologies.
147 The Impact of Tming of Primary Nerve Surgery on Shoulder Recovery in Neonatal Brachial Plexus Palsy
Authors: Muhlestein Whitney , Smith Brandon W. , Chang Kate , Jun-San Yang Lynda
Published: March 2023

INTRODUCTION:

Neonatal brachial plexus palsy (NBPP) almost universally impacts shoulder abduction, forward flexion, and external rotation. While nerve reconstruction options are available for restoration of these movement, the outcomes for nerve surgery for shoulder have lagged behind those at other joints. Operative timing is a potentially modifiable variable but remains controversial.

METHODS:

We interrogated a prospective database of all patients with NBPP who underwent primary nerve surgery at a single tertiary referral center between 2005-2020. The cohort was divided into those who underwent surgery ≤6 months old, 6-9 months old, and >9 months old. AROM for shoulder abduction, forward flexion, and external rotation was plotted over time for each group and a logistic regression and 95% confidence interval fit to each plot to visualize both absolute and rate of recovery of AROM for each group.

RESULTS:

99 children with 2196 AROM measurements were included in the analysis with average follow-up of 46 months. 26 underwent surgery ≤6 months old, 47 between 6-9 months, and 26 >9 months old. Those who underwent surgery ≤9 months old had more rapid and better overall recovery of shoulder abduction and forward flexion than those who had surgery >9 months. Timing of operation did not clearly impact recovery of external rotation. Patients who presented to a multidisciplinary clinic earlier were more likely to have earlier operations.

CONCLUSIONS:

Surgery prior to 9 months old may improve long-term recovery of shoulder AROM in NBPP. Early referral should be encouraged to optimize timing of operative intervention.
157 Identifying Spatial Transcriptomics Signaling Networks in Human Glioblastoma Using Graph-Based Machine Learning
Authors: Miyagishima Danielle F. , Kuchroo Manik , Steach Holly , Phan Duy , Godavarthi Abhinav , Takeo Yutaka , Barak Tanyeri , Youlten Scott , Gorur Ketu Mishra , Moliterno Jennifer Alissa , Erson-Omay Zeynep , McGuone Declan , Krishnaswamy Smita , Gunel Murat
Published: March 2023

INTRODUCTION:

The median survival for glioblastoma multiforme (GBM) has only improved by 4.6 months in more than 100 years, underlying the need for innovative methods for understanding this devastating tumor. Spatial transcriptomics is a new method of whole-transcriptome assessment which allows for simultaneous visualization of mRNA expression in situ with histopathology.

METHODS:

We applied spARC to 25,517 Unique Molecular Identifiers from 10 surgically resected human IDH-mutant astrocytic gliomas (Grade II (n = 3) and Grade III (n = 3)) and GBMs (n = 4). spARC uses manifold learning, graph filters, data diffusion and diffusion filtration to enable discovery of gene-gene relationships, spatial co-localization of genes, and receptor-ligand interactions applicable across a variety of spatial transcriptomic methods. A Neuropathologist annotated whole-slide images blind to our computational analysis and we used in-situ hybridization and immunohistochemistry to demonstrate that spaRC imputation recovery of gene expression is superior to raw expression.

RESULTS:

We demonstrate that spARC can identify spatially restricted tumor niches of dense tumor, leading edge, infiltration/high tumor burden, hemoglobin, and vasculature with high specificity. These clusters can be identified with genes including CD44, VIM, LDHA (dense tumor); SNAP25, UCHL1, OLMF1 (leading edge); OLIG2, MBP, PDGFRA (Infiltrating/High Tumor Burden). In our assessment of ligand-receptor interactions we found that GBM samples were enriched for SPP1-CD44 signaling. We validated this using GBM TCGA data stratifying patients based on expression of SPP1 and CD44 genes and found that high expression conferred lower survival at 12 months.

CONCLUSIONS:

Spatial transcriptomics paired with graph-based machine learning methods applied to human GBMs is a powerful technique able to uncover signaling networks relevant to patient survival and may aid in developing new therapeutic strategies.
159 Neuroplastic Changes Across Multiple Brain Resections in Glioma Patients: Identification of Patterns that Predict Beneficial Repeat Resection
Authors: Valdes Pablo Andres , Ng Sam , Herbet Guillaume , Duffau Hugues
Published: March 2023

INTRODUCTION:

The brain displays degrees of functional reorganization, i.e., neuroplasticity, that enable interventions that were previously thought to be impossible (e.g., resection of “Broca’s area”). Studies have described the static, single-point in time neuroplastic potential in diffuse low-grade gliomas (DLGG) following one surgery.

METHODS:

We studied n=103 patients with a DLGG that underwent multiple brain resections achieved up to critical neural networks identified under awake mapping by means of direct cortical and subcortical electrostimulation. We used normalized postoperative images to generate probability overlap, atlas-based cortical and subcortical parcellation, and functional compensation maps for both surgeries. We performed statistical analysis correcting for multiple comparisons across all cortical parcels and tracts to determine differences at the cortical and subcortical levels between surgeries.

RESULTS:

We show for the first time the dynamics of neuroplastic changes occurring in DLGG that undergo multiple awake resections. We created residual and resection cavity overlap probability maps; cortical parcel damage and subcortical tract disconnection maps and the difference between surgeries; and functional compensation maps and subcortical volumes. We discovered the following four main patterns that constrain how and to what degree this dynamic reorganization occurs between surgeries: cortical vs subcortical, superficial vs deep, unimodal vs multimodal, and left vs right. We found greater plasticity at the cortical level, superficial terminations of white matter tracts, multimodal networks, and left ventral and right dorsal networks.

CONCLUSIONS:

These newly discovered patterns of reorganization provide a unifying model to understand the dynamics of neuroplasticity in DLGG patients undergoing multiple resections. These dynamics with its patterns that constrain mechanisms of neuroplasticity, can help guide neurosurgeons to predict which patients are likely to benefit from a repeat resection.
170 Towards Global Availability of Patient-Specific Cranial Implants: Creation and Validation of CranialRebuild Freeware Application
Authors: Forbes Jonathan Andrew , Xu Alice , Alfawares Yara , Ghalsasi Omkar , Venugopal Vysakh , Aryal Manish , McConaha Matthew , Cheng Josh , Matur Abhijith V. , Yang George Liu , Ngwenya Laura Benjamin , Anand Sam
Published: March 2023

INTRODUCTION:

Financial restrictions limit attainment of hermetically-precise, patient-specific cranial implants (PSCIs) after decompressive hemicraniectomy (DHC) in developing countries. Several authors have reported use of image-segmentation, modeling software, and 3D printers to develop low-cost alternatives for PSCIs. However, technical expertise and time requirements have prevented widespread utilization of this technique.

METHODS:

A freeware algorithm titled CranialRebuild was constructed with the following capabilities: after upload of DICOM files, the normal side is analyzed in reference to the side of DHC, a Boolean subtraction algorithm is used to obtain a virtual image of the desired implant, a two-piece virtual (.STL) model of a negative of the implant is then generated. Following construction, CranialRebuild was evaluated in four cadaveric specimens. In each specimen, a standard DHC was performed. Post-DHC CT imaging were used to obtain a virtual model of the negative of the implant, which was then printed using low-cost polylactic acid (PLA). Methylmethacrylate cement was used to generate a PSCI from the PLA mold. The PSCIs were re-implanted into cadaveric specimens. Pictures were obtained, and cosmesis was subjectively evaluated using a 5-point Likert scale.

RESULTS:

Two of the four heads received a grade of 4/5, indicating optimal cosmesis could be obtained following minimal post-processing modification. Two of the heads were graded as 3/5, indicating optimal cosmesis could be obtained following moderate post-processing modification.

CONCLUSIONS:

The CranialRebuild freeware algorithm can be used to create low-cost, hermetically-precise PSCIs at a fraction of the price of third-party vendors. This technology is expected to greatly improve accessibility of customized cranial implants worldwide.
173 The State of Neurosurgical Disparities Research: Past, Present, and Future
Authors: Pugazenthi Sangami , Barpujari Awinita , Rogers James Louis , Patel Saarang , Hardi Angela , Lee Hedwig , Strahle Jennifer
Published: March 2023

INTRODUCTION:

Social determinants of health (SDH), which influence health care access, patient outcomes, and population-level burden of disease, contribute to health disparities experienced by marginalized patient populations.

METHODS:

Embase, Ovid-MEDLINE, Scopus, Web of Science, Cochrane Library, and ProQuest Dissertations databases were queried for original research on health disparities regarding access to, outcomes of, or postoperative-management following neurosurgical procedures in the U.S. with at least one neurosurgical-affiliated author.

RESULTS:

Of 642 studies screened, 109 were included. Eighty-eight articles met all inclusion criteria other than having a neurosurgical-affiliated author and were excluded. Six studies were published prior to 2010 and 56 in the past 5 years with 62% utilizing national databases, 28% institutional databases, and 11% employing local/state/regional databases. Disparities analyzed were racial/ethnic (79%), economic/socioeconomic (59%), gender (19%), and disabled populations (0.9%) with 43% analyzing multiple/intersecting disparities. Common outcome measures were postoperative outcomes (59%), access to neurosurgical procedures (48%), and post-operative management (9%). Neuro-oncology was the most prevalent subspecialty evaluated (28%) followed by spine (26%), then pediatrics (14%), functional (11%), vascular (12%), general (7%), and trauma (3%). Senior authors with neurosurgical affiliations accounted for 87% of papers, 99% of whom were academically affiliated, and were most located in the South (29%), followed by the Northeast (28%), West (27%), and Midwest (15%).

CONCLUSIONS:

The majority of studies used national databases, assessed racial/ethnic disparities, and focused on postoperative outcomes. Many articles did not have a neurosurgery-affiliated author and the subspecialties of pediatrics, functional, vascular, and trauma were relatively underrepresented. Future research regarding SDH for neurosurgical patients will be crucial to increase healthcare access, improve outcomes, and achieve equity for marginalized patient populations. Moreover, it will be crucial for neurosurgery-affiliated researchers to engage in SDH research to increase visibility and impact of this area in neurosurgery.
180 FDA Trial of Decompression and Dynamic Sagittal Tether for Degenerative Spondylolisthesis: 24-Months Clinical and Radiographic Follow-Up
Authors: Kim Kee Duk , Sasso FAANS; Rick , Hu Serena , Bae Hyun , Villavicencio Alan T. , Lavelle William F. , Yoon Tim , Sandhu Harvinder S. , Perez-Cruet Mick J. , Bains FAANS; Ravi , Kuo Calvin , Stauff Michael , Gum Jeffrey Lynn , Deutsch Harel , Mermer Matthew , Crandall Dennis Grant , Fischgrund Jeffrey S. , Sethi Khalid Ahmed , Ray Wilson Zachary , Davis Reginald J. , Yu Elizabeth , Wang Michael Y. , Berven Sigurd , Chapman Jens , Guyer Richard D. , Shimer Adam , White Andrew Patrick , Fielding Louis , Alamin Todd , Carragee Eugene , Welch William Charles
Published: March 2023

INTRODUCTION:

Degenerative spondylolisthesis (DS) with lumbar spinal stenosis (LSS) is commonly treated with decompression and fusion. The LimiFlex Dynamic Sagittal Tether (DST) is an investigational stabilization device for patients with DS and LSS.

METHODS:

Patients with single-level Grade 1 DS with LSS were enrolled in FDA-IDE study (NCT03115983) comparing decompression with DST and decompression with TLIF. Clinical and radiographic outcomes were assessed at baseline through 24mo postop. All propensity score (PS) selected patients who had 24mo follow-up were included in this interim analysis.

RESULTS:

At 24 mo, 224 PS-selected patients (125DST/99TLIF) had clinical follow-up. Mean characteristics of DST/TLIF groups were: age 65.8/64.1 yrs; BMI 28.1/30.0; CCI 2.5/2.4; and 57.9%/70.1% female. Mean perioperative outcomes for DST/TLIF were: procedure time 112/187 min; EBL 52/240mL; LOS 0.6/2.9 d. Mean improvements at 24mo for the DST/TLIF groups were -58.0/-57.5 mm VAS-leg/hip, -48.3/-42.2 VAS-back and -40.0/-33.4 ODI with 91%/83% achieving 15pt ODI improvement. Within 24 months, 6.5% of DST and 7.6% of TLIF patients had additional surgery at the index or adjacent level. Radiographically, at 24mo, mean reductions for the DST/TLIF groups were -1.7°/-3.7° in flexion/extension ROM and -0.4 mm/-1.0 mm in dynamic translation. At baseline/24mo, the index segment accounted for 30%/27% of index+adjacent segments ROM in the DST group and 29%/12% in the TLIF group.

CONCLUSIONS:

These results suggest that decompression+DST stabilization for DS can achieve significant clinical improvement like fusion, without an increase in reoperations within 24 mo. Imaging demonstrated no increased instability in the DST group with maintained distribution of motion between the index+adjacent segments. Further follow-up should include PS-adjusted analysis of the study composite clinical success and longer follow-up to demonstrate clinical durability of this treatment.
186 A Multi-Center, Randomized, Placebo-Controlled, Double-Blinded Trial of Efficacy and Safety of Riluzole in Acute Spinal Cord Injury Study (RISCIS)
Authors: Fehlings Michael G. , Moghaddamjou Ali , Harrop James S. , Stanford Ralph , Ball Jonathan , Aarabi Bizhan , Freeman Brian , Guest James D. , Kurpad Shekar N. , Schuster James M. , Nassr Ahmad , Schmitt Karl M. , Wilson Jefferson R. , Brodke Darrel S. , Ahmad Faiz U. , Yee Albert , Ray Zack , Brooks Nathaniel P. , Wilson Jason , Kopjar Branko , Arnold Paul M.
Published: March 2023

INTRODUCTION:

Riluzole, a sodium-glutamate antagonist which is FDA approved for ALS has shown promising pre-clinical results and is clinically safe in SCI patients.

METHODS:

The RISCIS trial is an international, multi-center, prospective, double-blinded, randomized, placebo-controlled Phase II/III trial. Patients with ASIA A-C, C4-C8 SCI and <12 hours from injury were randomized between Riluzole, at an oral dose of 100mg BID for the first 24 hours followed by 50mg BID for the following 13 days, and placebo control.

RESULTS:

Due to the impact of the global COVID-19 pandemic this trial was terminated prior to completion. 193 patients were randomized with a follow-up rate of 82.7% at 180-days. No statistical difference was noted in the demographics and baseline injury characteristics between the two groups. At 6 months there was a median gain in total motor scores (TOTM) of 30.0 in the Riluzole group compared to 20.0 for the Placebo group. The improved motor outcomes did not reach statistical significance. Given the decreased sample size, additional sensitivity analyses were conducted. In the ASIA-C population, Riluzole was a significant improver of total motor scores (coefficient estimate: 14.10, p = 0.020) and upper motor scores (CE: 7.68, p = 0.040) at 6 months. ASIA B patients had higher reported independence, as measured by the SCIM score (45.3 vs. 27.3; p = 0.071) and change in mental health scores as measured by the SF-36 mental health domain (2.01 vs. -11.58; p: 0.0205) at 180 days.

CONCLUSIONS:

Despite the premature termination of the RISCIS trial due to the COVID-19 pandemic, 193 subjects were recruited into this trial. Primary analysis showed a 10-motor point gain in riluzole-treated subjects which did not reach significance. However, on secondary analysis, incomplete cervical SCI subjects (AIS B and C) showed significant gains in functional recovery.
193 Expansile Duraplasty Improves Motor Outcomes After Acute Traumatic Spinal Cord Injury
Authors: Greil Madeline , Robinson Emily , Saigal Rajiv
Published: March 2023

INTRODUCTION:

Traumatic spinal cord injury (SCI) can lead to debilitating motor weakness. Early surgical decompression and optimization of spinal cord perfusion have emerged as potential therapies to prevent secondary injury caused by edema, ischemia, and inflammation. Expansile duraplasty extends decompression to the intrathecal space to optimize spinal cord perfusion. There remains a paucity of data on whether this provides a clinical benefit.

METHODS:

We included patients who underwent decompression and stabilization surgery for traumatic SCI from February 2017 to June 2021 at our level 1 trauma center. In duraplasty patients, a 1.5cm x3.5cm acellular, expansile patch was sutured into the dura at the injury site. We collected demographics, injury type, surgery performed, and American Spinal Injury Association (ASIA) motor scores (range 0-100) pre-operatively and at the time of hospital and inpatient rehabilitation discharge.

RESULTS:

101 patients were included: 12 treated with expansile duraplasty and 89 without duraplasty. The mean pre-operative motor score was 48.7 ± 29.3 for all patients, 50.5 ± 19.7 for non-duraplasty and 35.7 ± 23.0 for expansile duraplasty (p = 0.06). At rehabilitation discharge, mean change in motor score from pre-operative exam was significantly higher in duraplasty patients (19.9 ± 11.0 for duraplasty vs. 10.9 ± 13.4 for non-duraplasty, p = 0.02). There were no wound complications in the duraplasty group.

CONCLUSIONS:

In this single-center, retrospective study, SCI patients undergoing expansile duraplasty had significantly greater improvement in ASIA motor scores at rehabilitation discharge compared to non-duraplasty controls. There was no increase in wound complications nor CNS infection. These data present an independent validation of preliminary data from international centers in favor of expansile duraplasty. Further prospective studies are warranted to assess whether this technique is efficacious in treating acute traumatic SCI.
194 Intraoperative Neurophysiology Clues to Predict Success from Selective Dorsal Rhizotomy for Spastic Diplegic and Hemiplegic Cerebral Palsy
Authors: Busse Shaye , Gegg Christopher
Published: March 2023

INTRODUCTION:

Selective dorsal rhizotomy (SDR) involves differential lesioning of divided sensory rootlets at the L1-S1 spinal levels based on interpretations of intraoperative neurophysiologic recordings. It has been shown to improve spasticity related to Cerebral Palsy, but the relationship of specific intraoperative neurophysiology measurements with clinic findings and improvements from surgery has not been investigated.

METHODS:

We performed a retrospective chart review of 39 consecutive SDRs on pediatric patients with spastic diplegia and hemiplegia, recording preoperative and postoperative toeing, scissoring, crouching, ability to walk, intraoperative stimulation frequencies, the spread of activated muscles, and whether a rootlet was lesioned. Improvement in clinical findings was analyzed as the correlate of surgical success.

RESULTS:

There was greater improvement in walking ability with more rootlets having a contralateral spread (p = .009), when more of the lesioned rootlets had contralateral spread (p = .005), and when some rootlets with contralateral spread were spared (p = .001). Among patients with preoperative toeing, there was more muscle activation intraoperatively (p < .001), greater improvement in walking ability (p < .001), and greater improvement of toeing when a lower percentage of rootlets were lesioned intraoperatively (p = .033). Among patients with preoperative crouching, there was greater improvement in crouching with smaller differences in stimulation frequency threshold between the motor and sensory roots (p = .041) and when some rootlets with contralateral spread were spared (p = .028).

CONCLUSIONS:

There is a correlation between preoperative clinical findings, intraoperative neurophysiology measurements, and postoperative clinical findings. These allow for the prediction of intraoperative recordings based on preoperative presentation. We have shown that success from SDR can be predicted using specific intraoperative measurements.
198 Endoscope-Assisted Suturectomy for Metopic Synostosis: 15-year Experience at Boston Children’s Hospital
Authors: Hori Yusuke , Albanese John , Staffa Steven , Piwowarczyk Paulina , Northam Weston , Proctor Mark R.
Published: March 2023

INTRODUCTION:

Metopic synostosis is a subtype of craniosynostosis characterized by trigonocephaly. Endoscope-assisted suturectomy has shown its relevance as an alternative option with a lower rate of transfusion, short hospital length of stay (LOS) while maintaining comparable cosmetic outcome when compared with open repair. However, no previous reports have shown the long-term results of this procedure and factors associated with outcome.

METHODS:

133 pediatric patients with metopic synostosis treated with endoscope-assisted suturectomy between 2006 and 2021were retrospectively reviewed. Peri- and post-operative variables were extensively collected. LOS and the length of helmet therapy were defined as primary outcome. Logistic regression or median regression analysis was conducted for multivariable analysis to identify factors associated with longer LOS and length of helmet therapy. P<0.05 was defined as statistically significant.

RESULTS:

Median age was 93-days, median weight was 5.8 kg and median cranial index 0.82. Eighty-two percent of patients were male. Median surgical time was 48 minutes and estimated blood loss was 40 mL. 10 patients (7.5%) received intra- or post-op transfusion. Median pre-op Hb level was 10.1 g/dL with immediate postop level of 7.4 g/dL. Median hospital LOS was 1 day. The median length of helmet therapy was 6 months. Only one patient required minor correctional surgery for recurrence in long-term. In multivariable analysis, larger number of the pain medications administered within 24 hours after the operation (OR 1.79; P<0.001) and lower weight (OR 2.33 per kg lower; P=0.024) were significantly associated with longer LOS. Larger pre-op cranial index (OR 11.8; P=0.022) was significantly associated with longer length of helmet therapy.

CONCLUSIONS:

Our comprehensive study demonstrates that endoscope-assisted suturectomy is a safe and effective treatment for metopic synostosis and novel predictive factors associated with outcomes.
204 Radiation Exposure May Increase Risk of Malignant Peripheral Nerve Sheath Tumors in Neurofibromatosis: A Propensity-Matched Population-Level Analysis
Authors: Bhanja Debarati , Caldwell Catherine , Patel Neel T. , Sciscent Bao Y. , Freedman Zachary , Nwaneri Nkemjika , Rizk Elias Boulos
Published: March 2023

INTRODUCTION:

Neurofibromatosis type 1 (NF1) is a hereditary condition characterized by growth of neurofibromas, which can transform into aggressive malignant peripheral nerve sheath tumors (MPNSTs). We hypothesize MPNST onset may be increasingly susceptible in the setting of prior radiation exposure in NF1 patients.

METHODS:

We performed a population-level retrospective cohort study using data collected from the TriNetX Research Network, a multi-institutional database comprising 92 healthcare organizations. Patients with NF1 were identified using ICD-10 codes. The presence or absence of radiation procedural codes prior to MPNST onset determined the radiation exposure status. NF1 patients, with and without prior radiation exposure, were propensity score matched on age, sex, and significant comorbidities. MPNST incidence and median overall survival (OS) at 1, 3, and 5 years were assessed. Kaplan Meier curves were evaluated with log-rank tests and Cox Proportional-Hazards models.

RESULTS:

A total of 35,378 NF1 patients, including 884 radiation-exposed and 34,494 radiation-naive were identified. The incidence of MPNST was 24.55% in the radiation-exposed cohort compared to 1.00% in the radiation-naive cohort. Significant risk of MPNST onset was demonstrated in the setting of prior radiation history (Risk ratio, 19.64 [95% CI 10.79-35.73], p < 0.0001). After matching, rates of OS at 5 years were 43.89% and 71.73% for NF1 patients with and without radiation, respectively. Cox proportional hazards ratios (HR, 1.57 [95% CI, 1.04-2.42]) and log-rank tests (p = 0.031) showed significant mortality in the radiation-exposed NF1-MPNST group.

CONCLUSIONS:

Patients with NF1 who had prior radiation exposure had a significantly higher incidence of MPNST, as well as lower overall survival when compared to radiation-naive NF1 patients. This suggests that radiation in NF1 patients may be cautioned, and providers may consider different treatment paradigms in their NF1 patients to limit radiation exposure.
216 Indications and Outcome of Endoscopic Transorbital Surgery for Trigeminal Schwannoma Based on the Classification: A multicenter Study With 50 cases (Korean Society of Endoscopic Neurosurgery - 009)
Authors: Kong Doo-Sik , Hong Chang-Ki , Kim Young-Hoon , Kim Yong-Hwy
Published: March 2023

INTRODUCTION:

Trigeminal schwannoma is a rare central nervous system tumor and involves multi-compartmental skull base. Recently, endoscopic transorbital approach (ETOA) has been emerging technique as a minimally invasive surgery.

METHODS:

Between Sep. 2016 and Feb. 2022, we performed ETOA in 50 patients with trigeminal schwannoma at four tertiary hospitals. There were 15 men and 35 women with the mean age of 46.9 years. All tumors were classified type A (mainly involving the middle cranial fossa), type B (mainly posterior cranial fossa), type C (dumbbell-shaped tumor involving middle and posterior fossa), type D (Extracranial type). Type D tumors were also classified the ophthalmic division (D1), maxillary division (D2), mandibular division (D3).

RESULTS:

In this study, overall gross or near total resection was performed in 45 of 50 patients (90.0%). Median follow-up period was 21.9 months ranging from 1 to 61.7 months. There was no regrowing or recurrence during the follow-up period. Based on the classification, there were 17 tumors with type A, 1 type B, 19 type C and 13 type D. In particular, seven tumors were belong to D1, one D2, and five D3. For type A tumors, GTR/NTR was achieved with ETOA in 16 of 17 patients (94.1%). 18 of 20 patients with type C received GTR/NTR. For type D tumors, GTR was achieved in 5 of 7 patients who underwent ETOA.

CONCLUSIONS:

This study showed that trigeminal schwannomas can be effectively treated with a minimally invasive ETOA in all types of tumor except tumors mainly involving posterior fossa (type B). Especially, trigeminal schwannoma involving orbit (D1) or infratemporal fossa (D3) can be successfully removed with ETOA alone or combined ETOA with the endoscopic endonasal approach.
303 Frameless Angiography-Based Gamma Knife Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations
Authors: Al Saiegh Fadi , Liu Haisong , El Naamani Kareem , Mouchtouris Nikolaos , Chen Ching-Jen , Khanna Omaditya , Abbas Rawad , Velagapudi Lohit , Schmidt Richard , Tjoumakaris Stavropoula I. , Gooch M. Reid , Rosenwasser Robert H. , Shi Wenyin , Jabbour Pascal
Published: March 2023

INTRODUCTION:

Traditional GammaKnife radiosurgery (GKRS) of brain arteriovenous malformations (AVMs) using digital subtraction angiography requires head immobilization using a stereotactic frame.

METHODS:

This is a retrospective review of unruptured AVM patients who underwent frameless GKRS. Thin-cut magnetic resonance imaging and 3-dimensional DSA were obtained without a stereotactic frame for all patients. The imaging studies were merged for contouring of the AVM nidus. During GKRS treatment, patients were immobilized using an individually molded thermoplastic mask.

RESULTS:

Thirty-one patients were included in the analysis. The median age is 45.0 years (IQR 28.0-55.0). The median nidus size is 3.0 cm (IQR 2.0-3.4). One patient had a Spetzler-Martin grade I, 11 had a grade II, 11 had a grade III, 6 had a grade IV, and 2 had a grade IV AVM. Eleven patients underwent pre-radiosurgical embolization, two patients had previous microsurgical resection, and one patient had prior radiosurgery. The median administered dose was 20 Gy (IQR 18.0-21.0). Twenty-three patients were treated in a single fraction, 6 in 3 fractions, and two patients received 5 fractions. All patients completed their treatment with the planned radiation dose without complications.

CONCLUSIONS:

This is the first study that integrates digital subtraction angiography in the treatment planning of brain AVMs using GKRS without utilizing a stereotactic head frame. Frameless GKRS provides numerous advantages over frame-based techniques including improved patient experience, the capability of fractionation, thus, expanding the eligibility of more AVMs for radiosurgery, while maintaining high spatial resolution of the AVM using angiography data.
310 "The "Bright Falx" Sign - Midline Embolic Penetration is Associated With Faster Resolution of CSDH Following MMA Embolization
Authors: Samarage Hasitha Milan , Kim Wi Jin , Colby Geoffrey P.
Published: March 2023

INTRODUCTION:

CSDHs are common in the elderly and patients taking antiplatelet/anticoagulation medications. MMA embolization has become an adjunctive treatment to observation and surgery. Despite many embolization techniques, best practices for optimal CSDH resolution remain unknown.

METHODS:

Retrospective chart review was done on all patients who underwent MMA embolization for CSDHs between January 2017 and June 2021. Patient demographics, clinical presentation, anticoagulant use, and radiographic features were collected. Pre- and post-embolization CT scans were analyzed for volumetric changes and assessed for midline penetration of embolic material in the falx.

RESULTS:

MMA embolization was performed in 37 patients and 53 hemispheres. Older patients took longer to obtain complete resolution of CSDHs (r = 0.47, p = 0.03). Patients with larger pre-embolization (r = 0.57, p = 0.007) and post-embolization (r = 0.56, p = 0.008) CSDH volumes took longer to completely resolve. Patients who had nBCA embolization with midline penetration, as evidenced by the "bright falx" sign, had faster improvement rates than those who did not (5.64 cm3/d vs. 1.2 cm3/d, p = 0.02).

CONCLUSIONS:

Distal penetration of embolic material, particularly nBCA, into the falx may lead to more rapid improvement of CSDH.
313 Passive Flow-Reversal With Balloon-Guide Catheter for Transfemoral Carotid Artery Stenting: Proof of Concept, Technical Description and Experience
Authors: Monteiro Andre , Cappuzzo Justin Mark , Waqas Muhammad , Lim Jaims , Baig Ammad , Khawar Wasiq , Popoola Daniel , Davies Jason , Siddiqui Adnan Hussain , Levy Elad I. , Snyder Kenneth Vincent
Published: March 2023

INTRODUCTION:

The use of modern transfemoral balloon guide catheters (BGC) for flow reversal during carotid artery stenting (CAS) is scarcely described in literature but represents a promising and efficient technique for embolic protection.

METHODS:

We performed a retrospective analysis of patients ≥ 18-year-old who underwent elective CAS with the use of flow-reversal through the Walrus BGC. The BGC is positioned in the common carotid artery and inflated, followed by opening of the stop-cock for passive reversal of flow. We utilized a robotic transcranial Doppler monitoring during this technique for proof of concept. Patients’ characteristics, procedural details and clinical follow-up were evaluated.

RESULTS:

One-hundred and ten patients were included. Mean age was 69.1 years ± SD 9.6 and 30 (27.3%) were female. Most common comorbidities were hyperlipidemia (81.8%) and hypertension (73.6%). 54 (49.1%) patients were symptomatic. 102 (92.7%) patients had stenosis ≥70%. Contralateral stenosis ≥50% was present in 54 (49.1%) patients. Distal filters were used in 91 (82.7%) cases. Angioplasty was performed in 86 (78.2%) patients. Stenting was successful in 100% of cases. There were no periprocedural TIA or stroke. Stroke or TIA and mortality were both observed in only two (1.8%) patients during 30-days follow-up, of which one was due to non-compliance with antiplatelet regimen.

CONCLUSIONS:

In our institution’s experience, this technique was safe, feasible and efficient, with 100% technical success and no periprocedural thromboembolic complications. More extensive studies are needed to establish the role of proximal protection with flow-reversal using modern BGCs.
315 Use of Flow Diverter in the Treatment of Anterior Communicating Artery Aneurysms: A Multicenter Experience (FEAR ME study)
Authors: Benalia Victor , Cortez Gustavo , Mounayer Charbel , Saatci Isil , Cekirge Saruhan , Koçer Nací , Islak Civan , Dabus Guilherme , Brinjikji Waleed , Baltacıoğlu Feyyaz , Pereira Vitor Mendes , Nishi Hidehisa , Siddiqui Adnan , Lopes Demetrius K. , Aghaebrahim Amin , Sauvageau Eric , Hanel Ricardo A.
Published: March 2023

INTRODUCTION:

The anterior communicating artery (AcomA) is among the most common s ites of intracranial aneurysms and has an increased risk of rupture compared to other locations. The safety and efficacy of flow diverters utilization for aneurysm treatment have been demonstrated for many locations, less consistently for AcomA Complex. We present the most extensive analysis in the neurosurgical literature for flow diverter treatment in AcomA aneurysms.

METHODS:

Databases from nine centers were retrospectively reviewed for AcomA aneurysms treated with flow diverters. Demographic information, clinical presentation, radiographic characteristics, procedural complications, and post-procedure outcomes were obtained.

RESULTS:

A total of 181 patients harboring 186 AcomA aneurysms were treated between January 2012 to December 2021. Ninety-one were female (54.1%), median age was 61[51 – 68]. Most aneurysms were unruptured and located at the AcomA itself. Half of the cohort had similar anterior cerebral artery sizes (51.8%). The most common morphology was saccular (91.9%), with a branch involvement in 30.4% of cases. Median vessel diameter was 2.35 mm, and Pipeline Flex was the most prevalent device (39.8%). Median follow-up time was 16 months, with a complete occlusion rate of 85.6% in the last follow-up. Functional independence (mRS 0-2) was reported in 96.7% of patients at the last follow-up. Major complication rate was 2.2%, and mortality rate was 2.2% (4/181).

CONCLUSIONS:

Our results suggest that flow diverter is a useful tool as treatment modality for AcomA aneurysms. Mid-term results indicated favorable aneurysm occlusion rates and a lower complication rate. Additional prospective studies with longer follow-up and independent adjudication are warranted to assess these results better.
316 Neurosurgical Federated Learning: A Multi-Center Collaboration to Detect Intracranial Hemorrhage Without Directly Sharing Data
Authors: Cheung Alexander , Moin Mustafa Nasir , Kwon Fred , Guan Jiahui , Liu Chris , Jiang Lavender , Raimondo Christian , Chotai Silky , Chambless Lola Blackwell , Ahmad Hasan S. , Chauhan Daksh , Yoon Jang Won , Hollon Todd Charles , Buch Vivek , Kondziolka Douglas , Chen Dinah , Al-Aswad Lama , Aphinyanaphongs Yindalon , Oermann Eric
Published: March 2023

INTRODUCTION:

The development of accurate and generalizable machine learning algorithms requires sufficient quantities of diverse data. This poses a challenge in healthcare due to the sensitive and siloed nature of biomedical information. Decentralized algorithms through a federated learning (FL) paradigm avoid the need for data aggregation by instead distributing algorithms to the data itself before centrally updating one global model.

METHODS:

Five academic neurosurgery departments across the US collaborated to establish a federated network using computed tomography (CT) scans for prototyping. We trained a convolutional neural network to detect the presence of ICH through FL and benchmarked this against a standard, centralized training approach. Models were validated on each site’s data and tested on a held-out dataset to determine the area under the ROC curve (AUROC).

RESULTS:

A federated network of practicing neurosurgeon-scientists was successfully initiated and used to train a model for predicting ICH across the US. The federated model achieved an average AUROC of 0.9487 at predicting all types of ICH compared to a benchmark non-FL model AUROC of 0.9753, although performance varied by hemorrhage subtype. Subdural bleeds had the lowest AUROC (0.9257) while intraventricular bleeds had the highest (0.9751) on hold-out data. The global FL model consistently achieved top-three performance (of five) when validated on data from each site, suggesting improved generalizability. A qualitative survey of participants revealed that a majority found the process of connecting to the federated network easy.

CONCLUSIONS:

This study demonstrates the feasibility of implementing a federated network for multi-institutional collaboration amongst clinicians and using FL to conduct machine learning research without the transfer of data between sites, thereby opening up a new paradigm for neurosurgical collaboration.