bluuebunny/crossref_metadata_2025 huggingface dataset:
453 Long-Term Outcomes Following Minimally Invasive Laminectomy for the Treatment of Lumbar Synovial Cysts
Authors: Chesney Kelsi , Elsouri Mohamad , Stylli Jack , Phelps Emily , Fayed Islam , Voyadzis Jean-Marc , Sandhu Faheem A.
Published: March 2022

INTRODUCTION:

Lumbar synovial cysts (LSC), most often occurring at L4-5, can cause painful radiculopathy and/or sensory or motor deficits when symptomatic. The etiology of these lesions is thought to be related to degeneration of the facet joints. Historically, the first-line surgical treatment has been decompression with fusion. More recently, minimally invasive laminectomy without fusion has been shown to achieve equal or superior results to traditional decompression and fusion methods.

METHODS:

A retrospective review was performed at a single institution, over a 10-year period, of patients undergoing minimally invasive laminectomy for symptomatic LSCs. The primary outcome in this study was the rate of revision surgery requiring fusion. Secondary outcomes were based on analysis of baseline patient characteristics, operative details, and postoperative outcomes.

RESULTS:

Eighty-five patients with symptomatic LSC underwent minimally invasive laminectomy alone from January 2010 to August 2020 at our institution. The most common location was L4-5 (71%), followed by L5-S1 (17%), and then L3-4 (11%). The average patient was 65 years old with a BMI of 28.6. All patients (100%) presented with symptoms of painful radiculopathy. Pre-operative imaging identified spondylolisthesis in 44 (57%) patients, none of which were considered unstable on dynamic X-rays. Average length of the procedure was 93 minutes, with 78% of patients discharged home on the same day of their procedure. There was only one reported intraoperative durotomy. Over 45 months of mean follow-up, seventeen patients (20%) required eighteen revision operations. Of those, 15 were primary spinal fusions (17.6%), 2 were washouts for epidural hematoma (2.4%), and 1 was a revision decompression for recurrent cyst (1.2%). Mean time to fusion surgery was 31 months. There were no identifiable risk factors on multivariate regression analysis that predicted the need for fusion.

CONCLUSION:

After minimally invasive laminectomy for lumbar synoval cyst, only 18% of the 85 patients in our cohort went on to require a fusion over a ten-year period.
458 Pulsed Electromagnetic Fields (PEMF) Used in Cervical Spine Fusion for Patients with Risk Factors for Non-Union
Authors: Wind Joshua J. , Weinstein Marc , Radcliff Kris , Lansford Todd , Aleem Ilyas , Patel Vikas V. , Vokshoor Amir A.
Published: March 2022

INTRODUCTION:

A post market prospective study was conducted to examine the effect of the adjunctive use of a pulsed electromagnetic field (PEMF) device on cervical fusion rate in subjects with risk factors for non-union. PEMF has been shown to stimulate bone healing and can be a valuable tool to help overcome biological deficiencies in patients at risk for non-union.

METHODS:

Patients undergoing cervical fusion surgery were identified for enrollment from 11 investigator sites based on being classified as having one or more risk factors for non-union. Subjects were those having a multi-level (2 or more) fusion, prior cervical spine fusion, diabetes, osteoporosis, or smokers. Subjects were required to wear the PEMF device for 4 hours/day for 6 months. Compliance was measured based on usage data downloaded from the device. The primary outcome measure was fusion status at 12 month follow-up period as indicated by x-ray and CT. Fusion status was determined by the site investigator using A/P, lateral, and flexion/extension radiographs in addition to CT (without contrast).

RESULTS:

Out of 152 subjects, 138 (90.8%) were graded as fused (all levels) at the 12 month visit About half of the subjects (49.3%) had 3 or more levels fused. Fusion success for subjects with 2 or more risk factors was 88.5%, and was 94.4% for subjects with a single risk factor. On average, compliance rates (minutes using device/minutes prescribed) were 83.8% and 74.9% for the 3 and 6 month visit, respectively. The followup rate at the 12 month visit was 97%.

CONCLUSION:

The results of our study suggest that adjunctive use of PEMF is effective in cervical spine fusion patients with factors associated with non-union. Favorable fusion rates were obtained with patients having elevated comorbidity and/or complex surgeries. Further research is planned to include a control group in a real world setting to better assess the impact of the PEMF device in this population.
463 Incidence and Impact of Surgical Glove Contamination on Surgical Site Infection (SSI)
Authors: Herbert Joseph , Litofsky N. Scott , Vallabhaneni Ahdarsh
Published: March 2022

INTRODUCTION:

Surgical site infection (SSI) is a significant source of increased cost and morbidity among patients undergoing elective neurosurgical operations. Although much research has focused on the impact of various patient and surgical factors on SSI, studies examining the role of unintended surgical glove contamination (SGC) on SSI are unavailable.

METHODS:

Patients undergoing elective neurosurgical operations were prospectively collected over 1 year in this prospective quality improvement project. At the conclusion of the key portion of the operation, just prior to the start of closure, the gloves of the attending, resident, and scrub tech were swabbed using standard culture swabs and sent for aerobic and anaerobic culture. Preoperative antibiotics, choice of skin preparation, length of operation, and type of wound dressing were also recorded. Any wound infection or breakdown during follow up was recorded.

RESULTS:

Ninety-seven patients (36 spine and 56 cranial, and 5 “other” operations) were included for analysis. Overall incidence of SSI was 4.12%. SGC incidence was 10.3%, with the majority of positive cultures (60%) found on the scrub tech’s gloves. None of the patients in which SGC was identified went on to develop SSI.

CONCLUSION:

The incidence of SGC in our cohort was over 10%. SGC identified at the time of closure did not correlate with development of SSI. SSI does not appear to result from wound contamination prior to closure.
464 Hospital Frailty Risk Score and Healthcare Resource Utilization After Surgery for Metastatic Spinal Column Tumors
Authors: Elsamadicy Aladine A. , Koo Andrew B. , Reeves Benjamin , Pennington Zach , Yu James , Goodwin C. Rory , Kolb Luis , Laurans Maxwell S. H. , Lo Sheng-fu L. , Shin John H. , Sciubba Daniel
Published: March 2022

INTRODUCTION:

The Hospital Frailty Risk Score (HFRS) was recently developed utilizing ICD-10 diagnostic codes to identify frailty and predict adverse outcomes in large national database studies. While other studies have examined frailty in spine oncology, HFRS has not been assessed in this patient population.

METHODS:

A retrospective cohort study was performed using the National Inpatient Sample (NIS) database from the years 2016 to 2018. All adult patients (=18 years-old) undergoing surgery metastatic spinal column tumor were identified using the ICD-10-CM diagnostic and procedural coding systems. Patients were categorized into two cohorts based on the criteria of the HFRS: No Frailty (HFRS <5) and Frail (HFRS = 5). A multivariate logistic regression analysis was used to identify independent predictors of prolonged LOS, non-routine discharge, and increased cost.

RESULTS:

Of the 8,500 patients identified, 3,230 (38.0%) were found to be Frail by HFRS criteria. Compared to the Non-Frail cohort, the Frail cohort was found to have a significantly longer LOS (Non-Frail: 7.9 ± 5.0 vs Frail: 14.8 ± 13.0, p < 0.001), a significantly higher rate of Non-Routine discharge (Non-Frail: 639.8% vs Frail: 61.7%, p = 0.001), and a significantly greater mean total cost of hospital admission (Non-Frail: $48,108 ± $29,654 vs Frail: $66,798 ± $45,712, p < 0.001). On multivariate regression analysis, Frailty was found to be a significant predictor of both prolonged LOS [OR: 4.02, CI (3.06, 5.27), p < 0.001] and non-routine discharge [OR: 2.13, CI (1.68, 2.71), p < 0.001].

CONCLUSION:

Our study is the first to use the HFRS to assess the impact of frailty on patients with metastatic bony spinal tumors. We found that in this patient population, Frailty was associated with prolonged hospital LOS, non-routine discharge and total hospital costs.
466 Influence of Race on Early Outcomes of Elective Lumbar Interbody Fusions: An Updated Propensity-Matched and Subgroup Analysis
Authors: Alomari Safwan , Porras Jose L. , Jud Brendan F. , Witham Timothy F. , Bydon Ali
Published: March 2022

INTRODUCTION:

Several studies have consistently found that black patients, when compared to white patients, were more likely to have postoperative morbidity and mortality. However, these studies have several limitations.

METHODS:

Patients who underwent (PLIF/TLIF) or (ALIF/LLIF) between 2015-2018 were reviewed from ACS-NSQIP database. Propensity score matching and subgroup (single/multi-level) analysis were used

RESULTS:

17,471 PLIF/TLIF cases and 8,760 ALIF/LLIF cases met inclusion criteria and were reviewed. In both single/multi-level PLIF/TLIF and ALIF/LLIF, black patients were more likely to be younger, have higher BMI, be of female gender, have inpatient admission status, have an ASA class 3 or more, be a smoker, have baseline dyspnea, have hypertension and be functionally dependent. In both single/multi-level ALIF/LLIF, black patients were more likely to have diabetes mellitus. In both groups (single/multi-level PLIF/TLIF and ALIF/LLIF), except for the higher incidence of DVT in the black cohort, there were no significant differences in morbidity and mortality measures between the black and white cohorts.

CONCLUSION:

In contrast to prior literature, our analysis did not identify black race as an independent risk factor for higher perioperative morbidity or mortality in patients undergoing elective lumbar fusion, except for the higher incidence of venous thromboembolism. The findings of the present study are important for clinicians and spine surgeons while counseling patients undergoing these types of procedures. It is important to address patient’s concerns and to explain that the previously reported inferior perioperative morbidity and mortality outcomes in black patients might be due differences in baseline health status, and not due to the race difference itself.
477 Development and Validation of a Second-generation of PupilScreen, a Smartphone-based Pupillometer, in Healthy Population
Authors: Lim Do , Maxin Anthony , Gulek Bernice G. , Buzytsky Chungeun (Chloe) Lee; Ilya , Coppess Steve , Alfieri Robin , Bly Randall , Law Anthony , Levitt Michael R. , Kelly Cory , McGrath Lynn
Published: March 2022

INTRODUCTION:

Although there are continuous efforts towards promoting pupillary light reflex (PLR) as a biomarker, its use has been limited due to the expense and limited mobility of pupillometry devices. With demands for non-invasive methods, the expanded use and improved accuracy of PLR are vital to advancing neurological care in myriad settings.

METHODS:

PLR was captured with both a commercial pupillometer and the PupilScreen app for n=21 subjects, utilizing a standard iPhone camera in a standard clinical environment. The captured data was processed via our machine learning model utilizing a fully convolutional neural network to generate the PLR parameters. Then the parameters were compared to standard pupillometry for both eyes: initial pupil size(px), latency(s), the percentage change in size, average and peak constriction velocity (px/s), average and peak dilatation velocity (px/s), and construction amplitude (px) were analyzed and compared in consideration of age, gender, ethnicity, and the eye color.

RESULTS:

The second generation of PupilScreen continues to meet the gold standard accuracy of manual pupillometry, despite no longer requiring control of external conditions. Mean parameters were as followed for pupillometry and PupilScreen respectively: mean latency 0.22s(L)/0.23(R) vs via 0.17s(L/R) (p<0.05), mean percent diameter change 36%(L/R) vs 39% (L/R) (p=0.07), and mean constriction velocity 3.1mm/s(L)/3.0mm/s(R) vs 3.0mm/s(L)/2.9mm/s(R) (p<0.05). Demographics subjects: Mean age: 35 years; 62% female; Race/Ethnicity: White 76%, Black/African-American 10%, Asian 14%. Eye color was 38% brown, 29% blue, 33% mixed.

CONCLUSION:

These results validate the accuracy that the second generation of PupilScreen, can provide estimates of PLR that meet or exceed the accuracy of manual pupillometry and current clinical gold standard digital infrared pupillometry, with the advantage of its being able to be used anywhere there’s a smartphone.
494 Enhanced Senescence Phenotype In Human Medulloblastoma via Protein Phosphatase 2A Inhibition and Radiation Therapy
Authors: Mondal Isha , Lu Rongze , Ho Winson , Chiou Brandon , Das Oishika , McFadden Elizabeth , Ahn Julia , Wang Junying
Published: March 2022

INTRODUCTION:

Medulloblastoma is the most common malignant pediatric brain tumor. Radiation(RT) is a part of standard care but causes significant neurocognitive impairment. Strategies to sensitize RT is critical to improving the quality of life and long-term survival of patients. Previous studies show that inhibition of protein-phosphatase 2A(PP2A)–a ubiquitous serine/threonine phosphatase–enhanced sensitivity to RT in multiple brain tumor xenografts. However, the mechanism behind enhanced radio-cytotoxicity is poorly understood. We hypothesize that PP2A inhibition combined with RT will increase cytoplasmic double-stranded DNA (dsDNA) and induce cGAS-cGAMP-STING signaling, promoting cellular senescence and thereby decreasing tumor growth.

METHODS:

D425-WT, a human group-3 medulloblastoma cell line, was used to generate a CRISPR sgPP2A knock out, D425-KO. We radiated WT and KO cells in vitro, quantified dsDNA in cytoplasmic extract using dsDNA Assay kit, and measured cGAMP levels in whole cell lysate using ELISA. Through FACS, we quantified the proportion of b-gal-expressing senescent cells. We measured protein expression of senescence markers (p21, p16, g-h2aX) by Western blot(WB). Finally, we injected D425 WT or KO cells orthotopically into cerebellum of nude NU/J mice followed by RT (10Gy) 3 days post-injection and monitored survival.

RESULTS:

In response to RT, D425-KO compared to WT showed significant increase in cytoplasmic dsDNA and intracellular cGAMP--a cyclic di-nucleotide STING agonist. There was also an increase in b-gal+ senescent cells and senescence markers expression in WB. In vivo, PP2AKO alone extended longevity, but PP2AKO with RT further prolonged survival compared to KO or RT alone.

CONCLUSION:

PP2A inhibition enhances RT induced cytosolic dsDNA damage and STING activation, promoting cellular senescence in vitro and sensitivity to RT in vivo.
504 Improving Precision of Resection Limits in Surgery for High-grade Gliomas: Preliminary Experience with an In Vivo Raman Spectroscopy Probe
Authors: Herta Johannes , Cho Anna , Roetzer Thomas , Kronreif Gernot , Wolfsberger Stefan
Published: March 2022

INTRODUCTION:

Supramaximal resection of gliomas to anatomic-functional boundaries is currently widely employed. This leads to removal of potentially tumor-negative thus healthy brain tissue. Therefore, a device that detects glioma tissue infiltrating the white matter in vivo would be valuable.

METHODS:

Patients and methods. An in vivo Raman spectroscopic system (Sentry 1000, ODS Medical, Montreal, Canada) with an early stage binary classifier trained on 501 samples from 17 patients (tumor n=211 and pure normal n=290 from Montreal Neurological Hospital, Montreal, Canada) has been employed in 15 patients with high-grade gliomas . Of those, 172 samples were collected from 2 areas: n=18 from the central tumor core and n=154 from the adjacent glioma-infiltrated white matter until Raman negative or until an anatomic or functional boundary was reached. All samples were reviewed for the presence of glioma cells by histopathology.

RESULTS:

Sensitivity of Raman spectroscopy for correct high-grade glioma cells was 79%, specificity for non-infiltrated white matter was 52%. Median resection volume outside MR contrast enhancement was 78 ± 143 cm3. Removal of the infiltration zone guided by Raman spectroscopy revealed a non-concentric growth mainly along white matter fiber bundles.

CONCLUSION:

According to our data, Raman spectroscopy has the potential to improve the precision of high-grade glioma resection. This may allow a more selective removal of the tumor-infiltrated white matter.
506 Evaluating Traditional and Non-Traditional Eloquent Areas in Patients with Brain Tumors: Large-scale Network Analysis Using a Machine Learning-Based Platform
Authors: Morell Alexis A. , Eichberg Daniel G. , Luther Evan , Shah Ashish H. , Lu Victor M. , Komotar Ricardo J. , Ivan Michael E.
Published: March 2022

INTRODUCTION:

Developing mapping tools that allow identification of traditional or non-traditional eloquent areas is necessary to minimize the risk of postoperative neurologic deficits. The objective of our study is to evaluate the use of a novel cloud-based platform that uses machine learning to identify cerebral networks in patients with brain tumors.

METHODS:

We retrospectively included all adult patients who underwent surgery for brain tumor resection or thermal ablation at our Institution between the 16th of February and the 15th of May of 2021. Pre and postoperative contrast-enhanced MRI with T1-weighted and high-resolution Diffusion Tensor Imaging (DTI) sequences were uploaded into the Quicktome platform. After processing the data, we categorized the integrity of seven large-scale brain networks: sensorimotor, visual, ventral attention, central executive, default mode, dorsal attention and limbic. Affected networks were correlated with pre and postoperative clinical data, including neurologic deficits.

RESULTS:

Thirty-five (35) patients were included in the study. The average age of the sample was 63.2 years, and 51.4% (n=18) were females. The most affected network was the central executive network (40%), followed by the dorsal attention and default mode networks (31.4%), while the least affected were the visual (11%) and ventral attention networks (17%). Patients with preoperative deficits showed a significantly higher number of altered networks before the surgery (p=0.021), compared to patients without deficits. In addition, we found that patients without neurologic deficits had an average of 2.06 large-scale networks affected, with 75% of them not being related to traditional eloquent areas as the sensorimotor, language or visual circuits.

CONCLUSION:

The Quicktome platform is a practical tool that allows automatic visualization of large-scale brain networks in patients with brain tumors. Although further studies are needed, it may assist in the surgical management of traditional and non-traditional eloquent areas.
507 Rational Radiomic Design for Stepwise Diagnosis of Posterior Fossa Pediatric Tumors
Authors: Zhang Michael , Wong Samuel , Wright Jason , Toescu Sebastian , Mohammadzadeh Maryam , Han Michelle , Lummus Seth , Wagner Matt , Yecies Derek W. , Lai Hollie , Eghbal Azam , Radmanesh Alireza , Nemelka Jordan , Harward Stephen C. , Malinzak Michael , Laughlin Suzanne , Perreault Sebastien , Braun Kristina , Vosough Arastoo , Poussaint Tina Y. , Goetti Robert , Ertl-Wagner Birgit , Ho Chang , Oztekin Ozgur , Ramaswamy Vijay , Mankad Kshitij , Vitanza Nick , Cheshier Samuel H. , Said Mourad , Aquilina Kristian , Thompson Eric M. , Jaju Alok , Grant Gerald A. , Lober Robert , Yeom Kristen
Published: March 2022

INTRODUCTION:

Medulloblastoma (MB), pilocytic astrocytoma (PA), and ependymoma (EP) compose the majority of posterior fossa (PF) pediatric tumors and share similar features on MRI. Pre-operative anticipation of pathology can inform the surgical approach, extent of resection, and potential complications.

METHODS:

We extracted 1800 Image features from T2- and gadolinium-enhanced T1-weighted images in a multinational cohort of 274 MB, 156 PA, and 97 EP. We designed a two-step classifier—first ruling out PA with a three-way classifier, and next distinguishing MB from EP with a binary classifier. For each step, we selected the best performing classifier model from six candidates following LASSO-feature reduction. Final multi-class classifier performance was measured on a holdout test set with the micro-averaged F1-score.

RESULTS:

Optimal diagnostic performance was achieved using two decision steps, each with their respective feature set and classifier method. An initial three-way (MB, PA, and EP) logistic regression classifier exhibited a micro-averaged F1-score of 0.739. From a reduced feature set of 61 features, T2-Uniformity and T1-Contrast were the most relevant for distinguishing PA. A subsequent two-way neural net classifier distinguished MB from EP with F1-score 0.9189. In the second reduced feature set of 39 features, T2-Sphericity and T1-Flatness were most relevant. Performing the two classifiers sequentially for MB, PA, and EP classification produced a micro-averaged F1-score of 0.9179.

CONCLUSION:

A sequential radiomic improved upon a single-step radiographic classifier for pediatric PF tumors. Strong overlap between MB and EP prevented a single-step classifier from distinguishing all three pathologies at once. PA-relevant features aligned with avid gadolinium-enhancement and non-enhancing cystic components. MB and EP-related features correlated to how each conform within and extrude from the fourth ventricle, respectively.
512 TMS Seeded DTI Tractography Provides Superior Identification of Eloquent Cortex Compared to Anatomic Seeded Tractography
Authors: Muir Matthew , Prinsloo Sarah , Traylor Jeffrey I. , Bastos Dhiego , Prabhu Sujit S.
Published: March 2022

INTRODUCTION:

Previous studies have shown the feasability of seeding DTI tractography using transcranial magnetic stimulation (TMS) points for the cortical region of interest (ROI). Previous work from our group has shown that resection of TMS points with connecting white matter tracts identified by TMS tractography leads to permanent neurological deficits.

METHODS:

We selected a cohort of 42 patients with perirolandic gliomas who underwent preoperative TMS mapping with subsequent resection. The primary outcome collected from the chart was new or worsened motor deficit present at 3 month follow up. We overlayed the postoperative resection cavity onto the preoperative MRI containing the tractography data, seeded either by TMS points or the precentral gyrus. We used a confusion matrix to model the predictive value of permanent deficits for each tractography scheme. Positive predictive value denotes the likelihood that a patient with the corresponding tract resected develops a permanent deficit, while negative predictive value denotes the likelihood that a patient with the corresponding tract preserved does not develop a permanent deficit.

RESULTS:

22/42 patients showed TMS positive points significantly displaced from the precentral gyrus. With respect to prediction of permanent deficit upon resection of relevant tracts versus preservation of relevant tracts, TMS seeded tractography showed a positive predictive value (PPV) of 87% and negative predictive value (NPV) of 97%. Anatomic tractography showed a positive predictive value (PPV) of 50% and negative predictive value (NPV) of 91%.

CONCLUSION:

Over half of the patients in our cohort exhibited tumor induced plasticity measured by TMS. TMS seeded tractography provided significantly higher positive and negative predictive value for identifying true non-resectable, eloquent cortex compared to anatomic seeded tractography.
801 Middle Meningeal Artery Embolization Versus Conventional Treatment of Chronic Subdural Hematomas
Authors: Enriquez-Marulanda Alejandro , Gomez-Paz Santiago , Salem Mohamed M. , Mallick Akashleena , Arle Jeffrey E. , Stippler Martina , Papavassiliou Efstathios , Alterman Ron L. , Ogilvy Christopher S. , Moore Justin M. , Thomas Ajith J.
Published: March 2022

INTRODUCTION:

Middle meningeal artery (MMA) embolization is an emerging minimally invasive endovascular technique for chronic subdural hematoma (cSDH). Currently, limited amount of literature exists on its safety and efficacy compared with conventional treatment (open-surgical-evacuation-only).

METHODS:

Retrospective analysis of patients with cSDHs treated with MMA embolization in a single center from 2018-2019 was performed. Comparisons were made with a historical conventional treatment cohort from 2006-2016. Propensity score matching (PSM) analysis was used to assemble a balanced group of subjects.

RESULTS:

A total of 357 conventionally treated cSDH and 45 with MMA embolization were included. After balancing with PSM, a total of 25 pairs of cSDH were analyzed. Comparing the embolization with the conventional treatment group yielded no significant differences in complications (4% vs. 4%; p>0.99), clinical improvement (82.6% vs. 83.3%; p=0.95), cSDH recurrence (4.3% vs. 21.7%; p=0.08), overall re-intervention rates (12% vs. 24%; p=0.26), mRS >2 on last follow-up (17.4% vs. 32%; p=0.24) as well as mortality (0% vs. 12%; p=0.09). Radiographic improvement at last follow-up was significantly higher in the open surgery cohort (73.9% vs. 95.6%; p=0.04). However, there was a trend for lengthier last follow-up for the historical cohort (72 vs. 104 days; p=0.07).

CONCLUSIONS:

There was a trend for lower recurrence and mortality rates in the embolization era cohort. There were significantly higher radiological improvement rates on last follow-up in the surgical only cohort era. There were no significant differences in complications and clinical improvement.
807 Peak Force of the Posterior Ligamentous Complex is Lower in Patients with Adult Spinal Deformity Requiring Revision Surgery
Authors: Shahidi Bahar , Anderson Brad , Malone Hani , Iannacone Tina , Moltzen Courtney , Eastlack Robert , Mundis Gregory M.
Published: March 2022

INTRODUCTION:

Proximal Junctional Kyphosis (PJK) is observed in up to 40% of those undergoing fusion surgery for adult spinal deformity (ASD). Despite common use of surgical techniques reinforcing ligamentous integrity (e.g. tethering, augmentation), it is unknown whether ligamentous biomechanics are impaired in this population.

METHODS:

Sample: 23 consented individuals with a diagnosis of ASD undergoing primary (N=14) or revision (N=9) multilevel spinal fusions (>4 levels). Intraoperative biopsies of the PLC were harvested 2 levels below the upper instrumented level (primary) or at the failed junctional segment (revision). Peak force (strength) and elastic modulus (stiffness) were compared between primary and revision groups using independent student t-tests, and relationships between biomechanical parameters and patient characteristics evaluated.

RESULTS:

Participants in the revision group were older (73.3(3.6) years) than the primary group (54.7(19.2)years), p=0.02, but did not differ in number of fused vertebrae (12.0(4.3); primary and (11.3(3.4); revision), p=0.71). Mean pre-operative Vitamin D levels were 40.6(11.5), spino-vertebral angle (SVA) was 54.4(56.8) degrees, Pelvic Tilt (PT) was 24.1(11.0) degrees, Pelvic Incidence-Lumbar Lordosis mismatch (PI-LL) was 15.3(22.4) degrees, and Proximal Junctional Kyphosis (PJK) was 9.4(8.1) degrees. Mean post-operative SVA was 8.3(28.2) degrees, PT was 20.6(6.9) degrees, PI-LL was 4.4(10.0) degrees, and PJK was 12.0 (10.5) degrees. Peak force was significantly lower in the revision group (143.1(72.5) N) compared to the primary group (238.5(109.8) N), p=0.03. There were no differences in ligament stiffness between the primary (5.9(2.0) MPa) and revision groups (5.3(3.1) MPa), p=0.92). There was a significant association between greater peak force and lower age (r=-0.56, p=0.003), larger ligament area (r=0.50, p=0.015), lower vitamin D levels (r=-0.63, p=0.015), and lower pre-operative PI-LL (r=-0.53, p=0.014). There was also a significant association between greater ligament stiffness and greater post-operative PJK (r=0.60, p=0.013).

CONCLUSIONS:

Peak force of the posterior ligamentous complex in individuals undergoing revision surgery was <60% of those undergoing primary surgery, suggesting an important role of ligament in stabilization of the proximal junctional interface in patients with ASD, particularly in older individuals.
811 Lesional Hemorrhage and Hemorrhage-Negative Patients May Confound the Study of Severe TBI Using Institutional Trauma Databases: Results from a Single Level I Trauma Center
Authors: Bonney Phillip A. , Lin Michelle , Cote David J. , Attenello Frank
Published: March 2022

INTRODUCTION:

Single institution trauma databases are frequently used for outcomes studies in severe traumatic brain injury (sTBI). The etiology of hemorrhage is commonly uncertain at the time of presentation in the neurologically impaired patient, who may be considered potentially traumatic during initial resuscitation. The complexity of intracranial hemorrhage and coding practices serve as barriers to the effective characterization of sTBI patients.

METHODS:

The LAC+USC trauma database was queried from 2010 to 2018. Patients greater than 18 years of age with initial Glasgow Coma Scale 3 to 8 and abbreviated injury scale head score (AIS-H) of 3 to 5 were selected as those with putative sTBI. Initial and subsequent CT scans of the head and radiology reports were reviewed. Hemorrhages suggestive of spontaneous etiologies including lesional hemorrhages and hypertensive hemorrhages were noted. Review of angiographic studies was performed when relevant.

RESULTS:

Of 24,763 database patients, 1,310 (5.3%) were adults with putative blunt sTBI. Among this cohort, 119 (9.1%) did not survive to CT scan. Among patients receiving CTH, 87 patients (6.6%) had no acute intracranial findings, and 12 (0.9%) had ischemic stroke or diffuse anoxic injury. Non-traumatic etiologies were present in 31 patients (2.4%), consisting of 8 lesional hemorrhages and 23 hypertensive hemorrhages.

CONCLUSIONS:

19% of patients did not meet sTBI criteria. The study of sTBI in institutional databases may be confounded by non-hemorrhagic injuries and non-traumatic intracranial hemorrhages.
814 Differences in Human, Pig, and Rat Spinal Cord Stem Cells in Response to Inflammatory and Regenerative Factors In Vitro
Authors: Kassab Abdul Mounnem
Published: March 2022

INTRODUCTION:

The translation of preclinical science to human applications, including regenerative strategies for spinal cord injury, has been poor. Historically, animal models, such as rats and pigs, have been used to model human spinal cord given the difficulty in obtaining live human spinal cord.

METHODS:

To mimic post-injury inflammation, primary-derived NSPCs from adult humans (n=8), rats (n=6), and pigs (n=5) were treated with interleukin-6 (IL-6), tumor necrosis factor- α (TNFα), or transforming growth factor- β (TGFβ). To direct regeneration, NSPCs were treated with retinoic acid (RA), platelet-derived growth factor (PDGFα), or bone morphogenic protein-4 (BMP4) to induce neurons, oligodendrocytes or astrocytes, respectively. NSPCs were treated for 7 or 14 days and characterized by immunocytochemistry (GFAP, β-iii tubulin, O4).

RESULTS:

IL-6, TNFα and TGFβ induced astrogenesis of rat NSPCs (3.9±0.7, 5.0±0.9, and 4.0±0.6 fold, respectively) and reduced neurogenesis (0.14±0.90, 0.07±0.04, 0.07±0.05 fold, respectively) after 7 days. Pig NSPCs increased astrogenesis (1.38±0.04, 1.26±0.05, and 1.45±0.04 fold, respectively) after 14 days. Human NSPCs had reduced astrogenesis (0.14±0.07, 0.6±0.2, and 0.12±0.07 fold, respectively) over 14 days, but generated more neurons with IL-6 and TGFβ treatments (1.23±0.05 and 1.34±0.04 fold, respectively). RA increased neurogenesis of human and rat NSPCs, PDGFα increased oligodendrocyte differentiation of rat NSPCs, and BMP4 increased astrogenesis of human and rat NSPCs at low (40ng/mL) and high (100ng/mL) concentrations, respectively.

CONCLUSIONS:

For the first time, we have compared primary-derived adult spinal cord NSPCs from humans, pigs, and rats and identified differences in their response to pathophysiological and regenerative factors which would impact successful translation of stem cell-based therapies.
823 IPAX-1: Phase ½ Study of 4-L-[131l] IODO-Phenylalanine (131I-IPA) Combined with External Radiation Therapy (XRT) as Treatment for Patients with Glioblastoma Multiforme
Authors: Pichler Joseph , Hayward Colin , Jessel Mary
Published: March 2022

INTRODUCTION:

Many tumor types, including glioblastoma multiforme (GBM),overexpress the L-type amino transporter 1 (LAT-1). I-iodo-phenylalanine( I-IPA) is a small-molecule amino acid derivative taken up by LAT-1 withdesignated orphan status in the United States and European Union for thetreatment of GBM. Tumor accumulation of I-IPA was shown in a proof-of-principlestudy and confirmed with single dosing of 2–7 GBq I-IPA in combination with XRT in recurrentGBM. The I-IPA + XRT as Treatment for Patients with GBM (IPAX-1) study evaluates the safety,tolerability, dosing schedule, and preliminary efficacy of I-IPA in combinationwith second-line XRT in patients with recurrent GBM.

METHODS:

IPAX-1 is a multi-center, open-label, phase 1/2, dose-finding study recruiting patients with previously confirmed histological diagnosis of GBM and evidence of first recurrence, history of GBM standard therapy, at least 6 months since end of first-line XRT, pathologically increased amino acid tumor uptake shown by molecular imaging, and current indication for repeat radiation. Participants receive intravenous I-IPA either as a single fraction (1f) followed by XRT, or as three equal fractions (3f) at weekly intervals followed by XRT commencing between the first and second I-IPA administration.

RESULTS:

Good tolerability and safety profile Promising progression free survival median 4.33 months and overall survival median 15.97 months Patients with unmethylated MGMT have a worse response to therapy than methylated MGM.

CONCLUSIONS:

Early evidence indicates that the combination of 131I-IPA and XRT may have an anti-neoplastic effect.
830 SPECT-CT as a Predictor of Pain Generators in Patients Undergoing Intraarticular Injections for Chronic Neck and Back Pain
Authors: Garcia Diogo P. , Sousa-Pinto Bernardo , Akinduro Oluwaseun , De Biase Gaetano , Deen Hugh Gordon , Nottmeier Eric W. , Chen Selby G. , Bydon Mohamad , Sandhu Sukhwinder , Scholten Paul , Quinones-Hinojosa Alfredo , Abode-Iyamah Kingsley O.
Published: March 2022

INTRODUCTION:

The ability to accurately predict pain generators for chronic neck and back pain remains elusive. The use of hybrid single-photon emission computerized tomography- computerized tomography (SPECT-CT) to guide facet injections has emerged as a potential approach to improve patient outcomes with unclear effectiveness.

METHODS:

A retrospective review was completed on all patients who had a SPECT-CT for evaluation of chronic back pain between January 2016 and June 2020 at a single tertiary academic center. Patients’ records were reviewed for demographic, clinical, imaging, and outcomes data. Only patients who had facet injections following SPECT-CT were included in this evaluation. Patients undergoing injections targeted at foci of abnormal radiotracer uptake were compared to patients without uptake concerning immediate positive response, visual analog score – VAS -, and need for additional injection or surgery at the target level.

RESULTS:

A total of 2849 patients were evaluated with a SPECT-CT for chronic neck and back pain. Of those, 340 (11.9%) patients received facet joint injections following SPECT-CT. A propensity score regression analysis adjusted for age, gender, bone mass index (BMI), hypertension, multiple targets injections and injection location showed uptake targeted injections not being associated with an improved immediate positive response (OR=0.64; 95%CI=0.34-1.21; p=0.172). In patients with a failed facet injection preceding SPECT-CT, adding SPECT-CT to guide facet injections was associated with a decrease in VAS pain scores two weeks after injection (p=0.018), particularly when changes were made to the facets being targeted (p=0.047).

CONCLUSIONS:

This study suggests that there is benefit with SPECT-CT especially to guide facet injections after a failed prior facet injections.
831 Pain Networks Connectivity Changes Following the Relief of Prolonged Cancer Pain
Authors: Berger Assaf , Jalon Itamar , Gonen Tal , Shofty Ben , Tellem Rotem , Hochberg Uri , Artzi Moran , Ben-Bashat Dafna , Hendler Talma , Strauss Ido
Published: March 2022

INTRODUCTION:

The “salience network” is normally engaged in humans’ response to acute internal or environmental stimuli, including pain. It comprises connections between the anterior insula (AI) and dorsal anterior cingulate cortex (dACC), among others. Chronic pain conditions have been associated with abnormally increased functional connectivity (FC) within the salience network in comparison to healthy individuals.

METHODS:

We prospectively followed patients that underwent cervical cordotomy (n=15) and cingulotomy (n=11) for relief of intractable oncological pain during the years 2016-2019. All patients did resting-state functional Magnetic Resonance Imaging (rsfMRI) before and after the procedures. Clinical data was collected, including pre- and post-operative numeric rating scale (NRS) pain scores.

RESULTS:

All patients (aged 62±11) reported a significant improvement in their pain from NRS 9±1 to 1±1 in cordotomy (p=0.001) and 2±3 in cingulotomy (p=0.005). By comparing pre- and post-operative rsfMRI scans, we demonstrated a significant decrease in the FC between components of the salience network following both cordotomy (p=0.007) and cingulotomy (p=0.009). In the cordotomy group we found a significant decrease in the connectivity between the thalamus and dACC (p=0.019) and within the sensory-motor cortex (p=0.003).

CONCLUSIONS:

Surgical interventions along the pain pathways can lead to a sudden relief of chronic pain in parallel to a significant decrease in the functional connectivity within pain related networks.
834 Whole-Brain Visualization of Single-Neuron Activity During the Development of Neuropathic Pain
Authors: Moosa Shayan , Coley Justin , Liu Chang-Chia , Elias W. Jeffrey , Kapur Jaideep
Published: March 2022

INTRODUCTION:

Chronic neuropathic pain is severely disabling and difficult to treat. The pathophysiological mechanisms behind the transition from an acute to chronic neuropathic pain state are not well defined.

METHODS:

TRAP2 mice are genetically engineered to express tdTomato under dual control of a c-Fos gene promoter and estrogen receptor activation. Seven adult TRAP2 mice underwent unilateral chronic constrictive injury (CCI) of the sciatic nerve, while another six underwent exposure of the nerve without constriction. The mice were administered 4-OHT (to “TRAP” active neurons) one week, three weeks, or six weeks post-injury and maintained for six days before transcardial perfusion. Tissue clarification and confocal imaging/processing allowed for active neuronal populations in distinct brain regions to then be quantified and compared between groups.

RESULTS:

Allodynia developed in only the CCI groups, as confirmed by paw withdrawal thresholds. Active neuronal populations in the medial thalamus became significantly increased from baseline in all CCI groups. The anterior insula, secondary somatosensory cortex, and lateral parabrachial nucleus demonstrated significantly increased activity from baseline at one week post-injury, but this activity decreased at three and six weeks post-injury. Neuronal activity in the ventral orbital cortex was significantly increased from baseline only at three weeks post-injury, while activity in the anterior nucleus of the periventricular thalamus increased with time and became significantly elevated from baseline at three and six weeks post-injury.

CONCLUSIONS:

Our model demonstrates a clear increase in the neuronal activity of pain-related medial thalamic and cortical structures in mice who develop a chronic neuropathic pain state. The TRAP model is an ideal method to study brain plasticity during the transition from an acute pain state to chronic pain condition - enhancing our understanding of the mechanisms responsible for central sensitization to chronic neuropathic pain.
835 The Use of In-patient Concussion Consultation for Patient Education as a Model for Anticipatory Guidance in a Cohort of Pediatric Patients to Improve Symptom Score and Associated Health Outcomes
Authors: Henson Jeffrey Curran , Hanks-Clark Elizabetheth , Cook Alicia , Ocal Eylem
Published: March 2022

INTRODUCTION:

It is estimated that 10% of all pediatric emergency room visits are due to concussions, and although most children recover without complications, problems including physical, emotional, somatic symptoms and sleep disturbances may occur. Pediatric populations are especially sensitive to these damaging sequelae as the plasticity of the developing neural networks of children are highly dynamic. It is with these considerations we have decided to undertake this study to evaluate if early in-patient concussion consultation in patients who have suffered traumatic brain injury (TBI) decreases recovery time, increases symptom reduction, and improves recovery to baseline neurocognitive functioning.

METHODS:

The patient cohort consisted of an initial 74 patients who were an in-patient concussion consultation using the acute concussion evaluation (ACE) tool to assess symptom score [0-22]. Patient files were queried for demographic information, comorbidities, and covariates of interest. The primary endpoints are clinical follow-up and reduction in symptom score between initial evaluation and clinical follow-up. All statistical analysis was performed using a significance level of α = 0.05.

RESULTS:

Delta score as a primary outcome was assessed only on patients retained during clinical follow-up. The difference in initial consult score compared to score at clinical follow-up was significant, p < 0.001, with means of 12.125, and 3.889 respectively. Delta score was found to have resulted in a mean 8.289 reduction in symptom score, and a positive correlation was observed between initial symptom score and delta score. The results for linear and logistic regression of covariates will be presented during CNS 2021.

CONCLUSIONS:

The use of an in-patient concussion consultation provides families with an invaluable tool regarding education and management of concussion symptoms. Our initial results verify this modality of early intervention as an important tool to educate and highlight the importance of early engagement in increasing clinical retention and reducing concussive symptoms in this sensitive patient population.
836 Value of Clinical and Ultrasonic Parameters as Preoperative Predictors of Risk of Developing Hydrocephalus Post Myelomeningocele Repair: A Cohort Study
Authors: Adebayo Bamidele Oludele , Okezie  , Bankole Olufemi B. , Omidiji Olubukola
Published: March 2022

INTRODUCTION:

The risk of developing hydrocephalus after myelomeningocele repair may be determined by using preoperative clinical and transcranial ultrasound parameters.

METHODS:

A prospective longitudinal cohort study from November 2016 to October 2018, that involved 28 patients with myelomeningocele who presented to a tertiary hospital in southwestern Nigeria. Transcranial ultrasound was done before myelomeningocele repair and patients followed up for six months to detect hydrocephalus. Analysis of the state of the anterior fontanelle, the occipitofrontal circumference (OFC), ventricular index, bicaudate diameter, lateral ventricular ratio, thalamo-occipital distance and maximum transverse lateral ventricular diameter were done to determine their predictive values for the development of hydrocephalus after myelomeningocele repair.

RESULTS:

Age range was 1 -120 days with a mean of 20 days and the average age at the time of myelomeningocele repair was 23 days. There were 16 (57.1%) females and 12(42.9%) males in the study. OFC range at presentation was 31- 42cm with a mean of 34.7cm ±2.6 SD. The probability that a patient will develop hydrocephalus after myelomeningocele repair increased by 1.74 times for every1cm increase in the OFC above 34.5cm before myelomeningocele repair, p= 0.03. However, the state of the anterior fontanelle as well as the trans cranial ultrasound parameters were not found to be predictors of hydrocephalus post myelomeningocele repair.

CONCLUSIONS:

The OFC of the patients before myelomeningocele repair was predictive of development of hydrocephalus post repair, but the state of the anterior fontanelle and pre-operative trans fontanelle ultrasound parameters were not.
The Chronically Blocked Ear – A dive into external auditory exostosis
Authors: Montebello Bianca , Vella Stephanie , Grech Reuben
Published: March 2022

Numerous papers have reported the presence of reactive but benign bony exostosis in the external auditory canal of swimmers; of both cold and warm water. This outgrowth may lead to stenosis of the canal with associated complications such as repeated cerumen impaction, infections and also hearing loss. In this case report, we will present the case of a 62-year-old gentleman who was referred for imaging by an ENT specialist following difficulty with visualisation of the tympanic membrane during otoscopy.
Ανάπτυξη οργανοκαταλυτών ως ενεργοποιητών του μοριακού οξυγόνου προς εφαρμογή αερόβιων οξειδωτικών διαδικασιών
Authors: Πετσή Μαρίνα
Published: March 2022

Τα πυρρολο-ιμιδάζολο αλκαλοειδή αποτελούν μια σημαντική υποκατηγορία αλκαλοειδών φυσικών προϊόντων. Αποτελούν μια ολοένα και αυξανόμενη οικογένεια αλκαλοειδών, που προέρχονται από θαλάσσιους οργανισμούς αριθμώντας μέχρι σήμερα πάνω από 150 είδη, με μεγάλο βιολογικό ενδιαφέρον. Διαθέτουν ιδιαίτερη δομική πολυπλοκότητα, συμπαγή και πλούσιο στερεογονικά σκελετό, με μεγάλη αναλογία ατόμων Ν:C (1:2), με αποτέλεσμα όλο και περισσότερες βιολογικές μελέτες να προσελκύουν έναν αυξανόμενο αριθμό ερευνητών από πολυάριθμες επιστήμες, παγκοσμίως. Οι μονοξυγενάσες δεν αποτελούν μόνο εξαιρετικά ευέλικτης λειτουργικότητας μηχανές στην καθημερινή ζωή, αλλά και μερικά από τα πιο μελετημένα ένζυμα στη σύγχρονη οργανική σύνθεση. Παρέχουν γνώση, αλλά και αποτελούν πηγή έμπνευσης για τον τρόπο που το μοριακό οξυγόνο, μπορεί να ενεργοποιηθεί και να χρησιμοποιηθεί για να επιτελέσει εκλεκτικές οξειδώσεις. Στα πλαίσια της συγκεκριμένης διδακτορικής διατριβής, έγιναν προσπάθειες για τη σύνθεση κυκλοποιημένων μορίων 2,5-δικετοπιπεραζινών, οι οποίες θεωρούνται πρόδρομα μόρια των πυρρολο-ιμιδαζολο αλκαλοειδών φυσικών προϊόντων, στα οποία και στόχευε πρώιμα η συγκεκριμένη εργασία. Πιο συγκεκριμένα, πραγματοποιήθηκε η σύνθεση διπεπτιδίων πυρρολίου-προλίνης, μέσω πεπτιδικής σύζευξης, αλλά και μια βιβλιοθήκη 2,5-δικετοπιπεραζινών με σκοπό τη συνθετική προσέγγιση των επιθυμητών μονομερών αλλά και διμερών φυσικών προϊόντων. Σε προκαταρτικές μελέτες παρατηρήθηκε ο ευοξείδωτος χαρακτήρας των 2,5-πυρρολο-προλινο δικετοπιπεραζινών, ενώ παράλληλα διαπιστώθηκε η ομοιότητα της οξειδωτικής συμπεριφοράς των 2,5-δικετοπιπεραζινών με τις ριβοφλαβίνες. Πραγματοποιήθηκαν δοκιμές οξείδωσης της συντιθέμενης δικετοπιπεραζίνης (231) με μοναδικό οξειδωτικό μέσο το μοριακό οξυγόνο, και μελετήθηκε σε βάθος η οξείδωσή της, απ’ όπου προέκυψε ο αυθόρμητος σχηματισμός υπεροξειδικών προϊόντων παρουσία Ο2, τα οποία με τη σειρά τους κατέληγαν σε οξειδωμένα προϊόντα, αλλά και προϊόντα πολυμερισμού. Ακόμη, δοκιμάστηκε η χρήση των 2,5-δικετοπιπεραζινών ως οργανοκαταλυτών κατά την πραγματοποίηση ποικίλων οξειδωτικών διεργασιών και προτάθηκε ένα βελτιστοποιημένο αερόβιο πρωτόκολλο για τη χημειοεκλεκτική οξείδωση θειοαιθέρων προς σουλφοξείδια, την εποξείδωση και την αλλυλική οξείδωση ηλεκτρονιακά πλούσιων αλκενίων. Διενεργήθηκαν κινητικά πειράματα και πειράματα δευτερίου, ενώ οι μελέτες ολοκληρώθηκαν με την επιτυχή εφαρμογή του προτεινόμενου αερόβιου πρωτοκόλλου στον οξειδωτικό διμερισμό και τη διασταυρούμενη σύζευξη των ναφθολών/φαινολών, όπως επίσης και κατά την οξείδωση των βορονικών οξέων προς φαινόλες. Τέλος, εξετάστηκε η δυνατότητα των οργανοκαταλυτών δικετοπιπεραζινών να επάγουν εναντιοεκλεκτικότητα κατά την οξείδωση ποικίλων υποστρωμάτων κάτω από τις βέλτιστες συνθήκες αντίδρασης, ώστε να επιχειρηθεί η πρόταση ενός αερόβιου πρωτοκόλλου για την ασύμμετρη οξείδωση υποστρωμάτων.