bluuebunny/crossref_metadata_2025 huggingface dataset:
347 Cancer-associated Fibroblasts Affect GBM Progression
Authors: Kim Timothy Y. , Srivastava Siddhartha , Medikonda Ravi , Pant Ayush , Patel Kisha K. , Rodriguez Fausto , Lim Michael
Published: March 2022

INTRODUCTION:

Glioblastoma is an extremely aggressive form of brain cancer and despite the many advances made in therapeutic options, outcome and quality of life remains poor. Fibroblasts have been demonstrated to play a role in various systemic cancers by remodeling and reprogramming the tumor microenvironment immunologically and metabolically. Recently, cancer-associated fibroblasts (CAFs) have been identified in glioblastoma (GBM) patients and there is reason to believe that CAFs may have a protumoral effect in GBM progression.

METHODS:

Nine patients with resected GBM tumor samples were identified by pathology reports and embedded in paraffin, sectioned, and then stained with antibodies for alpha-SMA and GFAP. Ten 40x high-power fields per slide were visualized by a Zeiss Axio Observer microscope and counted by two independent researchers and verified by a board-certified neuropathologist. For in vivo work, 6-week C57BL/6J wild-type female mice were intracranially implanted with either Gl261-luciferase (Gl261-luc) tagged cells alone or in combination with NIH3T3 embryonic fibroblasts. Tumor burden was assessed on post-implantation day 7 via bioluminescent IVIS imaging.

RESULTS:

We found that fibroblasts were consistently present in human glioblastoma samples albeit in minute quantities of <1%. We then discovered on IVIS that Gl261 cells mixed with NIH3T3 fibroblasts produced larger tumors on day 7 post-implantation. Implantation of these exogenous fibroblasts significantly worsened survival although this effect was not dose-dependent.

CONCLUSION:

Fibroblasts are present in glioblastoma patient samples. Despite their scarcity, they may still have the ability to affect the tumor microenvironment. Exogenous intracranial implantation of fibroblasts led to increased proliferation of gl261-luc tumor cells. As expected, these larger tumors had a negative effect on mouse survival and suggest that fibroblasts may be a potential avenue of glioblastoma therapy that needs further exploration.
354 Improving Perioperative Communication Using a Mobile Application
Authors: Hubbard Zachary , Kalhorn Stephen
Published: March 2022

INTRODUCTION:

Introduction of perioperative measures, such as the pre-operative time out, has shown to improve communication and outcomes across various surgical subspecialties. We utilized a standardized preoperative workflow using a technological platform in an effort to reduce operative inefficiency and improve preparedness.

METHODS:

Data was collected prospectively from neurosurgical cases before (July – October 2020) and after (October – January 2021) implantation of a mobile app designed to improve perioperative workflow and communication. All faculty and residents operating at the MUSC University Hospital during the intervention period were invited to use the mobile application. We used a double-blinded design to assess surgical team performance over the data collection period. The circulating/scrub nurses/technicians completed surveys detailing impression of resident preparedness, operative teamwork, last minute requests, near misses, and patient safety reports. Analysis of the cases in the intervention period was based on participating neurosurgical attendings, regardless of whether the cases were assigned, briefed, and/or debriefed on the application.

RESULTS:

112 cases were performed over the duration of the study period. Perception of resident preparation (0-5 score) was 4.13 before and 4.66 after implementation of the app (P<0.05). Resident familiarity (0-5 score) was 4.23 before and 4.58 after (P<0.05). Adverse events occurred in 11 pre-app cases and 4 in post app cases (P=0.77). Patient safety intelligence reports occurred in 0 cases before and after implementation. Impression of case efficiency averaged 4.48 (0-5) before use of the app and 4.61 after (P<0.05).

CONCLUSION:

Use of the mobile app significantly increased perceived resident preparedness, familiarity of the case plan, and teamwork. There were fewer adverse events after use of the app, however this did not reach statistical significance. There was no change in patient safety intelligence events following implementation of the app.
360 CyberKnife Radiosurgery Versus Radiofrequency Thermocoagulation in Patients with Trigeminal Neuralgia With or Without Multiple Sclerosis: A Single-Center Comparison
Authors: Loebel Franziska , Senger Carolin , Acker Gueliz , Conti Alfredo , Vajkoczy Peter , Budach Volker , Dengler Nora
Published: March 2022

INTRODUCTION:

Treatment of refractory trigeminal neuralgia (TN), especially in patients with Multiple Sclerosis (MS), remains challenging. Single-fraction Cyberknife radiosurgery (CK) and retrogasserian thermocoagulation (TC) are possible therapeutic options. Comparative studies regarding treatment efficacy and outcome in patients with refractory TN treated with CK or TC, with additional consideration to MS, are scarce.

METHODS:

Clinical and radiographic data of patients with TN treated with single-fraction CK or TC at a single academic institution were analyzed. Pain level was evaluated using the Barrow Neurological Institute (BNIp) pain scale pre-intervention and 3, 6, 12 months and last follow-up (LFU) post-interventionally. Subgroup analysis was performed in patients with MS.

RESULTS:

113 patients were treated with 161 treatments. Median age of the cohort was 61.1 (31.1–98.4) years. There were no significant differences between the cohorts regarding age, side, branch distribution and pre-procedural BNIp. Median follow-up time was 44.3 (3.0–135.9) months. After CK, improved outcome was reported in 59.1%, 57.9%, 66.7%, and 67.3% at 3, 6, 12 months and LFU, while after TC, improved outcome was reported in 85.0%, 77.4%, 70.8% and 55.9%. Patients were more likely to benefit initially and at 3 months follow-up from a TC procedure (p<.0001), but improved outcome at LFU was more pronounced in the CK cohort (p=.077). Repeated treatments were significantly more common in the TC cohort (p=.02). MS was the most frequent neurological co-morbidity. Exclusive analysis of the MS subgroup revealed similar results regarding pain improvement at 3-months follow-up (TC: 95.5% vs. CK: 54.0%; p<.001) and at LFU, (TC: 72% vs. 86.0%; p=.009). Incidence of new-onset hypesthesia was not significantly different in both cohorts (p=.550).

CONCLUSION:

Both therapies present safe and efficient treatment strategies for patients with refractory TN. Initial BNIp improvement was significantly better in patients treated with TC, while longterm effects were more pronounced in the CK cohort. This was also true for patients with MS.
363 Efficacy of Flexible Intrathecal Morphine Delivery in the Treatment of Chronic Pain
Authors: Jalal Muhammad , Jalaluddin Muhammad
Published: March 2022

INTRODUCTION:

The use of intrathecal morphine via a morphine drug delivery system has been shown as a promising alternative to the treatment of chronic pain. These programmable devices can deliver morphine via simple or flexible programs. Simple programs release morphine continuously at the same rate over a 24-hour period, whereas flexible programs are optimized to release different dosages at different times.

METHODS:

Patients were enrolled at St. James Mercy Hospital, University of Rochester, New York from February 2016 to February 2020. An out-patient intrathecal morphine trial was performed by injecting a single dose of 0.1-0.3 mg of preservative free morphine in the lumbar intrathecal space. Following at least 60% reduction in pain compared to baseline, a permanent intrathecal catheter and morphine pump were implanted. The drug delivery system was programmed to deliver morphine doses in a simple continuous or flexible mode. Follow up visits occurred between 12 and 60 months, and the efficacy of the flexible dosing was assessed.

RESULTS:

58 patients enrolled (34 female, 24 male, median age 59), 46 patients were on flexible dose morphine and 12 were on simple dose morphine. Statistical analysis found a significant difference in pain reduction between the two groups (p < 0.01). The flexible sample had a mean reduction in pain of 8.72 and the simple sample had a mean reduction in pain of 8.17 out of 10 points on the 0-10 pain scale. There were no infections or complications present in the study.

CONCLUSION:

While both flexible and simple program intrathecal morphine drug delivery system proved effective in reducing chronic pain, flexible programs were significantly more effective. A future multi-center study with a larger sample size is desired.
369 Toward a Complete Mechanism of Action in Epidural Spinal Cord Stimulation - Including Threshold Accommodation
Authors: Arle Jeffrey E.
Published: March 2022

INTRODUCTION:

Multiple waveform variations have been introduced for treating neuropathic pain with epidural spinal cord stimulation. These include higher frequencies (eg up to 10kHz) and different cadences of bursting signals. Prior understanding of mechansims of action for reducing pain have relied upon the reduction in WDR cell firing through retrograde stimulation of the largest Ab axons in the dorsal columns. However, prior models did not include details about diameter dependent threshold changes in the dorsal column axons. We sought to include this critical detail toward determining a deeper understand of how all of the waveform variations, including non-paresthetic stimuli, might also acheive pain relief.

METHODS:

Prior FEM and axonal models were used to achieve this analysis with additional adjustments of adding empirically-derived threshold accomodation to the axon membrane properties. These were calibrated based on axon diameter. Software was programmed in COMSOL and Mathematica, as well as proprietary programs using C++, Java, and JavaScript.

RESULTS:

Tonic stimulation above 100-300Hz and with increasing PW show accomodation changes and threshold inversions. Also, however, Burst and HF waveforms also showed threshold inversions and led to non-paresthetic activity within dorsal column fibers. Amplitudes were found to achive this phenomenon within typically-used clinical ranges.

CONCLUSION:

By accounting for known threshold accommodation, related to axon diameters within the dorsal coulmns, a clear mechnism of action could be ascribed to all known waveforms being used clinically. The results show that there would likely not be paresthesia experienced at clinically relevant amplitudes for many of these waveforms and a coherent complete mechanism of action for achieving pain relief is derived from this approach.
376 Hemoglobin Disrupts Microglial Function in the Developing Brain
Authors: Pandya Chirayukumar , Trout Amanda , Miller Brandon
Published: March 2022

INTRODUCTION:

Intraventricular hemorrhage of prematurity (IVH) interrupts normal white matter development. During normal brain development, microglia play an important role in myelination by producing insulin-like growth factor 1 (IGF-1) which is necessary for oligodendrocyte progenitor cells (OPCs) to mature into myelinating oligodendrocytes. IGF-1 is produced by a subpopulation of microglia that express the antigen CD11c, and these microglia are enriched during early brain development.

METHODS:

A cell culture system of isolated microglia was used for in vitro studies. A rat model of neonatal IVH was used for in vivo studies. Magnetic bead sorting was used to isolate CD11c+ microglia. Real-time PCR was used to quantify IGF-1 expression. ELISA was used to measure IGF-1 and cytokine production. Immunohistochemistry was used to quantify white matter and label OPCs, microglia, and CD11c.

RESULTS:

Hemoglobin induced a greater degree of TNFa production compared to an equivalent dose of whole blood. in vitro, hemoglobin reduced the percentage of microglia that expressed CD11c, and reduced the IGF-1production measured by ELISA. In an animal model of neonatal IVH, where hemoglobin injection reduces white matter development but not OPC survival, CD11c+ cells decreased their IGF-1 production as measured by real-time PCR.

CONCLUSION:

Hemoglobin is a potent pro-inflammatory stimulus for microglia in the developing brain. Hemoglobin induces classically proinflammatory microglial activation, with production of cytokines and reduction of IGF-1 production. CD11c+ microglia, the cells that provide the IGF-1 critical for myelination, reduce IGF-1 production in vivo when exposed to hemoglobin. This loss of microglial IGF-1 may be the reason OPCs fail to mature and myelinate effectively. Replacing IGF-1 maybe a therapeutic strategy for neonatal IVH.
378 Sacral Dimpling and GI/GU Symptoms in KBG Patients May Indicate Comorbid Tethered Cord Syndrome (TCS)
Authors: Pugacheva Alisa , Klinge Petra Margarete
Published: March 2022

INTRODUCTION:

KBG is an autosomal dominant disorder characterized by costovertebral bony anomalies, scoliosis, and intellectual disability, and neurological disability. Tethered Cord Syndrome (TCS) is tissue tethering of the spinal cord due to a persistent embryological filum terminale causing subsequent bladder and bowel incontinence, scoliosis, and neurological signs and symptoms in the lower extremities. Tethered cord syndrome in genetic constellations, given the congenital nature, warrants further epidemiological studies.

METHODS:

Beyond the Diagnosis (https://www.beyondthediagnosis.org/), a local nonprofit organization in Rhode Island distributed an optional survey to members of their Facebook page in August 2020. Patients themselves or a family member chose to complete the optional survey about current symptoms and provided their age, sex, and consent to the responses being used in further research. Responses were anonymized and analyzed in Excel. Symptom prevalences across the responses and correlations between specific symptoms were calculated to explore whether a subset of symptoms among the patient sample was comorbid.

RESULTS:

83 KBG patients answered the survey (dTCS, n = 10, sTCS, n = 73, average age = 9.71). The most prevalent symptoms were sacral dimple (60%), severe constipation (60%), and poor coordination (50%) among dTCS patients, and sacral dimple (65.75%), gait changes/leg weakness (58.90%), and severe constipation (43.84%) among sTCS patients. Objective signs of TCS were combined into GI/GU, neurocutaneous, and orthopedic sign clusters. Pearson matrix analysis showed a correlation (R = 0.339) between GI/GU and orthopedic signs, especially between bladder/bowel changes and orthopedic signs (R = 0.468).

CONCLUSION:

Surveyed sTCS patients had a high prevalence of TCS symptoms such as sacral dimples and GI/GU issues. Upon symptom clustering, there was a notable correlation between bladder/bowel changes and orthopedic signs.
407 Residual and Recurrent Spinal Cord Cavernous Malformations: Outcomes and Technical Notes for Optimal Resection
Authors: Srinivasan Visish M. , Karahalios Katherine , Shlobin Nathan A. , Koester Stefan , Nguyen Candice , Rumalla Kavelin , Rahmani Redi , Catapano Joshua , Labib Mohamed , Mitha Alim P. , Lawton Michael T.
Published: March 2022

INTRODUCTION:

Intramedullary spinal cord cavernous malformations (SCCMs) account for a small proportion (5%) of CMs overall and of spinal vascular malformations. However, they are well reported in the literature, with over 700 cases as of 2020. To date, the occurrence of recurrent or residual SCCMs has not been assessed or discussed, nor have the technical nuances of resection related to this issue.

METHODS:

An institutional database of vascular malformations was queried for all surgically managed cases of intramedullary cavernous malformations. Demographic, radiologic, intraoperative findings, and surgical outcomes data were obtained and retrospectively analyzed. A systematic review was performed using three databases (PubMed, Ovid MEDLINE, and Scopus) to analyze all cases of spinal cavernous malformations in the literature, to augment a prior review.

RESULTS:

146 cases of SCCM surgeries were identified in the database, including 17 recurrent lesions. Recurrences occurred at various time points, from as few as 3 to 264 months following initial resection. At the postoperative exam, 10 patients had better outcome scores than preoperative scores, 1 of which was status post resection of a recurrent lesion. A total of 21 patients had worse outcome scores, 4 of which were status post resection of recurrent lesion.

CONCLUSION:

Intramedullary spinal cord cavernous malformations are rare findings but may cause significant symptoms. Resection of these lesions is technically challenging, akin to the resection of brainstem cavernous malformations. Care should be taken to avoid leaving residual lesion, as this can leave the patient vulnerable to future hemorrhagic events and neurological morbidity. Satisfactory results are still achievable even with secondary or tertiary resections.
409 Impact of COVID-19 on the Hospitalization, Treatment, and Outcomes of Intracerebral Hemorrhage and Subarachnoid Hemorrhage in the United States
Authors: Ravindra Vijay , Grandhi Ramesh , de Havenon Adam
Published: March 2022

INTRODUCTION:

The novel coronavirus severe acute respiratory syndrome-CoV-2 (SARS-CoV-2) led to a global pandemic of patients with COVID-19, The clinical outcomes of patients with intracranial hemorrhage with COVID-19 are not fully known, with only small cohorts of patients with intracranial hemorrhage and comorbid COVID-19 published to date.

METHODS:

We performed a retrospective analysis using the Vizient Clinical Data Base and separately compared cohorts of patients with COVID-19 admitted April 1–October 31, 2020—patients with intracerebral hemorrhage (ICH) and those with subarachnoid hemorrhage (SAH)—with control patients with ICH or SAH who did not have COVID-19 admitted at the same hospitals in 2019. The primary outcome was in-hospital death. Favorable discharge and length of hospital and intensive-care stay were secondary outcomes.

RESULTS:

There were 559 ICH-COVID patients and 23,378 ICH controls from 194 hospitals. In the ICH-COVID cohort versus controls, there was a significantly higher proportion of Hispanic patients (24.5% vs. 8.9%), Black patients (23.3% vs. 20.9%), nonsmokers (11.5% vs. 3.2%), obesity (31.3% vs. 13.5%), and diabetes (43.4% vs. 28.5%), and patients had a longer hospital stay (21.6 vs. 10.5 days), a longer intensive-care stay (16.5 vs. 6.0 days), and a higher in-hospital death rate (46.5% vs. 18.0%). Patients with ICH-COVID had an adjusted odds ratio (aOR) of 2.43 [1.96-3.00] for the outcome of death and an aOR of 0.55 [0.44-0.68] for favorable discharge. There were 212 SAH-COVID patients and 5,029 controls from 119 hospitals. The hospital (26.9 vs. 13.4 days) and intensive-care (21.9 vs. 9.6 days) length of stays and in-hospital death rate (42.9% vs. 14.8%) were higher in the SAH-COVID cohort compared with controls. Patients with SAH-COVID had an aOR of 1.81 [1.26-2.59] for death and an aOR of 0.54 [0.37-0.78] for favorable discharge.

CONCLUSION:

Patients with spontaneous ICH or SAH and comorbid COVID infection were more likely to be a racial or ethnic minority, diabetic, and obese and had higher rates of death and longer hospital length of stay.
415 Correlation of Platelet Reactivity Testing and CYP2C19 Metabolizer Status in Patients Undergoing Endovascular Neurointervention
Authors: Benish Alam , Lucke-Wold Brandon , Laurent Dimitri , Elchynski Amanda , Cicali Emily , Wiisanen Kristin , Cavallari Larissa , Hoh Brian L.
Published: March 2022

INTRODUCTION:

Dual-antiplatelet therapy (DAPT) is clinically indicated for patients undergoing endovascular procedures. Clopidogrel is the most commonly used P2Y12 inhibitor used for DAPT, and is a prodrug bioactivated by the CYP2C19 enzyme. Inferring platelet response can be done by genotyping CYP2C19 to determine metabolizer status. Patients with two functional alleles are considered normal metabolizers (NM), patients with one or two increased activity alleles are rapid (RM) or ultra-rapid metabolizers (UM), respectively, and patients with one or two loss-of-function (LOF) alleles are intermediate (IM) or poor metabolizers (PM), respectively. Another method of measuring antiplatelet response to clopidogrel is the VerifyNow Platelet assay (measured in platelet reactivity units [PRUs]), but the optimal range of PRUs in neuro-endovascular procedures has not yet been established. At UF Health, platelet reactivity testing is routine, but CYP2C19 genotyping is less frequent in patients undergoing these procedures.

METHODS:

Data were collected from the EMR patients who had a CYP2C19 genotype result ordered by the neurosurgical department. We assessed platelet reactivity tests and antiplatelet medication changes between different phenotype groups. Phenotypes included ultra-rapid, rapid, normal, intermediate and poor metabolizers. Patients were categorized as non-responders to clopidogrel if their platelet reactivity tests were >204 PRUs prior to medication change, hyper-responders if their platelet reactivity tests were <20 PRUs, and optimal responders if reactivity fell between 20-204 PRUs.

RESULTS:

41 neurosurgical patients were genotyped. CYP2C19 phenotypes included ultra-rapid metabolizers (10%), rapid metabolizers (34%), normal metabolizers (37%), intermediate metabolizers (12%) and poor metabolizers (7%). Six patients had dose decreased to 75 mg QOD; 83% were hyper-responders. Three patients had their dose halved; 100% were hyper-responders. Four patients were switched to ticagrelor; 100% were clopidogrel non-responders.

CONCLUSION:

Patients who had their clopidogrel dose reduced were generally classified as hyper-responders based on platelet reactivity testing, and majority had increased CYP2C19 enzyme activity based on genotype. Of the non-responders who had a medication change to alternative P2Y12 therapy,majority had decreased CYP2C19 enzyme activity.
417 Predicting Hematoma Expansion after Spontaneous Intracerebral Hemorrhage Through a Noncontrast Computed Tomography Based Model
Authors: Seymour Samantha , Rava Ryan , Ionita Ciprian , Snyder Kenneth V. , Waqas Muhammad , Davies Jason , Levy Elad I. , Siddiqui Adnan H.
Published: March 2022

INTRODUCTION:

Spontaneous Intracerebral Hemorrhage (ICH) accounts for 15% of all acute strokes and is the deadliest stroke subtype with a 40% mortality rate after one month. More than 75% of all ICH patients are severely disabled or deceased after the first year. 30% of patients continue to bleed and demonstrate significant hematoma expansion (HE). Once HE occurs in ICH patients, treatment options are limited and the patient prognosis is significantly decreased.

METHODS:

NCCT scans for 200 ICH patients (70 expansion, 130 non-expansion) who presented with stroke-like symptoms between August 2016 and December 2019 were collected for this study. The patients had at least one of the following hemorrhages: intraparenchymal (n = 181), intraventricular (n = 45), subdural (n = 13), or subarachnoid (n = 19). Data augmentation and skull-stripping was conducted. A deep neural network was used to identify and segment the hemorrhagic region. Two networks were trained using two-dimensional images created by taking the standard deviation and mean of the voxel intensities over the entire volume to classify hematoma expansion using a training:testing split of 80:20 and 20 iterations of Monte Carlo cross validation.

RESULTS:

Hematoma expansion metrics using st.dev images are seen with a 95% confidence interval as: accuracy = 0.65 ± 0.04, sensitivity = 0.79 ± 0.06, specificity = 0.58 ± 0.06, precision = 0.51 ± 0.04, negative predictive value (NPV) = 0.84 ± 0.03. Metrics using mean images are: accuracy = 0.64 ± 0.03, sensitivity = 0.68 ± 0.08, specificity = 0.63 ± 0.07, precision = 0.49 ± 0.02, NPV = 0.78 ± 0.03.

CONCLUSION:

CNNs have the ability to predict hematoma expansion by utilizing two-dimensional images created from flattening NCCT volumes. Taking the st.dev over the NCCT volume within the hemorrhagic region is a better predictor of HE due to its more cautious approach indicated by a higher sensitivity metric.
418 First-line Stent Retriever Thrombectomy vs Direct Aspiration for Acute Basilar Artery Occlusion: A Systematic Review and Meta-analysis
Authors: Texakalidis Pavlos , Xenos Dimitrios , Karras Constantine L. , Murthy Nikhil , Hopkins Benjamin , Kontzialis Marinos , Rivet Dennis J. , Reavey-Cantwell John
Published: March 2022

INTRODUCTION:

Mechanical thrombectomy (MT) for acute anterior circulation stroke is an already established therapy. Recently, MT has been also increasingly utilized for basilar artery occlusion (BAO); the mainstay of MT modalities are stent retriever (SR) and direct aspiration (DA). Several studies have been recently published comparing the two approaches.

METHODS:

A systematic review and meta-analysis was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

RESULTS:

Overall, eight studies comprising 693 patients with acute BAO were included (SR: 457; DA: 236). The SR group was associated with statistically significant lower odds for successful recanalization defined as modified Thrombolysis in Cerebral Infarction (mTICI) 2b/3 (SR:81.9%, DA: 88.2%; OR:0.54; 95%CI:0.31-0.94; I2:0%) and mTICI 3 (SR: 51%, DA: 62.5%; OR:0.47; 95%CI:0.23-0.95; I2:62.1%) compared to DA. Favorable outcome rates defined as modified Rankin Scale (mRS) = 2, were similar between the two groups (SR: 37.8%, DA: 41.9%; OR:0.83; 95%CI: 0.60-1.16; I2:0%). The rates of symptomatic ICH (sICH) were higher in the SR group compared to the DA group (SR: 8.7% vs DA: 0.9%, however statistical significance was not reached OR: 3.57; 95%CI: 0.75-16.95; I2:0%). Similarly, subarachnoid hemorrhage (SAH) (SR: 5%, DA:0%; OR:4.71; 95%CI: 0.82-26.90; I2:0%) and vessel perforation (SR: 3.4%, DA: 1.1%; OR: 2.64; 95%CI: 0.43-16.33; I2:0%) rates were higher in the SR group but again significance was not reached. The rates of 90-day mortality were similar between the two groups (SR: 27.5%, DA: 28.1%; OR: 1.07; 95%CI: 0.67-1.70; I2:0%). Procedure duration was significantly shorter when DA was used compared to SR (WMD: 26.10;95%CI:13.28-38.92; I2:35.3%).

CONCLUSION:

DA is associated with statistically significant higher odds of successful mTICI 2b/3 and mTICI 3 recanalization rates and shorter procedure duration compared to SR. In addition, in absolute numbers, SR was associated with higher rates of sICH, SAH and vessel perforation, however, statistical significance was not reached most likely due to the relatively low sample size.
419 Long Sheath Use in Stroke Thrombectomy Leads to Improved Outcomes in Octogenerians
Authors: Nowicki Kamil W. , Dolia Jay , Shah Kavit , Alattar Ali A. , Tonetti Daniel , Jadhav Ashutosh , Lang Michael J. , Gross Bradley A.
Published: March 2022

INTRODUCTION:

Comparative evaluation of efficacy of using a long sheath-first approach in stroke thrombectomy patients where no initial arch information is available does not exist. Lower door-to-reperfusion times are associated with better outcomes in stroke thrombectomy. Multiple factors affect reperfusion times including approach, arch navigability, and the amount of support provided by equipment.

METHODS:

Study Design and Setting: An institutional review-board-approved, prospectively maintained endovascular arterial thrombectomy database from 2016 to 2018 was reviewed. Inclusion criteria: manual aspiration thrombectomy or stent-assisted, femoral approach, >80 yo, and LVO in anterior circulation. Study Variables: Demographic information such as age, sex, medical comorbidities, NIHSS score on presentation, tPA administration, and thrombus location were extracted. Arch navigability was defined by time from puncture to first base catheter run. Procedural times, and angiographic results (TICI score) were recorded and used as metrics for efficacy. Ninety-day outcome was also evaluated based on modified Rankin scale. The analysis was performed based on an intention-to-treat analysis. Statistical Analysis: Univariate statistical analysis was performed using an unpaired t test with Bonferonni correction for continuous variables and Fisher’s exact test for categorical variables. Statistically significant differences between groups were defined as p < 0.05. Procedural Technique: All procedures were performed emergently under local anesthesia. Consent was obtained from the patient or their next of kin under our institution’s guidelines.

RESULTS:

A total of n = 287 patients were included in the final analysis. There were no significant differences in baseline demographics. Upfront “long-sheath first” approach resulted in improved outcomes: time to first run (15.6 vs 32 min, p = 0.0005), time to first pass (21.4 vs 40 min, p < 0.0001), time to final reperfusion (35.8 vs 50 min, p < 0.0001), delta NIHSS (2.2 vs 6.6, p < 0.0001).

CONCLUSION:

Upfront “long-sheath first” approach results in improved outcomes during stroke thrombectomy in octogenerian population.
420 Task Related Physiology of the Dentalothalamocortical Circuit in Naïve and Stroke Rats
Authors: Momin Arbaz , Hermann John , Baker K. , Machado André
Published: March 2022

INTRODUCTION:

As stroke mortality has declined, a growing number of patients are left with chronic, residual post-stroke hemiparesis. Targeted, neurostimulation-based upregulation of activity of the dentatothalamocortical (DTC) pathway, a disynaptic pathway with net excitatory effects on widespread areas of the cerebral cortex, has been proposed previously as a potential approach to enhance cortical excitability in surviving, perilesional cortical regions and promote motor rehabilitation after a stroke.

METHODS:

13 rats (7 naÏve and 6 stroke) were implanted unilaterally with a 9 channel recording electrode in the DN (ipsilateral to dominate forepaw) and cortical EEG screws (contralateral to dominate forepaw) were placed over the perilesional area. LFPs were recorded from the DN and motor cortex during a reach/pull task for 4 weeks after surgery.

RESULTS:

At a 25g force threshold, DN LFPs were diminished in the 8-12 hz in the pre-movement and movement phase in stroke rats compared with naÏve rats. At a 5g force threshold, 8-12 hz LFPs in the DN were significantly diminished in the stroke animals relative to naive during the pre-movement and movement phase (p < .05). At a 50g force threshold, cortical 1.5-4 hz oscillations were significantly diminished during the pre-movement and movement phase in stroke rats compared to naÏve rats (p < .05).

CONCLUSION:

Diminished 8-12 hz reach-related LFP activity in the DN of stroke rats relative to naÏve rats during the pre-movement and movement phase of a reaching task, may function as a potential predefined trigger for the onset of deep brain stimulation as a therapeutic intervention to promote motor rehabilitation for chronic post-stroke hemiparesis.
421 Coherence Between the Subthalamic Nucleus and the Primary Motor Cortex in Patients With Parkinson's Disease
Authors: Souza de Castro Joao P.
Published: March 2022

INTRODUCTION:

DBS is established as a safe and effective treatment for Parkinson’s Disease (PD). The development of second generation stimulators based on closed loop systems is dependent upon deeper understanding of the cortical control of motricity and its coupling with STN oscillations.

METHODS:

Experimental study on human subjects involving 10 patients with idiopathic PD with indication for deep brain stimulation implants into the STN. Primary motor area of the hands were identified preoperatively with fMRI. Corkscrew electrodes were implanted in the scalp to obtain C3-Cz and C4-Cz derivations of the EEG. Needle electrodes were implanted into the thenar and hypothenar muscles of both hands to record motor evoked potentials and voluntary myoelectric activity. At the time of implantation of the definitive macro-electrodes, the best contacts were connected to the electrophysiological monitoring device to record STN local field potentials (LFP) from 1 side at a time. During the next 3 minutes, the patient was asked to perform closing and opening movements of the hand contralateral to the implant. Simultaneously recordings of hand-EMG, EEG signals from M1, and STN field potentials were acquired for off line analysis.

RESULTS:

Our data indicate that during epochs of hand movements, theta and beta range components of the EEG related to M1 were significantly increased as compared with rest epochs. Additionally, we demonstrated that, during movement, the cross correlation between STN-LFP and M1 significantly increased (p < 0.001).

CONCLUSION:

Movement control is highly dependent upon theta and beta EEG components and upon a high coherence between STN and M1 specifically occurring during movement. The development of closed-loop stimulation devices should consider this physiology to reach better results.
422 Safety and Efficacy of Responsive Neurostimulation for the Treatment of Medically Refractory Epilepsy: A 5-Year Follow-Up Study
Authors: Roa Jorge A. , Feng Rui , Schupper Alexander J. , Fields Madeline , Marcuse Lara , Germano Isabelle M. , Bederson Joshua B. , Ghatan Saadi , Panov Fedor
Published: March 2022

INTRODUCTION:

Despite antiepileptic drugs (AEDs), >30% of patients with epilepsy continue to have seizures. Responsive Neurostimulation (RNS) provides a nondestructive treatment option for patients with drug-resistant epilepsy (DRE). To date, the safety and efficacy of RNS have not been fully studied due to the lack of prospective data.

METHODS:

We performed a retrospective analysis of prospectively collected data of DRE patients who underwent RNS implantation between September 2015-December 2020 at our Institution. Patients were followed postoperatively to evaluate seizure-freedom and complications. For each patient, response to RNS was determined as an overall percentage based on the relative reduction in seizure duration/severity, medication requirements and post-ictal state.

RESULTS:

A total of 103 patients underwent RNS placement. Seven patients developed infections: three required partial salvaging of the system, and only two (1.9%) required complete removal of the RNS device. Six (5.8%) patients experienced small asymptomatic post-operative hemorrhages; none required re-intervention. No cases of stroke or device malfunction/migration were seen. The average follow-up period was 20±13.6 months. Of 74 patients with = 6-month follow-up available, 15 (20.3%) became seizure-free, 18 (24.3%) achieved 75-99% control of seizures, 19 (25.7%) achieved 50-74%, 15 (20.3%) achieved 25-49% and 7 (9.5%) achieved <25% success. Patients with seizures originated in the mesial temporal lobe had a tendency to achieve =75% seizure control (OR = 1.4, P = 0.056). Variables associated with worse outcome (<25% seizure control) included: younger age at epilepsy onset (OR = 2.4, P = 0.043), syndromic etiology (OR = 3.6, P = 0.041), prior no response to =5 AEDs (OR 4.3, P = 0.026) and prior surgical intervention (OR = 1.8, P = 0.052).

CONCLUSION:

RNS achieved = 50% seizure control in ∼70% of patients. Infections and tract-hemorrhages are the most common complications, but rarely require re-intervention. Seizure-freedom after RNS implantation may be significantly lower in patients affected by aggressive epileptogenic syndromes since a young age, and those who have failed to respond to >5 drugs and prior surgical interventions.
424 The Role of the Mid Fusiform Gyrus in Lexical Retrieval
Authors: Snyder Kathryn , Donos Cristian , Forseth Kiefer , Rollo Patrick , Breier Joshua , Fischer-Baum Simon , Tandon Nitin
Published: March 2022

INTRODUCTION:

Temporal lobe resections for epilepsy or neoplasms often result in significant confrontation naming decline. This can be socio-economically disabling and prevent patients from returning to independent functioning. While the exact substrates responsible are unknown, it was previously assumed that injury to the superior temporal gyrus or resection size predicts these declines. A clear understanding of the most critical constituents might influence surgical strategies to minimize language declines.

METHODS:

Data were obtained from 95 patients who underwent surgical resection in the dominant left temporal lobe for medication-resistant epilepsy. Patients underwent neuropsychological testing and MRI prior to and 6 months following surgery. Lesion masks were traced on postoperative MRIs and aligned to a normative space. The effects of preoperative scores and seizure outcomes were removed from postoperative scores via linear regression. VLSM using multivariate support vector regression was used to assess postoperative test scores. Beta maps were converted to p values and corrected using a permutation-based cluster level correction. Additionally, a surface-based mixed-effects multilevel analysis was used to estimate broadband gamma activity during picture naming across a subset of subjects with ECoG recordings, and results were integrated with VLSM. Lastly, fMRI (picture naming) was used to assess SNR in significant regions.

RESULTS:

VLSM analysis revealed that the loss of basal temporal regions was associated with a prominent decline in BNT scores (p < 0.005). Similarly, ECoG analysis showed a significant increase in activity in the mid fusiform gyrus (mFus) immediately preceding articulation. Many of these voxels were associated with low SNR on fMRI, perhaps explaining why this region has been under-appreciated as the locus responsible for postoperative deficits.

CONCLUSION:

The importance of the ventral temporal cortex in lexical access is shown using multivariate VLSM and supported with ECoG. While it has previously been assumed that mFus lesions do not cause pervasive impairment, our data and recent work (FATES study) argue against this and support the role of the mFus as a critical semantic access hub.
429 Racial Disparities Persist Despite Increased Utilization of Deep Brain Stimulation Surgery for Parkinson’s Disease
Authors: Cramer Samuel , Do Truong , Palzer Elise , Naik Anant , Rice Abigail , Novy Savannah , Hanson Jacob , Piazza Amber , Howard Madeleine , Huling Jared , Chen Clark C. , McGovern Robert A.
Published: March 2022

INTRODUCTION:

Deep brain stimulation (DBS) provides improved quality of life for properly selected individuals with Parkinson’s disease (PD). Though DBS is a widely accepted and efficacious therapy for PD, significant racial disparities have been reported in the access to DBS, particularly for Black patients.

METHODS:

The National Inpatient Sample (NIS) was queried to identify PD patients who underwent DBS placement between 2002 and 2018. We examined DBS utilization relative to PD admissions, patient characteristics over time, and whether ACA passage was associated with changes in insurance and DBS utilization among different racial/ethnic groups.

RESULTS:

In 2014-2018, the odds of PD patients receiving DBS therapy increased 56% compared to 2002-2005 (p < 0.001). In a multivariate logistic regression analysis, the most important factors affecting the likelihood of DBS surgery were race, insurance status and the presence of comorbidities. Black PD patients were 1/5 as likely as White patients to undergo DBS placement (p < 0.001). Individuals with = 2 comorbidities were 20 times less likely to undergo DBS. Patients insured privately compared to those insured by Medicare/Medicaid were 5.22 times as likely to undergo DBS. Passage of the ACA was associated with 2.62 times higher odds of DBS in 2010-2013 for Black PD patients compared to 2002-2005 (p = 0.008). During the period 2014-2018, Black PD patients were 2.33 times more likely to undergo DBS compared to the period 2002-2005 (p = 0.008).

CONCLUSION:

DBS is increasingly used for healthy, privately insured PD patients. Significant racial disparities persist in the use of DBS for PD despite a modest improvement following passage of the ACA, but prior to most of its implementation, indicating other factors contributed to this change.
430 Trans-cerebellar Stereotactic-guided Cisternoperitoneal Shunt Placement for Idiopathic Intracranial Hypertension
Authors: Cho Steve S. , Wakim Andre , Teng Clare W. , Sarris Christina E. , Smith Kris
Published: March 2022

INTRODUCTION:

Idiopathic intracranial hypertension (IIH, pseudotumor cerebri) mainly affects young, obese females and can cause debilitating symptoms as well as optic nerve ischemia if not treated. Cerebrospinal fluid (CSF) diversion is often necessary to reduce intracranial pressure (ICP). Ventriculoperitoneal shunts (VPS) and lumboperitoneal shunts (LPS) are the main methods of CSF diversion but both are fraught with high rates of shunt failures in IIH patients. We propose the novel trans-cerebellar stereotactic-guided cisternoperitoneal shunt (TCSG-CPS) technique, which places the proximal shunt catheter in the posterior cisterna magnum, which is a non-collapsible CSF space.

METHODS:

Retrospective data regarding perioperative and postoperative data from all patients who underwent TCSG-CPS placement from 2015-2020 for IIH were collected. Intraoperatively, patients are positioned as for VPS but with the head turned further laterally to adequately expose the retrosigmoid space. Using neuronavigation, the transverse and sigmoid sinuses are located and an opening is made at the transverse-sigmoid junction. The proximal catheter is then inserted transcerebellarly into the posterior foramen magnum using electromagnetic neuronavigation to accurately track the catheter tip.

RESULTS:

Thirty-two patients underwent TCSG-CPS placement. 91% were female, with a mean BMI of 36.0 ± 7.5. Fourteen patients had undergone prior VPS or LPS placement with shunt failures. Shunt placement, including removal of prior shunts when applicable, took an average of 150 minutes. There were no intraoperative complications and patients were discharged uneventfully after mean 1.7 days. On follow-up visits at 6 months, 81% had relief of their presenting symptoms. Shunt survival without revision at 1 and 3 year were 86% and 67%, respectively. Overall infection rate was 0% in the study period.

CONCLUSION:

The TCSG-CPS offers an alternative solution to VPS and LPS for CSF diversion in patients with IIH and demonstrates a lower failure rate and more durable symptom relief compared to historical data on VPS and LPS. Using the proper techniques and equipment promotes safe and facile placement of the proximal catheter.
434 Reduced Postoperative Narcotics Consumption With Intraoperative Thoracolumbar Interfascial Plane (TLIP) Block Compared to Traditional Field Block
Authors: Brusko Gregory D. , Lu Victor M. , Borowsky Peter , Levi David , Wang Michael Y.
Published: March 2022

INTRODUCTION:

Given the increasing burden of narcotics usage, spine surgeons have adopted several innovative methods to reduce postoperative pain and narcotics consumption. Local infiltrative anesthetics are commonly administered intraoperatively to provide a local field block for several days after surgery. However, these blocks are limited to the areas in which the anesthetic is injected and is technique-dependent.

METHODS:

A retrospective review of a single surgeon, single institution series of adult patients was conducted between July 2019 and November 2020. Patients were divided into the TLIP or Traditional group depending on which infiltration technique was used. All patients underwent thoracolumbar fusion. Baseline and demographic characteristics and daily narcotics consumption were collected for each patient. All opioid amounts were converted into morphine milligram equivalents (MMEs) for standardization. Analyses were conducted using chi-square exact test and Wilcoxon rank-sum test for categorical and continuous data, respectively.

RESULTS:

A total of 136 patients were included. Sixty-four (47%) and 72 (53%) managed by TLIP and traditional approaches respectively. Overall mean age was 66.1 years (range, 26-85) with 63 (46%) males and 73 (54%) females, with no significant difference between groups. TLIP patients on average required less hydromorphone than Traditional patients on POD1 (25.1 vs 58.1 mg, P = 0.03) and overall (99.2 vs 184 mg, P = 0.04), less diazepam overall (4.1 vs 10.4 mg, P = 0.01) and less overall opioid medication on POD1 (65.9 vs 95.6 MME, P = 0.04) and overall (221 vs 325 MME, P = 0.03). There was no statistical difference in Percocet use, or any opioid. medications on POD0. TLIP patients experienced shorter length of stay compared to the Traditional group although this difference did not achieve significance (3.0 vs 3.6, P = 0.28). Complication rates were comparable between groups.

CONCLUSION:

TLIP patients required less hydromorphone and diazepam, as well as total narcotics during their hospital stay, indicating that on average they experienced less severe pain and muscle spasms postoperatively.
435 Internal Neurolysis for Trigeminal Neuralgia: Systematic Review
Authors: Sabourin Victor , Karsy Michael , Lavergne Pascal , Stefanelli Anthony , Al Saiegh Fadi , Evans James J.
Published: March 2022

INTRODUCTION:

Trigeminal neuralgia (TN) remains a challenging disease with debilitating symptoms and variable efficacy of treatment options. Internal neurolysis (IN) is a technique to dissect out the cisternal portion of the trigeminal nerve into multiple “fascicles”, and has shown potential as a treatment option.

METHODS:

Studies from 2000-2021 that assessed IN for TN were aggregated and independently reviewed. Outcomes evaluated included post-operative pain scores as defined by the BNI-PS or UCSF-PS, recurrence rates, hypesthesia scores as defined by the BNI-HS, and complications. Outcome were stratified as either excellent (BNI-PS: I or UCSF: excellent), good (BNI-PS: I/II or UCSF: excellent) or fair (BNI-PS: I-III and UCSF: excellent/good). Recurrence rates were considered for any pain recurrence and for significant recurrence defined as BNI-PS I/II transitioning to III-V. Weighted averages for demographics, outcomes and complications were generated.

RESULTS:

A total of 520 patients in 12 studies were identified with 384 patients undergoing IN. The mean follow-up was 36.5 months (range 12-90 months). Overall, an excellent to good outcome was seen in 83.7% of patients. Pain outcomes at 1 year were excellent: 58-78.4%, good: 77-93.75%, and fair: 80-93.75%. Overall pain outcomes were excellent: 47-82.1%, good: 62.5-87.1% and fair: 80-100%. Hypesthesia following IN was seen in as many as 96% post-operatively, however at follow-up remained in only 1.75-10%. The 1-year and overall recurrence rates of any pain were: 3.92-42% and 3.6-50%. The 1-year and overall rates for significant recurrence of pain were: 3.92-17% and 3.6-25%.

CONCLUSION:

IN represents a potentially promising approach for the surgical treatment of TN in the absence of vascular compression and cases of recurrence. It may also be an adjunct option to MVD in cases of low grade vascular compression. Further study is required to evaluate the impact of IN.