bluuebunny/crossref_metadata_2025 huggingface dataset:
175 Extraforaminal Extra-articular Full-endoscopic Access with Foraminoplasty for the Treatment of Lateral Compressive Diseases of the Lumbar Spine
Authors: Sandon Luiz H. , Bergamaschi João P. , Defino Helton L. A.
Published: March 2022

INTRODUCTION:

Although the use of lumbar pedicular extra-foraminal access has emerged as an option to minimize traumatic damage to emerging nerve roots, studies evaluating this strategy are scarce.

METHODS:

The following instruments were used for the analysis of the results: analog pain scale (EVA), physical disability index (Oswestry), and wellbeing assessment (MacNab) preoperatively (T0), 2 days (T1), 1 month (T2), 3 months (T3), 6 months (T4), 12 months (T5),and 24 months (T6) postoperatively.

RESULTS:

The most frequent diagnosis was herniated disc with stenosis of the lateral and foraminal recesses. The most frequent surgical level among patients was between L4-L5 and on the left side. Pain decreased significantly over time. There was a statistical reduction over the evaluated times for evaluating pain in the lumbar, gluteal, leg, and foot regions.

CONCLUSION:

Extraforaminal extra-articular full-endoscopic access with foraminoplasty is an efficient, less invasive, and safe procedure, very well indicated in cases of hernia and stenosis of the lateral and foraminal recesses, for patients with symptoms of radiculopathy, and for those who were unresponsive to conventional rehabilitation treatment or chronic pain management. It had a low rate of complications, most of which were treated clinically.
190 Brain Structural MRI Predicts Outcome of Radiosurgical Treatment in Trigeminal Neuralgia
Authors: Albano Luigi , Agosta Federica , Basaia Silvia , Castellano Antonella , Messina Roberta , Parisi Veronica , Barzaghi Lina R. , Falini Andrea , Mortini Pietro , Filippi Massimo
Published: March 2022

INTRODUCTION:

Growing evidence supports the role of the central nervous system (CNS) in the modulation of pain in trigeminal neuralgia (TN) patients.

METHODS:

Thirty patients with idiopathic or classic TN, who underwent GKSRS and were followed for at least 24 months, were retrospectively included. Pre-treatment structural MRI and pre- and serial, post-operative clinical features were investigated. Fifteen age- and sex-matched healthy controls were also enrolled. Cortical thickness and gray matter (GM) volumes were assessed in TN patients relative to controls, as well as between patient subgroups according to treatment outcomes (initial responders/non-responders, patients with pain recurrence/long-lasting pain relief at the last follow-up). Clinical and MRI predictors of treatment outcomes were explored.

RESULTS:

Cortical thinning of temporal, prefrontal, cingulate, somatosensory and occipital areas bilaterally was found in TN patients relative to controls. No cortical thickness and GM volume differences were observed when TN initial responders and non-responders were compared. Patients who experienced TN recurrence after initial pain relief were characterized by thicker parahippocampal and temporal cortices bilaterally and greater volume of right amygdala and hippocampus compared to patients with long-lasting pain relief. In TN patients, disease duration and baseline cortical thinning of right parahippocampal, left fusiform and middle temporal cortices were associated with poor outcome after GKSRS at the last follow-up (R2 = 0.57, p < 0.001).

CONCLUSION:

The study provides novel insights into structural brain alterations of TN patients, which might contribute to disease development and pain maintenance.
197 Gold Nanoparticle Enhanced X-ray Nanotomography Reveals Region-Specific CSF Pathways Through the Brain and Spinal Cord that are Altered in Post-hemorrhagic Hydrocephalus
Authors: Pan Shelei , DeFreitas Dakota , Ramagiri Sruthi , Bayguinov Peter , Huang Hengbo , Tang Rui , Esakky Prabagaran , Strahle Jennifer
Published: March 2022

INTRODUCTION:

Cerebrospinal fluid (CSF) is essential for the healthy development and function of the brain, but understanding the mechanisms of its distribution in and around the central nervous system (CNS) remains a major challenge. To address this need, we developed a new technique, gold nanoparticle-enhanced x-ray nanotomography (AuNp-XRM), to achieve micrometer-scale resolution visualization of CSF pathways across the entire brain and spinal cord of rodents with further applications to a model of interventricular hemorrhage/post-hemorrhagic hydrocephalus (IVH/PHH).

METHODS:

P4 rodents were injected with aCSF or hemoglobin to create the control and IVH conditions. 72 hours later, animals underwent MRIs to determine onset of PHH. Animals were then injected with 1.9 nm and 15 nm gold nanoparticles and imaged using XRM. Following XRM, the brains, spines and meninges were harvested for histology.

RESULTS:

Using AuNp-XRM, we demonstrate visualization of previously characterized glymphatic, cranial nerve, and choroid plexus-mediated CSF circulation patterns, and present evidence to further identify CSF interactions with the leptomeninges, choroid plexus, and parenchyma of the brain and spinal cord. We also identified an intraparenchymal CSF circulation that targets stem-cell rich and cholinergic neuronal populations. CSF distribution to these areas was mediated by flow of CSF through the paravascular spaces of perforators originating from the large blood vessels of the basal cisterns and was significantly decreased in an animal model of PHH.

CONCLUSION:

Our findings using AuNp-XRM show that cholinergic cell populations in the brain and spinal cord differentially handle CSF, and that PHH alters CSF distribution to these areas of the brain. These region-specific patterns of CSF distribution may have critical relevance to normal brain development, brain development following PHH, and other neuropathological conditions.
203 Opioid Reduction After SCS
Authors: Hatcher Stacy , Jacobs David , Air Ellen L.
Published: March 2022

INTRODUCTION:

Spinal cord stimulation (SCS) is frequently used as a primary method to treat intractable back and extremity pain with the secondary goal of replacing or reducing adjunct opioid use. Our study investigates pre and post-operative changes in morphine milligram equivalents (MME) for patients who have undergone SCS.

METHODS:

Data was extracted from the Henry Ford Department of Neurosurgery RedCap spinal cord stimulator database. Descriptive statistics of means, standard deviations, medians, interquartile ranges (IQR) and percentages were computed for the outcomes of interest. Signed rank tests were done to compare pre to post measurements of MME. The testing level was set at 0.05 and all analyses were done using SAS version 9.4.

RESULTS:

There were a total of 241 cases included in the RedCap SCS database out of which 196 were included in our analysis. A significant reduction was seen in the use of opioid pain medication from the pre-operative MME measurement as compared to the 3-month postoperative MME measurement (median = 9.5, IQR = (0, 27.5), p < 0.001). However, the differences in opioid use between pre and postoperative week 6 and 2-year measurements were not significant.

CONCLUSION:

SCS has traditionally been used in patients with intractable back and/or extremity pain and potentially helps to decrease opioid use as the primary method of pain relief in these patients. Careful consideration should be given when choosing candidates for SCS implantation as well a long-term follow up to track post-operative MME use.
206 Real-Time, High-Velocity Prosthetic Finger Movements Using Brain-Machine Interfaces with Biomimetic Artificial Neural Networks
Authors: Willsey Matthew , Nason Samuel , Ensel Scott , Temmar Hisham , Mender Matthew , Costello Joseph , Patil Parag G. , Chestek Cynthia
Published: March 2022

INTRODUCTION:

Injuries that cause hand paralysis are devastating, but brain-machine interfaces (BMIs) offer hope to those with lost function. Unfortunately, brain-controlled prostheses have yet to function at speeds similar to the native limb.

METHODS:

Two male rhesus macaques were implanted with Utah arrays in motor cortex and trained to perform a two-dimensional finger task using a manipulandum. The spike-band power, a low power proxy for spiking rate, informed a five-layer neural network decoder that is first trained in manipulandum-control mode. NN was then used to decode finger trials and further refined by the ReFIT technique developed for the Kalman filter. Over 4700 trials, across 8 days, were conducted using either the ReFIT neural network (RN), NN, or RK decoders, impemented without online hyperparameter tuning, and performance was compared.

RESULTS:

The RN decoder produced finger velocities, 1.35 ± 0.04 u/sec (mean ± SEM) for Mky N and 0.94 ± 0.04 u/sec for Mky W, that were higher than RK velocities of 0.55 ± 0.02 u/sec for Mky N and 0.39 ± 0.04 u/sec for Mky W, where u denotes arbitrary distance such that 1 was full flexion and 0 full extension. Averaging across days, trials were completed in 1270 ± 30 ms (Mky N) and 2220 ± 70 ms (Mky W) for RN vs. 1940 ± 50 ms (Mky N) and 3310 ± 130 ms (Mky W) for RK.

CONCLUSION:

Using an architecture loosely inspired by biological motor pathways, this novel neural network decoder substantially outperforms the current state-of-the-art by achieving higher velocities more similar to naturalistic finger movements.
207 Dendritic Cells Immunotherapy in the Treatment of Glioblastoma
Authors: Rehder Roberta , Lepski Guilherme A. , Barbuto José A. M. , Santos Patricia C. B. , Peres Nataly , Pinho Mariana P.
Published: March 2022

INTRODUCTION:

Immunotherapy is gradually being established as a relevant adjuvant therapy against cancer. Cell vaccination is a promising strategy for the treatment of glioblastoma (GBM). CarT and dendritic cells (DC) have been associated with partial response therapy in recent publications.

METHODS:

Clinical data were evaluated including overall survival, disease-free survival, global health scales, and quality of life in neuro-oncology. Analysis of overall survival and survival after recurrence and after vaccination is presented. Immunological panel with CD4/CD8 T-cell counts and lymphokines count were obtained on each vaccination session.

RESULTS:

A significant increase in overall survival was observed in the vaccinated group (33.16 ± 9.42 months, versus 13.56 ± 0.95 months in the previous group control (log rank p = 0.0021). The median overall survival from the first recurrence for the vaccinated population was 8.1 ± 1.9 months, and 5.0 ± 1.4 counted from the start of vaccination. The immunological data strengthen the importance of Th1 response pattern for tumor control, and Th-17 pattern linked to recurrence.

CONCLUSION:

The preliminary data support the safety and possible efficacy of DC vaccination in increasing overall survival in patients with recurrent GBM. The immune data provide important insights on the mechanisms beyond tumor control and recurrence.
208 Proposed Revision to Meningioma Classification System to Utilize Methylation Status of EGFR
Authors: Kjos Ava , Yang Isaac , Duong Courtney , Anderson Roan
Published: March 2022

INTRODUCTION:

Meningiomas are among the most common brain tumors, making up about 13-26% of all intracranial tumors. They arise from the arachnoid cap and most commonly appear along the lining of the skull base and the venous cavities. The current classification system for meningiomas was established by the World Health Organization (WHO) and designates tumors as WHO grades I-III depending on histological characteristics. While WHO grade does strongly correlate with tumor recurrence, it has serious shortcomings. In particular, some WHO grade I tumors, which are supposedly benign, end up becoming highly aggressive and recurrent. A more accurate method of classifying tumors to provide better insight into prognosis is needed. Epidermal growth factor receptor (EGFR) is a highly expressed protein in meningiomas that has been linked to angiogenesis and other tumor-promoting properties.

METHODS:

A retrospective chart analysis was first performed to gather clinical and demographic information for 291 patients diagnosed with meningioma and treated with surgical intervention. Primary tissue samples were available for 25 patients and an analysis of EGFR promoter methylation status was performed.

RESULTS:

A significant association was found between EGFR promoter methylation and tumor recurrence (p = 0.02176*). Of note, there was a 100% positivity rate for EGFR hypermethylation in patients with tumor progression within 10 months post-surgery (n =9). Every tumor sample classified as WHO grade II-III had EGFR hypermethylation (n = 10), as well as 7 out of the 15 WHO grade I tumors. In total, over half of the meningioma patients with EGFR hypermethylation had tumor progression within 10 months of surgery.

CONCLUSION:

These findings suggest that assessing methylation status of EGFR could be a valuable tool for identifying highly aggressive meningiomas and determining patient prognosis early in the game. This would allow for improved postoperative treatment regimens to be developed, reducing the chances of tumor progression.
212 Continuous Mapping of Brain Tumor Resection Progression During Surgery
Authors: Juvekar Parikshit , Bastos Dhiego , Bi W. Linda , Golby Alexandra J. , Frisken Sarah
Published: March 2022

INTRODUCTION:

Maximal safe extent of resection extends survival for gliomas. Surgical adjuncts including neuronavigation, intraoperative MRI (iMRI), intraoperative ultrasonography (iUS), and fluorescence imaging can help surgeons minimize unintentional residual tumor; each with associated limitations including cost, availability, susceptibility to brain shift and complex tumor shapes.

METHODS:

During tumor resection, surgical instruments, including navigation pointer, ultrasonic aspirator, suction, and bipolar forceps, were optically tracked. Data was streamed to 3D Slicer (https://www.slicer.org/) via OpenIGTLink (http://openigtlink.org/) and 3D maps of the resection cavity were computed using instrument tip locations. iMRI was performed after substantial resection and used to evaluate the resection maps.

RESULTS:

In 25 of 28 cases where residual tumor was identified on iMRI, the ‘difference map’ obtained by subtracting the resection map from the preoperative tumor contour correctly ascertained the location of residual. In 18 of these 25, the difference map reliably predicted the extent of residual as well. In 3 cases, false-positive overlap >30% of the contoured residual volume was noted and likely attributable to brain shift or collapse of the resection cavity during surgery. Even in these cases, surgeons reported that the general shape of the resection map helped them mentally compensate for brain shift and identify potential residual in visually inaccessible regions. Additionally, we present solutions to overcome line-of-sight challenges in optical tracking during dynamic resection.

CONCLUSION:

Our real-time navigated tracking system reliably maps resection progress during surgery and can direct attention to residual. It operates synergistically with commercial neuronavigation without disruption to surgical flow and can, in conjunction with iUS, compensate for brain shift and resection cavity collapse.
302 Outcomes in Aneurysmal Subarachnoid Hemorrhage Patients with Diabetes on Sulfonylureas: A Propensity Match Analysis
Authors: Catapano Joshua , Farhadi Dara , Rumalla Kavelin , Srinivasan Visish M. , Cole Tyler S. , Baranoski Jacob F. , Winkler Ethan A. , Graffeo Christopher S. , Jadhav Ashutosh , Ducruet Andrew F. , Albuquerque Felipe , Lawton Michael T. , Jha Ruchira
Published: March 2022

INTRODUCTION:

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with an increase blood-brain-barrier permeability, disruption of tight junctions, and increased cerebral edema. Sulfonylureas has been associated with less disturbance in tight junctions and reduced edema following aSAH in animal models.

METHODS:

Patients from the Post-Barrow Ruptured Aneurysm Trail (PBRAT) databse from August 1st, 2007, to July 31st, 2019, were retrospectively reviewed. Initial analysis grouped patients into two cohorts: diabetes and no-diabetes. A second analysis in diabetic patients separated patients based on prescription of sulfonylureas on hospital admission. A 4:1 nearest neighbor propensity match (match for age, gender, Hunt and Hess (HH), Fisher Grade, aneurysm location, aneurysm size, aneurysm type, Charlson Comorbidity Score (CCI), and treatment) was performed. Primary outcome was neurological status at last follow-up, with a poor outcome defined as a modified Rankin Score >2 and a good outcome as mRS </= 2. Significance was established as p < 0.05.

RESULTS:

A total of 1014 aSAH patients were treated during the study period. Of these patients, 129 (13%) were found to have a history of diabetes on admission. Compared to non-diabetic patients, the diabetic cohort had an increase age (59, sD 14. vs 55, sD 14.1; p < 0.006) and a higher CC I(2.5 vs 1.5; p < 0.001). Patients with diabetes (N = 77, 60%) were found to have a significantly higher odd of a mRS >2 on last follow-up compared to non-diabetics (N = 43, 49%) (p = 0.02). In the diabetic cohort, 16 patients (12%) were found to be on a sulfonylurea medication. Following propensity score matching, diabetic patients on a sulfonylurea (31%, N = 5) were found to have a significantly decrease percentage of a mRS >2 on last follow-up compared to non-sulfonylurea patients (63%, N = 40/64) (p = 0.02). On univariate analysis, besides the administration of a sulfonylurea, a HH < 4 was found to be associated with a decrease percentage of a mRS >2 (49%, N = 28 of 57) (p = 0.04). However, on multivariable logistic regression analysis, only the administration of a sulfonylurea was found to be a predictor of a good neurological outcome (OR 3.4, 95% CI: 1.1-11.3, p = 0.04).

CONCLUSION:

Diabetes appears to be associated with poor neurological outcomes in aSAH patients. However, the poor neurological outcome in diabetic patients appears to be mitigated by the administration of sulfonylureas.
315 Incidence of Infections in Full-Endoscopic Spine Surgery: A Multicenter Study Including 1262 Patients
Authors: Prasse Tobias , Wagner Ralf , Mahan Mark A. , Kim Robert , Sivakanthan Sananthan , Telfeian Albert E. , Bergquist Julia , Bredow Jan , Kashlan Osama , Hofstetter Christoph P.
Published: March 2022

INTRODUCTION:

Full-endoscopic spine surgery (FESS) is a rapidly growing field. There is emerging class I data that it results in equal or better functional outcomes compared to traditional surgery while minimizing approach related morbidity and perioperative complications.

METHODS:

569 women (45.1%) and 693 men (54.9%) were identified in our prospectively collected cohort at two different spine centers. Demographic data, complications in particular occurrence of infections was analyzed. The Charlson Comorbidity Index was used to quantify the comorbidities in relation to the patients’ age by predicting the 10-year survival.

RESULTS:

The average age of the patients was 56.6 years (±15.5), 100 cases were cervical (7.9%), 24 thoracic (1.9%) and 1138 lumbosacral (90.2%). The mean Charlson Comorbidity Index was 1.95 (±1.8). 68 patients (5.4%) took immunosuppressive drugs. 21 complications were found in 1262 cases (1.7%). None of our patients had a superficial or deep wound infection. Eight patients had dural tears (0.6%), of which one presented as a cutaneous fistula with delayed wound healing. Bacterial cultures and DNA tests were negative, there were no clinical signs for infection and the patient did not need revision surgery, but was treated by lumbar drain placement. Postoperatively, 3 epidural hematomas (0.2%), 2 transient ischemic attacks (0.2%), 2 hypertensive crises (0.2%) and one myocardial infarction (0.08%) were observed. Only 5 (0.4%) of the patients had a recurrent disc herniation.

CONCLUSION:

Full-endoscopic spine surgery is associated with a favorably low rate of wound-related complications such as infections or dehiscence. We hypothesize this is due to coverage of the skin edge by the tubular retractor avoiding spreading skin flora into the surgical area as well as constant irrigation of the operative field. Low rate of adverse outcomes strongly supports utilization of this technique when indicated.
330 Electrophysiologically-defined Parameterization of Intracranial Neuromodulation to Define DBS Settings for Treatment-resistant Depression
Authors: Metzger Brian , Adkinson Joshua , Oswalt Denise , Xiao Jiayang , Allawala Anusha , Goodman Wayne , Pouratian Nader , Sheth Sameer A. , Bijanki Kelly R.
Published: March 2022

INTRODUCTION:

Deep brain stimulation settings for treatment resistant depression are typically selected through a process of behaviorally-defined trial-and-error, which is prone to substantial variability in treatment response.

METHODS:

Intracranial EEG (iEEG) was collected concurrently with 426 unique DBS configurations varied along 5 dimensions: DBS target, segmented DBS configuration, frequency, amplitude, pulse width. Multiple sessions of baseline resting-state iEEG were also recorded, from which sessions associated with the lowest and highest depression scores were selected as desired and undesired target patterns, respectively. After decomposing iEEG data into frequency bands of interest, we created correlation matrices across the spatial/spectral space of stimulation-evoked changes in power, and rank-ordered the output in terms of similarity for each stimulation configuration to the template patterns. Iterative model fitting then determined which parameter components contributed most to the matching score.

RESULTS:

To validate the approach, we compared rank-order for desired state to undesired state and found a negative correlation between them (r = -0.45, p < 0.0001), suggesting that high-ranking stimulation parameters matched to the desired state are low-ranking when matched to the undesired state. In application of these stimulation settings for therapeutic stimulation, we saw a substantial reduction in depressive symptoms compared with the patient’s pre-DBS baselines (pre-DBS vs template-matching defined stimulation: MADRS 36 vs. 9; HAM-D 24 vs. 6).

CONCLUSION:

We have implemented spatiotemporal template matching by searching a set of 426 unique stimulation parameter sets for evoked neural states recapitulating the neural signature of a desired state in a patient with TRD. Preliminary data demonstrate that particular spatiotemporal neural signatures can be defined and matched to stimulation-evoked states.
331 Role of Functional Network Formation in Epilepsy
Authors: Boddeti Ujwal , Bachani Muznbanu , Moyer Mitchell , Owotade Jemima , Serra Riccardo , Zaveri Hitten , Ksendzovsky Alexander
Published: March 2022

INTRODUCTION:

Despite surgical resection of a defined epileptogenic focus (EF), about 50% of patients go on to have refractory seizures. Recently, focal epilepsy is being redefined as a network disorder and studies have demonstrated that resection of nodes outside the EF may contribute to better surgical outcomes. Additionally, our group has shown higher interictal connectivity between nodes involved in seizure onset in a cohort of epilepsy patients, further suggesting the presence of an underlying distributed epileptogenic network in focal epilepsy.

METHODS:

Primary mixed cultures of cortical neurons from P1 rat pups were cultured on 96-well multi-electrode array (MEA) plates with eight active electrodes per well for stimulation and recording. We developed an in vitro stimulation model of cortical epilepsy to study epilepsy network formation using a biphasic tetanic stimulation at 50 or 100 Hz, 500 μV, 250 μA applied for one hour daily for ten days.

RESULTS:

Four-days of daily in vitro stimulation demonstrated significant increases in neuronal baseline bursting, modeling kindled seizures. Tetanic stimulation with 50 Hz had the highest elevation in neuronal busting. In order to compare distributed network connectivity, we calculated and ranked coherences (13-32 Hz) across all electrode pairs (n = 24) and identified the top 15% for comparison to control. The average coherence across the top connected pairs was significantly higher in stimulated wells compared to controls (0.27 vs. 0.17, p = 0.0002). Furthermore, coherence across the highest-ranking electrode pair was strengthened with daily stimulation. This was not seen in control wells.

CONCLUSION:

Similar to human data, this in vitro model suggests an elevated interictal coherence among electrode pairs involved in seizure formation. Next, we aim to characterize the structure of this network quantifying axonal boutons and dendritic spines. Ultimately, our work aims to enable a better understanding of network formation in epilepsy that will inform future epilepsy surgery decision making.
337 Neural Network Changes with Loss of Consciousness in Parkinson's Disease
Authors: DiCesare Jasmine A. T. , Malekmohammadi Mahsa , Toker Daniel , Sparks Hiro , Hudson Andrew , Monti Martin , Pouratian Nader
Published: March 2022

INTRODUCTION:

Consciousness is likely mediated by multiple parallel yet interacting cortico-subcortical recurrent networks. The pallidocortical circuit is of particular interest given the putative role of pallidum in consciousness, according to the mesocircuit model, though this has not been well studied.

METHODS:

We characterized changes in pallidocortical circuits in awake versus propofol-induced unconscious states in humans by directly and simultaneously recording from perirolandic cortices and the pallidum in twelve Parkinson Disease (PD) patients undergoing implantation of therapeutic deep brain stimulation (DBS) leads.

RESULTS:

Propofol-induced LOC resulted in power increases up to 20 Hz in globus pallidus internus (GPi), 35 Hz in globus pallidus externus (GPe), and 100 Hz in sensorimotor cortices (S1/M1). At a network level, LOC resulted in increased pallidocortical alpha coherence with increases in Granger causality (GC) in the alpha/low beta range from GPe to all other nodes. In contrast, LOC was associated with decreased network-wide beta coherence with decreased GC in the beta range from M1 to the rest of the network.

CONCLUSION:

These results not only confirm the LOC-related changes in pallidocortical circuitry, but GC results suggest that widely reported LOC-related increases in alpha band power emanate from GPe. These findings support a significant role of the GPe in modulating consciousness. Simultaneous LOC-related suppression of beta synchrony from M1 to other nodes suggests that distinct oscillatory frequencies can act independently, conveying unique network level activity. Given the pathophysiologic role of beta synchrony in PD, LOC-related suppresion of beta synchrony may be amplified in this patient population, but may also highlight a parallel network mediating LOC-related loss of motor control.
342 Long-Term Follow-up of 54 Cases of Recurrent Glioblastoma Treated with Magnetic Resonance-Guided Laser Interstitial Thermal Therapy
Authors: Jubran Jubran H. , Shaftel Kelly T. , Hendricks Benjamin , Oladokun Femi , Farhadi Dara , Smith Kris
Published: March 2022

INTRODUCTION:

Magnetic resonance guided laser-induced thermal therapy (MRgLITT) is a novel minimally invasive procedural treatment for progressive cerebral lesions and cerebral edema related to post-radiation treatment effect.

METHODS:

We conducted a single-center retrospective study of pre-operative imaging, clinical characteristics and survival outcomes of 54 patients with previously treated (WHO Grade IV) between January 2013 to December 2020.

RESULTS:

The average age of patients was 58.7 ± 12.0 years. Patients underwent MRgLITT a median time of 21.6 ± 23.7 months from original diagnosis. 20% (n = 11) of patients had previous history of stereotactic radiosurgery, 61% (n = 33) intensity-modulated radiation therapy, and 80% (n = 43) chemotherapy. There was an average of 1.2 ± 0.7 prior surgical resections before MRgLITT was performed. 41% (n = 22) of patients were on dexamethasone at the time of treatment. The median pre-operative enhancing lesion volume on T1 gadolinium-enhanced magnetic resonance imaging (MRI) was 9.7 cm3 (standard error [SE], 2.0 cm3) and 27.0 cm3 (SE, 5.6 cm3) on T2 fluid-attenuated inversion recovery MRI. The pathology of the biopsies taken during MRgLITT confirmed tumor recurrence in 61% (n = 33) of patients, and treatment effect or reactive changes in 37% (n = 20) of patients. 67% (n = 28) experienced radiographic evidence of progression of the previously treated lesion, while 21% (n =9) and 12% (n = 5) experienced progression of a new lesion or both, respectively. Progression-free survival after MRgLITT was 3.5 months (standard error [SE], 0.6; 95% CI, 2.4-4.6). At the time of the study, 78% (n = 42) of patients were deceased. Mean overall survival time was 29.9 months (SE, 4.3; 95% CI, 21.4-38.3). Mean survival time after MRgLITT was 8.3 months (SE, 1.2; 95% CI, 5.9-10.6. Of the 12 remaining living patients, 36% (n = 4) had a decline in their clinical status at the time of last follow up, while 64% (n = 7) and 9% (n = 1) were stable or improved, respectively. Patients were followed for a mean time interval of 9.25 ± 12.2 months from MRgLITT.

CONCLUSION:

MRgLITT may be a viable, minimally invasive option for patients with glioblastoma but is associated with relatively short post-treatment progression-free survival.
343 Machine Learning Using Multiparametric MRI Radiomic Feature Analysis to Predict Ki-67 in Meningiomas
Authors: Khanna Omaditya , Kazerooni Anahita F. , Farrell Christopher J. , Baldassari Michael , Alexander Tyler , Karsy Michael , Garcia Jose , Sako Chiharu , Evans James J. , Judy Kevin D. , Andrews David W. , Sharan Ashwini D. , Shi Wenyin , Davatzikos Christos
Published: March 2022

INTRODUCTION:

Although WHO grade I meningiomas are considered ‘benign’ tumors, an elevated Ki-67 is one crucial factor that has been shown to influenceclinical outcomes. Machile learning using radiomic analysis can help predict tumor pathology and model outcomes.

METHODS:

A retrospective analysis was performed for a cohort of 306 patients that underwent surgical resection of WHO grade I meningiomas. MRI was used to perform radiomic feature extraction followed by machine learning using a support vector machine (SVM) through nested cross-validation on a discovery cohort (N = 230), to stratify tumors based on Ki-67. The final model was independently tested on a replication cohort (N = 76).

RESULTS:

The mean and median Ki-67 of tumor specimens were 4.84 ± 4.03% (range: 0.3 – 33.6) and 3.7% (Q1: 2.3%, Q3: 6%), respectively. Meningiomas with Ki-67=5% were larger in volume compared to tumors with Ki-67 < 5% (mean 38.65 ± 19.19 and 20.97 ± 35.57 cm3, respectively; p < 0.001), which held true in sub-group analysis of both skull base and non-skull base tumors. Similarly, meningiomas with Ki-67 = 5% had significantly larger peritumoral edema volumes compared to tumors with Ki67 < 5% (mean 22.11 ± 40.12 and 40.16 ± 42.34 cm3, respectively; p = 0.002). An area under the receiver operating curve (AUC) of 0.84 (95% CI: 0.78-0.90) with a sensitivity of 84.1% and specificity of 73.3% was achieved in the discovery cohort. When this model was applied to the replication cohort, a similar high performance was achieved, with an AUC of 0.83 (95% CI: 0.73-0.94), sensitivity and specificity of 82.6% and 85.5%, respectively. The model demonstrated similar efficacy when applied to skull base and non-skull base tumors.

CONCLUSION:

Our proposed radiomic feature analysis can be used to stratify meningiomas based on Ki-67 with excellent accuracy and can be applied to skull-base and non-skull base tumors.
353 Comprehensive Evaluation of Telehealth Service Effectiveness in the Neurosurgical Patient Population During the COVID-19 Pandemic
Authors: Sorour Omar , Slavin Justin
Published: March 2022

INTRODUCTION:

In recent years, remote access for medical care is increasingly being utilized. However its efficacy for neurosurgical patients is not widely studied, especially in the setting of a global pandemic.

METHODS:

A HIPAA-compliant survey was created via RedCap addressing satisfaction and utility of telehealth (televideo or telephone) in patients from 03/2020 – Present. Out of 246 currently emailed patients, 22 responses were recorded (televideo, n=11; telephone, n=11).

RESULTS:

Telephone users found the phone call a suitable method, with no preference for video format. However, 3 of these phone respondents (27.3%) still required an in-person visit. For televideo service, no user reported finding difficulty in accessing their appointment. Interestingly, 45.5% of televideo users (n=5) reported that the attending physician displayed multimedia tools, such as radiographic imaging, during the visit. When examining both telephone and televideo cohorts, 95.5% of respondents (n=21) felt satisfied overall with telehealth’s ability to meet their needs. Despite this high satisfaction rate, 22.7% of all respondents were either ambivalent (n=4) or strongly disagreed (n=1) that telehealth improved access to healthcare services.

CONCLUSION:

Our study illustrates the importance of differentiating between satisfaction—which can expectedly be high in a “stay-at-home” service—and efficacy in providing neurosurgical care. We suggest that telehealth is a technologically robust tool given its reported ease of use. Yet, preliminary results show that telehealth’s comprehensiveness may hold up less for patients who still require in-person evaluation for certain diagnoses and examinations. Almost a quarter of respondents believed that telehealth did not improve access to healthcare services, arguing that telehealth visits may be less useful for some.
367 Development of Machine Learning Based Models to Predict Treatment Response to Spinal Cord Stimulation
Authors: Hadanny Amir , Pilitsis Julie G.
Published: March 2022

INTRODUCTION:

Despite spinal cord stimulation’s (SCS) proven efficacy, failure rates are high with no clear understanding of which patients benefit long-term. Currently, patient selection for SCS is based on the subjective experience of the implanting physician.

METHODS:

A combined unsupervised (clustering) and supervised (classification) ML techniques was applied on a prospectively collected cohort of 151 patients which included 31 features. Clusters identified using unsupervised K-means clustering were fitted with individualized predictive models of logistic regression, random forest and XGboost.

RESULTS:

Two distinct clusters were found and patients in the cohorts significantly differed in age, duration of chronic pain, pre-operative numeric rating scale (NRS) and pre-operative pain catastrophizing scale scores. Using the 10 most influential features, logistic regression predictive models with a nested cross-validation demonstrated the highest overall performance with area under the curve (AUC) of 0.757 and 0.708 for each respective cluster.

CONCLUSION:

This combined unsupervised-supervised learning approach yielded high predictive performance, suggesting advance ML-derived approaches have potential to be utilized as a functional clinical tool to improve long-term SCS outcomes.
401 Risk Factors for Increased Mortality in Patients with ICH and COVID-19: Timing Matters
Authors: Selner Ashley , Arslan Danial , McGuire Laura S. , Mehta Ankit I.
Published: March 2022

INTRODUCTION:

Intracerebral hemorrhage (ICH) has been reported with comorbid COVID-19 infection and is associated with significant morbidity and mortality.

METHODS:

The NIH N3C national database was used to retrospectively analyze COVID-19 infected patients within 1 month of ICH admitted after March 11, 2020. The primary endpoint was death during admission, and the cohort of patients who suffered fatalities were compared to those discharged from admission. Additional analyses compared patients diagnosed with ICH after COVID-19 infection versus those presenting with ICH and subsequent COVID infection.

RESULTS:

1614 ICH-COVID patients from 55 sites were identified, 351 of which suffered fatalities. In the ICH-COVID fatality cohort versus those discharged, there was a significantly higher proportion of prior comorbid obesity (36.2% vs 28.3%), diabetes (48.1% vs 40.1%), atrial fibrillation (35.0% vs 24.8%), and heart failure (30.8% vs 23.8%). Racial and ethnic differences were not significant across the two cohorts. Of note, higher rates of hypertension and smoking were not observed. Increased complications of MI (18.2% vs 11.0%), PE (14.2% vs 9.5%), and DVT (19.7% vs 14.9%) were observed. The fatality cohort showed an increased proportion of patients presenting with ICH prior to COVID-19 infection compared to those diagnosed with ICH after COVID-19 infection. Analyses comparing the timing of ICH and COVID diagnoses regardless of outcome confirmed higher rates of mortality (28.4% vs 20.3%) in those with ICH followed by COVID-19 infection. To account for confounding non-survivable ICH in respective cohorts, fatalities within 2 days of ICH diagnosis were excluded and this finding remained significant.

CONCLUSION:

Fatalities from ICH and concurrent COVID-19 infection were increased for those with history of obesity, diabetes, atrial fibrillation and heart failure, and higher rates of MI, PE, and DVT were observed compared to non-fatal cases. Patients who presented with ICH and subsequently became COVID infected had higher mortality rate than those who suffered ICH after COVID.
427 Use of Antibacterial Envelopes for Prevention of Infection in Neuromodulation
Authors: Persad Amit R. L. , Ahmed Syed U. , Mercure-Cyr Rosalie , Waterhouse Karen , Vitali Aleksander
Published: March 2022

INTRODUCTION:

Neuromodulation is effective but carries a historic infection rate as high as 12%. TYRX antibacterial envelopes (Medtronic Inc., Minneapolis, MN), which are absorbable mesh envelopes that elute minocycline and rifampin, have been used in implantable cardiac devices with substantial risk reduction for infection.

METHODS:

We conducted a retrospective cohort study of consecutive implantable pulse generator (IPG) and intrathecal pump unit implantation with a TYRX antibacterial envelope© at our center between October 2014 and December 2019. This cohort was then compared to a historical cohort of consecutive patients undergoing IPG or pump placement or revision prior to the use of the envelopes (between October 2007 and April 2015).

RESULTS:

In the pre-envelope cohort of 151 IPGs placed in 116 patients, there was an infection rate of 18/151 (11.9%). In the antibacterial envelope cohort of 233 IPGs placed in 185 patients, there were 5 infections (2.1%). The absolute risk reduction of the antibacterial envelope was 4.6% (95% CI, 0.045-0.048), with a relative risk reduced by 77% (odds ratio, 0.23; 95% CI 0.05-1.08; P = 0.065). The NNT was 21 (95% CI 20.8-22.4). The pre-envelope cohort of 41 pumps placed in 39 patients, the infection rate was 6/41 (14.6%). In the antibacterial envelope cohort of 59 pumps in 54 patients, there was 1 infection (1.7%). The absolute risk reduction of the antibacterial envelope was 12.9% (95% CI 1.6-24.3), with a relative risk reduction of 88% (odds ratio, 0.13; 95% CI, 0.02-1.11; P = 0.04). The NNT was 7.7 (95% CI 4.4-32.3).

CONCLUSION:

Usage of an antibacterial envelope with device placement for neuromodulation therapy has resulted in a lower infection rate at our center. Based on these results, we can recommend the use of envelopes for infection prophylaxis.
428 The Lumbar Tap Trial Experience: An Analysis of Outcomes in 133 Adult Normal Pressure Hydrocephalus Patients Undergoing 2-Day Lumbar Tap Trial at a Single Center
Authors: Cunningham Coby , Leonardo Jody
Published: March 2022

INTRODUCTION:

Lumbar Tap Trial (LTT) with high volume cerebrospinal fluid (CSF) removal is one of the primary adjunct testing modalities at a neurosurgeon’s disposal in the diagnosis of normal pressure hydrocephalus (NPH). Patients responsive to LTT may receive permanent fluid diversion by way of shunt placement.

METHODS:

Retrospective review of the electronic medical records of 133 patients that underwent a 2-day LTT by a single surgeon at our adult hydrocephalus center was conducted. Each patient has been closely followed at our hydrocephalus clinic from the time of symptomatic presentation through LTT, eventual shunt placement (if performed), and frequent post-operative assessments. Assessment of improvement during LTT and following shunt placement includes a timed 25 ft. walk test at our clinic.

RESULTS:

From 2016 – present, 133 patients have undergone 136 completed LTTs. During initial LTT, no major complications such as death, infection, hemorrhage, or nerve-root injury were seen. Minor complications included post-tap low back pain, headache, and transient nerve-root irritation. Average improvement during timed 25 ft. walk test was 6.6 sec following LTT. Average improvement in timed walk test in patients receiving shunt placement was 13.9 sec compared to post LTT walk time.

CONCLUSION:

In patients with suspected NPH, high-volume LTT was found to be an effective and safe diagnostic tool in our patient population. Patients demonstrating significant objective improvement during a timed walk test are frequently recommended for shunting. Patients undergoing shunt placement following improvement on LTT continued to improve with a mean decrease in walk time post-operatively, highlighting the effectiveness of LTT in predicting symptomatic response to shunt placement.
439 A Colloidal Polymethyl-Methacrylate (PMMA) Microsphere-Based Treatment for Patients with Symptomatic Discogenic Disease: A Safety and Feasibility Clinical Trial
Authors: Brown Nolan J. , Shahrestani Shane , Lien Brian , Yang Chen Y. , Ton Emily , Diaz-Aguilar Luis D. , Sahyouni Ronald , Wali Arvin R. , Abraham Mickey E. , Taylor Sandra , Taylor William R.
Published: March 2022

INTRODUCTION:

Low Back Pain (LBP) is a global healthcare issue, and first line therapy for patients with LBP include physical therapy, oral pain relievers, and steroid injections. If unsuccessful, surgical procedures are indicated. Non-surgical second-line treatments for LBP are warranted, and one example is DiscSeal, a colloidal form of viscous gel composed of polymethyl-methacrylate microspheres and aqueous buffered sodium hyaluronate.

METHODS:

Six participants were enrolled. The study population comprised of males/females between the ages of 18 and 70, diagnosed with chronic LBP of six months or more prior to enrollment determined to be predominantly caused by discogenic disease of the lumbar spine who failed at least six weeks of conservative management. Participants completed visits at 7, 14, 42, 90, and 180 days.

RESULTS:

The mean age of participants was 38.8 ± 10.0 years. The mean DiscSeal volume administered was 1.62 ± 0.35 mL with a range between 1.1-2.0 mL. The mean procedure time was 10.8 minutes. Mean LBP visual analog scale (VAS) percentage changes from baseline were -27.0% at 90 days and -42.3% at 180 days, with 50.0% of participants maintaining LBP VAS scores <4 at 90- and 180-days post treatment with DiscSeal. Similarly, mean leg pain VAS percentage changes from baseline were -47.0% at 90 days and -36.6% at 180 days. Overall, participants' average improvement, assessed by Patient Rating Overall Health Status, was 55.2% at 90 days and 67.8% at 180 days.

CONCLUSION:

The results from this first-in-man trial suggest a favorable safety and efficacy profile for the continued study of DiscSeal. Future studies evaluating DiscSeal as a minimally invasive therapy for chronic discogenic LBP are warranted.
479 Validation and Comparison of Pupillary Reflex Indices in TBI and Matched Healthy Controls Using PupilScreen, a Smartphone-based Pupillometer
Authors: Gulek Bernice G. , Maxin Anthony , Lim Do , Lee Chungeun (Chloe) , Buzytsky Ilya , Coppess Steve , Alfieri Robin , Law Anthony , Levitt Michael R. , Bly Randy , Kelly Cory , McGrath Lynn
Published: March 2022

INTRODUCTION:

Pupillary light reflex (PLR) is one of the earliest biomarkers used to assess, diagnose, and treat neurological conditions, particularly traumatic brain injury (TBI). PLR indices have been examined as an indicator for specific neurological conditions using a pupillometer. We developed an alternative, mathematically driven stand-alone app to increase precision, to provide broader accessibility, and utilization of automated pupillometry.

METHODS:

The second-generation PupilScreen app was developed using a fully convolutional neural network (FCNN) model, using the standard iPhone light source and camera without any external environmental controls. We examined n=21 TBI subjects with n=21healthy controls matched to primary eye color. We analyzed known pupillary biomarkers for TBI and compared the metrics in both cohorts. Additionally, we examined age, gender, ethnicity, GCS, eye color, and primary lesion.

RESULTS:

Distribution of eye color was 38% brown eyes, 29% blue eyes, and 33% mixed eyes in both cohorts. Mean age was 54 vs 35 in TBI and healthy controls, respectively. Female sex was 19% versus 62% TBI and healthy controls sequentially. Ethnicities included White (TBI 67%, healthy controls 76%), African American (TBI 9%, healthy controls 10%), Asian (TBI 9%, healthy controls14%), Native American/Indian (TBI 5%, healthy controls 0%). Lesions consisted of subdural hematoma (61%), intraparenchymal hemorrhage (24%), contusions (10%), traumatic subarachnoid hemorrhage (5%), and 38% of lesions were multifocal. Mean GCS was 8, and 52% were classified as severe TBI. PupilScreen measurements included mean latency of 0.45s(L)/0.31s(R) in TBI and 0.17s (L/R) (p<0.05) healthy controls; mean % diameter change was 21%(L)/17%(R) in TBI, 39%(L/R) (p<0.05) in healthy controls; mean constriction velocity was 3.7px/s(L)/3.6px/s(R)in TBI and 11.4px/s(L)/11.1px/s(R) (p<0.05) n healthy controls; and the mean dilation velocity was 2.4px/s(L/R) and 4.1px/s(L)/4.5px/s(R) (p<0.05) in TBI and healthy cohorts respectively.

CONCLUSION:

The preliminary PupilScreen results demonstrated capability in identification of PLR biomarkers in TBI population compared to healthy cohort without the need for external environmental controls. Further development of PupilScreen app is warranted.
509 Microenvironmental Characteristics of Growing and Static Vestibular Schwannomata
Authors: Hannan Cathal , Lewis Daniel , MacArthur Joshua , Cooper Christopher , Hammerbeck-Ward Charlotte , Rutherford Scott A. , Lloyd Simon K. , Freeman Simon R. M. , Coope David J. , Pathmanaban Omar N. , Roncaroli Federico , King Andrew
Published: March 2022

INTRODUCTION:

Vestibular schwannomas (VS) display a wide variation in their natural history, with ∼60% exhibiting progressive growth, while the remainder do not grow. There is emerging evidence that the tumor microenvironment (TME) plays a central role in driving tumour growth. Previous studies in this area have been limited by small sample sizes, a shortcoming we addressed in the present study.

METHODS:

We identified 120 patients with sporadic VS from a prospectively maintained database. 100 consecutive growing cases and 20 consecutive static cases were included. Tumour volumes and growth rates were established by analysis of MR imaging using Brainlab ElementsTM. Tumour tissue was analysed using immunohistochemistry to assess for macrophage infiltrates (Iba1), microvessel surface area (CD31) and vascular permeability (Fibrinogen). Immunostains were quantified using ImageJ (www.imagej.nih.gov). Statistical analysis was performed using the appropriate non-parametric tests.

RESULTS:

The mean Iba1+ macrophages was significantly higher in growing VS when compared to static VS (591 vs. 317/x20 HPF, p=0.02). Growing VS also had a significantly higher microvessel surface area than static VS (2.16% vs. 1.37%, p=0.032), as well as higher vascular permeability as assessed by optical density of fibrinogen staining (0.64 vs. 0.45, p=0.038). There was a statistically significant correlation between tumour macrophage infiltration and tumour vascularity (rs=0.4189, p=<0.001).

CONCLUSION:

We documented marked differences in the TME of growing and static VS, validating our previous observation. Growing VS exhibited higher macrophage density, increased vascularity and higher vascular permeability. Targeting these processes may yield therapeutic benefit for patients with sporadic and neurofibromatosis type 2 related VS.