Compact and cost-effective laser-powered speckle contrast optical spectroscopy fiber-free device for measuring cerebral blood flow.

Significance: In the realm of cerebrovascular monitoring, primary metrics typically include blood pressure, which influences cerebral blood flow (CBF) and is contingent upon vessel radius. Measuring CBF noninvasively poses a persistent challenge, primarily attributed to the difficulty of accessing and obtaining signal from the brain. Aim: Our study aims to introduce a compact speckle contrast optical spectroscopy device for noninvasive CBF measurements at long source-to-detector distances, offering cost-effectiveness, and scalability while tracking blood flow (BF) with remarkable sensitivity and temporal resolution. Approach: The wearable sensor module consists solely of a laser diode and a board camera. It can be easily placed on a subject's head to measure BF at a sampling rate of 80 Hz. Results: Compared to the single-fiber-based version, the proposed device achieved a signal gain of about 70 times, showed superior stability, reproducibility, and signal-to-noise ratio for measuring BF at long source-to-detector distances. The device can be distributed in multiple configurations around the head. Conclusions: Given its cost-effectiveness, scalability, and simplicity, this laser-centric tool offers significant potential in advancing noninvasive cerebral monitoring technologies.

Neural interface-based motor neuroprosthesis in post-stroke upper limb neurorehabilitation: An individual patient data meta-analysis.

OBJECTIVE: To determine the efficacy of neural interface-, including brain-computer interface (BCI), based neurorehabilitation through conventional and individual patient data (IPD) meta-analysis, and to assess clinical parameters associated with positive response to neural interface-based neurorehabilitation. DATA SOURCES: PubMed, EMBASE, and Cochrane Library databases up to February 2022 were reviewed. STUDY SELECTION: Studies using neural interface-controlled physical effectors (FES and/or powered exoskeletons) and reported Fugl-Meyer Assessment-upper extremity (FMA-UE) scores were identified. This meta-analysis was prospectively registered on PROSPERO (#CRD42022312428). PRISMA guidelines were followed. DATA EXTRACTION: Change in FMA-UE scores were pooled to estimate the mean effect size. Subgroup analyses were performed on clinical parameters and neural interface parameters with both study-level variables and IPD. DATA SYNTHESIS: Forty-six studies containing 617 patients were included. Twenty-nine studies involving 214 patients reported IPD. FMA-UE score increased by a mean of 5.23 (95% CI: 3.85 to 6.61). Systems that used motor attempt resulted in greater FMA-UE gain than motor imagery, as did training lasting >4 versus ≤4 weeks. On IPD analysis, the mean time-to-improvement above MCID was 12 weeks (95% CI: 7 to not reached). At 6 months, 58% improved above MCID (95% CI: 41 to 70%). Patients with severe impairment (p=0.042) and age >50 years (p=0.0022) correlated with the failure to improve above the MCID on univariate log-rank tests. However, these factors were only borderline significant on multivariate Cox analysis (HR 0.15, p = 0.08 and HR 0.47, p = 0.06, respectively). CONCLUSION: Neural interface-based motor rehabilitation resulted in significant though modest reductions in post-stroke impairment and should be considered for wider applications in stroke neurorehabilitation.

Neuromodulation of Eating Disorders: A Review of Underlying Neural Network Activity and Neuromodulatory Treatments.

Eating disorders are a group of psychiatric conditions that involve pathological relationships between patients and food. The most prolific of these disorders are anorexia nervosa, bulimia nervosa, and binge eating disorder. The current standard of care involves psychotherapy, pharmacotherapy, and the management of comorbid conditions, with nutritional rehabilitation reserved for severe cases of anorexia nervosa. Unfortunately, many patients often fail to respond, leaving a concerning treatment gap between the current and requisite treatments for eating disorders. To better understand the neurobiology underlying these eating disorders, investigations have been undertaken to characterize the activity of various neural networks, primarily those activated during tasks of executive inhibition, reward processing, and self-reference. Various neuromodulatory techniques have been proposed to stimulate these networks with the goal of improving patients' BMI and mental health. The aim of this review is to compile a comprehensive summarization of the current literature regarding the underlying neural connectivity of anorexia nervosa, bulimia nervosa, and binge eating disorder as well as the numerous neuromodulatory modalities that have been investigated. Importantly, we aimed to summarize the most significant clinical trials to date as well as to provide an updated assessment of the role of deep brain stimulation, summarizing numerous recently published clinical studies that have greatly contributed to the literature. In this review, we found therapeutic evidence for transcranial magnetic stimulation and transcranial direct current stimulation in treating individuals suffering from anorexia nervosa, bulimia nervosa, and binge eating disorder. We also found significant evidence for the role of deep brain stimulation, particularly as an escalatory therapy option for the those who failed standard therapy. Finally, we hope to provide promising directions for future clinical investigations.

Is two-staged gamma knife surgery a reasonable management option for very large cerebellar metastases? A case series of three patients.

OBJECTIVE: Two-staged gamma knife surgery (GKS) is a method that may extend the upper tumor volume limit for using GKS in the management of brain metastases. However, the safety of treating very large posterior fossa lesions with this technique has not been well demonstrated. Therefore, we analyzed our experience in treating cerebellar metastases larger than 12 cm3 with two-staged GKS. METHODS: Four consecutive patients harboring 12 to 30 cm3 cerebellar metastases scheduled two-staged GKS were included in the study, and all but one patient completed the treatment. The treatment doses were 10-13 Gy. All patients were followed with regular MR imaging and clinical assessments, and the tumor volumes were measured on all treatment and follow-up images. RESULTS: Tumor progression was not demonstrated in any of the patients. Tumor volumes decreased by, on average, more than half between the two stages. The median survival was 22 months, and no patient died due to intracranial tumor progression. Peritumoral edema at the first GKS resolved in all patients, replaced by asymptomatic mild T2 changes in two of them not requiring any treatment. No radiation-induced complication has developed thus far. CONCLUSION: Staged GKS seems to be a feasible management option for very large cerebellar metastases.

A compact and cost-effective laser-powered speckle visibility spectroscopy (SVS) device for measuring cerebral blood flow.

In the realm of cerebrovascular monitoring, primary metrics typically include blood pressure, which influences cerebral blood flow (CBF) and is contingent upon vessel radius. Measuring CBF non-invasively poses a persistent challenge, primarily attributed to the difficulty of accessing and obtaining signal from the brain. This study aims to introduce a compact speckle visibility spectroscopy (SVS) device designed for non-invasive CBF measurements, offering cost-effectiveness and scalability while tracking CBF with remarkable sensitivity and temporal resolution. The wearable hardware has a modular design approach consisting solely of a laser diode as the source and a meticulously selected board camera as the detector. They both can be easily placed on a subject's head to measure CBF with no additional optical elements. The SVS device can achieve a sampling rate of 80 Hz with minimal susceptibility to external disturbances. The device also achieves better SNR compared with traditional fiber-based SVS devices, capturing about 70 times more signal and showing superior stability and reproducibility. It is designed to be paired and distributed in multiple configurations around the head, and measure signals that exceed the quality of prior optical CBF measurement techniques. Given its cost-effectiveness, scalability, and simplicity, this laser-centric tool offers significant potential in advancing non-invasive cerebral monitoring technologies.

An unusual case of dengue fever in aneurysmal subarachnoid haemorrhage: diagnosis and management nuances.

BACKGROUND: Dengue fever is highly prevalent in the Asia-Pacific region. Here we present an unusual case of dengue fever in a patient with a ruptured cerebral aneurysm causing subarachnoid (SAH) and intraventricular haemorrhage (IVH) and discuss the implications of dengue-related thrombopathies on the management of SAH and its complications. CASE REPORT: A 56-year-old female with a two-day history of high-grade pyrexia and myalgia presented with sudden-onset drowsiness (presenting Glasgow Coma Scale, GCS: E1V1M4). Imaging revealed extensive SAH and IVH due to a ruptured right middle cerebral artery (MCA) aneurysm, with extensive vasospasm. Blood test revealed thrombocytopenia and a positive NS-1 antigen. She subsequently suffered from two episodes of re-rupture of the aneurysm and elevated intracranial pressure which required a decompressive craniectomy in addition to coilingof the MCA aneurysm. Cerebral perfusion and rheology were maintained with the triple-H therapy. Her GCS improved to E4V1M6, but remained aphasic. DISCUSSIONS: Thrombocytopenia and deranged platelet functions in dengue infection might affect the stability of clot and increase the risk of re-rupture of aneurysm. Immediate securement of the aneurysm was paramount. In cases of severe dengue, plasma leakage could lead to intravascular depletion, and coupled with haemoconcentration and hypotension would further increase the risk for vasospasm.

Laser Interstitial Thermal Therapy for the Treatment of Primary and Metastatic Brain Tumors: A Systematic Review and Meta-Analysis.

BACKGROUND: Laser interstitial thermal therapy (LITT) is a minimally invasive treatment option for intracranial tumors that are challenging to treat via traditional methods; however, its safety and efficacy are not yet well validated in the literature. The objectives of the study were to assess the available evidence of the indications and adverse events (AEs) of LITT and 1-year progression-free survival and 1-year overall survival in the treatment of primary and secondary brain tumors. METHODS: A comprehensive literature search was conducted through the databases PubMed, Embase, and the Cochrane Library until October 2021. Comparative and descriptive studies, except for case reports, were included in the meta-analysis. Separate analyses by tumor type (high-grade gliomas, including World Health Organization grade 4 astrocytomas [which include glioblastomas] as a specific subgroup; low-grade gliomas; and brain metastases) were conducted. Pooled effect sizes and their 95% confidence intervals (CI) were generated via random-effects models. RESULTS: Forty-five studies met the inclusion criteria, yielding 826 patients for meta-analysis. There were 829 lesions in total, of which 361 were classified as high-grade gliomas, 116 as low-grade gliomas, 337 as metastatic brain tumors, and 15 as nonglial tumors. Indications for offering LITT included deep/inaccessible tumor (12 studies), salvage therapy after failed radiosurgery (9), failures of ≥2 treatment options (3), in pediatric patients (4), patient preference (1); indications were nonspecific in 12 studies. Pooled incidence of all (minor or major) procedure-related AEs was 30% (95% CI, 27%-40%) for all tumors. Pooled incidence of neurologic deficits (minor or major) was 16% (12%-22%); postprocedural edema 14% (8%-22%); seizure 6% (4%-9%); hematoma 20% (14%-29%); deep vein thrombosis 19% (11%-30%); hydrocephalus 8% (5%-12%); and wound infection 5% (3%-7%). One-year progression-free survival was 18.6% (11.3%-29.0%) in high-grade gliomas, 16.9% (11.6%-24.0%) among the grade 4 astrocytomas; and 51.2% (36.7%-65.5%) in brain metastases. One-year overall survival was 43.0% (36.0%-50.0%) in high-grade glioma, 45.9% (95% CI, 37.9%-54%) in grade 4 astrocytomas; 93.0% (42.3%-100%) in low-grade gliomas, and 56.3% (47.0%-65.3%) in brain metastases. CONCLUSIONS: New neurologic deficits and postprocedural edema were the most reported AEs after LITT, albeit mostly transient. This meta-analysis provides the best statistical estimates of progression and survival outcomes based on the available information. LITT is generally a safe procedure for selected patients, and future well-designed comparative studies on its outcomes versus the current standard of care should be performed.

Neural correlates of learning in a linear discriminant analysis brain-computer interface paradigm.

Objective.With practice, the control of brain-computer interfaces (BCI) would improve over time; the neural correlate for such learning had not been well studied. We demonstrated here that monkeys controlling a motor BCI using a linear discriminant analysis (LDA) decoder could learn to make the firing patterns of the recorded neurons more distinct over a short period of time for different output classes to improve task performance.Approach.Using an LDA decoder, we studied two Macaque monkeys implanted with microelectrode arrays as they controlled the movement of a mobile robotic platform. The LDA decoder mapped high-dimensional neuronal firing patterns linearly onto a lower-dimensional linear discriminant (LD) space, and we studied the changes in the spatial coordinates of these neural signals in the LD space over time, and their correspondence to trial performance. Direction selectivity was quantified with permutation feature importance (FI).Main results.We observed that, within individual sessions, there was a tendency for the points in the LD space encoding different directions to diverge, leading to fewer misclassification errors, and, hence, improvement in task accuracy. Accuracy was correlated with the presence of channels with strong directional preference (i.e. high FI), as well as a varied population code (i.e. high variance in FI distribution).Significance.We emphasized the importance of studying the short-term/intra-sessional variations in neural representations during the use of BCI. Over the course of individual sessions, both monkeys could modulate their neural activities to create increasingly distinct neural representations.

Survival Prediction After Neurosurgical Resection of Brain Metastases: A Machine Learning Approach.

BACKGROUND: Current prognostic models for brain metastases (BMs) have been constructed and validated almost entirely with data from patients receiving up-front radiotherapy, leaving uncertainty about surgical patients. OBJECTIVE: To build and validate a model predicting 6-month survival after BM resection using different machine learning algorithms. METHODS: An institutional database of 1062 patients who underwent resection for BM was split into an 80:20 training and testing set. Seven different machine learning algorithms were trained and assessed for performance; an established prognostic model for patients with BM undergoing radiotherapy, the diagnosis-specific graded prognostic assessment, was also evaluated. Model performance was assessed using area under the curve (AUC) and calibration. RESULTS: The logistic regression showed the best performance with an AUC of 0.71 in the hold-out test set, a calibration slope of 0.76, and a calibration intercept of 0.03. The diagnosis-specific graded prognostic assessment had an AUC of 0.66. Patients were stratified into regular-risk, high-risk and very high-risk groups for death at 6 months; these strata strongly predicted both 6-month and longitudinal overall survival ( P < .0005). The model was implemented into a web application that can be accessed through http://brainmets.morethanml.com . CONCLUSION: We developed and internally validated a prediction model that accurately predicts 6-month survival after neurosurgical resection for BM and allows for meaningful risk stratification. Future efforts should focus on external validation of our model.

A Prognostic Model Using Post-Steroid Neutrophil-Lymphocyte Ratio Predicts Overall Survival in Primary Central Nervous System Lymphoma.

Background: Ratios of differential blood counts (hematological indices, HIs) had been identified as prognostic variables in various cancers. In primary central nervous system lymphomas (PCNSLs), higher baseline neutrophil-lymphocyte ratio (NLR) in particular was found to portend a worse overall survival. However, it was often observed that differential counts shift drastically following steroid administration. Moreover, steroids are an important part of the arsenal against PCNSL due to its potent lymphotoxic effects. We showed that the effect of steroids on differential blood cell counts and HIs could be an early biomarker for subsequent progression-free (PFS) and overall survival (OS). Methods: This study retrospectively identified all adult patients who received a brain biopsy from 2008 to 2019 and had histologically confirmed PCNSL, and included only those who received chemoimmunotherapy, with documented use of corticosteroids prior to treatment induction. Different blood cell counts and HIs were calculated at three time-points: baseline (pre steroid), pre chemoimmunotherapy (post steroid) and post chemoimmunotherapy. Tumor progression and survival data were collected and analyzed through Kaplan−Meier estimates and Cox regression. We then utilized selected variables found to be significant on Kaplan−Meier analysis to generate a decision-tree prognostic model, the NNI-NCCS score. Results: A total of 75 patients who received chemoimmunotherapy were included in the final analysis. For NLR, OS was longer with higher pre-chemoimmunotherapy (post-steroid) NLR (dichotomized at NLR ≥ 4.0, HR 0.42, 95% CI: 0.21−0.83, p = 0.01) only. For platelet-lymphocyte ratio (PLR) and lymphocyte-monocyte ratio (LMR), OS was better for lower post-chemoimmunotherapy PLR (dichotomized at PLR ≥ 241, HR 2.27, 95% CI: 1.00 to 5.18, p = 0.05) and lower pre-chemoimmunotherapy (post-steroid) LMR (dichotomized at LMR ≥25.7, HR 2.17, 95% CI: 1.10 to 4.31, p = 0.03), respectively, only. The decision-tree model using age ≤70, post-steroid NLR >4.0, and pre-steroid (baseline) NLR <2.5 and the division of patients into three risk profiles­low, medium, and high­achieved good accuracy (area-under-curve of 0.78), with good calibration (Brier score: 0.16) for predicting 2-year overall survival. Conclusion: We found that post-steroid NLR, when considered together with baseline NLR, has prognostic value, and incorporation into a prognostic model allowed for accurate and well-calibrated stratification into three risk groups.

The Impact of Multimorbidity Burden, Frailty Risk Scoring, and 3-Directional Morphological Indices vs. Testing for CSF Responsiveness in Normal Pressure Hydrocephalus.

Objective: Multimorbidity burden across disease cohorts and variations in clinico-radiographic presentations within normal pressure hydrocephalus (NPH) confound its diagnosis, and the assessment of its amenability to interventions. We hypothesized that novel imaging techniques such as 3-directional linear morphological indices could help in distinguishing between hydrocephalus vs. non-hydrocephalus and correlate with responsiveness to external lumbar drainage (CSF responsiveness) within NPH subtypes. Methodology: Twenty-one participants with NPH were recruited and age-matched to 21 patients with Alzheimer's Disease (AD) and 21 healthy controls (HC) selected from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Patients with NPH underwent testing via the NPH programme with external lumbar drainage (ELD); pre- and post-ELD MRI scans were obtained. The modified Frailty Index (mFI-11) was used to stratify the NPH cohort, including Classic and Complex subtypes, by their comorbidity and frailty risks. The quantitative imaging network tool 3D Slicer was used to derive traditional 2-dimensional (2d) linear measures; Evans Index (EI), Bicaudate Index (BCI) and Callosal Angle (CA), along with novel 3-directional (3d) linear measures; z-Evans Index and Brain per Ventricle Ratio (BVR). 3-Dimensional (3D) ventricular volumetry was performed as an independent correlate of ventriculomegaly to CSF responsiveness. Results: Mean age for study participants was 71.14 ± 6.3 years (18, 85.7% males). The majority (15/21, 71.4%) of participants with NPH comprised the Complex subtype (overlay from vascular risk burden and AD); 12/21 (57.1%) were Non-Responders to ELD. Frailty alone was insufficient in distinguishing between NPH subtypes. By contrast, 3d linear measures distinguished NPH from both AD and HC cohorts, but also correlated to CSF responsiveness. The z-Evans Index was the most sensitive volumetric measure of CSF responsiveness (p = 0.012). Changes in 3d morphological indices across timepoints distinguished between Responders vs. Non-Responders to lumbar testing. There was a significant reduction of indices, only in Non-Responders and across multiple measures (z-Evans Index; p = 0.001, BVR at PC; p = 0.024). This was due to a significant decrease in ventricular measurement (p = 0.005) that correlated to independent 3D volumetry (p = 0.008). Conclusion. In the context of multimorbidity burden, frailty risks and overlay from neurodegenerative disease, 3d morphological indices demonstrated utility in distinguishing hydrocephalus vs. non-hydrocephalus and degree of CSF responsiveness. Further work may support the characterization of patients with Complex NPH who would best benefit from the risks of interventions.

Differences in outcomes of mandatory motorcycle helmet legislation by country income level: A systematic review and meta-analysis.

BACKGROUND: The recent Lancet Commission on Legal Determinants of Global Health argues that governance can provide the framework for achieving sustainable development goals. Even though over 90% of fatal road traffic injuries occur in low- and middle-income countries (LMICs) primarily affecting motorcyclists, the utility of helmet laws outside of high-income settings has not been well characterized. We sought to evaluate the differences in outcomes of mandatory motorcycle helmet legislation and determine whether these varied across country income levels. METHODS AND FINDINGS: A systematic review and meta-analysis were completed using the PRISMA checklist. A search for relevant articles was conducted using the PubMed, Embase, and Web of Science databases from January 1, 1990 to August 8, 2021. Studies were included if they evaluated helmet usage, mortality from motorcycle crash, or traumatic brain injury (TBI) incidence, with and without enactment of a mandatory helmet law as the intervention. The Newcastle-Ottawa Scale (NOS) was used to rate study quality and funnel plots, and Begg's and Egger's tests were used to assess for small study bias. Pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were stratified by high-income countries (HICs) versus LMICs using the random-effects model. Twenty-five articles were included in the final analysis encompassing a total study population of 31,949,418 people. There were 17 retrospective cohort studies, 2 prospective cohort studies, 1 case-control study, and 5 pre-post design studies. There were 16 studies from HICs and 9 from LMICs. The median NOS score was 6 with a range of 4 to 9. All studies demonstrated higher odds of helmet usage after implementation of helmet law; however, the results were statistically significantly greater in HICs (OR: 53.5; 95% CI: 28.4; 100.7) than in LMICs (OR: 4.82; 95% CI: 3.58; 6.49), p-value comparing both strata < 0.0001. There were significantly lower odds of motorcycle fatalities after enactment of helmet legislation (OR: 0.71; 95% CI: 0.61; 0.83) with no significant difference by income classification, p-value: 0.27. Odds of TBI were statistically significantly lower in HICs (OR: 0.61, 95% CI 0.54 to 0.69) than in LMICs (0.79, 95% CI 0.72 to 0.86) after enactment of law (p-value: 0.0001). Limitations of this study include variability in the methodologies and data sources in the studies included in the meta-analysis as well as the lack of available literature from the lowest income countries or from the African WHO region, in which helmet laws are least commonly present. CONCLUSIONS: In this study, we observed that mandatory helmet laws had substantial public health benefits in all income contexts, but some outcomes were diminished in LMIC settings where additional measures such as public education and law enforcement might play critical roles.

The topology of ventricle surfaces and its application in the analysis of hydrocephalic ventricles: a proof-of-concept study.

PURPOSE: The cerebral ventricles deform in a non-uniform fashion in response to increased CSF volume and/or pressure in hydrocephalic syndromes. Current research is focused on volumetric analyses, while topological analysis of ventricular surfaces remains understudied. We developed a method of quantitatively modeling the curvature of ventricular surfaces to analyze changes in ventricular surfaces in normal pressure hydrocephalus (NPH) and Alzheimer's disease (AD), using the left frontal horn as an example. METHODS: Twenty-one patients with NPH were recruited from our institution, and 21 healthy controls (HC) and patients with Alzheimer's disease (AD) were identified from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. On T1-weighted fine-cut magnetic resonance sequences, 3D Slicer was used to segment the left frontal horn. Next, the mean curvatures at a set of points on the ventricular surface were determined. The frontal horns were scaled and centered into normalized volumes, allowing for pooling across the study subjects. The frontal horn was divided into superolateral, superomedial, inferolateral, and inferomedial surfaces, and locoregional mean curvatures were analyzed. Statistical comparisons were made between NPH, AD, and HC groups. RESULTS: Significant differences in the mean curvature of lateral surfaces of the ventricles distinguished patterns of distortion between all three cohorts. Significant flattening of the superomedial surface discriminated NPH from HC and AD. However, significant rounding of the inferomedial surface compared to controls was a distinguishing feature of NPH alone. CONCLUSION: NPH ventricles deform non-uniformly. The pattern of surface distortion may be used as an additional tool to differentiate between these hydrocephalic conditions.

Intraoperative Magnetic Resonance Imaging for Low-Grade and High-Grade Gliomas: What Is the Evidence? A Meta-Analysis.

BACKGROUND: The benefit of intraoperative magnetic resonance imaging (iMRI) in gliomas remains unclear. We performed a meta-analysis of outcomes with iMRI-guided surgery in high-grade gliomas (HGGs) and low-grade gliomas (LGGs). METHODS: Databases were searched until November 29, 2018 for randomized controlled trials (RCTs) and observational studies (OBS) comparing iMRI use with conventional neurosurgery. Pooled risk ratios (RRs) or hazard ratios were evaluated with the random-effects model. Outcomes included extent of resection (EOR), gross total resection (GTR), progression-free survival (PFS), overall survival (OS), and length of surgery (LOS), stratified by study design and glioma grade. RESULTS: Fifteen articles (3 RCTs and 12 OBS) were included. In RCTs, GTR was higher in iMRI compared with conventional neurosurgery (RR, 1.42; 95% confidence interval [CI], 1.17-1.73; I2, 7%) overall, for LGGs (1.91; 95% CI, 1.19-3.06), but not HGGs (1.24; 95% CI, 0.89-1.73), with no difference in EOR, PFS, OS, and LOS. For OBS, GTR was higher (RR, 1.65; 95% CI, 1.43-1.90; I2, 4%) overall, and for LGGs (1.63; 95% CI, 1.17-2.28; I2, 0%) and HGGs (1.62; 95% CI, 1.36-1.92; I2, 19%). EOR was greater with iMRI (6%; 95% CI, 4%-8%; I2, 44%) overall, in LGGs (5%; 95% CI, 2%-8%; I2, 37%) and HGGs (7%; 95% CI, 4%-10%; I2, 13%). There was no difference in PFS, OS, and LOS with iMRI. CONCLUSIONS: IMRI use improved GTR in gliomas, including LGGs. However, no PFS and OS benefit was shown in the meta-analysis.

Motor deficits at presentation and predictors of overall survival in central nervous system lymphomas.

PURPOSE: Central nervous system lymphomas (CNSL) can present with motor and non-motor symptoms. In many central nervous system tumors, motor deficits are associated with significant morbidity and functional impairment, and correlate with worse prognosis. CNSLs however, often exhibit remarkable response to chemotherapy and radiotherapy with corresponding symptom improvement. We investigate the survival outcomes and trajectories of motor and functional recovery in a cohort of patients presenting with and without initial motor deficits. METHODS: Patients who underwent biopsy and with a histologically confirmed CNSL between 2008 and 2019 were retrospectively identified. Baseline demographic variables, comorbidities, presenting symptoms, histological type, neuroimaging features (location and number of lesions), and treatment administered (pre- and post-operative steroid use and chemotherapy regime) were recorded. Dates of death were obtained from the National Registry of Births and Deaths. Motor power and performance status at admission, 1 month and 6 months were determined. RESULTS: We identified 119 patients, of whom 34% presented with focal motor deficits. The median overall survival (OS) was 26.6 months. Those with focal motor deficits had longer OS (median 42.4 months) than those without (median 23.3 months; p = 0.047). In multivariate Cox analysis, age (HR 1.04 per year; p = 0.003), CCI (HR 1.31 per point; p < 0.001), leptomeningeal/ependymal involvement (HR 2.53; p = 0.016), thalamus involvement (HR 0.34; p = 0.019), neutrophil:lymphocyte ratio (HR 1.06 per point; p = 0.034), positive HIV status (HR 5.31; p = 0.003), preoperative steroids use (HR 0.49; p = 0.018), postoperative high-dose steroids (HR 0.26; p < 0.001) and postoperative low-dose steroids (HR 0.28; p = 0.010) were significant predictors of OS. By one month, 43% of surviving patients had full power, increasing to 61% by six months. CONCLUSION: A significant proportion of patients with initial motor deficits recovered in motor strength by six months. In our population, those presenting with motor deficits had paradoxically better overall survival.

Surgical management of vertebral metastatic gastrointestinal stromal tumor: Case illustration, literature review, and pooled analysis.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) very rarely metastasize to the vertebrae. Tyrosine kinase inhibitors (TKIs) confer favorable long-term survival and durable disease control for metastatic disease. Here, we reviewed a case and the literature to determine the various management options, and neurological outcomes for these patients. CASE DESCRIPTION: A 63-year-old Chinese female with metastatic jejunal GIST previously treated with various TKIs presented with the left lower limb weakness and a sensory level at T10. MRI revealed a T9 vertebral body tumor with cord compression. The tumor was excised and surgical fixation was performed. She received 30Gy of fractionated adjuvant radiotherapy. She achieved near-complete neurological recovery but died 2 months later from systemic disease progression. CONCLUSION: Based on this case and a review of the literature, surgical intervention and treatment with TKIs with adjuvant RT can lead to comparable survival and neurological outcomes.

Gender Differences in Preoperative Opioid Use in Spine Surgery Patients: A Systematic Review and Meta-analysis.

OBJECTIVE: Opioids are frequently used in spine surgeries despite their adverse effects, including physical dependence and addiction. Gender difference is an important consideration for personalized treatment. There is no review assessing the prevalence of opioid use between men and women before spine surgeries. DESIGN: We compared the prevalence of preoperative opioid use between men and women. SETTING: Spine surgery. SUBJECTS: Comparison between men and women. METHODS: PubMed, Embase, and Cochrane were searched from inception to November 9, 2018. Clinical characteristics and prevalence of preoperative opioid use were collected. Where feasible, data were pooled from nonoverlapping studies using random-effects models. RESULTS: Four studies with nonoverlapping populations were included in the meta-analysis (one prospective, three retrospective cohorts). The prevalence of preoperative opioid use was 0.64 (95% CI = 0.40-0.83). Comparing men with women, no statistically significant difference in preoperative opioid use was detected (relative risk [RR] = 0.99, 95% CI = 0.96-1.02). Surgery location (cervical, lumbar) and study duration (more than five years or five years or less) did not modify this association. All involved open spine surgery. Only one secondary analysis provided data on both pre- and postoperative opioid use stratified by gender, which showed a borderline significantly higher prevalence of postoperative use in women than men. CONCLUSIONS: The prevalence of opioid use before spine surgery was similar between men and women, irrespective of surgery location or study duration. More studies characterizing the pattern of opioid use between genders are still needed.

Long-Term Opioid Prescriptions After Spine Surgery: A Meta-Analysis of Prevalence and Risk Factors.

BACKGROUND: Opioids are frequently prescribed for back pain, but the prevalence of and risk factors for long-term opioid use after spine surgery were not clearly reported. We conducted a systematic review and meta-analysis to summarize the evidence for long-term opioid use (>90 days) among adults who underwent spine surgery. METHODS: PubMed, EMBASE, and Cochrane indexing databases were searched until November 9, 2018 for studies reporting the prevalence of and risk factors for long-term opioid use after spine surgery. Separate meta-analyses were conducted for commercial claims databases or registries (claims/registries) and nonclaims observational studies using the random-effects model to estimate the pooled odds ratio (OR). Prevalence meta-analysis was performed in a clinically homogeneous subset of these patients who underwent lumbar spine surgery. RESULTS: Eight claims and 5 nonclaims were meta-analyzed to avoid double-counting participants. The meta-analysis showed that preoperative opioid users (OR, 5.59; 95% confidence interval [CI], 3.37-9.27 vs. OR 4.21; 95% CI, 2.72-6.51) and participants with preexisting depression and/or anxiety (OR, 1.86, 95% CI, 1.43-2.42 and OR, 1.20; 95% CI, 0.83-1.74, respectively) had a statistically significantly higher odds of long-term postoperative opioids, compared with their peers. Males showed lower odds of long-term postoperative opioid use in the claims group (OR, 0.85; 95% CI, 0.79-0.92), but not in the nonclaims group (OR, 0.99; 95% CI, 0.71-1.39). The pooled prevalence of post-lumbar spine surgery long-term opioid use was 63% (95% CI, 50%-74%) in claims and 47% (95% CI, 38%-56%) in nonclaims. CONCLUSIONS: Patients undergoing spine surgery represent a high-risk surgical population requiring special attention and targeted interventions, with the strongest evidence for those treated with opioids before surgery and those with psychiatric comorbidities.

Aqueductal Compression by Dilated Virchow-Robin Spaces in the Mesencephalic-Pontine Region Presenting with Symptoms Mimicking Normal Pressure Hydrocephalus: A Case Report and Review of Literature.

BACKGROUND: Dilatation of Virchow-Robin spaces (dVRS) have been described in the development of hydrocephalic syndromes. We report an unusual case of a type III dVRS presenting as a mimic of normal pressure hydrocephalus (NPH), due to distortion at the level of the cerebral aqueduct. CASE DESCRIPTION: A 59-year-old woman presented with mild traumatic brain injury and possible NPH, due to a history of progressive gait disturbance, recurrent falls, and cognitive decline over a year, in the context of ventriculomegaly. Detailed structural imaging of the brain revealed multiple dilated cystic lesions consistent with dVRS causing distortion at the level of the cerebral aqueduct. Cerebrospinal fluid examination was negative for infection. The patient was treated with endoscopic third ventriculostomy; at 12 months postoperatively, she demonstrated a sustained improvement in gait and stabilization of cognitive decline. CONCLUSIONS: This is an illustrative case of a subacute obstructive hydrocephalus due to a collection of periaqueductal dVRS, leading to an insidious clinical presentation mimicking NPH. We reviewed the literature for key clinical presentations and describe neuroanatomical considerations as well as primary treatment strategies. Various hydrocephalic syndromes may present with classic symptoms from Hakim's triad; such symptoms are not specific to idiopathic NPH. Both endoscopic third ventriculostomy and shunting may be efficacious. In our case, dVRS may serve as both a cause of and compensatory mechanism in a subacute obstructive hydrocephalus of unknown etiology. Our case highlights the need to understand the neuroanatomy of aberrant cerebrospinal fluid spaces in hydrocephalic syndromes. Further studies of dVRS would provide valuable insights into the pathogenesis of hydrocephalus.