Faculty Bibliography

Microgliosis is a prominent pathological feature in many neurological diseases including multiple sclerosis (MS), a progressive auto-immune demyelinating disorder. The precise role of microglia, parenchymal central nervous system (CNS) macrophages, during demyelination, and the relative contributions of peripheral macrophages are incompletely understood. Classical markers used to identify microglia do not reliably discriminate between microglia and peripheral macrophages, confounding analyses. Here, we use a genetic fate mapping strategy to identify microglia as predominant responders and key effectors of demyelination in the cuprizone (CUP) model. Colony-stimulating factor 1 (CSF1), also known as macrophage colony-stimulating factor (M-CSF) - a secreted cytokine that regulates microglia development and survival-is upregulated in demyelinated white matter lesions. Depletion of microglia with the CSF1R inhibitor PLX3397 greatly abrogates the demyelination, loss of oligodendrocytes, and reactive astrocytosis that results from CUP treatment. Electron microscopy (EM) and serial block face imaging show myelin sheaths remain intact in CUP treated mice depleted of microglia. However, these CUP-damaged myelin sheaths are lost and robustly phagocytosed upon-repopulation of microglia. Direct injection of CSF1 into CNS white matter induces focal microgliosis and demyelination indicating active CSF1 signaling can promote demyelination. Finally, mice defective in adopting a toxic astrocyte phenotype that is driven by microglia nevertheless demyelinate normally upon CUP treatment implicating microglia rather than astrocytes as the primary drivers of CUP-mediated demyelination. Together, these studies indicate activated microglia are required for and can drive demyelination directly and implicate CSF1 signaling in these events.

Recently the coronavirus disease (COVID-19) outbreak has been declared a pandemic. Despite its aggressive extension and significant morbidity and mortality, risk factors are poorly characterized outside China. We designed a registry, HOPE COVID-19 (NCT04334291), assessing data of 1021 patients discharged (dead or alive) after COVID-19, from 23 hospitals in 4 countries, between 8 February and 1 April. The primary end-point was all-cause mortality aiming to produce a mortality risk score calculator. The median age was 68 years (IQR 52-79), and 59.5% were male. Most frequent comorbidities were hypertension (46.8%) and dyslipidemia (35.8%). A relevant heart or lung disease were depicted in 20%. And renal, neurological, or oncological disease, respectively, were detected in nearly 10%. Most common symptoms were fever, cough, and dyspnea at admission. 311 patients died and 710 were discharged alive. In the death-multivariate analysis, raised as most relevant: age, hypertension, obesity, renal insufficiency, any immunosuppressive disease, 02 saturation < 92% and an elevated C reactive protein (AUC = 0.87; Hosmer-Lemeshow test, p > 0.999; bootstrap-optimist: 0.0018). We provide a simple clinical score to estimate probability of death, dividing patients in four grades (I-IV) of increasing probability. Hydroxychloroquine (79.2%) and antivirals (67.6%) were the specific drugs most commonly used. After a propensity score adjustment, the results suggested a slight improvement in mortality rates (adjusted-OR_{hydroxychloroquine} 0.88; 95% CI 0.81-0.91, p = 0.005; adjusted-OR_antiviral 0.94; 95% CI 0.87-1.01; p = 0.115). COVID-19 produces important mortality, mostly in patients with comorbidities with respiratory symptoms. Hydroxychloroquine could be associated with survival benefit, but this data need to be confirmed with further trials. Trial Registration: NCT04334291/EUPAS34399.

Thorough assessment of performance validity has become an established standard of practice in neuropsychological assessment. While there has been a large focus on the development and cross-validation of embedded performance validity tests (PVTs) in recent years, new freestanding PVTs have also been developed, including the Word Choice Test (WCT) as part of the Advanced Clinical Solutions Effort System. And, while the WCT's general utility for identifying invalid performance has been demonstrated in the ensuing decade since its initial publication, optimal cut-scores and associated psychometric properties have varied widely across studies. This study sought to synthesize the existing diagnostic accuracy literature regarding the WCT via a systematic review and to conduct a meta-analysis to determine the performance validity cut-score that best maximizes sensitivity while maintaining acceptable specificity. A systematic search of the literature resulted in 14 studies for synthesis, with eight of those available for meta-analysis. Meta-analytic results revealed an optimal cut-score of ≤ 42 with 54% sensitivity and 93% specificity for identifying invalid neuropsychological test performance. Collectively, the WCT demonstrated adequate diagnostic accuracy as a PVT across a variety of populations. Recommendations for future studies are also provided.

BACKGROUND AND PURPOSE/OBJECTIVE:Indirect consequences of the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) pandemic include those related to failure of patients to seek or receive timely medical attention for seemingly unrelated disease. We report our experience with stroke code imaging during the early pandemic months of 2020. MATERIALS AND METHODS/METHODS:Retrospective review of stroke codes during the 2020 pandemic and both 2020 and matched 2019 prepandemic months was performed. Patient variables were age, sex, hospital location, and severity of symptoms based on the NIHSS. We reviewed the results of CT of the head, CTA, CTP, and MR imaging examinations and classified a case as imaging-positive if any of the imaging studies yielded a result that related to the clinical indication for the study. Both year-to-year and sequential comparisons were performed between pandemic and prepandemic months. RESULTS:= .03). CONCLUSIONS:During our pandemic period, there was a significantly decreased number of stroke codes but simultaneous increases in positivity rates, symptom severity, and inpatient codes. We postulate that this finding reflects the documented reluctance of patients to seek medical care during the pandemic, with the shift toward a greater proportion of inpatient stroke codes potentially reflecting the neurologic complications of the virus itself.

De novo, heterozygous, loss of function variants were identified in Pou domain, class 4, transcription factor 1 (POU4F1) via whole exome sequencing in four independent probands presenting with ataxia, intention tremor, and hypotonia. POU4F1 is expressed in the developing nervous system, and mice homozygous for null alleles of Pou4f1 exhibit uncoordinated movements with newborns being unable to successfully right themselves to feed. Head magnetic resonance imaging of the four probands was reviewed and multiple abnormalities were noted including significant cerebellar vermian atrophy and hypertrophic olivary degeneration in one proband. Transcriptional activation of the POU4F1 p.Gln306Arg protein was noted to be decreased when compared to wild-type. These findings suggest that heterozygous, loss-of-function variants in POU4F1 are causative of a novel ataxia syndrome. This article is protected by copyright. All rights reserved.

Cell-free DNA (cfDNA) from cerebrospinal fluid (CSF) offers unique opportunities for genomic profiling of tumors involving the central nervous system but remains uncommonly used in clinical practice. We describe our clinical experience using cfDNA from CSF for routine molecular testing using Memorial Sloan Kettering Integrated Mutation Profiling of Actionable Cancer Targets (targeting 468 cancer-related genes). In all, 148 cfDNA samples were assessed, comparing results of cfDNA versus genomic DNA (gDNA; gDNA from cell pellets) derived from the same CSF sample and the primary tumor. Of these, 71.6% (106/148) were successfully sequenced. Somatic alterations (mutations and fusions) were observed in 70.8% (75/106) of the samples; 97.3% (73/75) comprised variants confirming central nervous system involvement by a previously diagnosed tumor, 14.7% (11/75) had additional variants consistent with a therapy-related resistance mechanism, and 2.7% (2/75) had variants that independently diagnosed a new primary. Among samples with paired cfDNA and gDNA sequencing results, cfDNA was more frequently positive for at least one mutation [43.6% (55/126) versus 19.8% (25/126)] and harbored 1.6× more mutations (6.94 versus 4.65; P = 0.005), with higher mean variant allele fractions (41.1% versus 13.0%; P < 0.0001). Among mutation-positive cfDNAs, the corresponding gDNA was frequently negative (44.6%; 25/55) or failed sequencing (17.8%; 9/55). Routine molecular profiling of cfDNA is superior to gDNA from CSF, facilitating the capture of mutations at high variant allele frequency, even in the context of a negative cytology.

BACKGROUND:There are no established ranges for metabolic values prior to death by neurologic criteria/brain death determination (DNC/BD) and the thresholds required by institutional protocols and accepted by neurointensivists is unknown. METHODS:We designed a survey that addressed 1) the metabolic tests required in institutional guidelines prior to brain death determination, 2) the metabolic tests the respondent reviewed prior to brain death determination, and 3) the metabolic test thresholds for laboratory tests that were perceived to preclude or permit clinical DNC/BD determination. The survey was distributed online to physicians in the Neurocritical Care Society from September to December 2019. Respondents were dichotomized based on the number of brain death evaluations they had performed (≤20 vs. > 20) and responses were compared between groups. RESULTS:The survey was completed by 84 physicians. Nearly half (47.6%) of respondents did not believe their institutions required metabolic testing. The metabolic testing for which institutions most commonly provided a defined threshold were arterial pH (34.5%, 29/84), sodium (28.6%, 24/84), and glucose (15.5%, 13/84). Nearly all (97.6%) respondents routinely reviewed metabolic tests prior to brain death evaluation, the most common of which were: sodium (91.7%, 77/84), arterial pH (83.3%, 70/84), and glucose (79.8%, 67/84). Respondents who had performed > 20 evaluations were less likely to check thyroxine and total bilirubin (3.6%, 2/55 vs. 20.7%, 6/29 (p = 0.011) and 12.7%, 7/55 vs. 31%, 9/29 (p = 0.042), respectively), and had a more liberal upper limit of potassium (6.3 mEq/L vs 6.0 mEq/L, p = 0.045). CONCLUSION/CONCLUSIONS:Prior to brain death evaluation, neurocritical care providers commonly review similar metabolic tests and have similar thresholds regarding values that would preclude clinical brain death determination. This finding is independent of experience with brain death determination.

OBJECTIVE:Recent studies on a rodent model of Parkinson's disease (PD) have raised the possibility of increased blood-brain barrier (BBB) permeability, demonstrated by histology, autoradiography, and positron emission tomography (PET). However, in human PD patients, in vivo evidence of increased BBB permeability is lacking. We examined the hypothesis that levodopa treatment increases BBB permeability in human subjects with PD, particularly in those with levodopa-induced dyskinesia (LID). METHODS:Rb concentration in brain tissue and blood, was estimated with good stability as a local measure of the volume of distribution. RESULTS:measured off- and on-levodopa infusion were also not significant for dyskinetic and non-dyskinetic subjects. CONCLUSION/CONCLUSIONS:Rb PET did not reveal significant changes in BBB permeability in PD patients.

INTRODUCTION/BACKGROUND:According to evidence-based clinical practice guidelines, patients presenting with disabling stroke symptoms should be treated with intravenous tissue plasminogen activator (IV tPA) within 4.5 hours of time last known well. However, 25% of strokes are detected upon awakening ('wake-up strokes'; WUS) which renders patients ineligible for IV tPA administered via time-based treatment algorithms because it is impossible to establish a reliable time of symptom onset. We performed a systematic review and meta-analysis of the efficacy and safety of IV tPA compared with normal saline, placebo, or no treatment in patients with WUS using imaging-based treatment algorithms. METHODS:We searched Medline, Web of Science, and Scopus between January 1, 2006 and April 30, 2020. We included controlled trials (randomized or nonrandomized), observational cohort studies (prospective or retrospective), and single-arm studies in which adults with WUS were administered IV tPA after MR- or CT-based imaging. Our primary outcome was recovery at 90 days (defined as a modified Rankin Scale [mRS] score of 0-2) and our secondary outcomes were symptomatic intracranial hemorrhage (sICH) within 36 hours, mortality, and other adverse effects. RESULTS:We included 16 studies that enrolled a total of 14,017 patients. Most studies were conducted in Europe (37.5%) or North America (37.5%), and 1,757 patients (12.5%) received IV tPA. All studies used MRI-based (5 studies) or CT-based (10 studies) imaging selection and one study used a combination of modalities. Sixty-one percent of patients receiving IV tPA achieved mRS of 0-2 at 90 days (95% CI 51% to 70%; 12 studies), with a relative risk (RR) of 1.21 compared with patients not receiving IV tPA (95% CI 1.01 to 1.46; 4 studies). Three percent of patients receiving IV tPA experienced sICH within 36 hours (95% CI 2.5% to 4.1%; 16 studies), an RR of 4.00 compared with patients not receiving IV tPA (95% CI 2.85 to 5.61; 7 studies). CONCLUSIONS:This systematic review and meta-analysis suggests that IV tPA is associated with a better functional outcome at 90 days despite the increased but acceptable risk of sICH. Based on these results, IV tPA should be offered as a treatment for WUS patients with favorable neuroimaging findings.