Remote Ischemic Conditioning With Medical Management or Reperfusion Therapy for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Remote ischemic conditioning (RIC) is a low-cost, accessible, and noninvasive neuroprotective treatment strategy, but its efficacy and safety in acute ischemic stroke are controversial. With the publication of several randomized controlled trials (RCTs) and the recent results of the RESIST trial, it may be possible to identify the patient population that may (or may not) benefit from RIC. This systematic review and meta-analysis aims to evaluate the effectiveness and safety of RIC in patients with ischemic stroke receiving different treatments by pooling data of all randomized controlled studies to date.

METHODS

We searched the PubMed, Embase, Cochrane, Elsevier, and Web of Science databases to obtain articles in all languages from inception until May 25, 2023. The primary outcome was the modified Rankin Scale (mRS) score at the specified endpoint time in the trial. The secondary outcomes were change in NIH Stroke Scale (NIHSS) and recurrence of stroke events. The safety outcomes were cardiovascular events, cerebral hemorrhage, and mortality. The quality of articles was evaluated through the Cochrane risk assessment tool. This study was registered in PROSPERO (CRD42023430073).

RESULTS

There were 7,657 patients from 22 RCTs included. Compared with the control group, patients who received RIC did not have improved mRS functional outcomes, regardless of whether they received medical management, reperfusion therapy with intravenous thrombolysis (IVT), or mechanical thrombectomy (MT). In the medical management group, patients who received RIC had decreased incidence of stroke recurrence (risk ratio 0.63, 95% CI 0.43-0.92, p = 0.02) and lower follow-up NIHSS score by 1.72 points compared with the control group (p < 0.00001). There was no increased risk of adverse events including death or cerebral hemorrhage in the IVT or medical management group.

DISCUSSION

In patients with ischemic stroke who are not eligible for reperfusion therapy, RIC did not affect mRS functional outcomes but significantly improved the NIHSS score at the follow-up endpoint and reduced stroke recurrence, without increasing the risk of cerebral hemorrhage or death. In patients who received IVT or MT, the benefit of RIC was not observed.

Exercise Improves Cerebral Blood Flow and Functional Outcomes in an Experimental Mouse Model of Vascular Cognitive Impairment and Dementia (VCID)

Vascular cognitive impairment and dementia (VCID) are a growing threat to public health without any known treatment. The bilateral common carotid artery stenosis (BCAS) mouse model is valid for VCID. Previously, we have reported that remote ischemic postconditioning (RIPostC) during chronic cerebral hypoperfusion (CCH) induced by BCAS increases cerebral blood flow (CBF), improves cognitive function, and reduces white matter damage. We hypothesized that physical exercise (EXR) would augment CBF during CCH and prevent cognitive impairment in the BCAS model. BCAS was performed in C57/B6 mice of both sexes to establish CCH. One week after the BCAS surgery, mice were randomized to treadmill exercise once daily or no EXR for four weeks. CBF was monitored with an LSCI pre-, post, and 4 weeks post-BCAS. Cognitive testing was performed for post-BCAS after exercise training, and brain tissue was harvested for histopathology and biochemical test. BCAS led to chronic hypoperfusion resulting in impaired cognitive function and other functional outcomes. Histological examination revealed that BCAS caused changes in neuronal morphology and cell death in the cortex and hippocampus. Immunoblotting showed that BCAS was associated with a significant downregulate of AMPK and pAMPK and NOS3 and pNOS3. BCAS also decreased red blood cell (RBC) deformability. EXR therapy increased and sustained improved CBF and cognitive function, muscular strength, reduced cell death, and loss of white matter. EXR is effective in the BCAS model, improving CBF and cognitive function, reducing white matter damage, improving RBC deformability, and increasing RBC NOS3 and AMPK. The mechanisms by which EXR improves CBF and attenuates tissue damage need further investigation.

Angiotensin II Type 2 Receptor Agonism Alleviates Progressive Post-stroke Cognitive Impairment in Aged Spontaneously Hypertensive Rats

Hypertension and aging are leading risk factors for stroke and vascular contributions to cognitive impairment and dementia (VCID). Most animal models fail to capture the complex interplay between these pathophysiological processes. In the current study, we examined the development of cognitive impairment in 18-month-old spontaneously hypertensive rats (SHR) before and following ischemic stroke. Sixty SHRs were housed for 18 months with cognitive assessments every 6 months and post-surgery. MRI scans were performed at baseline and throughout the study. On day 3 post-stroke, rats were randomized to receive either angiotensin II type 2 receptor (AT2R) agonist Compound 21 (C21) or plain water for 8 weeks. SHRs demonstrated a progressive cognitive decline and significant MRI abnormalities before stroke. Perioperative mortality within 72 h of stroke was low. Stroke resulted in significant acute brain swelling, chronic brain atrophy, and sustained sensorimotor and behavioral deficits. There was no evidence of anhedonia at week 8. C21 enhanced sensorimotor recovery and ischemic lesion resolution at week 8. SHRs represent a clinically relevant animal model to study aging and stroke-associated VCID. This study underscores the importance of translational disease modeling and provides evidence that modulation of the AT2R signaling via C21 may be a useful therapeutic option to improve sensorimotor and cognitive outcomes even in aged animals.

Effect of Remote Ischemic Conditioning in Ischemic Stroke Subtypes: A Post Hoc Subgroup Analysis From the RESIST Trial

BACKGROUND

Remote ischemic conditioning (RIC) is a simple and noninvasive procedure that has proved to be safe and feasible in numerous smaller clinical trials. Mixed results have been found in recent large randomized controlled trials. This is a post hoc subgroup analysis of the RESIST trial (Remote Ischemic Conditioning in Patients With Acute Stroke), investigating the effect of RIC in different acute ischemic stroke etiologies, and whether an effect was modified by treatment adherence.

METHODS

Eligible patients were adults (aged ≥18 years), independent in activities of daily living, who had prehospital stroke symptoms with a duration of less than 4 hours. They were randomized to RIC or sham. The RIC treatment protocol consisted of 5 cycles with 5 minutes of cuff inflation alternating with 5 minutes with a deflated cuff. Acceptable treatment adherence was defined as when at least 80% of planned RIC cycles were received. The analysis was performed using the entire range (shift analysis) of the modified Rankin Scale (ordinal logistic regression).

RESULTS

A total of 698 had acute ischemic stroke, 253 (36%) were women, and the median (interquartile range) age was 73 (63-80) years. Median (interquartile range) overall adherence to RIC/sham was 91% (68%-100%). In patients with a stroke due to cerebral small vessel disease, who were adherent to treatment, RIC was associated with improved functional outcome, and the odds ratio for a shift to a lower score on the modified Rankin Scale was 2.54 (1.03-6.25); P=0.042. The association remained significant after adjusting for potential confounders. No significant associations were found with other stroke etiologies, and the overall test for interaction was not statistically significant (χ2, 4.33, P=0.23).

CONCLUSIONS

In patients with acute ischemic stroke due to cerebral small vessel disease, who maintained good treatment adherence, RIC was associated with improved functional outcomes at 90 days. These results should only serve as a hypothesis-generating for future trials.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03481777.

Allogeneic Stem Cell Therapy for Acute Ischemic Stroke: The Phase 2/3 TREASURE Randomized Clinical Trial

Importance

Cell therapy is a promising treatment approach for stroke and other diseases. However, it is unknown whether MultiStem (HLCM051), a bone marrow-derived, allogeneic, multipotent adult progenitor cell product, has the potential to treat ischemic stroke.

Objective

To assess the efficacy and safety of MultiStem when administered within 18 to 36 hours of ischemic stroke onset.

Design, Setting, and Participants

The Treatment Evaluation of Acute Stroke Using Regenerative Cells (TREASURE) multicenter, double-blind, parallel-group, placebo-controlled phase 2/3 randomized clinical trial was conducted at 44 academic and clinical centers in Japan between November 15, 2017, and March 29, 2022. Inclusion criteria were age 20 years or older, presence of acute ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score of 8-20 at baseline), confirmed acute infarction involving the cerebral cortex and measuring more than 2 cm on the major axis (determined with diffusion-weighted magnetic resonance imaging), and a modified Rankin Scale (mRS) score of 0 or 1 before stroke onset. Data analysis was performed between May 9 and August 15, 2022.

Exposure

Patients were randomly assigned to either intravenous MultiStem in 1 single unit of 1.2 billion cells or intravenous placebo within 18 to 36 hours of ischemic stroke onset.

Main Outcomes and Measures

The primary end points were safety and excellent outcome at day 90, measured as a composite of a modified Rankin Scale (mRS) score of 1 or less, a NIHSS score of 1 or less, and a Barthel index score of 95 or greater. The secondary end points were excellent outcome at day 365, mRS score distribution at days 90 and 365, and mRS score of 0 to 1 and 0 to 2 at day 90. Statistical analysis of efficacy was performed using the Cochran-Mantel-Haenszel test.

Results

This study included 206 patients (104 received MultiStem and 102 received placebo). Their mean age was 76.5 (range, 35-95) years, and more than half of patients were men (112 [54.4%]). There were no between-group differences in primary and secondary end points. The proportion of excellent outcomes at day 90 did not differ significantly between the MultiStem and placebo groups (12 [11.5%] vs 10 [9.8%], P = .90; adjusted risk difference, 0.5% [95% CI, -7.3% to 8.3%]). The frequency of adverse events was similar between treatment groups.

Conclusions and Relevance

In this randomized clinical trial, intravenous administration of allogeneic cell therapy within 18 to 36 hours of ischemic stroke onset was safe but did not improve short-term outcomes. Further research is needed to determine whether MultiStem therapy for ischemic stroke has a beneficial effect in patients who meet specific criteria, as indicated by the exploratory analyses in this study.

Trial Registration

ClinicalTrials.gov Identifier: NCT02961504.

Inhalant Cannabidiol Inhibits Glioblastoma Progression Through Regulation of Tumor Microenvironment

Introduction: Glioblastoma (GBM) is the most common invasive brain tumor composed of diverse cell types with poor prognosis. The highly complex tumor microenvironment (TME) and its interaction with tumor cells play important roles in the development, progression, and durability of GBM. Angiogenic and immune factors are two major components of TME of GBM; their interplay is a major determinant of tumor vascularization, immune profile, as well as immune unresponsiveness of GBM. Given the ineffectiveness of current standard therapies (surgery, radiotherapy, and concomitant chemotherapy) in managing patients with GBM, it is necessary to develop new ways of treating these lethal brain tumors. Targeting TME, altering tumor ecosystem may be a viable therapeutic strategy with beneficial effects for patients in their fight against GBM. Materials and Methods: Given the potential therapeutic effects of cannabidiol (CBD) in a wide spectrum of diseases, including malignancies, we tested, for the first time, whether inhalant CBD can inhibit GBM tumor growth using a well-established orthotopic murine model. Optical imaging, histology, immunohistochemistry, and flow cytometry were employed to describe the outcomes such as tumor progression, cancer cell signaling pathways, and the TME. Results: Our findings showed that inhalation of CBD was able to not only limit the tumor growth but also to alter the dynamics of TME by repressing P-selectin, apelin, and interleukin (IL)-8, as well as blocking a key immune checkpoint-indoleamine 2,3-dioxygenase (IDO). In addition, CBD enhanced the cluster of differentiation (CD) 103 expression, indicating improved antigen presentation, promoted CD8 immune responses, and reduced innate Lymphoid Cells within the tumor. Conclusion: Overall, our novel findings support the possible therapeutic role of inhaled CBD as an effective, relatively safe, and easy to administer treatment adjunct for GBM with significant impacts on the cellular and molecular signaling of TME, warranting further research.

A multi-laboratory preclinical trial in rodents to assess treatment candidates for acute ischemic stroke

Human diseases may be modeled in animals to allow preclinical assessment of putative new clinical interventions. Recent, highly publicized failures of large clinical trials called into question the rigor, design, and value of preclinical assessment. We established the Stroke Preclinical Assessment Network (SPAN) to design and implement a randomized, controlled, blinded, multi-laboratory trial for the rigorous assessment of candidate stroke treatments combined with intravascular thrombectomy. Efficacy and futility boundaries in a multi-arm multi-stage statistical design aimed to exclude from further study highly effective or futile interventions after each of four sequential stages. Six independent research laboratories performed a standard focal cerebral ischemic insult in five animal models that included equal numbers of males and females: young mice, young rats, aging mice, mice with diet-induced obesity, and spontaneously hypertensive rats. The laboratories adhered to a common protocol and efficiently enrolled 2615 animals with full data completion and comprehensive animal tracking. SPAN successfully implemented treatment masking, randomization, prerandomization inclusion and exclusion criteria, and blinded assessment of outcomes. The SPAN design and infrastructure provide an effective approach that could be used in similar preclinical, multi-laboratory studies in other disease areas and should help improve reproducibility in translational science.

Safety and Tolerability of Direct Ischemic Postconditioning Following Thrombectomy for Acute Ischemic Stroke

BACKGROUND

Experimental studies have demonstrated the neuroprotection of ischemic postconditioning (IPostC) in acute ischemic stroke by attenuating ischemia-reperfusion injury. This study aimed to investigate the safety and tolerability of direct IPostC in both a dog model and patients with acute ischemic stroke treated with thrombectomy.

METHODS

The study involved 2 parts. First, IPostC was induced by repeated balloon inflation and deflation in dogs, where a low-pressure balloon was navigated to the anterior spinal artery, and 4 cycles of 5-minute ischemia followed by 5-minute reperfusion were performed. Vascular injuries were assessed using angiography and vascular tissue specimens. Then, a 3+3 dose-escalation trial was conducted in patients with acute ischemic stroke following successful thrombectomy recanalization. Patients received direct IPostC with ischemia and reperfusion durations in progressive increments of 0, 1, 2, 3, 4, and 5 minutes ×4 cycles. Major adverse responses were defined as vessel perforation, rupture, dissection, reocclusion, severe vasospasm, thrombotic events, and rupture of the balloon.

RESULTS

IPostC was investigated in 4 dogs. No vessel perforation or rupture, dissection, or vasospasm was observed under the angiography. Only 1 vessel experienced mild injury between the intima and the internal elastic membrane detected on a histopathologic slide. Then, 18 patients were recruited. The duration of IPostC was progressively escalated with no major response happened. No patient experienced agitation, discomfort, or other tolerability issues. Five patients (27.8%) experienced any intracranial hemorrhage after thrombectomy, and 1 (5.6%) was symptomatic. At 3-month follow-up, no patient died, and 9 patients (50%) achieved functional independence.

CONCLUSIONS

Direct IPostC inducing by 4 cycles of 5-minute ischemia followed by 5-minute reperfusion is safe, feasible, and tolerable in patients with acute ischemic stroke treated with thrombectomy. Further investigations are needed to determine the safety and preliminary efficacy of direct IPostC.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT05153655.

Remote Ischemic Conditioning: Challenges and Opportunities

Remote ischemic conditioning (RIC) has been investigated as a promising, safe, and well-tolerated nonpharmacological therapy for cardio-cerebrovascular disease over the past 3 decades; variable results have been found when it is used in cerebrovascular versus cardiovascular disease. For patients with cardiovascular disease, milestone studies suggest that the roles of RIC may be limited. Recently, however, 2 large trials investigating RIC in patients with cerebrovascular disease found promising results, which may reignite the field's research prospects after its setbacks in the cardiovascular field. This perspectives article highlights several important clinical trials of RIC in the cardio-cerebrovascular disease and describes the many challenges of RIC in clinical translation. Finally, based on the available evidence, several promising research directions such as chronic RIC, early initiation in target population, improvement of compliance, better understanding of dosing, and identification of specific biomarkers are proposed and should be investigated before RIC can become applied into clinical practice for patient benefit.

Rapid Lineage Assignment of Severe Acute Respiratory Syndrome Coronavirus 2 Cases through Automated Library Preparation, Sequencing, and Bioinformatic Analysis

The coronavirus disease 2019 (COVID-19) pandemic has provided a stage to illustrate that there is considerable value in obtaining rapid, whole-genome-based information about pathogens. This article describes the utility of a commercially available, automated severe acute respiratory syndrome associated coronavirus 2 (SARS-CoV-2) library preparation, genome sequencing, and a bioinformatics analysis pipeline to provide rapid, near-real-time SARS-CoV-2 variant description. This study evaluated the turnaround time, accuracy, and other quality-related parameters obtained from commercially available automated sequencing instrumentation, from analysis of continuous clinical samples obtained from January 1, 2021, to October 6, 2021. This analysis included a base-by-base assessment of sequencing accuracy at every position in the SARS-CoV-2 chromosome using two commercially available methods. Mean turnaround time, from the receipt of a specimen for SARS-CoV-2 testing to the availability of the results, with lineage assignment, was <3 days. Accuracy of sequencing by one method was 100%, although certain sites on the genome were found repeatedly to have been sequenced with varying degrees of read error rate.

Altered endocannabinoid metabolism compromises the brain-CSF barrier and exacerbates chronic deficits after traumatic brain injury in mice

Endocannabinoids [2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA)], endogenously produced arachidonate-based lipids, are anti-inflammatory physiological ligands for two known cannabinoid receptors, CB1 and CB2, yet the molecular and cellular mechanisms underlying their effects after brain injury are poorly defined. In the present study, we hypothesize that traumatic brain injury (TBI)-induced loss of endocannabinoids exaggerates neurovascular injury, compromises brain-cerebrospinal fluid (CSF) barriers (BCB) and causes behavioral dysfunction. Preliminary analysis in human CSF and plasma indicates changes in endocannabinoid levels. This encouraged us to investigate the levels of endocannabinoid-metabolizing enzymes in a mouse model of controlled cortical impact (CCI). Reductions in endocannabinoid (2-AG and AEA) levels in plasma were supported by higher expression of their respective metabolizing enzymes, monoacylglycerol lipase (MAGL), fatty acid amide hydrolase (FAAH), and cyclooxygenase 2 (Cox-2) in the post-TBI mouse brain. Following increased metabolism of endocannabinoids post-TBI, we observed increased expression of CB2, non-cannabinoid receptor Transient receptor potential vanilloid-1 (TRPV1), aquaporin 4 (AQP4), ionized calcium binding adaptor molecule 1 (IBA1), glial fibrillary acidic protein (GFAP), and acute reduction in cerebral blood flow (CBF). The BCB and pericontusional cortex showed altered endocannabinoid expressions and reduction in ventricular volume. Finally, loss of motor functions and induced anxiety behaviors were observed in these TBI mice. Taken together, our findings suggest endocannabinoids and their metabolizing enzymes play an important role in the brain and BCB integrity and highlight the need for more extensive studies on these mechanisms.

Abstract WP226: Circadian Rhythm Influences Immune Response In Ischemic Stroke Mice

Background: Stroke leads to disability and death worldwide. There is evidence that stroke affects the immune system function, and the clock gene controls the immune system. Stroke elevates the inflammatory cascade. Immune response controls the stroke pathology. However, it is unclear if the circadian rhythm influences the immune system in ischemic stroke mice and affects stroke outcomes.

Hypothesis: We hypothesized that immune response might be affected by a circadian rhythm that aggravates stroke pathology in a mouse suture occlusion model

Methods: Seven to eight-month-old C57BL/6J (Wild Type, n=8-10 mice/group) mice were randomly assigned to do stroke at the different time points of the day following zeitgeber time at ZT0, ZT6, ZT12, and Z18. Cerebral Ischemia was induced by occlusion of the middle cerebral artery (MCAO) for 60 min. Whole blood was analyzed using flow cytometry, and we observed macrophages (M1, M2), neutrophils (N1, N2), Anti-inflammatory IL10, and pro-inflammatory TNF-α cytokines at 24h and 48h. Forty-eight hours after stroke, TTC staining was done to estimate brain infarction, and the infarct area was measured using NIH-Image J software.

Results: There was a significant increase ( p <0.005) in TNF-α (9±2.50) and significant low IL-10 (5.12±1.35) ( p <0001) at (ZT6, noon) stroke at 48h during a deep sleep period (ZT6, noon) stroke in comparison to fully awake period stroke. We found a significant increase ( p <001) in M1 (54.12±5.16) macrophage and a significant decrease ( p <001) in M2 (45.87±5.16) macrophage at ZT6 (noon) compare to other zeitgeber time points. We also found a significantly higher M1:M2 ratio (1.17) at ZT6. Additionally, we found that neutrophil N1 (66.88±4.39) level was significantly ( p <0001) elevated while neutrophil N2 (33.88±4.43) was significantly reduced at ZT6 (noon) sleep period in comparison to ZT0, ZT12, and Z18 time points. We also found a considerably higher N1:N2 ratio (1.97) at ZT6.

Conclusion: This study demonstrates that mice brain infarcts are influenced by immune responses that aggravate stroke pathology during their sleep period (noon/ZT6) than during their awake period (midnight/ZT18).

The time dimension to stroke: Circadian effects on stroke outcomes and mechanisms

The circadian system is widely involved in the various pathological outcomes affected by time dimension changes. In the brain, the master circadian clock, also known as the "pacemaker," is present in the hypothalamus's suprachiasmatic nucleus (SCN). The SCN consists of molecular circadian clocks that operate in each neuron and other brain cells. These circadian mechanisms are controlled by the transcription and translation of specific genes such as the clock circadian regulator (Clock) and brain and muscle ARNT-Like 1 (Bmal1). Period (Per1-3) and cryptochrome (Cry1 and 2) negatively feedback and regulate the clock genes. Variations in the circadian cycle and these clock genes can affect stroke outcomes. Studies suggest that the peak stroke occurs in the morning after patients awaken from sleep, while stroke severity and poor outcomes worsen at midnight. The main risk factor associated with stroke is high blood pressure (hypertension). Blood pressure usually dips by 15-20% during sleep, but many hypertensives do not display this normal dipping pattern and are non-dippers. A sleep blood pressure is the primary determinant of stroke risk. This article discusses the possible mechanism associated with circadian rhythm and stroke outcomes.

Recycled Translation: Repurposing Drugs for Stroke

Stroke, which continues to be a leading cause of death and long-term disability worldwide, has often been described as a clinical graveyard. While multiple small molecule therapeutics have undergone clinical trials in stroke, currently only one Food and Drug Administration (FDA)-approved medication exists for the treatment of stroke, the biological, recombinant tissue plasminogen activator (rt-PA). Repurposing of therapeutics which have previously gained FDA approval for alternative indications serves as a prospective option for stroke therapeutic translation. In contrast to de novo drug development, repurposing strategies have patient-centered and economic advantages. These include increased safety, increased chance of approval, decreased time to approval, and decreased capital investment. Presently, 37 active stroke clinical trials utilize repurposed therapeutics with various initial indications and dosing paradigms. The currently studied repurposed therapeutics fall into six mechanistic categories: (1) anticoagulation; (2) vasculature integrity, response, or red blood cell (RBC) alterations; (3) immune system regulation; (4) neurotransmission; and (5) neuroprotection. Directed hypothesis-driven computational investigation utilizing drug databases, in silico drug-protein interaction modeling, genomic data, and consensus methodology can determine if the current mechanistic repurposing categories have the highest chance of translational success or if other mechanistic avenues should be explored. With this increased focus on repurposed therapeutic strategies over de novo strategies, evolution and optimization of regulatory protections are needed to incentivize innovators and investigators.

Neuropsychiatric sequelae of long COVID-19: Pilot results from the COVID-19 neurological and molecular prospective cohort study in Georgia, USA

Background

As the coronavirus disease 2019 (COVID-19) pandemic continues, there has been a growing interest in the chronic sequelae of COVID-19. Neuropsychiatric symptoms are observed in the acute phase of infection, but there is a need for accurate characterization of how these symptoms evolve over time. Additionally, African American populations have been disproportionately affected by the COVID-19 pandemic. The COVID-19 Neurological and Molecular Prospective Cohort Study in Georgia (CONGA) was established to investigate the severity and chronicity of these neurologic findings over the five-year period following infection.

Methods

The CONGA study aims to recruit COVID-19 positive adult patients in Georgia, United States from both the inpatient and outpatient setting, with 50% being African American. This paper reports our preliminary results from the baseline visits of the first 200 patients recruited who were on average 125 days since having a positive COVID-19 test. The demographics, self-reported symptoms, comorbidities, and quantitative measures of depression, anxiety, smell, taste, and cognition were analyzed. Cognitive measures were compared to demographically matched controls. Blood and mononuclear cells were drawn and stored for future analysis.

Results

Fatigue was the most reported symptom in the study cohort (68.5%). Thirty percent of participants demonstrated hyposmia and 30% of participants demonstrated hypogeusia. Self-reported neurologic dysfunction did not correlate with dysfunction on quantitative neurologic testing. Additionally, self-reported symptoms and comorbidities were associated with depression and anxiety. The study cohort performed worse on cognitive measures compared to demographically matched controls, and African American patients scored lower compared to non-Hispanic White patients on all quantitative cognitive testing.

Conclusion

Our results support the growing evidence that there are chronic neuropsychiatric symptoms following COVID-19 infection. Our results suggest that self-reported neurologic symptoms do not appear to correlate with associated quantitative dysfunction, emphasizing the importance of quantitative measurements in the complete assessment of deficits. Self-reported symptoms are associated with depression and anxiety. COVID-19 infection appears to be associated with worse performance on cognitive measures, though the disparity in score between African American patients and non-Hispanic White patients is likely largely due to psychosocial, physical health, and socioeconomic factors.

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Neuropsychiatric symptoms are often reported following COVID-19 infection.

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Self-reported symptoms may not be associated with objective dysfunction.

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Self-reported symptoms may be associated with depression and anxiety.

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Cognitive testing may overestimate clinical impairment in disadvantaged populations.

Pilot Study of Remote Ischemic Conditioning in Acute Spontaneous Intracerebral Hemorrhage

Spontaneous Intracerebral hemorrhage (ICH) is a devastating injury that accounts for 10–15% of all strokes. The rupture of cerebral blood vessels damaged by hypertension or cerebral amyloid angiopathy creates a space-occupying hematoma that contributes toward neurological deterioration and high patient morbidity and mortality. Numerous protocols have explored a role for surgical decompression of ICH via craniotomy, stereotactic guided endoscopy, and minimally invasive catheter/tube evacuation. Studies including, but not limited to, STICH, STICH-II, MISTIE, MISTIE-II, MISTIE-III, ENRICH, and ICES have all shown that, in certain limited patient populations, evacuation can be done safely and mortality can be decreased, but functional outcomes remain statistically no different compared to medical management alone. Only 10–15% of patients with ICH are surgical candidates based on clot location, medical comorbidities, and limitations regarding early surgical intervention. To date, no clearly effective treatment options are available to improve ICH outcomes, leaving medical and supportive management as the standard of care. We recently identified that remote ischemic conditioning (RIC), the non-invasive, repetitive inflation-deflation of a blood pressure cuff on a limb, non-invasively enhanced hematoma resolution and improved neurological outcomes via anti-inflammatory macrophage polarization in pre-clinical ICH models. Herein, we propose a pilot, placebo-controlled, open-label, randomized trial to test the hypothesis that RIC accelerates hematoma resorption and improves outcomes in ICH patients. Twenty ICH patients will be randomized to receive either mock conditioning or unilateral arm RIC (4 cycles × 5 min inflation/5 min deflation per cycle) beginning within 48 h of stroke onset and continuing twice daily for one week. All patients will receive standard medical care according to latest guidelines. The primary outcome will be the safety evaluation of unilateral RIC in ICH patients. Secondary outcomes will include hematoma volume/clot resorption rate and functional outcomes, as assessed by the modified Rankin Scale (mRS) at 1- and 3-months post-ICH. Additionally, blood will be collected for exploratory genomic analysis. This study will establish the feasibility and safety of RIC in acute ICH patients, providing a foundation for a larger, multi-center clinical trial.

The Stroke Preclinical Assessment Network: Rationale, Design, Feasibility, and Stage 1 Results

Cerebral ischemia and reperfusion initiate cellular events in brain that lead to neurological disability. Investigating these cellular events provides ample targets for developing new treatments. Despite considerable work, no such therapy has translated into successful stroke treatment. Among other issues-such as incomplete mechanistic knowledge and faulty clinical trial design-a key contributor to prior translational failures may be insufficient scientific rigor during preclinical assessment: nonblinded outcome assessment; missing randomization; inappropriate sample sizes; and preclinical assessments in young male animals that ignore relevant biological variables, such as age, sex, and relevant comorbid diseases. Promising results are rarely replicated in multiple laboratories. We sought to address some of these issues with rigorous assessment of candidate treatments across 6 independent research laboratories. The Stroke Preclinical Assessment Network (SPAN) implements state-of-the-art experimental design to test the hypothesis that rigorous preclinical assessment can successfully reduce or eliminate common sources of bias in choosing treatments for evaluation in clinical studies. SPAN is a randomized, placebo-controlled, blinded, multilaboratory trial using a multi-arm multi-stage protocol to select one or more putative stroke treatments with an implied high likelihood of success in human clinical stroke trials. The first stage of SPAN implemented procedural standardization and experimental rigor. All participating research laboratories performed middle cerebral artery occlusion surgery adhering to a common protocol and rapidly enrolled 913 mice in the first of 4 planned stages with excellent protocol adherence, remarkable data completion and low rates of subject loss. SPAN stage 1 successfully implemented treatment masking, randomization, prerandomization inclusion/exclusion criteria, and blinded assessment to exclude bias. Our data suggest that a large, multilaboratory, preclinical assessment effort to reduce known sources of bias is feasible and practical. Subsequent SPAN stages will evaluate candidate treatments for potential success in future stroke clinical trials using aged animals and animals with comorbid conditions.

Abstract WMP118: Preclinical Evaluation Of Circadian Rhythm In Ischemic Stroke Outcomes

Background: Stroke is a leading cause of disability and death worldwide. There is evidence that there is a circadian rhythm in stroke with peak occurrence in the morning (6 to 10 am). However it is not clear if the size of infarcts and the outcomes of stroke also varies during the 24 hour period

Hypothesis: We hypothesized that the size of cerebral infarct and outcome from stroke would show circadian variation in a mouse suture occlusion model.

Methods: Seven to eight-month-old C57BL/6J (Wild Type, n=10-15 mice/group) mice were randomly assigned to do stroke at the different time points of the day following zeitgeber time at ZT0, ZT6, ZT12, and Z18. Cerebral Ischemia was induced by occlusion of the middle cerebral artery (MCAO) for 60 min. Blood flow was monitored by Laser Speckle before, after occlusion, and at 24h. Neurological deficit was observed by using Bederson score at 24h and 48h. The corner test was used to detect unilateral abnormalities of sensory and motor functions in the stroke mice at 48h. TTC staining was done, 48 hours after stroke, to estimate brain infarction, and the infarct area was measured by using NIH-Image J software.

Results: We did not find a significant difference in CBF at any time points. There was a significant increased ( p <0.05) neurological deficit (Bederson score) at 48h during deep sleep period (ZT6, noon) stroke (1.55±0.17) in comparison to fully awake period stroke (1.1±0.1). In the corner test, we found right turn preference significantly higher ( p <0.005) at noon/ZT6 (9.5±0.34) compared to the fully awake (5.5±0.34) (midnight, ZT18) period. Similarly, the infarction volume was significantly higher ( p <0.05) during the sleep (ZT6, noon) period (29.32±5.03) in comparison to a fully awake midnight/ZT18 period (15.68±2.38).

Conclusion: This is the first report demonstrating that mice have larger infarcts and worse short term outcomes during their sleep period (noon/ZT6) than during their awake period (midnight/ZT18).

Abstract WMP13: Delayed Stimulation Of Angiotensin II Type 2 Receptor Ameliorates Sensorimotor Deficits And Cognitive Decline After Stroke In Aged Hypertensive Rats

Hypertension and aging are leading risk factors for stroke and cognitive decline. Animal models fail to capture the complex interplay between these two pathophysiologic processes, limiting human translation of interventions. In the current study, we investigated the development of cognitive impairment in 18-month-old spontaneously hypertensive rats (SHRs) prior to and following a 30-minute tMCAO or SHAM. Sixty SHRs were kept for 18 months with cognitive assessments performed prior to and post-surgery. Baseline brain MRI was done at 18 months and then at day 3 and week 8 post-surgery. At day 3, rats were randomly assigned to blindly receive either C21 or normal drinking water for 8 weeks.

Results: Over 18 months, SHRs demonstrated a progressive cognitive decline and significant abnormalities on MRI. Aged SHRs demonstrated an acceptably low 14% peri-operative mortality within 72 hours of tMCAO. Stroke resulted in sustained, significant sensorimotor deficits and C21 effectively enhanced sensorimotor recovery at week 8. Progressive cognitive decline continued after surgery, but C21 enhanced post-stroke, subacute associative and reference memory at week 5. There was no evidence of anhedonia at 8 weeks. MRI scans revealed no difference in ischemic lesion resolution between C21 and control. However, C21 treated rats had less cortical atrophy and reduced WM injury at 8 weeks.

Conclusions: Aged SHRs with minor stroke demonstrated persistent sensorimotor deficits, which were significantly lessened with C21. The dramatic decline in exploration time with age was ameliorated with C21 treatment, evidence of preserved cognition.

Abstract WMP117: Effects Of Chronic Remote Ischemic Conditioning In A VCID Mouse Appears RBCNOS3 Dependent

Background and Purpose: Chronic remote ischemic conditioning (C-RIC) is effective at improving cerebral blood flow (CBF) inducing vascular remodeling, and improving cognition in a bilateral carotid artery stenosis (BCAS) mouse model, a model for Vascular Cognitive Impairment and Dementia (VCID). This augmentation is associated with increases of plasma nitrite. Our aim was to determine if the beneficial effect of C-RIC was red blood cell (NOS3) dependent.

Methods: Microcoil (01.8 mm) induced BCAS model was used to induce chronic hypoperfusion. Aged RBCNOS3-KO and its control groups, NOS3flox-flox male mice (>12 months ) were randomly assigned to Sham RIC and RIC of both strains. RIC was started 7d post-surgery daily for 4 weeks. Behavioral test and CBF was performed before termination. Functional outcomes were assessed using novel object recognition (NOR) test for non-spatial working memory, and hanging wire and beam walk test for motor/muscular impairment. Histopathological staining was also assessed of the brain tissues.

Results: C-RIC-therapy for 4 weeks did not improve CBF in the RBCNOS3KO groups at 4 th weeks compared to ShamRIC groups. However, C-RIC therapy for 4 weeks significantly improved CBF in NOS3flox-flox groups compared to ShamRIC groups. Similarly, there was no significant change in the RBCNOS3 KO mice between the ShamRIC and RIC groups in the discrimination index/exploration time as determined by the NOR test or poor motor function as determined by hanging wire and beam walk test whereas the NOS3flox-flox mice did show improved cognition with RIC.

Conclusions: The beneficial effect of C-RIC in the BCAS model is abrogated in RBCNOS3 KO mice indicating that the effect of C-RIC is NOS3 dependent.

Inflammaging and Cannabinoids

Aging is a complex phenomenon associated with a wide spectrum of physical and physiological changes affecting every part of all metazoans, if they escape death prior to reaching maturity. Critical to survival, the immune system evolved as the principal component of response to injury and defense against pathogen invasions. Because how significantly immune system affects and is affected by aging, several neologisms now appear to encapsulate these reciprocal relationships, such as Immunosenescence. The central part of Immunosenescence is Inflammaging -a sustained, low-grade, sterile inflammation occurring after reaching reproductive prime. Once initiated, the impact of Inflammaging and its adverse effects determine the direction and magnitudes of further Inflammaging. In this article, we review the nature of this vicious cycle, we will propose that phytocannabinoids as immune regulators may possess the potential as effective adjunctive therapies to slow and, in certain cases, reverse the pathologic senescence to permit a more healthy aging.

Preclinical evaluation of circadian rhythm in ischemic stroke outcomes

Stroke is a leading cause of disability and death worldwide. There is evidence that there is a circadian rhythm in stroke with peak occurrence in the morning (6 to 10 am). However, it is not clear if the size of infarcts and the outcome of stroke also varies during the 24-hour period. We hypothesized that the size of cerebral infarct and outcome from stroke would show circadian variation in a mouse suture occlusion model. Seven to eight-month-old C57BL/6J (n =10-12 mice/group) mice were randomly assigned to undergo middle cerebral artery occlusion (MCAO) for 60 minutes at different time points during the 24h day following zeitgeber time at ZT0, ZT6, ZT12, and Z18. Cerebral blood flow was monitored by Laser Speckle Contrast Imaging at baseline after occlusion, and again at 24h post-occlusion. Neurological deficit was observed by using Bederson score at 24h and 48h. The corner test was used to detect unilateral abnormalities in sensory and motor functions in the stroke mice at 48h. To estimate brain infarction, 2,3,5-tryphenyltetrazolium chloride staining was performed 48h after stroke and the infarct area was quantified using NIH-Image J software. We did not find a significant difference in cerebral blood flow at any time point. There was a significant decrease in neurological deficit as assessed using the Bederson Score from 24h (1.82 ± 1.11) to 48h (1.10 ± 0.12) in the ZT18 (midnight) period (p = 0.0025), however there were no differences between groups at 48h. In the corner test, we found right turn preference significantly higher (p = 0.0348) at noon/ZT06 (9.5 ± 1.06) compared to the fully awake (5.5 ± 4.06) (midnight, ZT18) period and ZT0 (6 am, 4.8 ± 0.97, p = 0.0087). Similarly, the infarction volume was significantly higher (p = 0.0220) during the sleep (ZT06, noon) period (35.22 ± 20.77) than when the ischemic mice were fully awake during the midnight/ZT18 period (15.68 ± 7.54). This is the first report demonstrating that mice have larger infarcts and worse short-term outcomes during their sleep period (noon/ZT06) than during their awake period (midnight/ZT18).

Profound Racial Disparities in COVID-19 Associated Hospitalizations in Rural Southwest Georgia

Background

The coronavirus disease 2019 (COVID-19) is responsible for one of the largest public health crises the United States has seen to date. This study explores the outcomes of African American and non-African American COVID-19-positive patients hospitalized in rural Southwest Georgia to identify differences in morbidity and mortality between the groups.

Methods

We performed a retrospective cohort analysis among adults aged ≥18 years admitted with COVID-19 between March 2, 2020 and June 17, 2020 at Phoebe Putney Health System. Data on demographics, comorbidities, presenting symptoms, and hospital course were obtained. Patients were divided into two groups: African Americans and non-African Americans. We examined differences in patient characteristics between groups using chi-square tests for categorical variables, t-test for parametric continuous variables, and Wilcoxon rank-sum tests for non-parametric continuous variables. Statistical Analysis Software (SAS) version 9.4 was used for statistical analysis.

Results

Among 710 patients, median age was 63 years, 43.8% were males, and 83.3% were African Americans. African Americans had higher prevalence of obesity and hypertension, were more likely to present with fever, and present with longer duration of symptoms prior to presentation. In-hospital mortality was similar between the groups, as was need for mechanical ventilation, ICU care, and new dialysis. African Americans were more likely to be discharged home compared to non-African Americans.

Conclusions

There was no difference in in-hospital mortality; however, African Americans had disproportionately higher hospitalizations, likely to significantly increase the morbidity burden in this population. Urgent measures are needed to address this profound racial disparity.

Rescuing mitochondria in traumatic brain injury and intracerebral hemorrhages - A potential therapeutic approach

Mitochondria are dynamic organelles responsible for cellular energy production. Besides, regulating energy homeostasis, mitochondria are responsible for calcium homeostasis, signal transmission, and the fate of cellular survival in case of injury and pathologies. Accumulating reports have suggested multiple roles of mitochondria in neuropathologies, neurodegeneration, and immune activation under physiological and pathological conditions. Mitochondrial dysfunction, which occurs at the initial phase of brain injury, involves oxidative stress, inflammation, deficits in mitochondrial bioenergetics, biogenesis, transport, and autophagy. Thus, development of targeted therapeutics to protect mitochondria may improve functional outcomes following traumatic brain injury (TBI) and intracerebral hemorrhages (ICH). In this review, we summarize mitochondrial dysfunction related to TBI and ICH, including the mechanisms involved, and discuss therapeutic approaches with special emphasis on past and current clinical trials.

Mechanisms of Preconditioning Exercise-Induced Neurovascular Protection in Stroke

Ischemic stroke is a leading cause of death and disability. Tissue plasminogen activator is the only U.S. Food and Drug Administration approved thrombolytic therapy for ischemic stroke patients till date. However, its use is limited due to increased risk of bleeding and narrow therapeutic window. Most of the preclinically tested pharmacological agents failed to be translated to the clinic. This drives the need for alternative therapeutic approaches that not only provide enhanced neuroprotection, but also reduce the risk of stroke. Physical exercise is a sort of preconditioning that provides the body with brief ischemic episodes that can protect the body from subsequent severe ischemic attacks like stroke. Physical exercise is known to improve cardiovascular health. However, its role in providing neuroprotection in stroke is not clear. Clinical observational studies showed a correlation between regular physical exercise and reduced risk and severity of ischemic stroke and better outcomes after stroke. However, the underlying mechanisms through which prestroke exercise can reduce the stroke injury and improve the outcomes are not completely understood. The purpose of this review is to: demonstrate the impact of exercise on stroke outcomes and show the potential role of exercise in stroke prevention and recovery; uncover the underlying mechanisms through which exercise reduces the neurovascular injury and improves stroke outcomes aiming to develop novel therapeutic approaches.

A potential role for cannabichromene in modulating TRP channels during acute respiratory distress syndrome

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a life-threatening clinical syndrome whose potential to become one of the most grievous challenges of the healthcare system evidenced by the COVID-19 pandemic. Considering the lack of target-specific treatment for ARDS, it is absolutely exigent to have an effective therapeutic modality to reduce hospitalization and mortality rate as well as to improve quality of life and outcomes for ARDS patients. ARDS is a systemic inflammatory disease starting with the pulmonary system and involves all other organs in a morbid bidirectional fashion. Mounting evidence including our findings supporting the notion that cannabinoids have potential to be targeted as regulatory therapeutic modalities in the treatment of inflammatory diseases. Therefore, it is plausible to test their capabilities as alternative therapies in the treatment of ARDS. In this study, we investigated the potential protective effects of cannabichromene (CBC) in an experimental model of ARDS.

METHODS

We used, for the first time, an inhalant CBC treatment as a potential therapeutic target in a murine model of ARDS-like symptoms. ARDS was induced by intranasal administration of Poly(I:C), a synthetic mismatched double-stranded RNA, into the C57BL/6 mice (6-10 male mice/group, including sham, placebo, and CBC treated), three once-daily doses followed by a daily dose of inhalant CBC or placebo for the period of 8 days starting the first dose 2 h after the second Poly(I:C) treatment. We employed histologic, immunohistochemistry, and flow cytometry methods to assess the findings. Statistical analysis was performed by using one way analysis of variance (ANOVA) followed by Newman-Keuls post hoc test to determine the differences among the means of all experimental groups and to establish significance (p < 0.05) among all groups.

RESULTS

Our data showed that CBC was able to reverse the hypoxia (increasing blood O₂ saturation by 8%), ameliorate the symptoms of ARDS (reducing the pro-inflammatory cytokines by 50% in lung and blood), and protect the lung tissues from further destruction. Further analysis showed that CBC may wield its protective effects through transient receptor potential (TRP) cation channels, TRPA1 and TRPV1, increasing their expression by 5-folds in lung tissues compared to sham and untreated mice, re-establishing the homeostasis and immune balance.

CONCLUSION

Our findings suggest that inhalant CBC may be an effective alternative therapeutic target in the treatment of ARDS. In addition, Increased expression of TRPs cation channels after CBC treatment proposes a novel role for TRPs (TRPA1 and TRPV2) as new potential mechanism to interpret the beneficial effects of CBC as well as other cannabinoids in the treatment of ARDS as well as other inflammatory diseases. Importantly, delivering CBC through an inhaler device is a translational model supporting the feasibility of trial with human subjects, authorizing further research.

Cannabidiol Ameliorates Cognitive Function via Regulation of IL-33 and TREM2 Upregulation in a Murine Model of Alzheimer's Disease

There is a dire need for due innovative therapeutic modalities to improve outcomes of AD patients. In this study, we tested whether cannabidiol (CBD) improves outcomes in a translational model of familial AD and to investigate if CBD regulates interleukin (IL)-33 and triggering receptor expressed on myeloid cells 2 (TREM2), which are associated with improved cognitive function. CBD was administered to 5xFAD mice, which recapitulate early onset, familial AD. Behavioral tests and immunoassays were used to evaluate cognitive and motor outcomes. Our findings suggest that CBD treatment enhanced IL-33 and TREM2 expression, ameliorated the symptoms of AD, and retarded cognitive decline.

AIM2 inflammasome mediates hallmark neuropathological alterations and cognitive impairment in a mouse model of vascular dementia

Chronic cerebral hypoperfusion is associated with vascular dementia (VaD). Cerebral hypoperfusion may initiate complex molecular and cellular inflammatory pathways that contribute to long-term cognitive impairment and memory loss. Here we used a bilateral common carotid artery stenosis (BCAS) mouse model of VaD to investigate its effect on the innate immune response-particularly the inflammasome signaling pathway. Comprehensive analyses revealed that chronic cerebral hypoperfusion induces a complex temporal expression and activation of inflammasome components and their downstream products (IL-1β and IL-18) in different brain regions, and promotes activation of apoptotic and pyroptotic cell death pathways. Polarized glial-cell activation, white-matter lesion formation and hippocampal neuronal loss also occurred in a spatiotemporal manner. Moreover, in AIM2 knockout mice we observed attenuated inflammasome-mediated production of proinflammatory cytokines, apoptosis, and pyroptosis, as well as resistance to chronic microglial activation, myelin breakdown, hippocampal neuronal loss, and behavioral and cognitive deficits following BCAS. Hence, we have demonstrated that activation of the AIM2 inflammasome substantially contributes to the pathophysiology of chronic cerebral hypoperfusion-induced brain injury and may therefore represent a promising therapeutic target for attenuating cognitive impairment in VaD.

A County-Level Analysis of Socioeconomic and Clinical Predictors of COVID-19 Incidence and Case-Fatality Rates in Georgia, March-September 2020

OBJECTIVES

The global COVID-19 pandemic has affected various populations differently. We investigated the relationship between socioeconomic determinants of health obtained from the Robert Wood Johnson Foundation County Health Rankings and COVID-19 incidence and mortality at the county level in Georgia.

METHODS

We analyzed data on COVID-19 incidence and case-fatality rates (CFRs) from the Georgia Department of Public Health from March 1 through August 31, 2020. We used repeated measures generalized linear mixed models to determine differences over time in Georgia counties among quartile health rankings of health outcomes, health behaviors, clinical care, social and economic factors, and physical environment.

RESULTS

COVID-19 incidence per 100 000 population increased across all quartile county groups for all health rankings (range, 23.1-51.6 in May to 688.4-1062.0 in August). COVID-19 CFRs per 100 000 population peaked in April and May (range, 3312-6835) for all health rankings, declined in June and July (range, 827-5202), and increased again in August (range, 1877-3310). Peak CFRs occurred later in counties with low health rankings for health behavior and clinical care and in counties with high health rankings for social and economic factors and physical environment. All interactions between the health ranking quartile variables and month were significant (P < .001). County-level Gini indices were associated with significantly higher rates of COVID-19 incidence (P < .001) but not CFRs.

CONCLUSIONS

From March through August 2020, COVID-19 incidence rose in Georgia's counties independent of health rankings categorization. Differences in time to peak CFRs differed at the county level based upon key health rankings. Public health interventions should incorporate unique strategies to improve COVID-19-related patient outcomes in these environments.

Conditioning medicine for ischemic and hemorrhagic stroke

Remote ischemic conditioning (RIC) is a promising safe, feasible, and inexpensive treatment for acute stroke, both ischemic and hemorrhagic. It is applied with a blood pressure cuff on the limbs and is ideal for the prehospital setting. RIC is a form of preconditioning with similarities to physical exercise. Its mechanisms of action are multiple and include improvement of collateral cerebral blood flow (CBF) and RIC acts as a "collateral therapeutic". The increased CBF is likely related to nitric oxide synthase 3 in the endothelium and more importantly in circulating blood cells like the red blood cell. The RESIST clinical trial is a 1500 subject multicenter, randomized, sham-controlled trial of RIC in the prehospital setting in Denmark and should address the questions of whether RIC is safe and effective in acute stroke and whether the effect is mediated by an effect on nitric oxide/nitrite metabolism.

Decreased parenchymal arteriolar tone uncouples vessel-to-neuronal communication in a mouse model of vascular cognitive impairment

Chronic hypoperfusion is a key contributor to cognitive decline and neurodegenerative conditions, but the cellular mechanisms remain ill-defined. Using a multidisciplinary approach, we sought to elucidate chronic hypoperfusion-evoked functional changes at the neurovascular unit. We used bilateral common carotid artery stenosis (BCAS), a well-established model of vascular cognitive impairment, combined with an ex vivo preparation that allows pressurization of parenchymal arterioles in a brain slice. Our results demonstrate that mild (~ 30%), chronic hypoperfusion significantly altered the functional integrity of the cortical neurovascular unit. Although pial cerebral perfusion recovered over time, parenchymal arterioles progressively lost tone, exhibiting significant reductions by day 28 post-surgery. We provide supportive evidence for reduced adenosine 1 receptor-mediated vasoconstriction as a potential mechanism in the adaptive response underlying the reduced baseline tone in parenchymal arterioles. In addition, we show that in response to the neuromodulator adenosine, the action potential frequency of cortical pyramidal neurons was significantly reduced in all groups. However, a significant decrease in adenosine-induced hyperpolarization was observed in BCAS 14 days. At the microvascular level, constriction-induced inhibition of pyramidal neurons was significantly compromised in BCAS mice. Collectively, these results suggest that BCAS uncouples vessel-to-neuron communication-vasculo-neuronal coupling-a potential early event in cognitive decline.

The Immunomodulatory Capacity of Induced Pluripotent Stem Cells in the Post-stroke Environment

Inflammation has proven to be a key contributing factor to the pathogenesis of ischemic and hemorrhagic stroke. This sequential and progressive response, marked by proliferation of resident immune cells and recruitment of peripheral immune populations, results in increased oxidative stress, and neuronal cell death. Therapeutics aimed at quelling various stages of this post-stroke inflammatory response have shown promise recently, one of which being differentiated induced pluripotent stem cells (iPSCs). While direct repopulation of damaged tissues and enhanced neurogenesis are hypothesized to encompass some of the therapeutic potential of iPSCs, recent evidence has demonstrated a substantial paracrine effect on neuroinflammation. Specifically, investigation of iPSCs, iPSC-neural progenitor cells (iPSC-NPCs), and iPSC-neuroepithelial like stem cells (iPSC-lt-NESC) has demonstrated significant immunomodulation of proinflammatory signaling and endogenous inflammatory cell populations, such as microglia. This review aims to examine the mechanisms by which iPSCs mediate neuroinflammation in the post-stroke environment, as well as delineate avenues for further investigation.

Altered mental status is an independent predictor of mortality in hospitalized COVID-19 patients

BACKGROUND/AIMS

Limited data exists on the outcomes of COVID-19 patients presenting with altered mental status (AMS). Hence, we studied the characteristics and outcomes of hospitalized COVID-19 patients who presented with AMS at our hospital in rural southwest Georgia.

METHODS

Data from electronic medical records of all hospitalized COVID-19 patients from March 2, 2020, to June 17, 2020, were analyzed. Patients were divided in 2 groups, those presenting with and without AMS. Primary outcome of interest was in-hospital mortality. Secondary outcomes were needed for mechanical ventilation, need for intensive care unit (ICU) care, need for dialysis, and length of stay. All analyses were performed using SAS 9.4 and R 3.6.0.

RESULTS

Out of 710 patients, 73 (10.3%) presented with AMS. Majority of the population was African American (83.4%). Patients with AMS were older and more likely to have hypertension, chronic kidney disease (CKD), cerebrovascular disease, and dementia. Patients with AMS were less likely to present with typical COVID-19 symptoms, including dyspnea, cough, fever, and gastrointestinal symptoms. Predictors of AMS included age ≥ 70 years, CKD, cerebrovascular disease, and dementia. After multivariable adjustment, patients with AMS had higher rates of in-hospital mortality (30.1% vs 14.8%, odds ratio (OR) 2.139, p = 0.019), ICU admission (43.8% vs 40.2%, OR 2.59, p < 0.001), and need for mechanical ventilation (27.4% vs 18.5%, OR 2.06, p = 0.023). Patients presenting with AMS had increased length of stay.

CONCLUSIONS

Patients with COVID-19 presenting with AMS are less likely to have typical COVID-19 symptoms, and AMS is an independent predictor of in-hospital mortality, need for ICU admission, and need for mechanical ventilation.

AMPK induces regulatory innate lymphoid cells after traumatic brain injury

The CNS is regarded as an immunoprivileged organ, evading routine immune surveillance; however, the coordinated development of immune responses profoundly influences outcomes after brain injury. Innate lymphoid cells (ILCs) are cytokine-producing cells that are critical for the initiation, modulation, and resolution of inflammation, but the functional relevance and mechanistic regulation of ILCs are unexplored after acute brain injury. We demonstrate increased proliferation of all ILC subtypes within the meninges for up to 1 year after experimental traumatic brain injury (TBI) while ILCs were present within resected dura and elevated within cerebrospinal fluid (CSF) of moderate-to-severe TBI patients. In line with energetic derangements after TBI, inhibition of the metabolic regulator, AMPK, increased meningeal ILC expansion, whereas AMPK activation suppressed proinflammatory ILC1/ILC3 and increased the frequency of IL-10-expressing ILC2 after TBI. Moreover, intracisternal administration of IL-33 activated AMPK, expanded ILC2, and suppressed ILC1 and ILC3 within the meninges of WT and Rag1-/- mice, but not Rag1-/- IL2rg-/- mice. Taken together, we identify AMPK as a brake on the expansion of proinflammatory, CNS-resident ILCs after brain injury. These findings establish a mechanistic framework whereby immunometabolic modulation of ILCs may direct the specificity, timing, and magnitude of cerebral immunity.

Cannabidiol (CBD) modulation of apelin in acute respiratory distress syndrome

Considering lack of target-specific antiviral treatment and vaccination for COVID-19, it is absolutely exigent to have an effective therapeutic modality to reduce hospitalization and mortality rate as well as to improve COVID-19-infected patient outcomes. In a follow-up study to our recent findings indicating the potential of Cannabidiol (CBD) in the treatment of acute respiratory distress syndrome (ARDS), here we show for the first time that CBD may ameliorate the symptoms of ARDS through up-regulation of apelin, a peptide with significant role in the central and peripheral regulation of immunity, CNS, metabolic and cardiovascular system. By administering intranasal Poly (I:C), a synthetic viral dsRNA, while we were able to mimic the symptoms of ARDS in a murine model, interestingly, there was a significant decrease in the expression of apelin in both blood and lung tissues. CBD treatment was able to reverse the symptoms of ARDS towards a normal level. Importantly, CBD treatment increased the apelin expression significantly, suggesting a potential crosstalk between apelinergic system and CBD may be the therapeutic target in the treatment of inflammatory diseases such as COVID-19 and many other pathologic conditions.

COVID-19 and neurological symptoms: is the SARS-CoV-2 virus neurotropic?

IMPORTANCE

The most notable symptoms of the Coronavirus Disease 2019 (COVID-19) pandemic are fever, cough, dyspnea, and in severe cases, adult respiratory distress syndrome (ARDS.) But neurological symptoms including confusion, stroke, and encephalopathy are reported, and anosmia and hypogeusia are also common indicating that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may be neurotropic.

OBSERVATIONS

The SARS-Co-1 and 2 viruses bind to angiotensin converting enzyme 2 (ACE2), which is present on human brain endothelium and non-neuronal cells in the nasopharynx and lingual epithelium. However, SARS-CoV-1 and 2 do not bind rodent ACE2 avidly, which has required the generation of humanized ACE2 transgenic animal models of disease. Transgenic mouse models suggest that the SARS- CoV-1 and Middle East respiratory syndrome (MERS)-CoV are neurotropic and infect and damage the brain, including the cardiorespiratory centers in the medulla. The symptoms of anosmia and hypogeusia indicate a portal to the brain. The relationship between encephalitis lethargica and post encephalitis parkinsonism to the Spanish Flu (H1N1 influenza virus) is unclear but raises the question of long term neurological complications of pandemics.

CONCLUSIONS AND RELEVANCE

There is a concern that there may be long term neurological sequelae of infection with SARS-CoV-2. Registries and long term neurological follow up with longitudinal cohort studies of COVID19 positive patients are needed.

Neurological consequences of COVID-19: what have we learned and where do we go from here?

The coronavirus disease-19 (COVID-19) pandemic is an unprecedented worldwide health crisis. COVID-19 is caused by SARS-CoV-2, a highly infectious pathogen that is genetically similar to SARS-CoV. Similar to other recent coronavirus outbreaks, including SARS and MERS, SARS-CoV-2 infected patients typically present with fever, dry cough, fatigue, and lower respiratory system dysfunction, including high rates of pneumonia and acute respiratory distress syndrome (ARDS); however, a rapidly accumulating set of clinical studies revealed atypical symptoms of COVID-19 that involve neurological signs, including headaches, anosmia, nausea, dysgeusia, damage to respiratory centers, and cerebral infarction. These unexpected findings may provide important clues regarding the pathological sequela of SARS-CoV-2 infection. Moreover, no efficacious therapies or vaccines are currently available, complicating the clinical management of COVID-19 patients and emphasizing the public health need for controlled, hypothesis-driven experimental studies to provide a framework for therapeutic development. In this mini-review, we summarize the current body of literature regarding the central nervous system (CNS) effects of SARS-CoV-2 and discuss several potential targets for therapeutic development to reduce neurological consequences in COVID-19 patients.

Cannabidiol Modulates Cytokine Storm in Acute Respiratory Distress Syndrome Induced by Simulated Viral Infection Using Synthetic RNA

Introduction: In the absence of effective antivirals and vaccination, the pandemic of COVID-19 remains the most significant challenge to our health care system in decades. There is an urgent need for definitive therapeutic intervention. Clinical reports indicate that the cytokine storm associated with acute respiratory distress syndrome (ARDS) is the leading cause of mortality in severe cases of some respiratory viral infections, including COVID-19. In recent years, cannabinoids have been investigated extensively due to their potential effects on the human body. Among all cannabinoids, cannabidiol (CBD) has demonstrated potent anti-inflammatory effects in a variety of pathological conditions. Therefore, it is logical to explore whether CBD can reduce the cytokine storm and treat ARDS. Materials and Methods: In this study, we show that intranasal application of Poly(I:C), a synthetic analogue of viral double-stranded RNA, simulated symptoms of severe viral infections inducing signs of ARDS and cytokine storm. Discussion: The administration of CBD downregulated the level of proinflammatory cytokines and ameliorated the clinical symptoms of Poly I:C-induced ARDS. Conclusion: Our results suggest a potential protective role for CBD during ARDS that may extend CBD as part of the treatment of COVID-19 by reducing the cytokine storm, protecting pulmonary tissues, and re-establishing inflammatory homeostasis.

COVID-19-Related Stroke

The COVID-19 pandemic is associated with neurological symptoms and complications including stroke. There is hypercoagulability associated with COVID-19 that is likely a "sepsis-induced coagulopathy" and may predispose to stroke. The SARS-CoV-2 virus binds to angiotensin-converting enzyme 2 (ACE2) present on brain endothelial and smooth muscle cells. ACE2 is a key part of the renin angiotensin system (RAS) and a counterbalance to angiotensin-converting enzyme 1 (ACE1) and angiotensin II. Angiotensin II is proinflammatory, is vasoconstrictive, and promotes organ damage. Depletion of ACE2 by SARS-CoV-2 may tip the balance in favor of the "harmful" ACE1/angiotensin II axis and promote tissue injury including stroke. There is a rationale to continue to treat with tissue plasminogen activator for COVID-19-related stroke and low molecular weight heparinoids may reduce thrombosis and mortality in sepsis-induced coagulopathy.

Neutrophil extracellular traps exacerbate neurological deficits after traumatic brain injury

Traumatic brain injury (TBI) is a major cause of mortality and morbidity. Preventative measures reduce injury incidence and/or severity, yet one-third of hospitalized patients with TBI die from secondary pathological processes that develop during supervised care. Neutrophils, which orchestrate innate immune responses, worsen TBI outcomes via undefined mechanisms. We hypothesized that formation of neutrophil extracellular traps (NETs), a purported mechanism of microbial trapping, exacerbates acute neurological injury after TBI. NET formation coincided with cerebral hypoperfusion and tissue hypoxia after experimental TBI, while elevated circulating NETs correlated with reduced serum deoxyribonuclease-1 (DNase-I) activity in patients with TBI. Functionally, Toll-like receptor 4 (TLR4) and the downstream kinase peptidylarginine deiminase 4 (PAD4) mediated NET formation and cerebrovascular dysfunction after TBI. Last, recombinant human DNase-I degraded NETs and improved neurological function. Thus, therapeutically targeting NETs may provide a mechanistically innovative approach to improve TBI outcomes without the associated risks of global neutrophil depletion.

Impact of Participation in a Telestroke Network on Clinical Outcomes

BACKGROUND

A telestroke program, known as the Remote Evaluation for Acute Ischemic Stroke program, has been implemented in Georgia since 2003. This study examined whether a hospital's participation in a telestroke network was associated with improvement in clinical outcomes and quality indicators.

METHODS AND RESULTS

An observational study was conducted using data from the Georgia Coverdell Acute Stroke Registry between September 2005 and September 2016 for patients aged ≥18 years with ischemic stroke. We use a difference-in-differences approach to compare the following clinical outcomes and quality indicators among those admitted at hospitals within and outside of the Remote Evaluation for Acute Ischemic Stroke network: tPA (tissue-type plasminogen activator) use, complications related to tPA use, door-to-needle time, ambulation at discharge, discharge status, and destination. Logistic regression models and a propensity score weighting approach were performed to adjust for patients' age, sex, race, insurance coverage, arrival mode, ambulatory status before the current stroke, stroke severity, medical history, admission time, and hospital bed size. A total of 25 494 patients with ischemic stroke admitted at 15 nonteaching hospitals located outside of the Atlanta metropolitan area were included in the analysis. After propensity score weighting, hospitals participated in a telestroke network was not associated with a significant increase in the rate of tPA use, while it was significantly associated with a modest decline in the rate of complications related to tPA (-5.9%; 95% CI, -9.2% to -2.6%). Telestroke participation showed no significant difference in other clinical outcomes and quality measures except for a marginally significant decrease in in-hospital mortality (-1.1%; 95% CI, -2.2% to -0.1%).

CONCLUSIONS

Although a slight decrease in tPA complication was observed among hospitals participating in the telestroke network, overall the impact of telestroke participation on a hospital's stroke care quality was not statistically significant based on our observational study.

Abstract WP480: Beneficial Effect of Chronic-Remote Ischemic Conditioning (C-RIC) is Dependent Upon Circulating Blood Cell NOS3 in a Vascular Cognitive Impairment and Dementia (VCID) Model

Background and Purpose: Chronic remote ischemic conditioning (C-RIC) is effective at improving cerebral blood flow (CBF) inducing vascular remodeling, and improving cognition in a bilateral carotid artery stenosis (BCAS) mouse model, a model for Vascular Cognitive Impairment and Dementia (VCID). This effect is lost in NOS3-KO mice. We wanted to determine if the beneficial effect of C-RIC can be restored by bone marrow cell-derived NOS3.

Methods: We prepared BM chimera from adult WT (B6.SJL-Ptprc a ; CD45.1) to adult NOS3-KO (B6.129; CD45.2) & vice versa in male mice (5-6 months) following confirmation for BM engrafting with flow cytometry at 2 weeks. Microcoil (0.18 mm) induced BCAS model was used to induce chronic hypoperfusion. Mice were randomly assigned to 3-groups: (1) Sham (2) BCAS and (3) BCAS+RIC. RIC was started 7d post-surgery daily for 3-4 weeks. Behavioral test and CBF was performed before termination. Functional outcomes were assessed using novel object recognition (NOR) test for non-spatial working memory, and hanging wire and beam walk test for motor/muscular impairment. We measured whole blood P-NOS3, P-AMPK and VEGFR2/CD31 by flow cytometry.

Results: C-RIC-therapy for 3-4 weeks improves CBF in engrafted BM of WT into NOS3-KO in the BCAS+RIC groups at both 2 weeks and 4 weeks compared to BCAS (Sham RIC groups).No effect of C-RIC was shown in engrafted BM of NOS3 into WT. There was significant change between the BCAS and BCAS+RIC groups in the functional outcomes and histopathological evidences also reflects major changing in the groups in the BM of WT into NOS3-KO mice. Whole blood P-NOS3, P-AMPK and VEGFR2/CD31 was increased by C-RIC. However, no effect was shown in the NOS3-KO into WT chimera.

Conclusions: The Beneficial effect of C-RIC is dependent upon bone marrow derived NOS3.Further studies are needed to determine if the red blood cell is the key cell carrying NOS3

Establishment of an internationally agreed minimum data set for acute telestroke

INTRODUCTION

Globally, the use of telestroke programmes for acute care is expanding. Currently, a standardised set of variables for enabling reliable international comparisons of telestroke programmes does not exist. The aim of the study was to establish a consensus-based, minimum dataset for acute telestroke to enable the reliable comparison of programmes, clinical management and patient outcomes.

METHODS

An initial scoping review of variables was conducted, supplemented by reaching out to colleagues leading some of these programmes in different countries. An international expert panel of clinicians, researchers and managers (n = 20) from the Australasia Pacific region, USA, UK and Europe was convened. A modified-Delphi technique was used to achieve consensus via online questionnaires, teleconferences and email.

RESULTS

Overall, 533 variables were initially identified and harmonised into 159 variables for the expert panel to review. The final dataset included 110 variables covering three themes (service configuration, consultations, patient information) and 12 categories: (1) details about telestroke network/programme (n = 12), (2) details about initiating hospital (n = 10), (3) telestroke consultation (n = 17), (4) patient characteristics (n = 7), (5) presentation to hospital (n = 5), (6) general clinical care within first 24 hours (n = 10), (7) thrombolysis treatment (n = 10), (8) endovascular treatment (n = 13), (9) neurosurgery treatment (n = 8), (10) processes of care beyond 24 hours (n = 7), (11) discharge information (n = 5), (12) post-discharge and follow-up data (n = 6).

DISCUSSION

The acute telestroke minimum dataset provides a recommended set of variables to systematically evaluate acute telestroke programmes in different countries. Adoption is recommended for new and existing services.

Short-Term Acute Exercise Preconditioning Reduces Neurovascular Injury After Stroke Through Induced eNOS Activation

Physical exercise is known to reduce cardiovascular risk but its role in ischemic stroke is not clear. It was previously shown that an acute single bout of exercise reduced increased eNOS activation in the heart and reduced myocardial infarction. However, the impact of a single bout or short-term exercise on eNOS-induced neuroprotection after stroke was not previously studied. Accordingly, this study was designed to test the hypothesis that short-term acute exercise can provide "immediate neuroprotection" and improve stroke outcomes through induced eNOS activation. Male Wistar rats (300 g) were subjected to HIIT treadmill exercise for 4 days (25 min/day), break for 2 days, and then one acute bout for 30 min. Exercised animals were subjected to thromboembolic stroke 1 h, 6 h, 24 h, or 72 h after the last exercise session. At 24 h after stroke, control (sedentary) and exercised rats were tested for neurological outcomes, infarct size, and edema. The expression of active eNOS (p-S1177-eNOS) and active AMPK (p-T172-AMPK) was measured in the brain, cerebral vessels, and aorta. In an additional cohort, animals were treated with the eNOS inhibitor, L-NIO (I.P, 20 mg/kg), and stroked 1 h after exercise and compared with non-exercise animals. Acute exercise significantly reduced infarct size, edema, and improved functional outcomes, and significantly increased the expression of peNOS and pAMPK in the brain, cerebral vessels, and aorta. eNOS inhibition abolished the exercise-induced improvement in outcomes. Short-term acute preconditioning exercise reduced the neurovascular injury and improved functional outcomes after stroke through eNOS activation.

Proceedings from the Albert Charitable Trust Inaugural Workshop on white matter and cognition in aging

This third in a series of vascular cognitive impairment (VCI) workshops, supported by "The Leo and Anne Albert Charitable Trust," was held from February 8 to 12 at the Omni Resort in Carlsbad, CA. This workshop followed the information gathered from the earlier two workshops suggesting that we focus more specifically on brain white matter in age-related cognitive impairment. The Scientific Program Committee (Frank Barone, Shawn Whitehead, Eric Smith, and Rod Corriveau) assembled translational, clinical, and basic scientists with unique expertise in acute and chronic white matter injury at the intersection of cerebrovascular and neurodegenerative etiologies. As in previous Albert Trust workshops, invited participants addressed key topics related to mechanisms of white matter injury, biomarkers of white matter injury, and interventions to prevent white matter injury and age-related cognitive decline. This report provides a synopsis of the presentations and discussions by the participants, including the existing knowledge gaps and the delineation of the next steps towards advancing our understanding of white matter injury and age-related cognitive decline. Workshop discussions and consensus resulted in action by The Albert Trust to (1) increase support from biannual to annual "White Matter and Cognition" workshops; (2) provide funding for two collaborative, novel research grants annually submitted by meeting participants; and (3) coordinate the formation of the "Albert Research Institute for White Matter and Cognition." This institute will fill a gap in white matter science, providing white matter and cognition communications, including annual updates from workshops and the literature and interconnecting with other Albert Trust scientific endeavors in cognition and dementia, and providing support for newly established collaborations between seasoned investigators and to the development of talented young investigators in the VCI-dementia (VCID) and white matter cognition arena.