Vascular Dysfunction in Brain Hemorrhage: Translational Pathways to Developing New Treatments from Old Targets

Exacerbation of Pre-existing Neurological Symptoms With COVID-19 in Patients With Chronic Neurological Diseases: An Updated Systematic Review

The neurotropism of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can potentially explain the worsening of symptoms in patients with a history of neurological conditions such as stroke, Parkinson's disease, Alzheimer's, and epilepsy. Several studies have reported that these pre-existing conditions may worsen with a higher frequency of flare-ups, thus resulting in a more significant risk of patient mortality. In this review, we sought to provide an overview of the relationship between pre-existing neurological disorders and COVID-19, focusing on whether the initial infection directly influenced the severity of symptoms. We systematically searched the electronic database PubMed (MEDLINE) and used specific keywords related to our aims from January 2020 to July 2022. All articles published on COVID-19 with keywords pertaining to pre-existing neurological diseases were retrieved and subsequently analyzed. After independent review, the data from 107 articles were selected and evaluated. After analyzing the data from selected articles reviewing the effect of COVID-19 on neurological conditions, we have documented the relationship between said pre-existing neurological diseases, showing an increased risk of hospitalization, admission length, worsening of symptoms, and even mortality in COVID-19 patients.

The association between stroke and COVID-19-related mortality: a systematic review and meta-analysis based on adjusted effect estimates

Objective

To investigate the association between stroke and the risk for mortality among coronavirus disease 2019 (COVID-19) patients.

Methods

We performed systematic searches through electronic databases including PubMed, Embase, Scopus, and Web of Science to identify potential articles reporting adjusted effect estimates on the association of stroke with COVID-19-related mortality. To estimate pooled effects, the random-effects model was applied. Subgroup analyses and meta-regression were performed to explore the possible sources of heterogeneity. The stability of the results was assessed by sensitivity analysis. Publication bias was evaluated by Begg’s test and Egger’s test.

Results

This meta-analysis included 47 studies involving 7,267,055 patients. The stroke was associated with higher COVID-19 mortality (pooled effect = 1.30, 95% confidence interval (CI): 1.16–1.44; I² = 89%, P < 0.01; random-effects model). Subgroup analyses yielded consistent results among area, age, proportion of males, setting, cases, effect type, and proportion of severe COVID-19 cases. Statistical heterogeneity might result from the different effect type according to the meta-regression (P = 0.0105). Sensitivity analysis suggested that our results were stable and robust. Both Begg’s test and Egger’s test indicated that potential publication bias did not exist.

Conclusion

Stroke was independently associated with a significantly increased risk for mortality in COVID-19 patients.

Hemorrhagic and ischemic stroke in patients with coronavirus disease 2019: incidence, risk factors, and pathogenesis - a systematic review and meta-analysis

Background: In this study, we aimed to determine the global prevalence, chronological order of symptom appearance, and mortality rates with regard to hemorrhagic and ischemic stroke in patients with coronavirus disease 2019 (COVID-19) and to discuss possible pathogeneses of hemorrhagic and ischemic stroke in individuals with the disease.

Methods: We searched the PubMed, Scopus, and Web of Science databases for relevant articles published up to November 8, 2020. Data regarding study characteristics, hemorrhagic stroke, ischemic stroke, and COVID-19 were retrieved in accordance with the PRISMA guidelines. The Newcastle-Ottawa scale was used to assess the quality of the eligible studies. The pooled prevalence and mortality rate of hemorrhagic and ischemic stroke were calculated.

Results: The pooled estimate of prevalence of hemorrhagic stroke was 0.46% (95% CI 0.40%–0.53%; I ²=89.81%) among 67,155 COVID-19 patients and that of ischemic stroke was 1.11% (95% CI 1.03%–1.22%; I ²=94.07%) among 58,104 COVID-19 patients. Ischemic stroke was more predominant (incidence: 71.58%) than hemorrhagic stroke (incidence: 28.42%) in COVID-19 patients who experienced a stroke. In COVID-19 patients who experienced a stroke, hospital admission with respiratory symptoms was more commonly reported than that with neurological symptoms (20.83% for hemorrhagic stroke and 5.51% for ischemic stroke versus 6.94% for hemorrhagic stroke and 5.33% for ischemic stroke, respectively). The pooled mortality rate of COVID-19 patients who experienced a hemorrhagic and ischemic stroke was 44.72% (95% CI 36.73%–52.98%) and 36.23% (95% CI 30.63%–42.24%), respectively.

Conclusions: Although the occurrence of hemorrhagic and ischemic stroke is low, the mortality rates of both stroke types in patients with COVID-19 are concerning, and therefore, despite several potential pathogeneses that have been proposed, studies aimed at definitively elucidating the mechanisms of hemorrhagic and ischemic stroke in individuals with COVID-19 are warranted.

PROSPERO registration: CRD42020224470 (04/12/20)

Biomarkers of cavernous angioma with symptomatic hemorrhage

BACKGROUNDCerebral cavernous angiomas (CAs) with a symptomatic hemorrhage (CASH) have a high risk of recurrent hemorrhage and serious morbidity.METHODSEighteen plasma molecules with mechanistic roles in CA pathobiology were investigated in 114 patients and 12 healthy subjects. The diagnostic biomarker of a CASH in the prior year was derived as that minimizing the Akaike information criterion and validated using machine learning, and was compared with the prognostic CASH biomarker predicting bleeding in the subsequent year. Biomarkers were longitudinally followed in a subset of cases. The biomarkers were queried in the lesional neurovascular unit (NVU) transcriptome and in plasma miRNAs from CASH and non-CASH patients.RESULTSThe diagnostic CASH biomarker included a weighted combination of soluble CD14 (sCD14), VEGF, C-reactive protein (CRP), and IL-10 distinguishing CASH patients with 76% sensitivity and 80% specificity (P = 0.0003). The prognostic CASH biomarker (sCD14, VEGF, IL-1β, and sROBO-4) was confirmed to predict a bleed in the subsequent year with 83% sensitivity and 93% specificity (P = 0.001). Genes associated with diagnostic and prognostic CASH biomarkers were differentially expressed in CASH lesional NVUs. Thirteen plasma miRNAs were differentially expressed between CASH and non-CASH patients.CONCLUSIONShared and unique biomarkers of recent symptomatic hemorrhage and of future bleeding in CA are mechanistically linked to lesional transcriptome and miRNA. The biomarkers may be applied for risk stratification in clinical trials and developed as a tool in clinical practice.FUNDINGNIH, William and Judith Davis Fund in Neurovascular Surgery Research, Be Brave for Life Foundation, Safadi Translational Fellowship, Pritzker School of Medicine, and Sigrid Jusélius Foundation.

Hydrogen improves neurological function through attenuation of blood-brain barrier disruption in spontaneously hypertensive stroke-prone rats

Background

Enhanced oxidative stress occurs in spontaneously hypertensive stroke-prone rats (SHRSP), and is important in blood–brain barrier (BBB) disruption. Hydrogen can exert potent protective cellular effects via reduction in oxidative stress in various diseases. The present study investigated whether long-term hydrogen treatment can improve neurological function outcome in the SHRSP model, and the effects of hydrogen on BBB function, especially the oxidative stress and the activity of matrix metalloproteinases (MMPs) in this model. Fifty-six animals were randomly assigned to 2 groups and treated as follows: SHRSP treated with hydrogen-rich water (HRW) (HRW group, n = 28); and SHRSP treated with regular water (control group, n = 28). The effect of HRW on overall survival and neurological function, and the effects of HRW on reactive oxygen species, BBB function, and MMP activities were examined.

Results

HRW treatment improved neurological function and tended to improve overall survival but without significant difference. The numbers of bleeds and infarcts were lower in the cortex and hippocampus in the HRW group. The HRW group exhibited a significantly lower number of 8-hydroxy-2'-deoxyguanosine-positive cells and vessels of extravasated albumin in the hippocampus compared with the control group. MMP-9 activity was reduced in the hippocampus in the HRW group compared with the control group.

Conclusions

The present study suggests that ingestion of HRW can improve neurological function outcome in the SHRSP model. This beneficial effect may be due to attenuation of BBB disruption via reduction in reactive oxygen species and suppression of MMP-9 activity in the hippocampus.

Ligusticum wallichii Extract Inhibited the Expression of IL-1β after AMI in Rats

This study investigated the effects of Ligusticum wallichii on IL-1β expression in myocardium and central nervous system after AMI. AMI rat was administrated with Ligusticum wallichii extract. A series of assays were used to detect the effects of Ligusticum wallichii extract on infarct size, left ventricular ejection fraction, expression of TLR-4, NF-κB, and IL-1β in myocardium, IL-1β expression in serum and hypothalamus, and NPY expression in hypothalamus. We observed that Ligusticum wallichii extract improved the left ventricular ejection fraction and reduced infarct area enlargement after AMI, by inhibiting the expression of IL-1β in myocardium, serum, and hypothalamus. Ligusticum wallichii extract reduced the expression of IL-1β in myocardium by regulating TLR4-NF-κB signaling pathway and inhibited IL-1β in hypothalamus by regulating NPY mRNA expression.

Effects of remote ischemic preconditioning on the coagulation profile of patients with aneurysmal subarachnoid hemorrhage: a case-control study

BACKGROUND

Animal studies suggest that ischemic preconditioning prolongs coagulation times.

OBJECTIVE

Because coagulation changes could hinder the translation of preconditioning into clinical settings where hemorrhage may be an issue, such as ischemic or hemorrhagic stroke, we evaluated the effects of remote ischemic preconditioning (RIPC) on coagulation in patients undergoing RIPC after aneurysmal subarachnoid hemorrhage (SAH).

METHODS

Twenty-one patients with SAH (mean age, 56.3 years) underwent 137 RIPC sessions 2 to 12 days after SAH, each consisting of 3 to 4 cycles of 5 to 10 minutes of lower limb ischemia followed by reperfusion. Partial thromboplastin time (PTT), prothrombin time (PT), and international normalized ratio (INR) were analyzed before and after sessions. Patients were followed for hemorrhagic complications.

RESULTS

No immediate effect was identified on PTT (mean pre-RIPC, 27.62 s; post-RIPC, 27.54 s; P = .82), PT (pre-RIPC, 10.77 s; post-RIPC, 10.81 s; P = .59), or INR (pre-RIPC, 1.030; post-RIPC, 1.034; P = .57) after each session. However, statistically significant increases in PT and INR were identified after exposure to at least 4 sessions (mean PT pre-RIPC, 11.33 s; post-RIPC, 12.1 s; P = .01; INR pre-RIPC, 1.02; post-RIPC, 1.09; P = .014, PTT pre-RIPC, 27.4 s; post-RIPC, 27.85 s; P = .092) with a direct correlation between the number of sessions and the degree of increase in PT (Pearson correlation coefficient = 0.59, P = .007) and INR (Pearson correlation coefficient = 0.57, P = .010). Prolonged coagulation times were not observed in controls. No hemorrhagic complications were associated with the procedure.

CONCLUSION

RIPC by limb ischemia appears to prolong the PT and INR in human subjects with SAH after at least 4 sessions, correlating with the number of sessions. However, values remained within normal range and there were no hemorrhagic complications.

Drug-like property profiling of novel neuroprotective compounds to treat acute ischemic stroke: guidelines to develop pleiotropic molecules

The development of novel neuroprotective compounds to treat acute ischemic stroke (AIS) has been problematic and quite complicated, since many candidates that have been tested clinically lacked significant pleiotropic activity, were unable to effectively cross the blood brain barrier (BBB), had poor bioavailability or were toxic. Moreover, the compounds did not confer significant neuroprotection or clinical efficacy measured using standard behavioral endpoints, when studied in clinical trials in a heterogeneous population of stroke patients. To circumvent some of the drug development problems describe above, we have used a rational funnel approach to identify and develop promising candidates. Using a step-wise approach, we have identified a series of compounds based upon two different neuroprotection assays. We have then taken the candidates and determined their "drug-like" properties. This guidelines article details in vitro screening assays used to show pleiotropic activity of a series of novel compounds; including enhanced neuroprotective activity compared to the parent compound fisetin. Moreover, for preliminary drug de-risking or risk reduction during development, we used compound assessment in the CeeTox assay, ADME toxicity using the AMES test for genotoxicity and interaction with Cytochrome P450 using CYP450 inhibition analysis against a spectrum of CYP450 enzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4) as a measure of drug interaction. Moreover, the compounds have been studied using a transfected Madin Darby canine kidney (MDCK) cell assay to assess blood brain barrier penetration (BBB). Using this series of assays, we have identified 4 novel molecules to be developed as an AIS treatment.

Transcranial near-infrared laser therapy applied to promote clinical recovery in acute and chronic neurodegenerative diseases

One of the most promising methods to treat neurodegeneration is noninvasive transcranial near-infrared laser therapy (NILT), which appears to promote acute neuroprotection by stimulating mitochondrial function, thereby increasing cellular energy production. NILT may also promote chronic neuronal function restoration via trophic factor-mediated plasticity changes or possibly neurogenesis. Clearly, NILT is a treatment that confers neuroprotection or neurorestoration using pleiotropic mechanisms. The most advanced application of NILT is for acute ischemic stroke based upon extensive preclinical and clinical studies. In laboratory settings, NILT is also being developed to treat traumatic brain injury, Alzheimer's disease and Parkinson's disease. There is some intriguing data in the literature that suggests that NILT may be a method to promote clinical improvement in neurodegenerative diseases where there is a common mechanistic component, mitochondrial dysfunction and energy impairment. This article will analyze and review data supporting the continued development of NILT to treat neurodegenerative diseases.