Silent brain infarcts: a systematic review

Functional roles of polyamines and their metabolite acrolein in eukaryotic cells

Among low molecular weight substances, polyamines (spermidine, spermine and their precursor putrescine) are present in eukaryotic cells at the mM level together with ATP and glutathione. It is expected therefore that polyamines play important roles in cell proliferation and viability. Polyamines mainly exist as a polyamine-RNA complex and regulate protein synthesis. It was found that polyamines enhance translation from inefficient mRNAs. The detailed mechanisms of polyamine stimulation of specific kinds of protein syntheses and the physiological functions of these proteins are described in this review. Spermine is metabolized into acrolein (CH2 = CH-CHO) and hydrogen peroxide (H2O2) by spermine oxidase. Although it is thought that cell damage is mainly caused by reactive oxygen species (O2-, H2O2, and •OH), it was found that acrolein is much more toxic than H2O2. Accordingly, the level of acrolein produced becomes a useful biomarker for several tissue-damage diseases like brain stroke. Thus, the mechanisms of cell toxicity caused by acrolein are described in this review.

The high prevalence of abnormal MRI findings in non-neuropsychiatric patients with persistently positive antiphospholipid antibodies

OBJECTIVES

Thrombosis occurring in the central nerve system is common in antiphospholipid syndrome (APS) patients, leading to neuropsychiatric symptoms. We investigated the prevalence of silent brain abnormalities on magnetic resonance imaging (MRI) in primary antiphospholipid syndrome (PAPS) patients and antiphospholipid antibodies (aPL) carriers and assessed the association between the vascular risk factors, aPL profile, clinical manifestations, and MRI abnormalities.

METHODS

We consecutively included 44 PAPS patients, 24 aPL carriers and 23 healthy controls with comparable age and gender in a single-center, observational cross-sectional study. None of the patients had a history of stroke, TIA, migraine, dementia, epilepsy and bipolar disorders. On cerebral MRI, we assessed the imaging features and location of abnormality. Multivariate analysis was performed to identify the risk factors contributing to the MRI abnormalities.

RESULTS

38 (55.88%) patients persisted abnormal MRI findings, while only one healthy control showed some abnormalities in the MR findings. Lacunes were the most frequent MRI abnormality in aPL (+) group (31/68, 45.59%), which were followed by white matter hyperintensities (20/68, 29.41%). In all study population, age (OR = 1.086, p= 0.016) and LA positivity (OR = 5.191, p= 0.002) were the independent associated factors with the brain MRI abnormalities. When analyzed only in the aPL (+) group, age (OR = 1.116, p= 0.007), female gender (OR = 7.519, p= 0.025) and thrombocytopenia (OR = 8.336, p= 0.047) were the significant independent risk factors with abnormal MRI.

CONCLUSIONS

PAPS patients and aPL carriers showed a high prevalence of brain MRI abnormalities, indicating an increased cerebrovascular risk, which emphasized attention to silent cerebral lesions in persistently aPL positive patients.

Frequency and Patterns of Brain Infarction in Patients With Embolic Stroke of Undetermined Source: NAVIGATE ESUS Trial

BACKGROUND AND PURPOSE

The spectrum of brain infarction in patients with embolic stroke of undetermined source (ESUS) has not been well characterized. Our objective was to define the frequency and pattern of brain infarcts detected by magnetic resonance imaging (MRI) among patients with recent ESUS participating in a clinical trial.

METHODS

In the NAVIGATE ESUS trial (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism in Embolic Stroke of Undetermined Source), an MRI substudy was carried out at 87 sites in 15 countries. Participants underwent an MRI using a specified protocol near randomization. Images were interpreted centrally by those unaware of clinical characteristics.

RESULTS

Among the 918 substudy cohort participants, the mean age was 67 years and 60% were men with a median (interquartile range) of 64 (26-115) days between the qualifying ischemic stroke and MRI. On MRI, 855 (93%) had recent or chronic brain infarcts that were multiple in 646 (70%) and involved multiple arterial territories in 62% (401/646). Multiple brain infarcts were present in 68% (510/755) of those without a history of stroke or transient ischemic attack before the qualifying ESUS. Prior stroke/transient ischemic attack (P<0.001), modified Rankin Scale score >0 (P<0.001), and current tobacco use (P=0.01) were associated with multiple infarcts. Topographically, large and/or cortical infarcts were present in 89% (757/855) of patients with infarcts, while in 11% (98/855) infarcts were exclusively small and subcortical. Among those with multiple large and/or cortical infarcts, 57% (251/437) had one or more involving a different vascular territory from the qualifying ESUS.

CONCLUSIONS

Most patients with ESUS, including those without prior clinical stroke or transient ischemic attack, had multiple large and/or cortical brain infarcts detected by MRI, reflecting a substantial burden of clinical stroke and covert brain infarction. Infarcts most frequently involved multiple vascular territories.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02313909.

A narrative review of plaque and brain imaging biomarkers for stroke risk stratification in patients with atherosclerotic carotid artery disease

Objective

In this narrative review, we aim to review imaging biomarkers that carry the potential to non-invasively guide stroke risk stratification for treatment optimization.

Background

Carotid atherosclerosis plays a fundamental part in the occurrence of ischemic stroke. International guidelines select the optimal treatment strategy still mainly based on the presence of clinical symptoms and the degree of stenosis for stroke prevention in patients with atherosclerotic carotid plaques. These guidelines, based on randomized controlled trials that were conducted three decades ago, recommend carotid revascularization in symptomatic patients with high degree of stenosis versus a conservative approach for most asymptomatic patients. Due to optimization of best medical therapy and risk factor control, it is suggested that a subgroup of symptomatic patients is at lower risk of stroke and may not benefit from revascularization, whereas a selective subgroup of high-risk asymptomatic patients would benefit from this procedure.

Methods

A literature search was performed for articles published up to December 2020 using PubMed, EMBASE and Scopus. Based on the literature found, change in stenosis degree and volume, plaque echolucency, plaque surface, intraplaque haemorrhage, lipid-rich necrotic core, thin fibrous cap, inflammation, neovascularization, microembolic signals, cerebrovascular reserve, intracranial collaterals, silent brain infarcts, diffusion weighted imaging lesions and white matters lesions have the potential to predict stroke risk.

Conclusions

The applicability of imaging biomarkers needs to be further improved before the potential synergistic prognostic ability of imaging biomarkers can be verified on top of the clinical biomarkers. In the future, the routine and combined assessment of both plaque and brain imaging biomarkers might help to improve optimization of treatment strategies in individual patients with atherosclerotic carotid artery disease.

Comparing Pathological Risk Factors for Dementia between Cognitively Normal Japanese and Americans

The Alzheimer's Disease Neuroimaging Initiative showed that Japanese had significantly lower brain Aβ burden than Americans among a cognitively normal population. This cross-sectional study aimed to compare vascular disease burden, Aβ burden, and neurodegeneration between cognitively normal elderly Japanese and Americans. Japanese and American participants were matched for age (±4-year-old), sex, and Apolipoprotein E (APOE) genotype. Brain vascular disease burden and brain Aβ burden were measured using white matter lesions (WMLs) and 11C-labeled Pittsburgh Compound B (PiB) retention, respectively. Neurodegeneration was measured using hippocampal volumes and cortical thickness. A total of 95 Japanese and 95 Americans were recruited (50.5% men, mean age = 82). Compared to Americans, Japanese participants had larger WMLs, and a similar global Aβ standardized uptake value ratio (SUVR), cortical thickness and hippocampal volumes. Japanese had significantly lower regional Aβ SUVR in the anterior ventral striatum, posterior cingulate cortex, and precuneus. Cognitively normal elderly Japanese and Americans had different profiles regarding vascular disease and Aβ burden. This suggests that multiple risk factors are likely to be involved in the development of dementia. Additionally, Japanese might have a lower risk of dementia due to lower Aβ burden than Americans. Longitudinal follow-up of these cohorts is warranted to ascertain the predictive accuracy of these findings.

The vessel density of the superficial retinal capillary plexus as a new biomarker in cerebral small vessel disease: an optical coherence tomography angiography study

BACKGROUND

Optical coherence tomography angiography (OCTA) is a novel and noninvasive technique for the quantitative assessment of retinal microvascular perfusion. Since the retinal and cerebral small vessels share similar embryological origins, anatomical features, and physiological properties, altered retinal microvasculature might provide a new perspective on the mechanisms of cerebral small vessel disease (CSVD).

OBJECTIVE

We aimed to evaluate retinal vessel density (VD) in patients with CSVD using OCTA and identify associations with cerebral magnetic resonance imaging (MRI) markers and cognitive function.

METHODS

We prospectively recruited 47 CSVD patients and 30 healthy controls (HCs) to participate in the study. All participants underwent OCTA to evaluate retinal microvascular perfusion. The VDs of the macular region in the superficial retinal capillary plexus (SRCP), deep retinal capillary plexus (DRCP), and foveal avascular zone (FAZ) were determined, along with the VD of the optic nerve head (ONH) in the radial peripapillary capillary (RPC) network. Additionally, cerebral MRI and cognitive function tests were performed.

RESULTS

In the macula area, the VD of the CSVD patients was significantly lower than HCs in the temporal quadrant of SRCP. In the ONH area, CSVD patients had lower VD than HCs in the peripapillary RPC network. According to multiple linear regression analysis, decreased VD of the macular SRCP was associated with white matter hyperintensity scores after adjustment for age, hypertension, diabetes, and hyperlipidemia. Furthermore, the VD of the macular SRCP was significantly correlated with CSVD patients' cognitive function, especially global cognition, memory function, attention function, information processing, and executive function.

CONCLUSION

OCTA revealed a significant decrease in retinal microvascular perfusion in CSVD patients, and retinal hypoperfusion was related to MRI markers and cognitive function, suggesting that these parameters could have potential utility as early disease biomarkers.

A randomized evaluation of the TriGuard™ HDH cerebral embolic protection device to Reduce the Impact of Cerebral Embolic LEsions after TransCatheter Aortic Valve ImplanTation: the REFLECT I trial

AIMS

The REFLECT I trial investigated the safety and effectiveness of the TriGuard™ HDH (TG) cerebral embolic deflection device in patients undergoing transcatheter aortic valve replacement (TAVR).

METHODS AND RESULTS

This prospective, multicentre, single-blind, 2:1 randomized (TG vs. no TG) study aimed to enrol up to 375 patients, including up to 90 roll-in patients. The primary combined safety endpoint (VARC-2 defined early safety) at 30 days was compared with a performance goal. The primary efficacy endpoint was a hierarchical composite of (i) all-cause mortality or any stroke at 30 days, (ii) National Institutes of Health Stroke Scale (NIHSS) worsening at 2-5 days or Montreal Cognitive Assessment worsening at 30 days, and (iii) total volume of cerebral ischaemic lesions detected by diffusion-weighted magnetic resonance imaging at 2-5 days. Cumulative scores were compared between treatment groups using the Finkelstein-Schoenfeld method. A total of 258 of the planned, 375 patients (68.8%) were enrolled (54 roll-in and 204 randomized). The primary safety outcome was met compared with the performance goal (21.8% vs. 35%, P < 0.0001). The primary hierarchical efficacy endpoint was not met (mean efficacy score, higher is better: -5.3 ± 99.8 TG vs. 11.8 ± 96.4 control, P = 0.31). Covert central nervous system injury was numerically lower with TG both in-hospital (46.1% vs. 60.3%, P = 0.0698) and at 5 days (61.7 vs. 76.2%, P = 0.054) compared with controls.

CONCLUSION

REFLECT I demonstrated that TG cerebral protection during TAVR was safe in comparison with historical TAVR data but did not meet the predefined effectiveness endpoint compared with unprotected TAVR controls.

Association of Silent Cerebrovascular Disease Identified Using Natural Language Processing and Future Ischemic Stroke

BACKGROUND AND OBJECTIVE

Silent cerebrovascular disease (SCD), comprised of silent brain infarction (SBI) and white matter disease (WMD), is commonly found incidentally on neuroimaging scans obtained in routine clinical care. However, their prognostic significance is not known. We aimed to estimate the incidence of, and risk increase in, future stroke in patients with incidentally-discovered SCD. METHODS: Patients in Kaiser Permanente Southern California (KPSC) health system aged ≥ 50, without prior ischemic stroke, transient ischemic attack, or dementia/Alzheimer's disease receiving a head CT or MRI between 2009-2019 were included. SBI and WMD were identified by natural language processing (NLP) from the neuroimage report.

RESULTS

Among 262,875 individuals receiving neuroimaging, NLP identified 13,154 (5.0%) with SBI and 78,330 (29.8%) with WMD. The incidence of future stroke was 32.5 (95% CI 31.1, 33·9) per 1,000 patient-years for patients with SBI; 1.·3 (95% CI 18.9, 19.8) for patients with WMD and 6.8 (95% CI 6.7, 7.0) for patients without SCD. The crude HR associated with SBI was 3.40 (95% CI 3.25 to 3.56); and for WMD was 2.63 (95% CI 2.54 to 2·71). With MRI-discovered SBI, the adjusted HR was 2.95 (95% CI 2.53 to 3.44) for those < age 65 and 2.15 (95% CI 1.91 to 2.41) for those ≥ age 65. With CT scan, the adjusted HR was 2.48 (95% CI 2.19 to 2.81) for those < age 65 and 1.81 (95% CI 1.71 to 1.91) for those >= age 65. The adjusted HR associated with a finding of WMD was 1.76 (95% CI 1.69 to 1.82) and was not modified by age or imaging modality.

DISCUSSION

Incidentally-discovered SBI and WMD are common and associated with increased risk of subsequent symptomatic stroke representing an important opportunity for stroke prevention.

Neurologically asymptomatic patients frequently present cerebral injuries during malignant hypertension: a MRI study

BACKGROUND

Acute and diffuse microvascular damage characterizes malignant hypertension (MHT), the deadliest form of hypertension (HTN). Although its ophthalmological, renal and cardiological repercussions are well known, brain involvement is considered rare with few descriptions, although it is one of the main causes of death. We hypothesized that brain MRI abnormalities are common in MHT, even in patients without objective neurological signs.

METHOD

We analyzed retrospectively the brain MRI of patients admitted for acute MHT between 2008 and 2018 in Bordeaux University Hospital, regardless of their neurological status. A trained operator analyzed every brain MRI, looking for posterior reversible encephalopathy syndrome (PRES), ischemic stroke, intracerebral hematoma (ICH) and microangiopathy markers. We included 58 patients without neurological signs, 66% were men, and mean age was 45.6 ± 11.3 years.

RESULTS

Brain MRI were normal in 26% of patients but we found at least one acute abnormality on brain MRI in 29% and an Small Vessel Disease score (SVD score) of two or higher in 52%. In patients with neurological signs, these findings were 9, 53 and 70%, respectively. A PRES was found in 16% of asymptomatic patients and 31% had an ischemic stroke and/or a cerebral hematoma.

CONCLUSION

PRES, recent hematoma, ischemic stroke and severe cerebral microangiopathy are common findings in MHT patients without neurological signs on admission. The impact of these findings on patient management, and their cerebrovascular and cognitive prognostic value, should be established. Brain MRI might need to become systematic in patients suffering from MHT episodes.

White matter network damage mediates association between cerebrovascular disease and cognition

To determine whether white matter network disruption mediates the association between MRI markers of cerebrovascular disease (CeVD) and cognitive impairment. Participants (n = 253, aged ≥60 years) from the Epidemiology of Dementia in Singapore study underwent neuropsychological assessments and MRI. CeVD markers were defined as lacunes, white matter hyperintensities (WMH), microbleeds, cortical microinfarcts, cortical infarcts and intracranial stenosis (ICS). White matter microstructure damage was measured as fractional anisotropy and mean diffusivity by tract based spatial statistics from diffusion tensor imaging. Cognitive function was summarized as domain-specific Z-scores.Lacunar counts, WMH volume and ICS were associated with worse performance in executive function, attention, language, verbal and visual memory. These three CeVD markers were also associated with white matter microstructural damage in the projection, commissural, association, and limbic fibers. Path analyses showed that lacunar counts, higher WMH volume and ICS were associated with executive and verbal memory impairment via white matter disruption in commissural fibers whereas impairment in the attention, visual memory and language were mediated through projection fibers.Our study shows that the abnormalities in white matter connectivity may underlie the relationship between CeVD and cognition. Further longitudinal studies are needed to understand the cause-effect relationship between CeVD, white matter damage and cognition.

MTT and Blood-Brain Barrier Disruption within Asymptomatic Vascular WM Lesions

BACKGROUND AND PURPOSE

White matter lesions of presumed ischemic origin are associated with progressive cognitive impairment and impaired BBB function. Studying the longitudinal effects of white matter lesion biomarkers that measure changes in perfusion and BBB patency within white matter lesions is required for long-term studies of lesion progression. We studied perfusion and BBB disruption within white matter lesions in asymptomatic subjects.

MATERIALS AND METHODS

Anatomic imaging was followed by consecutive dynamic contrast-enhanced and DSC imaging. White matter lesions in 21 asymptomatic individuals were determined using a Subject-Specific Sparse Dictionary Learning algorithm with manual correction. Perfusion-related parameters including CBF, MTT, the BBB leakage parameter, and volume transfer constant were determined.

RESULTS

MTT was significantly prolonged (7.88 [SD, 1.03] seconds) within white matter lesions compared with normal-appearing white (7.29 [SD, 1.14] seconds) and gray matter (6.67 [SD, 1.35] seconds). The volume transfer constant, measured by dynamic contrast-enhanced imaging, was significantly elevated (0.013 [SD, 0.017] minutes-1) in white matter lesions compared with normal-appearing white matter (0.007 [SD, 0.011] minutes-1). BBB disruption within white matter lesions was detected relative to normal white and gray matter using the DSC-BBB leakage parameter method so that increasing BBB disruption correlated with increasing white matter lesion volume (Spearman correlation coefficient = 0.44; P < .046).

CONCLUSIONS

A dual-contrast-injection MR imaging protocol combined with a 3D automated segmentation analysis pipeline was used to assess BBB disruption in white matter lesions on the basis of quantitative perfusion measures including the volume transfer constant (dynamic contrast-enhanced imaging), the BBB leakage parameter (DSC), and MTT (DSC). This protocol was able to detect early pathologic changes in otherwise healthy individuals.

Clinical manifestation of acute cerebral infarcts in multiple arterial territories

OBJECTIVES

We aimed to assess frequencies and radiological aspects of single- and multiterritory clinical manifestation among patients with acute cerebral infarcts in multiple arterial territories (MACI).

MATERIALS & METHODS

We retrospectively reviewed admission records and diffusion-weighted magnetic resonance imaging of patients with MACI admitted to our stroke unit between 2006 and 2017. MACI was defined as acute cerebral ischemic lesions in at least two out of three arterial cerebral territories, that is, the left anterior, right anterior and the bilateral posterior territory. Patients with single- and multiterritory clinical manifestation were then compared for topographical distribution of the ischemic lesions, the number of ischemic lesions, and The Oxfordshire Community Stroke Project classification.

RESULTS

Out of 311 patients with MACI, 222 (71.4%) presented with single-territory clinical manifestation. Involvement of the left hemisphere (OR = 0.37, 95% CI 0.16-0.82), less than five ischemic lesions (OR = 0.58, 95% CI 0.35-0.97), and partial anterior circulation infarct clinical stroke syndrome (OR = 0.57, 95% CI 0.34-0.97) were associated with single-territory clinical manifestation. Involvement of all three territories (OR = 2.58, 95% = 1.48-4.50), more than 10 ischemic lesions (OR = 2.30, 95% CI 1.32-4.01) and total anterior circulation infarct clinical stroke syndrome (OR = 3.31, 95% CI 1.39-7.86) were associated with multiterritory clinical manifestation.

CONCLUSION

Most patients with MACI present with single-territory clinical manifestation on admission. Diffusion-weighted magnetic resonance imaging is therefore necessary for a definite diagnosis.

Guide de Pratique Clinique. Prise en charge de l’hypertension artérielle chez l’adulte en Tunisie

Ce document a été réalisé dans le cadre d'une collaboration entre l'Instance Nationale de l’Évaluation et de l'Accréditation en Santé (INEAS), la Société Tunisienne de Cardiologie et de Chirurgie Cardiovasculaire (STCCCV) et la Caisse Nationale d’Assurance Maladie (CNAM).

The selective estrogen receptor modulator tamoxifen protects against subtle cognitive decline and early markers of injury 24 h after hippocampal silent infarct in male Sprague-Dawley rats

Silent infarcts (SI) are subcortical cerebral infarcts occurring in the absence of typical ischemia symptoms and are linked to cognitive decline and dementia development. There are no approved treatments for SI. One potential treatment is tamoxifen, a selective estrogen receptor modulator. It is critical to establish whether treatments effectively target the early consequences of SI to avoid progression to complete injury. We induced SI in the dorsal hippocampal CA1 of rats and assessed whether tamoxifen is protective 24 h later against cognitive deficits and injury responses including gliosis, apoptosis, inflammation and changes in estrogen receptors (ERs). SI led to subtle cognitive impairment on the object place task, an effect ameliorated by tamoxifen administration. SI did not lead to detectable hippocampal cell loss but increased apoptosis, astrogliosis, microgliosis and inflammation. Tamoxifen protected against the effects of SI on all measures except microgliosis. SI increased ERα and decreased ERβ in the hippocampus, which were mitigated by tamoxifen. Exploratory data analyses using scatterplot matrices and principal component analysis indicated that SI rats given tamoxifen were indistinguishable from controls. Further, SI rats were significantly different from all other groups, an effect associated with low levels of ERα and increased apoptosis, gliosis, inflammation, ERβ, and time spent with the unmoved object. The results demonstrate that tamoxifen is protective against the early cellular and cognitive consequences of hippocampal SI 24 h after injury. Tamoxifen mitigates apoptosis, gliosis, and inflammation and normalization of ER levels in the CA1, leading to improved cognitive outcomes after hippocampal SI.

Carotid Atherosclerosis and Longitudinal Changes of MRI Visual Rating Measures in Stroke Survivors: A Seven-Year Follow-Up Study

OBJECTIVES

We aimed to assess longitudinal changes in MRI measures of brain atrophy and white matter lesions in stroke and transient ischemic attack (TIA) survivors, and explore whether carotid stenosis predicts progression of these changes, assessed by visual rating scales.

MATERIALS AND METHODS

All patients with a first-ever stroke or TIA admitted to Bærum Hospital, Norway, in 2007/2008, were invited in the acute phase and followed for seven years. Carotid ultrasound was performed during the hospital stay. Carotid stenosis was defined as ≥50% narrowing of lumen. MRI was performed one and seven years after the index event and analyzed according to the visual rating scales Fazekas scale (0-3), Medial Temporal Lobe Atrophy (MTLA) (0-4) score, and Global Cortical Atrophy (GCA) scale (0-3). Patients with MRI scans at both time points were included in this sub-study.

RESULTS

Of 227 patients recruited, 76 had both MRI examinations. Mean age 73.9±10.6, 41% women, and 9% had ≥50% carotid stenosis. Mean Fazekas scale was 1.7±0.9 and 1.8±1.0, mean MTLA score 1.0 ±1.0 and 1.7±1.0, and mean GCA scale score 1.4±0.7 and 1.4±0.6 after one and seven years, respectively. 71% retained the same Fazekas scale score, while 21% showed progression. Deterioration in GCA scale was seen in 20% and increasing MTLA score in 57%. Carotid stenosis was not associated with progression on Fazekas score, MTLA score or GCA scale.

CONCLUSIONS

Three out of five showed progression on the MTLA score. Carotid stenosis was not associated with longitudinal change of visual rating scales.

Association of Ischemic Imaging Phenotype With Progression of Brain Atrophy and Cerebrovascular Lesions on MRI: The SMART-MR Study

OBJECTIVE

To investigate the association of silent vascular lesions, imaging negative ischemia, and symptomatic cerebrovascular disease with long-term progression of brain atrophy and cerebrovascular lesions in patients with arterial disease.

METHODS

Within the SMART-MR study, stroke status of participants at baseline was classified as no cerebrovascular disease (reference group, n=829), symptomatic cerebrovascular disease (n=206), silent vascular lesion (n=157), and imaging negative ischemia (n=90) based upon clinical and MRI findings. Using linear mixed models, changes in brain and white matter hyperintensity (WMH) volumes at baseline and during 12 years of follow-up were studied in stroke classifications. Relative risks were estimated for new infarcts during follow-up associated with stroke classifications. Analyses were adjusted for age, sex, cardiovascular risk factors, and medications.

RESULTS

Symptomatic cerebrovascular disease associated with 0.35 SDs (95%CI 0.24-0.47) smaller brain volume and 0.61 SDs (95%CI 0.48-0.74) larger WMH volume at baseline, and increased risk for new infarcts during follow-up (risk ratio (RR) 2.89; 95%CI 2.00-4.16). Silent vascular lesions associated with 0.15 SDs (95%CI 0.01-0.88) smaller brain volume, 0.02 SDs (95%CI 0.01-0.03) steeper brain atrophy slope, and 0.48 SDs (95%CI 0.32-0.64) larger WMH volume at baseline, in addition to increased risk for lacunes (RR 2.08; 95%CI 1.48-2.94). Individuals with imaging negative ischemia had increased risk for cortical infarcts (RR=2.88; 95%CI 2.17-3.82).

CONCLUSIONS

Patients with symptomatic cerebrovascular disease, silent vascular lesions, or imaging negative ischemia have different course of brain volume loss and cerebrovascular lesions development. These findings may have implications for future stroke risk and dementia and need further investigation.

Efficacy and safety of cerebral embolic protection systems during transcatheter aortic valve replacement: a review of current clinical findings

INTRODUCTION

Cerebrovascular events are one of the most serious consequences after transcatheter aortic valve replacement (TAVR). More than half of the cerebrovascular events following TAVR are due to procedure-related emboli. Embolic protection devices (EPDs) have the potential to decrease cerebrovascular events during TAVR procedure. However, randomized controlled trials (RCTs) have not conclusively determined if EPDs are effective, likely because of small number of patients enrolled. However, meta-analyses and propensity-matched analyses from large registries have shown efficacy and suggest the importance of EPDs in prevention of stroke during TAVR and perhaps other structural heart procedures.

AREAS COVERED

This review will focus on clinical and histopathologic studies examining the efficacy, safety, and histopathologic device capture findings in the presence and absence of EPDs during TAVR procedures.

EXPERT OPINION

Clinical studies have not conclusively determined the efficacy of EPDs. Current ongoing large-scale RCT (PROTECTED TAVR [NCT04149535]) has the potential to prove their efficacy. Histopathological evaluation of debris captured by EPDs contributes to our understanding of the mechanisms of TAVR procedure-related embolic events and suggests the importance of preventing cerebral embolization of debris released during this and other structural heart procedures.

Incidence and risk factors of post-operative cognitive decline after ablation for atrial fibrillation

Background

Catheter ablation is widely used in atrial fibrillation (AF) management. In this study, we are aimed to investigate the incidence of postprocedural cognitive decline in a larger population undergoing AF ablation under local anesthesia, and to evaluate the associated risk factors.

Methods

This study included 287 patients with normal cognitive functions, with 190 ablated AF patients (study group) and 97 AF patients who are awaiting ablation (practice group). We assessed the neuropsychological function of each patient for twice (study group: 24 h prior to ablation and 48 h post ablation; practice group: on the day of inclusion and 72 h later but before ablation). The reliable change index was used to analyze the neuropsychological testing scores and to identify postoperative cognitive dysfunction (POCD) at 48 h post procedure. Patients in the study group accepting a 6-month follow up were given an extra cognitive assessment.

Results

Among the ablated AF patients, 13.7% (26/190) had POCD at 48 h after the ablation procedure. Multivariable analysis revealed that, a minimum intraoperative activated clotting time (ACT) < 300 s (OR 3.82, 95% CI 1.48–9.96, P = 0.006) and not taking oral anticoagulants within one month prior to ablation(OR 10.35, 95% CI 3.54–30.27, P < 0.001) were significantly related to POCD at 48 h post-ablation. In 172 patients of the study group accepting a 6-month follow up, there were 23 patients with POCD at 48 h post-ablation and 149 patients without POCD. The global cognitive scores were decreased in 48 h post-operation tests (0 ± 1 vs − 0.15 ± 1.10, P < 0.001) and improved significantly at 6 months post-operation (0 ± 1 vs 0.43 ± 0.92, P < 0.001). In the 23 patients with POCD at 48 h after the procedure, global cognitive performance at 6 months was not significantly different compared with that at baseline (− 0.05 ± 1.25 vs − 0.19 ± 1.33, P = 0.32), while 13 of them had higher scores than baseline level.

Conclusions

Incident of POCD after ablation procedures is high in the short term. Inadequate periprocedural anticoagulation are possible risk factors. However, most POCD are reversible at 6 months, and a general improvement was observed in cognitive function at 6 months after ablation.

Mobility speed predicts new-onset hypertension: a longitudinal study

The aim of this study was to investigate whether declining mobility and muscle strength predict new-onset hypertension in suburban-dwelling elderly individuals.

Neurovascular Coupling in Development and Disease: Focus on Astrocytes

Neurovascular coupling is a crucial mechanism that matches the high energy demand of the brain with a supply of energy substrates from the blood. Signaling within the neurovascular unit is responsible for activity-dependent changes in cerebral blood flow. The strength and reliability of neurovascular coupling form the basis of non-invasive human neuroimaging techniques, including blood oxygen level dependent (BOLD) functional magnetic resonance imaging. Interestingly, BOLD signals are negative in infants, indicating a mismatch between metabolism and blood flow upon neural activation; this response is the opposite of that observed in healthy adults where activity evokes a large oversupply of blood flow. Negative neurovascular coupling has also been observed in rodents at early postnatal stages, further implying that this is a process that matures during development. This rationale is consistent with the morphological maturation of the neurovascular unit, which occurs over a similar time frame. While neurons differentiate before birth, astrocytes differentiate postnatally in rodents and the maturation of their complex morphology during the first few weeks of life links them with synapses and the vasculature. The vascular network is also incomplete in neonates and matures in parallel with astrocytes. Here, we review the timeline of the structural maturation of the neurovascular unit with special emphasis on astrocytes and the vascular tree and what it implies for functional maturation of neurovascular coupling. We also discuss similarities between immature astrocytes during development and reactive astrocytes in disease, which are relevant to neurovascular coupling. Finally, we close by pointing out current gaps in knowledge that must be addressed to fully elucidate the mechanisms underlying neurovascular coupling maturation, with the expectation that this may also clarify astrocyte-dependent mechanisms of cerebrovascular impairment in neurodegenerative conditions in which reduced or negative neurovascular coupling is noted, such as stroke and Alzheimer’s disease.

Causes and consequences of baseline cerebral blood flow reductions in Alzheimer's disease

Reductions of baseline cerebral blood flow (CBF) of ∼10-20% are a common symptom of Alzheimer's disease (AD) that appear early in disease progression and correlate with the severity of cognitive impairment. These CBF deficits are replicated in mouse models of AD and recent work shows that increasing baseline CBF can rapidly improve the performance of AD mice on short term memory tasks. Despite the potential role these data suggest for CBF reductions in causing cognitive symptoms and contributing to brain pathology in AD, there remains a poor understanding of the molecular and cellular mechanisms causing them. This review compiles data on CBF reductions and on the correlation of AD-related CBF deficits with disease comorbidities (e.g. cardiovascular and genetic risk factors) and outcomes (e.g. cognitive performance and brain pathology) from studies in both patients and mouse models, and discusses several potential mechanisms proposed to contribute to CBF reductions, based primarily on work in AD mouse models. Future research aimed at improving our understanding of the importance of and interplay between different mechanisms for CBF reduction, as well as at determining the role these mechanisms play in AD patients could guide the development of future therapies that target CBF reductions in AD.

The unfolding palette of COVID-19 multisystemic syndrome and its neurological manifestations

Although our current knowledge of the pathophysiology of COVID-19 is still fragmentary, the information so far accrued on the tropism and life cycle of its etiological agent SARS-CoV-2, together with the emerging clinical data, suffice to indicate that the severe acute pulmonary syndrome is the main, but not the only manifestation of COVID-19. Necropsy studies are increasingly revealing underlying endothelial vasculopathies in the form of micro-haemorrhages and micro-thrombi. Intertwined with defective antiviral responses, dysregulated coagulation mechanisms, abnormal hyper-inflammatory reactions and responses, COVID-19 is disclosing a wide pathophysiological palette. An additional property in categorising the disease is the combination of tissue (e.g. neuro- and vasculo-tropism) with organ tropism, whereby the virus preferentially attacks certain organs with highly developed capillary beds, such as the lungs, gastrointestinal tract, kidney and brain. These multiple clinical presentations confirm that the acute respiratory syndrome as described initially is increasingly unfolding as a more complex nosological entity, a multiorgan syndrome of systemic breadth. The neurological manifestations of COVID-19, the focus of this review, reflect this manifold nature of the disease.

Association Between Cemented vs Cementless Hemiarthroplasty and Short-Term Change of In-Hospital Mortality in Elderly Patients with Femoral Neck Fracture: A Propensity-Score Matching Analysis in a Multicenter Database

Objective

Cemented hemiarthroplasty is recommended for the vulnerable hip fracture population because of beneficial long-term outcomes. However, the association between cemented hemiarthroplasty and short-term mortality is controversial. To increase a preparedness of potential complication after cemented hemiarthroplasty, we aimed to evaluate the trajectory of the effect of cemented hemiarthroplasty on short-term in-hospital outcomes.

Methods

We investigated in-hospital mortality and complications between cemented hemiarthroplasty and cementless hemiarthroplasty using a nationwide multicenter database from 2010 to 2016 with a propensity-score matching analysis. We analyzed in-hospital mortality from 1 to 14 days after surgery. We also investigated in-hospital complications that may associate with mortality.

Results

After matching of 31,322 cases, we found no significant difference in 30-day in-hospital mortality between the cemented and cementless hemiarthroplasty groups (hazard ratio, HR [95% confidence interval, CI], 1.2 [0.89-1.6], p = 0.23). However, the 1- to 10-day postoperative mortality rates were significantly higher in the cemented group and the association becomes weaker as the postoperative period increased (day 1; HR [95% CI]: 3.5 [1.6-7.68]; day 10; HR [95% CI]: 1.59 [1.07-2.37]). The incidence of stroke and intensive care unit (ICU) admission was also significantly higher in the cemented group.

Conclusion

Cemented hemiarthroplasty was not significantly associated with an increase in overall in-hospital mortality but was significantly associated with short-term mortality from 1-day to 10-day after surgery. The incidence of stroke and ICU admission was also significantly higher in the cemented group. Surgeons should pay more attention to the risk of mortality and stroke in patients undergoing cemented hemiarthroplasty, especially in the early days of hospitalization.

Focal Subcortical White Matter Lesions Disrupt Resting State Cortical Interhemispheric Functional Connectivity in Mice

The corpus callosum is the largest white matter tract and critical for interhemispheric connectivity. Unfortunately, neurocognitive deficits after experimental white matter lesions are subtle and variable, limiting their translational utility. We examined resting state functional connectivity (RSFC) as a surrogate after a focal lesion in the lateral corpus callosum induced by stereotaxic injection of L-NIO in mice. RSFC was performed via optical intrinsic signal imaging through intact skull before and on days 1 and 14 after injection, using interhemispheric homotopic and seed-based temporal correlation maps. We measured the lesion volumes at 1 month in the same cohort. L-NIO induced focal lesions in the corpus callosum. Interhemispheric homotopic connectivity decreased by up to 50% 24 h after L-NIO, partially sparing the visual cortex. All seeds showed loss of connectivity to the contralateral hemisphere. Moreover, ipsilesional motor and visual cortices lost connectivity within the same hemisphere. Sham-operated mice did not show any lesion or connectivity changes. RSFC imaging reliably detects acute disruption of long interhemispheric and intrahemispheric connectivity after a corpus callosum lesion in mice. This noninvasive method can be a functional surrogate to complement neurocognitive testing in both therapeutic and recovery studies after white matter injury.

Cerebral embolic protection during transcatheter aortic valve replacement

BACKGROUND

It is controversial that cerebral embolic protection devices (CEPDs) reduce clinical stroke during transcatheter aortic valve replacement (TAVR). Herein, we investigated the impact of CEPDs on in-hospital clinical stroke using a nationally representative sample.

METHODS AND RESULTS

Using the National Inpatient Sample (NIS) database, 109,240 patients who underwent TAVR between 2017 and 2018 were included. They were categorized into 2 groups according to usage of CEPDs; the CEPD and non-CEPD groups. After propensity score matching, 3805 pairs were acquired. Our main outcome was in-hospital clinical stroke. Other outcomes were in-hospital mortality, acute kidney injury (AKI), AKI leading to hemodialysis, bleeding requiring transfusion, overall bleeding complications, infectious complications, length of stay, and total cost. In-hospital clinical stroke did not significantly differ between the 2 groups (0.7% versus 1.1%, p = 0.449). The CEPD group was associated with a significantly lower in-hospital mortality (0.5% versus 1.4%, p = 0.029) and reduced total cost ($49,047 ± 19,666 versus $50,051 ± 23,190, p < 0.001), compared with the non-CEPD group, whereas there were no significant differences in the other outcomes.

CONCLUSIONS

By using the NIS database with a large number of cases, TAVR with CEPDs was not associated with a lower incidence of in-hospital clinical stroke compared with no use of CEPDs after matching.

Blood-Based Cardiac Biomarkers and the Risk of Cognitive Decline, Cerebrovascular Disease, and Clinical Events

[Figure: see text].

A Proposed Hypothesis on Dementia: Inflammation, Small Vessel Disease, and Hypoperfusion Is the Sequence That Links All Harmful Lifestyles to Cognitive Impairment

There is growing consensus that certain lifestyles can contribute to cognitive impairment and dementia, but the physiological steps that link a harmful lifestyle to its negative impact are not always evident. It is also unclear whether all lifestyles that contribute to dementia do so through the same intermediary steps. This article will focus on three lifestyles known to be risk factors for dementia, namely obesity, sedentary behavior, and insufficient sleep, and offer a unifying hypothesis proposing that lifestyles that negatively impact cognition do so through the same sequence of events: inflammation, small vessel disease, decline in cerebral perfusion, and brain atrophy. The hypothesis will then be tested in a recently identified risk factor for dementia, namely hearing deficit. If further studies confirm this sequence of events leading to dementia, a significant change in our approach to this debilitating and costly condition may be necessary, possible, and beneficial.

Endocan: A Novel Predictor of Endothelial Dysfunction in Silent Brain Infarction

Silent brain infarction (SBI) has been considered as a subclinical risk factor for symptomatic possible future stroke. We investigated the association between serum inflammatory markers and SBI. Patients (n = 54) diagnosed with SBI as the study group and 52 individuals as the control group were included in this study. Silent brain infarction is defined as a hyperintense lesion that was ≥3 mm in 1 dimension on fluid-attenuated inversion recovery T2-weighted magnetic resonance image, if the patient had normal neurological examination or had an abnormality that was not consistent with the brain lesion locations, after being evaluated by a neurologist. Serum endocan levels (P = .036) and high-sensitivity C-reactive protein (hsCRP; P = .022) were significantly higher in patients with SBI than the controls. Pentraxin 3, erythrocyte sedimentation rate, white blood count, lymphocyte, monocyte, neutrophil, low-density lipoprotein, and triglyceride levels were not significantly different when comparing the groups with and without SBI. There was a significant correlation (r = -0.196; P = .16) between hsCRP and endocan levels in the SBI group. Endocan, a novel biomarker of endothelial pathology, was significantly increased in patients with SBI and may be useful to predict the future risk of stroke.

Higher Cerebral Small Vessel Disease Burden in Patients with White Matter Recent Small Subcortical Infarcts

INTRODUCTION

Recent small subcortical infarcts (RSSI) are considered an acute manifestation of cerebral small vessel disease (CSVD). We assessed whether the topography of RSSI was related to CSVD markers on magnetic resonance imaging (MRI).

MATERIAL AND METHODS

We screened the local registries of two independent stroke centers in Catalonia and selected patients with a symptomatic RSSI on MRI performed during admission. RSSI location was classified into brainstem, supratentorial subcortical structures (SSS), and centrum semiovale (CSO) regions. Clinical variables, including vascular risk factors, were collected. Radiological markers of CSVD on MRI were evaluated individually and by means of the global CSVD burden score. The associations between each RSSI location and CSVD markers were studied in uni- and multivariate logistic regression analysis.

RESULTS

Among 475 patients with RSSI, 152 (32%) had an infarct in the brainstem, 227 (48%) in SSS, and 96 (20%) in CSO region. The median CSVD burden score was 2 (IQR, 1-3). After adjusting for confounding factors, a RSSI in CSO was associated with higher periventricular and deep white matter hyperintensity scores [OR 1.64 (95% CI, 1.16-2.33), and OR 1.44 (95% CI, 1.07-1.93), respectively]. Higher CSVD burden score was positively associated with CSO [OR 1.48 (95% CI, 1.22-1.81)] and inversely associated with SSS [0.85 (95% CI, 0.72-0.99)] location after adjusting for relevant confounders.

CONCLUSIONS

CSO RSSI were related to a higher burden of CSVD, particularly to white matter hyperintensities, compared to other RSSI locations. The pathophysiological significance of such findings should be investigated in the future with advanced neuroimaging techniques.

Aging-induced microbleeds of the mouse thalamus compared to sensorimotor and memory defects

The aim of this study is to investigate the relationship between aging and brain vasculature health. Three groups of mice, 3, 17-18, and 24 months, comparable to young adult, middle age, and old human were studied. Prussian blue histology and fast imaging with steady precession T2∗-weighted magnetic resonance imaging were used to quantify structural changes in the brain across age groups. The novel object recognition test was used to assess behavioral changes associated with anatomical changes. This study is the first to show that the thalamus is the most vulnerable brain region in the mouse model for aging-induced vascular damage. Magnetic resonance imaging data document the timeline of accumulation of thalamic damage. Histological data reveal that the majority of vascular damage accumulates in the ventroposterior nucleus and mediodorsal thalamic nucleus. Functional studies indicate that aging-induced vascular damage in the thalamus is associated with memory and sensorimotor deficits. This study points to the possibility that aging-associated vascular disease is a factor in irreversible brain damage as early as middle age.

Difference in risk factors of silent brain infarction between paroxysmal and persistent atrial fibrillation

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Differences in risk factors for SBI between paroxysmal and persistent AF was studied.

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NVAF patients (119 paroxysmal, 71 persistent) underwent brain MRI, TTE, and TEE.

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DM and CKD, which represents microvascular disease, predicted SBI in paroxysmal AF.

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There was no obvious therapeutic target for SBI after progression to persistent NVAF.

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Intervention for DM and CKD from paroxysmal NVAF may prevent SBI and future stroke.

Background

Although silent brain infarction is an independent risk factor for subsequent symptomatic stroke and dementia in patients with nonvalvular atrial fibrillation, little is known regarding differences in risk factors for silent brain infarction between patients with paroxysmal and persistent nonvalvular atrial fibrillation.

Methods

This study population consisted of 190 neurologically asymptomatic patients (mean age, 64 ± 11 years) with nonvalvular atrial fibrillation (119 paroxysmal, 71 persistent) who were scheduled for catheter ablation. All patients underwent brain magnetic resonance imaging to screen for silent brain infarction prior to ablation. Transthoracic and transesophageal echocardiography was performed to screen for left atrial abnormalities (left atrial enlargement, spontaneous echo contrast, or left atrial appendage emptying velocity) and complex plaques in the aortic arch.

Results

Silent brain infarction was detected in 50 patients (26%) [26 patients (22%) in paroxysmal vs. 24 patients (34%) in persistent, p = 0.09]. Multiple logistic regression analysis indicated that age and diabetes mellitus or chronic kidney disease (estimated glomerular filtration rate < 60 mL/min/1.73 m²) were associated with silent brain infarction in patients with paroxysmal nonvalvular atrial fibrillation (p < 0.05), whereas no modifiable risk factors of silent brain infarction were observed in patients with persistent nonvalvular atrial fibrillation.

Conclusions

These findings suggest that intensive intervention for diabetes mellitus and renal impairment from the paroxysmal stage or ablation therapy at the time of paroxysmal stage to prevent progression to persistent nonvalvular atrial fibrillation may prevent silent brain infarction and consequently reduce the risk of future symptomatic stroke.

Diagnostic and prognostic blood biomarkers in vascular dementia: From the viewpoint of ischemic stroke

Reliable quantitative blood biomarkers are important in vascular dementia (VaD) because early diagnosis and therapeutic intervention are effective in preventing progression of dementia. Although many blood biomarkers for acute ischemic stroke (AIS) or VaD have been reported, there are few reliable blood biomarkers. VaD and AIS have similar pathological conditions that are associated with small vessel disease (SVD) such as oxidative stress, inflammation, endothelial dysfunction, and neuronal injury. Therefore, it may be possible to find superior blood biomarkers of VaD among AIS blood biomarkers. Owing to recent developments, noncoding RNAs such as microRNA and long noncoding RNA, which can be analyzed using a single drop of blood, are also particularly reliable VaD markers because they stably reflect brain tissue damage. A multimarker combining several blood biomarkers or artificial intelligence technology may also be beneficial to compensate for insufficiencies of a single blood biomarker. This review describes the blood biomarkers of VaD and how they are related to blood biomarkers of AIS.

Reshaping the path of vascular cognitive impairment with resistance training: a study protocol for a randomized controlled trial

Background

Subcortical ischemic vascular cognitive impairment (SIVCI) is the most common form of vascular cognitive impairment. Importantly, SIVCI is considered the most treatable form of cognitive impairment in older adults, due to its modifiable risk factors such as hypertension, diabetes mellitus, and hypercholesterolemia. Exercise training is a promising intervention to delay the progression of SIVCI, as it actively targets these cardiometabolic risk factors. Despite the demonstrated benefits of resistance training on cognitive function and emerging evidence suggesting resistance training may reduce the progression of white matter hyperintensities (WMHs), research on SIVCI has predominantly focused on the use of aerobic exercise. Thus, the primary aim of this proof-of-concept randomized controlled trial is to investigate the efficacy of a 12-month, twice-weekly progressive resistance training program on cognitive function and WMH progression in adults with SIVCI. We will also assess the efficiency of the intervention.

Methods

Eighty-eight community-dwelling adults, aged > 55 years, with SIVCI from metropolitan Vancouver will be recruited to participate in this study. SIVCI will be determined by the presence of cognitive impairment (Montreal Cognitive Assessment < 26) and cerebral small vessel disease using computed tomography or magnetic resonance imaging. Participants will be randomly allocated to a twice-weekly exercise program of (1) progressive resistance training or (2) balance and tone training (i.e., active control). The primary outcomes are cognitive function measured by the Alzheimer’s Disease Assessment Scale-Cognitive-Plus (ADAS-Cog-13 with additional cognitive tests) and WMH progression.

Discussion

The burden of SIVCI is immense, and to our knowledge, this will be the first study to quantify the effect of progressive resistance training on cognitive function and WMH progression among adults with SIVCI. Slowing the rate of cognitive decline and WMH progression could preserve functional independence and quality of life. This could lead to reduced health care costs and avoidance of early institutional care.

Trial registration

ClinicalTrials.gov NCT02669394. Registered on February 1, 2016

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05156-1.

Cocaine Use and White Matter Hyperintensities in Homeless and Unstably Housed Women

OBJECTIVES

Cocaine use has been linked to stroke in several studies. However, few studies have considered the influence of cocaine use on stroke mechanisms such as small vessel disease (SVD). We conducted a study to assess associations between the toxicology-confirmed use of multiple drugs, including cocaine, and a marker of SVD, white matter hyperintensities (WMH).

MATERIALS AND METHODS

We conducted a nested case-control study (n = 30) within a larger cohort study (N = 245) of homeless and unstably housed women recruited from San Francisco community venues. Participants completed six monthly study visits consisting of an interview, blood draw, vital sign assessment and baseline brain MRI. We examined associations between toxicology-confirmed use of multiple substances, including cocaine, methamphetamine, heroin, alcohol and tobacco, and WMH identified on MRI.

RESULTS

Mean study participant age was 53 years, 70% of participants were ethnic minority women and 86% had a history of cocaine use. Brain MRIs indicated the presence of WMH (i.e., Fazekas score>0) in 54% (18/30) of imaged participants. The odds of WMH were significantly higher in women who were toxicology-positive for cocaine (Odd Ratio=7.58, p=0.01), but not in women who were toxicology-positive for other drugs or had several other cerebrovascular risk factors.

CONCLUSIONS

Over half of homeless and unstably housed women showed evidence of WMH. Cocaine use is highly prevalent and a significant correlate of WMH in this population, while several traditional CVD risk factors are not. Including cocaine use in cerebrovascular risk calculators may improve stroke risk prediction in high-risk populations and warrants further investigation.

Site of Origin of the Ophthalmic Artery Influences the Risk for Retinal Versus Cerebral Embolic Events

BACKGROUND

Embolic events leading to retinal ischemia or cerebral ischemia share common risk factors; however, it has been well documented that the rate of concurrent cerebral infarction is higher in patients with a history of transient ischemic attack (TIA) than in those with monocular vision loss (MVL) due to retinal ischemia. Despite the fact that emboli to the ophthalmic artery (OA) and middle cerebral artery share the internal carotid artery (ICA) as a common origin or transit for emboli, the asymmetry in their final destination has not been fully explained. We hypothesize that the anatomic location of the OA takeoff from the ICA may contribute to the differential flow of small emboli to the retinal circulation vs the cerebral circulation.

METHODS

We report a retrospective, comparative, case-control study on 28 patients with retinal ischemia and 26 patients with TIA or cerebral infarction caused by embolic events. All subjects underwent either computed tomography angiography or MRA. The location of the ipsilateral OA origin off the ICA was then graded in a blinded fashion and compared between cohorts. Vascular risk factors were collected for all patients, including age, sex, hypertension, hyperlipidemia, arrhythmia, diabetes, coronary artery disease, and smoking.

RESULTS

We find that in patients with retinal ischemia of embolic etiology, the ipsilateral OA takeoff from the ICA is more proximal than in patients with cerebral infarcts or TIA (P = 0.0002). We found no statistically significant differences in demographic, vascular, or systemic risk factors.

CONCLUSIONS

We find that the mean anatomical location of the OA takeoff from the ICA is significantly more proximal in patients with MVL due to retinal ischemia compared with patients with TIA or cerebral ischemia. This finding contributes significantly to our understanding of a long observed but poorly understood phenomenon that patients with MVL are less likely to have concurrent cerebral ischemia than are patients with TIA.

Reduced Superficial Capillary Density in Cerebral Infarction Is Inversely Correlated With the NIHSS Score

Purpose: The retina and the brain share similar neuronal and microvascular features, therein we aimed to assess the structural and microvascular changes in the macula and choriocapillaris (CC) in patients with cerebral infarction when compared with healthy controls using optical coherence tomography angiography (OCTA).

Methods: OCTA was used to image and measure the capillary density in the radial peripapillary capillaries (RPC), superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris (CC), and mean area of the foveal avascular zone (FAZ) in all participants. Twenty-two cerebral infarction patients based on their magnetic resonance imaging (MRI) and 25 healthy controls were included in our study.

Results: Density of the RPC (P < 0.001), SCP (P = 0.001), DCP (P < 0.001) and CC (P < 0.001) were significantly reduced in cerebral infarction patients when compared with healthy controls, respectively. Retinal thickness measurements (P < 0.05) were significantly reduced in cerebral infarction patients when compared with healthy controls. The mean FAZ area was significantly larger (P = 0.012) in cerebral infarction patients when compared with healthy controls. National Institute of HealthStroke Scale (NIHSS) inversely correlated with SCP density in cerebral infarction patients (Rho = −0.409, P = 0.001). Receiver operating characteristics curve analysis showed that the blood flow of the choriocapillaris had the highest index [area under the receiver operatingcharacteristic (AUROC) = 0.964] to discriminate cerebral infarction patients from the healthy controls.

Conclusions: Our study suggests that cerebral microcirculation dysfunction which occurs in cerebral infarction is mirrored in the macula and choroidal microcirculation. OCTA has the potential to non-invasively characterize the macula and choroidal changes in cerebral infarction in vivo.

Increased Intima-Media Thickness of the Ascending Aorta May Predict Neurological Complications Associated with TAVI

OBJECTIVES

Neurological complications associated with transcatheter aortic valve implantation (TAVI) are important due to its morbidity and mortality risks. The purpose of this study was to investigate the importance of the features of the aortic valve and ascending aorta to predict the neurological complications associated with TAVI.

METHODS

The patients for whom the heart team decided to perform TAVI were included in the study. In order to assess possible neurological complications, cerebral diffusionweighted magnetic resonance imaging(MRI) was performed pre- and post-operatively. The diameter of the patients' aortic root and ascending aorta, aortic valve scores, intima media thickness of the ascending aorta were measured from their transesophageal echocardiography records.

RESULTS

A total of 108 patients constituted the study population. 31 patients were found to develop a new lesion (MR+) detected on MRI after TAVI, while 76 patients did not have any new lesions (MR-). The groups did not have any significant differences in their aortic valve features and scores. However, AA-IMT was found to be higher in the MR+ group (1.8mm [1.6-2.3] vs 1.4mm [1.2-1.8] interquartile range). The multivariate logistic regression analysis conducted to detect new lesions revealed that AA-IMT led to a significantly increased risk.

CONCLUSION

The features of the ascending are more important than the demographic characteristics of patients and features of the native valve in predicting new lesions on MRI scans and thus neurological events after TAVI.

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Study of Symptomatic vs. Silent Brain Infarctions on MRI in Elderly Subjects

Brain infarctions are closely associated with future risk of stroke and dementia. Our goal was to report (i) frequency and characteristics that differentiate symptomatic vs. silent brain infarctions (SBI) on MRI and (ii) frequency and location by vascular distribution (location of stroke by major vascular territories) in a population based sample. From Mayo Clinic Study of Aging, 347 participants (≥50 years) with infarcts detected on their first MRI were included. Infarct information was identified visually on a FLAIR MRI image and a vascular territory atlas was registered to the FLAIR image data in order to identify the arterial territory of infarction. We identified the subset with a clinical history of stroke based on medical chart review and used a logistic regression to evaluate the risk factors associated with greater probability of a symptomatic stroke vs. SBI. We found that 14% of all individuals with infarctions had a history of symptomatic stroke (Silent: n = 300, symptomatic: n = 47). Factors associated with a symptomatic vs. SBI were size which had an odds ratio of 3.07 (p < 0.001), greater frequency of hypertension (odds ratio of 4.12, p = 0.025) and alcohol history (odds ratio of 4.58, p = 0.012). The frequency of infarcts was greater in right hemisphere compared to the left for SBI. This was primarily driven by middle cerebral artery (MCA) infarcts (right = 60%, left = 40%, p = 0.005). While left hemisphere strokes are more common for symptomatic carotid disease and in clinical trials, right hemispheric infarcts may be more frequent in the SBI group.

Structural and Functional Brain Changes in Migraine

Migraine is a prevalent primary headache disorder and is usually considered as benign. However, structural and functional changes in the brain of individuals with migraine have been reported. High frequency of white matter abnormalities, silent infarct-like lesions, and volumetric changes in both gray and white matter in individuals with migraine compared to controls have been demonstrated. Functional magnetic resonance imaging (MRI) studies found altered connectivity in both the interictal and ictal phase of migraine. MR spectroscopy and positron emission tomography studies suggest abnormal energy metabolism and mitochondrial dysfunction, as well as other metabolic changes in individuals with migraine. In this review, we provide a brief overview of neuroimaging studies that have helped us to characterize some of these changes and discuss their limitations, including small sample sizes and poorly defined control groups. A better understanding of alterations in the brains of patients with migraine could help not only in the diagnosis but may potentially lead to the optimization of a targeted anti-migraine therapy.

Risk Factors of New Cerebral Infarctions After Endovascular Treatment for Basilar Artery Stenosis Based on High-Resolution Magnetic Resonance Imaging

Objective: The current study aims to analyze the risk factors of new cerebral infarctions in the distribution of basilar artery (BA) detected by diffusion-weighted imaging (DWI) after endovascular treatment in patients with severe BA stenosis. Methods: Data was collected from the electronic medical records of patients with severely atherosclerotic basilar artery stenosis (≥70%) who underwent endovascular treatment. The plaque characteristics, including the plaque distribution, plaque burden, plaque enhancement index, remodeling ratio, and stenosis degree, were evaluated qualitatively and quantitatively using high-resolution magnetic resonance imaging (HR-MRI) and digital subtraction angiography (DSA). The characteristics of the procedure, such as the type of treatment, balloon diameter, balloon length, stent diameter, and stent length, were analyzed. Results: A total of 107 patients with severe basilar artery stenosis (≥70%) who underwent endovascular treatment were enrolled. The study participants included 77 men and 30 women, with an average age of 61.6 ± 8.1 years. The rate of postoperative new cerebral infarctions was 55.1% (59/107), of which 74.6% (44/59) were caused by artery-to-artery embolism, 6.8% (4/59) due to perforator occlusion, and 18.6% (11/59) were caused by a mixed mechanism. Twelve of 59 patients had ischemic events, with nine cases of stroke and three cases of transient ischemic attacks (TIA). The plaque burden in the DWI-positive group was significantly larger than that in the DWI-negative group (3.7% vs. -8.5%, p = 0.016). Positive remodeling was more common in the DWI-positive group than in the DWI-negative group (35.6% vs. 16.7%, p = 0.028). Smoking was inversely correlated with the rate of new cerebral infarctions (odds ratio, 0.394; 95% confidence interval, 0.167-0.926; p = 0.033). Conclusion: The plaque characteristics are not associated with new cerebral infarctions in the distribution of BA, although a large plaque burden and positive remodeling are more likely to appear in patients with new cerebral infarctions after BA stenting, which warrants further studies with a larger sample size. As for smoking, the inverse correlation with new cerebral infarctions in the BA territory needs large-scale prospective randomized controlled trials to verify.

[Clinical diagnosis and treatment of chronic dizziness]

Chronic dizziness is defined as a complex of symptoms lasting months or years, including oscillopsia, nystagmus, and postural instability. Diagnostic search includes peripheral vestibulopathy - chronic unilateral vestibulopathy resulting from vestibular neuronitis, schwannoma of the 8th pair of cranial nerves, medical or surgical ablation of the labyrinth, and bilateral vestibulopathy; central vestibulopathy - syndromes accompanied by central vertical nystagmus, small vessel disease in patients with chronic cerebral ischemia; general somatic diseases, peripheral polyneuropathy, side-effects of medications as well as persistent postural-perceptual dizziness. Often, when collecting an anamnesis, it is not possible to identify specific features of dizziness and instability, therefore, clinical and instrumental examination of the patient is of particular importance. In the otoneurological examination, the greatest attention is paid to static/coordination tests, oculomotor tests aimed at identifying signs of damage to the vestibulo-ocular reflex. The principles of treatment depend on the diagnosed cause of dizziness and instability and can, to varying degrees, combine pharmacotherapy, vestibular rehabilitation and psychotherapy, as well as correction of therapy for the underlying disease that caused vestibulopathy.

Association of the CHA2D(S2)-VASc Score and Its Components With Overt and Silent Ischemic Brain Lesions in Patients With Atrial Fibrillation

Background: Silent and overt ischemic brain lesions are common and associated with adverse outcome. Whether the CHA₂DS₂-VASc score and its components predict magnetic resonance imaging (MRI)-detected ischemic silent and overt brain lesions in patients with atrial fibrillation (AF) is unclear.

Methods: In this cross-sectional analysis, patients with AF were enrolled in a multicenter cohort study in Switzerland. Outcomes were clinically overt, silent [in the absence of a history of stroke/transient ischemic attack (TIA)] and any MRI-detected ischemic brain lesions. Logistic regression analyses were performed to assess the relationship of the CHA₂DS₂-VASc score and its components with ischemic brain lesions. An adapted CHA₂D-VASc score (excluding history of stroke/TIA) for the analyses of clinically overt and silent ischemic brain lesions was used.

Results: Overall, 1,741 patients were included in the analysis (age 73 ± 8 years, 27.4% female). At least one ischemic brain lesion was observed in 36.8% (clinically overt: 10.5%; silent: 22.9%; transient ischemic attack: 3.4%). The CHA₂D-VASc score was strongly associated with clinically overt and silent ischemic brain lesions {odds ratio (OR) [95% confidence interval (CI)] 1.32 (1.17–1.49), p < 0.001 and 1.20 (1.10–1.30), p < 0.001, respectively}. Age 65–74 years (OR 2.58; 95%CI 1.29–5.90; p = 0.013), age ≥75 years (4.13; 2.07–9.43; p < 0.001), hypertension (1.90; 1.28–2.88; p = 0.002) and diabetes (1.48; 1.00–2.18; p = 0.047) were associated with clinically overt brain lesions, whereas age 65–74 years (1.95; 1.26–3.10; p = 0.004), age ≥75 years (3.06; 1.98–4.89; p < 0.001) and vascular disease (1.39; 1.07–1.79; p = 0.012) were associated with silent ischemic brain lesions.

Conclusions: A higher CHA₂D-VASc score was associated with a higher risk of both overt and silent ischemic brain lesions.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT02105844.

Quantitative endophenotypes as an alternative approach to understanding genetic risk in neurodegenerative diseases

Endophenotypes, as measurable intermediate features of human diseases, reflect underlying molecular mechanisms. The use of quantitative endophenotypes in genetic studies has improved our understanding of pathophysiological changes associated with diseases. The main advantage of the quantitative endophenotypes approach to study human diseases over a classic case-control study design is the inferred biological context that can enable the development of effective disease-modifying treatments. Here, we summarize recent progress on biomarkers for neurodegenerative diseases, including cerebrospinal fluid and blood-based, neuroimaging, neuropathological, and clinical studies. This review focuses on how endophenotypic studies have successfully linked genetic modifiers to disease risk, disease onset, or progression rate and provided biological context to genes identified in genome-wide association studies. Finally, we review critical methodological considerations for implementing this approach and future directions.

A model of silent brain infarction induced by endovascular intervention with balloon in cynomolgus macaques: A pilot study

Silent brain infarction is a special type of cerebral infarction, which can be detected by MRI or CT. The most patients with silent brain infarction show no symptoms, but some have mild depression, vascular dementia and other symptoms that are easily overlooked. Silent brain infarction is one of the risk factors for symptomatic cerebral infarction, it can develop into symptomatic cerebral infarction placing a heavy burden on families and society. Therefore, it's prevention and treatment should be as important as symptomatic cerebral infarction. However, the pathogenesis of silent brain infarction has not been elucidated. Studies have shown that silent brain infarction models have been established in rats and mice. But compared with other animals, non-human primates are more similar to humans in neuroanatomical structure and clinical characteristics. Therefore, this study is the first time to explore the silent brain infarction model in cynomolgus macaques. In this study, a model of silent brain infarction was established by endovascular intervention using balloon occlusion at the end of internal carotid artery for 45 min, which can lay a foundation for the future research on the pathological mechanism of silent brain infarction.

Cerebrovascular assessments to help understand brain-related changes associated with aerobic exercise after stroke

Evidence suggests exercise is "good medicine" after stroke, yet consensus is lacking on the time to initiate, type, exertion level, and duration per session. It remains a challenge to identify outcome measures for stroke-exercise trials that are sufficiently sensitive to intervention parameters. Cerebrovascular assessments, namely cerebral blood flow and intracranial pulsatility, are herein discussed as examples of quantitative brain-specific measures that may be useful to monitor exercise-related brain changes and help to guide stroke rehabilitation interventions. Novelty: Cerebral blood flow and arterial stiffness are potential vascular targets for stroke exercise trials.

Covert strokes prior to Alzheimer's disease onset accelerate peri-lesional pathology but not cognitive deficits in an inducible APP mouse model

It is estimated that up to 1 in 3 healthy middle-aged adults will have had a covert stroke during their lifetime. Furthermore, post-stroke, survivors are more than twice as likely to develop dementia. In the present study, we aimed to model the impact of focal subclinical ischemia prior to the onset of AD pathogenesis in a preclinical model. We utilized endothelin-1 to induce ischemia in an iducible transgenic mouse model of Alzheimer's disease, APPsi:tTA, allowing for temporal control of APP gene expression. We induced the focal subclinical ischemic events in the absence of APP expression, thus prior to AD onset. T2 structural magnetic resonance imaging confirmed the volume and location of focal subclinical ischemic lesions to the medial prefrontal cortex. Following recovery from surgery and 7 weeks of APP expression, we found that two subclinical ischemic lesions resulted in a significant localized increase in amyloid load and in microglial activation proximal to the lesion. However, no differences were found in astrogliosis. A battery of behaviour tests was conducted, in which no significant differences were detected in activities of daily living and cognitive function between stroked and sham cohorts. Overall, our results demonstrated that APP expression was the sole driving force behind behavioural deficits. In conclusion, our results suggest that a history of two subclinical strokes prior to AD onset does not worsen early disease trajectory in a mouse model.

The role of biomarkers and neuroimaging in ischemic/hemorrhagic risk assessment for cardiovascular/cerebrovascular disease prevention

Stroke prevention in patients with atrial fibrillation is arguably one of the fastest developing areas in preventive medicine. The increasing use of direct oral anticoagulants and nonpharmacologic methods such as left atrial appendage closure for stroke prevention in these patients has increased clinicians' options for optimal care. Platelet antiaggregants are also commonly used in other ischemic cardiovascular and or cerebrovascular conditions. Long term use of oral anticoagulants for atrial fibrillation is associated with elevated risks of major bleeds including especially brain hemorrhages, which are known to have extremely poor outcomes. Neuroimaging and other biomarkers have been validated to stratify brain hemorrhage risk among older adults. A thorough understanding of these biomarkers is essential for selection of appropriate anticoagulant or left atrial appendage closure for stroke prevention in patients with atrial fibrillation. This article will address advances in the stratification of ischemic and hemorrhagic stroke risk among patients with atrial fibrillation and other conditions.

Potential recruitment into a clinical trial of vascular secondary prevention medications in cerebral small vessel disease, based on concomitant medication use

Background

Blood pressure-lowering medications, antiplatelet drugs and statins are often prescribed to asymptomatic patients with white matter hyperintensities (WMH). A clinical trial is needed, but potential trial participants would be excluded if they already had another indication to take the medication. It is likely that many patients with WMH would already have a recognised vascular-related indication for these drugs.

We used data from the UK Biobank study to determine what proportion of people with WMH were not taking these drugs and would be potentially able to enter a clinical trial of antiplatelet drugs, statins, or BP-lowering medication.

Methods

We used the UK Biobank MRI sub-study of healthy volunteers aged 40–70 years as our cohort. We considered that WMH volumes in the top quartile (2.7–89 mls) were severe enough for a patient to be at risk of progression and be offered treatment. Such patients could also be included in a hypothetical clinical trial if there were no contraindications. Using the product licenses, we defined exclusion criteria for four hypothetical clinical trials of aspirin, clopidogrel, statins, and tight BP control. We then calculated what proportion of patients would still be eligible if these criteria were applied.

Results

5794/23,179 patients had WMH in the top quartile. Of these, 4006/5794 69% (95% CI 68–70%) would be eligible for a trial of aspirin; with 81% (95% CI 80–82%) eligible for a trial of clopidogrel; 56% (95% CI 55–58%) of patients would be eligible to enter into a trial of a lower BP target, and 58% (95%CI 57–59%) would be able to enter a trial of a statin.

Conclusions

Over 80% of patients with WMH in the UK biobank would be eligible to enter a trial of an antiplatelet and just over half would be eligible to enter a trial of a statin or BP-lowering medication.