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ObjectivesIt has been suggested that diffusion tensor imaging (DTI) measures sensitive to white matter (WM) damage may predict future dementia risk not only in cerebral small vessel disease (SVD), but also in mild cognitive impairment. To determine whether DTI measures were associated with cognition cross-sectionally and predicted future dementia risk across the full range of SVD severity, we established the International OPtimising mulTImodal MRI markers for use as surrogate markers in trials of Vascular Cognitive Impairment due to cerebrAl small vesseL disease collaboration which included six cohorts.MethodsAmong the six cohorts, prospective data with dementia incidences were available for three cohorts. The associations between six different DTI measures and cognition or dementia conversion were tested. The additional contribution to prediction of other MRI markers of SVD was also determined.ResultsThe DTI measure mean diffusivity (MD) median correlated with cognition in all cohorts, demonstrating the contribution of WM damage to cognition. Adding MD median significantly improved the model fit compared to the clinical risk model alone and further increased in all single-centre SVD cohorts when adding conventional MRI measures. Baseline MD median predicted dementia conversion. In a study with severe SVD (SCANS) change in MD median also predicted dementia conversion. The area under the curve was best when employing a multimodal MRI model using both DTI measures and other MRI measures.ConclusionsOur results support a central role for WM alterations in dementia pathogenesis in all cohorts. DTI measures such as MD median may be a useful clinical risk predictor. The contribution of other MRI markers varied according to disease severity.

Cerebral small vessel disease (SVD) is a major cause of stroke and dementia. The underlying pathogenesis is poorly understood, but both neuroinflammation and increased blood–brain barrier permeability have been hypothesized to play a role, and preclinical studies suggest the two processes may be linked. We used PET magnetic resonance to simultaneously measure microglial activation using the translocator protein radioligand 11C-PK11195, and blood–brain barrier permeability using dynamic contrast enhanced MRI. A case control design was used with two disease groups with sporadic SVD (n = 20), monogenic SVD (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, CADASIL), and normal controls (n = 20) were studied. Hotspots of increased glial activation and blood–brain barrier permeability were identified as values greater than the 95th percentile of the distribution in controls. In sporadic SVD there was an increase in the volume of hotspots of both 11C-PK11195 binding (P = 0.003) and blood–brain barrier permeability (P = 0.007) in the normal appearing white matter, in addition to increased mean blood–brain barrier permeability (P

Background Stroke commonly affects cognition and, by definition, much vascular dementia follows stroke. However, there are fundamental limitations in our understanding of vascular cognitive impairment, restricting understanding of prevalence, trajectories, mechanisms, prevention, treatment and patient-service needs. Aims Rates, Risks and Routes to Reduce Vascular Dementia (R4VaD) is an observational cohort study of post-stroke cognition. We aim to recruit a wide range of patients with stroke, presenting to geographically diverse UK hospitals, into a longitudinal study to determine rates of, and risk factors for, cognitive and related impairments after stroke, to assess potential mechanisms and improve prediction models. Methods We will recruit at least 2000 patients within six weeks of stroke with or without capacity to consent and collect baseline demographic, clinical, socioeconomic, lifestyle, cognitive, neuropsychiatric and informant data using streamlined patient-centred methods appropriate to the stage after stroke. We will obtain more detailed assessments at four to eight weeks after the baseline assessment and follow-up by phone and post yearly to at least two years. We will assess diagnostic neuroimaging in all and high-sensitivity inflammatory markers, genetics, blood pressure and diffusion tensor imaging in mechanistic sub-studies. Planned outputs: R4VaD will provide reliable data on long-term cognitive function after stroke, stratified by prior cognition, stroke- and patient-related variables and improved risk prediction. It will create a platform enabling sharing of data, imaging and samples. Participants will be consented for re-contact, facilitating future clinical trials and providing a resource for the stroke and dementia research communities.

Background and Purpose— Cerebrovascular disease contributes to age-related cognitive decline, but the mechanisms underlying this phenomenon remain incompletely understood. We hypothesized that vascular risk factors would lead to cognitive impairment through the disruption of brain white matter network efficiency. Methods— Participants were 19 346 neurologically healthy individuals from UK Biobank that underwent diffusion MRI and cognitive testing (mean age=62.6). Global efficiency, a measure of network integration, was calculated from white matter networks constructed using deterministic diffusion tractography. First, we determined whether demographics (age, sex, ethnicity, socioeconomic status, and education), vascular risk factors (hypertension, hypercholesterolemia, diabetes mellitus, smoking, body mass index), and white matter hyperintensities were related to global efficiency using multivariate linear regression. Next, we used structural equation modeling to model a multiple regression. The dependent variable was a latent cognition variable using all cognitive data, while independent variables were a latent factor including all vascular risk factors (vascular burden), demographic variables, white matter hyperintensities, and global efficiency. Finally, we used mediation analysis to determine whether global efficiency explained the relationship between vascular burden and cognition. Results— Hypertension and diabetes mellitus were consistently associated with reduced global efficiency even after controlling for white matter hyperintensities. Structural equation models revealed that vascular burden was associated with cognition ( P =0.023), but not after adding global efficiency to the model ( P =0.09), suggesting a mediation effect. Mediation analysis revealed a significant indirect effect of global efficiency on cognition through vascular burden ( P Conclusions— Vascular burden is associated with reduced global efficiency and cognitive impairment in the general population. Network efficiency partially mediates the relationship between vascular burden and cognition. This suggests that treating specific risk factors may prevent reductions in brain network efficiency and preserve cognitive functioning in the aging population.

The COVID-19 pandemic affecting all parts of the world is having huge implications for stroke care. Not only do stroke patients appear to be more susceptible to severe infection, but the pandemic is having major implications on how we deliver stroke care, while ensuing safety of both our patients and health care professionals. COVID-19 infection itself has also been described as a risk factor for stroke. The World Stroke Organization has been monitoring the impact of the pandemic globally, and has identified an initial marked fall in stroke presentations as well as a widespread impact on stroke services. The pandemic is changing the way we deliver care, and has highlighted the enormous potential of telemedicine in stroke care.

The optimal management of post-stroke cognitive impairment remains controversial. These joint European Stroke Organisation (ESO) and European Academy of Neurology (EAN) guidelines provide evidence-based recommendations to assist clinicians in decision making around prevention, diagnosis, treatment and prognosis. These guidelines were developed according to ESO standard operating procedure and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. The working group identified relevant clinical questions, performed systematic reviews and, where possible, meta-analyses of the literature, assessed the quality of the available evidence and made specific recommendations. Expert consensus statements were provided where insufficient evidence was available to provide recommendations based on the GRADE approach. There was limited randomised controlled trial evidence regarding single or multicomponent interventions to prevent post-stroke cognitive decline. Interventions to improve lifestyle and treat vascular risk factors may have many health benefits but a beneficial effect on cognition is not proven. We found no evidence around routine cognitive screening following stroke but recognise the importance of targeted cognitive assessment. We described the accuracy of various cognitive screening tests but found no clearly superior approach to testing. There was insufficient evidence to make a recommendation for use of cholinesterase inhibitors, memantine nootropics or cognitive rehabilitation. There was limited evidence on the use of prediction tools for post-stroke cognitive syndromes (cognitive impairment, dementia and delirium). The association between post-stroke cognitive impairment and most acute structural brain imaging features was unclear, although the presence of substantial white matter hyperintensities of presumed vascular origin on acute MRI brain may help predict cognitive outcomes. These guidelines have highlighted fundamental areas where robust evidence is lacking. Further, definitive randomised controlled trials are needed, and we suggest priority areas for future research. ispartof: European Stroke Journal vol:6 issue:3 pages:1-177 ispartof: location:England status: Published online

Background and Objectives: To systematically assess the occurrence of cerebral microbleeds (CMBs) and white matter hyperintensities (WMHs) in the largest published cohort of adults with ataxia-telangiectasia (AT). Methods: We assessed 38 adults with AT (age range 18-55 years) including 15 classic and 23 variant AT, evaluated by two independent assessors. WMHs were quantified on T2-fluid attenuated inversion recovery images using the semiquantitative modified Scheltens and Fazekas scales and CMB on susceptibility-weighted imaging and T2*-weighted gradient echo sequences using the Brain Observer MicroBleed Scale. Results: CMBs were more frequently found in classic AT compared with variant AT (66.7% vs 5.9%) predominantly in cortical and subcortical regions. WMHs were seen in 25 (73.5%) probands and CMBs in 9 (31.0%). The burden of WMHs increased with age, and WMHs were focused in periventricular and deep white matter regions. WMHs were more frequently seen in variant than classic AT. Discussion: This cohort study confirms that WMHs and CMBs are a frequent finding in AT. Further longitudinal studies are required to understand how WMHs and CMBs relate to the neurodegeneration that occurs in AT and the predisposition to cerebral hemorrhage., M.Y.T. is supported by the Addenbrookes Charitable Trust (G103290). R.H. is a Wellcome Trust Investigator (109915/Z/15/Z), who receives support from the Medical Research Council (UK) (MR/N025431/1 and MR/V009346/1), the European Research Council (309548), the Newton Fund (UK/Turkey, MR/N027302/1), the Addenbrookes Charitable Trust (G100142), the Evelyn Trust, the Stoneygate Trust, the Lily Foundation and an MRC strategic award to establish an International Centre for Genomic Medicine in Neuromuscular Diseases (ICGNMD) MR/S005021/1. H.S.M. is supported by an NIHR Senior Investigator award. This research was supported by the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014).

ObjectiveTo determine the contribution of common genetic variants to risk of early onset ischemic stroke (IS).MethodsWe performed a meta-analysis of genome-wide association studies of early onset IS, ages 18-59, using individual level data or summary statistics in 16,927 cases and 576,353 non-stroke controls from 48 different studies across North America, Europe, and Asia. We further compared effect sizes at our most genome-wide significant loci between early and late onset IS and compared polygenic risk scores for venous thromboembolism between early versus later onset IS.ResultsWe observed an association between early onset IS and ABO, a known stroke locus. The effect size of the peak ABO SNP, rs8176685, was significantly larger in early compared to late onset IS (OR 1.17 (95% C.I.: 1.11-1.22) vs 1.05 (0.99-1.12); p for interaction = 0.008). Analysis of genetically determined ABO blood groups revealed that early onset IS cases were more likely to have blood group A and less likely to have blood group O compared to both non-stroke controls and to late onset IS cases. Using polygenic risk scores, we observed that greater genetic risk for venous thromboembolism, another prothrombotic condition, was more strongly associated with early, compared to late, onset IS (p=0.008).ConclusionThe ABO locus, genetically predicted blood group A, and higher genetic propensity for venous thrombosis are more strongly associated with early onset IS, compared with late onset IS, supporting a stronger role of prothrombotic factors in early onset IS.

Despite intensive investigations, about 30% of stroke cases remains of undetermined origin. After exclusion of common causes of stroke, there is a number of rare heritable and non-heritable conditions, which often remain misdiagnosed, that should be additionally considered in the diagnosis of cryptogenic stroke. The identification of these diseases requires a complex work up including detailed clinical evaluation for the detection of systemic symptoms and signs, an adequate neuroimaging assessment and a careful family history collection. The task becomes more complicated by phenotype heterogeneity since stroke could be the primary or unique manifestation of a syndrome or represent just a manifestation (sometimes minor) of a multisystem disorder. The aim of this review paper is to provide clinicians with an update on clinical and neuroradiological features and a set of practical suggestions for the diagnostic work up and management of these uncommon causes of stroke. The identification of these stroke causes is important to avoid inappropriate and expensive diagnostic tests, to establish appropriate management measures, including presymptomatic testing, genetic counseling, and, if available, therapy. Therefore, physicians should become familiar with these diseases to provide future risk assessment and family counseling.

ObjectiveTo determine whether a simple small vessel disease (SVD) score, which uses information available on rapid visual assessment of clinical MRI scans, predicts risk of cognitive decline and dementia, above that provided by simple clinical measures.MethodsThree prospective longitudinal cohort studies (SCANS [St George's Cognition and Neuroimaging in Stroke], RUN DMC [Radboud University Nijmegen Diffusion Imaging and Magnetic Resonance Imaging Cohort], and the ASPS [Austrian Stroke Prevention Study]), which covered a range of SVD severity from mild and asymptomatic to severe and symptomatic, were included. In all studies, MRI was performed at baseline, cognitive tests repeated during follow-up, and progression to dementia recorded prospectively. Outcome measures were cognitive decline and onset of dementia during follow-up. We determined whether the SVD score predicted risk of cognitive decline and future dementia. We also determined whether using the score to select a group of patients with more severe disease would reduce sample sizes for clinical intervention trials.ResultsIn a pooled analysis of all 3 cohorts, the score improved prediction of dementia (area under the curve [AUC], 0.85; 95% confidence interval [CI], 0.81–0.89) compared with that from clinical risk factors alone (AUC, 0.76; 95% CI, 0.71–0.81). Predictive performance was higher in patients with more severe SVD. Power calculations showed selecting patients with a higher score reduced sample sizes required for hypothetical clinical trials by 40%–66% depending on the outcome measure used.ConclusionsA simple SVD score, easily obtainable from clinical MRI scans and therefore applicable in routine clinical practice, aided prediction of future dementia risk.

Background and aims Observational studies have reported an association between periodontitis and cardiovascular disease but whether this association is causal is uncertain. We therefore used Mendelian randomization to test whether periodontitis is causally associated with stroke, coronary artery disease, or subclinical atherosclerosis. Methods A two-sample Mendelian randomization analysis was carried out using five single nucleotide polymorphisms previously associated with periodontitis in genome-wide association studies. Summary data were drawn from MEGASTROKE and combined with de novo analyses of UK Biobank for stroke and its major subtypes (up to 44,221 cases, 739,957 controls) and CARDIoGRAMplusC4D and UK Biobank for coronary artery disease (122,733 cases, 424,528 controls). We used existing data on carotid intima-media thickness in UK Biobank as a marker of subclinical atherosclerosis (N = 22,179). Causal estimates were obtained using inverse-variance weighted Mendelian randomization. Sensitivity analyses were performed using weighted median and MR-Egger approaches. Results No association was found between periodontitis and any stroke (odds ratio [OR] per doubling in the odds of periodontitis 0.99, 95% confidence interval [CI] 0.97 to 1.02), ischaemic stroke (OR 1.00, 95% CI 0.97 to 1.03) or its major subtypes (p > 0.4), or coronary artery disease (OR 1.01, 95% CI 0.99 to 1.03). Similarly, we found no association for periodontitis and subclinical atherosclerosis (β −0.002, 95% CI -0.004 to 0.001). These results were consistent across a series of sensitivity analyses. Conclusions These findings provide no robust evidence for a causal relationship between periodontitis and stroke or coronary artery disease. This suggests that associations reported in observational studies may represent confounding., Graphical abstract Image 1, Highlights • Periodontitis and cardiovascular disease correlate in observational studies. • Mendelian randomization does not support a causal association. • Results do not support treatment of periodontitis to reduce atherosclerotic disease.

Supplemental Digital Content is available in the text., Background and Purpose— Cerebral small vessel disease (SVD) is the most common cause of vascular cognitive impairment, with a significant proportion of cases going on to develop dementia. We explore the extent to which diffusion tensor image segmentation technique (DSEG; which characterizes microstructural damage across the cerebrum) predicts both degree of cognitive decline and conversion to dementia, and hence may provide a useful prognostic procedure. Methods— Ninety-nine SVD patients (aged 43–89 years) underwent annual magnetic resonance imaging scanning (for 3 years) and cognitive assessment (for 5 years). DSEG-θ was used as a whole-cerebrum measure of SVD severity. Dementia diagnosis was based Diagnostic and Statistical Manual of Mental Disorders V criteria. Cox regression identified which DSEG measures and vascular risk factors were related to increased risk of dementia. Linear discriminant analysis was used to classify groups of stable versus subsequent dementia diagnosis individuals. Results— DSEG-θ was significantly related to decline in executive function and global cognition (P

Background and Purpose— The role of inflammation in ischemic white matter disease is increasingly recognized, and further understanding of the pathophysiology might inform future treatment strategies. Multiple sclerosis (MS) is a chronic autoimmune condition in which inflammation plays a central role that also affects the white matter. We hypothesized that white matter injury might share common mechanisms and used statistical genetics techniques to assess whether having genetically elevated white matter hyperintensity (WMH) volume was associated with increased MS risk. Methods— We investigated the genetic association in 2 cohorts with magnetic resonance imaging-quantified ischemic white matter lesion volume (WMH in stroke; n=2797 and UK Biobank; n=8353) and 14 802 cases of MS and 26 703 controls from the International Multiple Sclerosis Genetics Consortium. We further performed individual-level polygenic risk score calculations for MS and measures of structural white matter disease in UK Biobank. Finally, we looked for evidence of overlapping risk across the whole genome. Results— There was no association of genetic variants influencing MS with WMH volume using summary statistics in the WMH in stroke cohort (relative risk score =1.014; 95% CI, 0.936–1.110) or in the UK Biobank cohort (relative risk score =1.030; 95% CI, 0.932–1.117). Conversely, assessing the contribution of single nucleotide polymorphisms significantly associated with WMH on the risk of MS there was no significant association (relative risk score =0.930; 95% CI, 0.736–1.191). There were no significant associations between polygenic risk scores calculations; these results were robust to the selection of single nucleotide polymorphisms at a range of significance thresholds. Whole genome analysis did not reveal any overlap of risk between the traits. Conclusions— Our results do not provide evidence to suggest a shared mechanism of white matter damage in ischemia and MS. We propose that inflammation acts in distinct pathways because of the differing nature of the primary insult.

Introduction: Real tennis is a growing, unique, and well-established sport. To date, there has been no epidemiological data on real tennis injuries. The primary aim of this retrospective study is to record the incidence and document any trends in real tennis musculoskeletal injuries, so as to improve injury awareness of common and possibly preventable injuries. Methods: A surveillance questionnaire e-mailed to 2,036 Tennis & Rackets Association members to retrospectively capture injuries sustained by amateur and professional real tennis players over their playing careers. Results: A total of 485 (438 males and 47 females) questionnaires were fully completed over 4 weeks. A total of 662 musculoskeletal injuries were recorded with a mean of 1.4 injuries per player (range 0-7). The incidence of sustaining an acute real tennis musculoskeletal injury is 0.4/1000 hrs. The three main anatomical locations reported injured were elbow 15.6% (103/662), knee 11.6% (77/662), and face 10.0% (66/662). The most common structures reported injured were muscle 24% (161/661), tendon 23.4% (155/661), ligament 7.0% (46/661), soft tissue bruising 6.5% (43/661), and eye 6.2% (41/661). The majority of the upper limb injuries were gradual onset (64.7%, 143/221), and the lower limb injuries were sudden onset (72.0%, 188/261). Conclusion: This study uniquely provides valuable preliminary data on the incidence and patterns of musculoskeletal injuries in real tennis players. In addition, it highlights a number of reported eye injuries. The study is also a benchmark for future prospective studies on academy and professional real tennis players.

Background and Purpose— Providing ongoing care for rare neurological conditions is challenging. Telemedicine can reduce patient travel. We set up and evaluated a telemedicine service for patients with a genetic form of stroke and dementia cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy. Methods— One hundred fourteen patients with mutation-positive cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (64 telemedicine and 50 face-to-face) were recruited. Patient and clinician satisfaction questionnaires rated the service to create a mean satisfaction score for both face-to-face and telemedicine follow-up appointments. Results— There was no difference in mean (SD) patient or clinician satisfaction scores between telemedicine and face-to-face appointments (patient: 4.57 [0.56] and 4.69 [0.42]; P =0.99; clinician: 4.55 [0.49] and 4.60 [0.43]; P =0.44). Conclusions— Telemedicine follow-up was suited to patients with stroke and dementia and offered satisfaction levels similar to that for face-to-face consultations.

International audience; The aim of the present European Stroke Organisation guideline is to provide clinically useful evidence-based recommendations on the management of extracranial artery dissection (EAD) and intracranial artery dissection (IAD). EAD and IAD represent leading causes of stroke in the young, but are uncommon in the general population, thus making it challenging to conduct clinical trials and large observational studies. The guidelines were prepared following the Standard Operational Procedure for European Stroke Organisation guidelines and according to GRADE methodology. Our four recommendations result from a thorough analysis of the literature comprising two randomized clinical trials (RCTs) comparing anticoagulants to anti-platelets in the acute phase of ischemic stroke and twenty-six comparative observational studies. In EAD patients with acute ischemic stroke we recommend using intravenous thrombolysis (IVT) with alteplase within 4.5 hours of onset if standard inclusion/exclusion criteria are met, and mechanical thrombectomy in patients with large vessel occlusion of the anterior circulation. We further recommend early endovascular or surgical intervention for IAD patients with subarachnoid hemorrhage (SAH). Based on evidence from two phase 2 RCTs that have shown no difference between the benefits and risks of anticoagulants versus anti-platelets in the acute phase of symptomatic EAD, we strongly recommend that clinicians can prescribe either option. In post-acute EAD patients with residual stenosis or dissecting aneurysms and in symptomatic IAD patients with an intracranial dissecting aneurysm and isolated headache, there is insufficient data to provide a recommendation on the benefits and risks of endovascular/surgical treatment. Finally, nine expert consensus statements, adopted by 8 to 11 of the 11 experts involved, propose guidance for clinicians when the quality of evidence was too low to provide recommendations. Some of these pertain to the management of IAD (use of IVT, endovascular treatment, and antiplatelets versus anticoagulation in IAD with ischemic stroke and use of endovascular or surgical interventions for IAD with headache only). Other expert consensus statements address the use of direct anticoagulants and dual antiplatelet therapy in EAD-related cerebral ischemia, endovascular treatment of the EAD/IAD lesion and multidisciplinary assessment of the best therapeutic approaches in specific situations.

A 44-year-old Caucasian man presented with seizures and cognitive impairment. He had marked retinal drusen, and MR brain scan showed features of cerebral small vessel disease; he was diagnosed with a leukoencephalopathy of uncertain cause. He died at the age of 46 years and postmortem brain examination showed widespread small vessel changes described as a vasculopathy of unknown cause. Seven years postmortem, whole-genome sequencing identified a homozygous nonsense HTRA1 mutation (p.Arg302Ter), giving a retrospective diagnosis of cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy.

Cerebral amyloid angiopathy is a devastating cause of intracerebral hemorrhage for which there is no specific secondary stroke prevention treatment. Here we review the current literature regarding cerebral amyloid angiopathy pathophysiology and treatment, as well as what is known of the fibrinolytic pathway and its interaction with amyloid. We postulate that tranexamic acid is a potential secondary stroke prevention treatment agent in sporadic cerebral amyloid angiopathy, although further research is required.

A year ago the World Stroke Organisation (WSO) highlighted the enormous global impact of the COVID-19 pandemic on stroke care. In this review, we consider a year later where we are now, what the future holds, and what the long-term effects of the pandemic will be on stroke. Stroke occurs in about 1.4% of patients hospitalized with COVID-19 infection, who show an excess of large vessel occlusion and increased mortality. Despite this association, stroke presentations fell dramatically during the pandemic, although emerging data suggest that total stroke mortality may have risen with increased stroke deaths at home and in care homes. Strategies and guidelines have been developed to adapt stroke services worldwide, and protect healthcare workers. Adaptations include increasing use of telemedicine for all aspects of stroke care. The pandemic is exacerbating already marked global inequalities in stroke incidence and mortality. Lastly, the pandemic has had a major impact on stroke research and funding, although it has also emphasized the importance of large scale collaborative research initiatives.

BackgroundCysteine-altering NOTCH3 variants identical to those causing the rare monogenic form of stroke, CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy), have been reported more common than expected in the general population, but their clinical significance and contribution to stroke and dementia risk in the community remain unclear.MethodsCysteine-altering NOTCH3 variants were identified in UK Biobank whole-exome sequencing data (N=200 632). Frequency of stroke, vascular dementia and other clinical features of CADASIL, and MRI white matter hyperintensity volume were compared between variant carriers and non-carriers. MRIs from those with variants were visually rated, each matched with three controls.ResultsOf 200 632 participants with exome sequencing data available, 443 (~1 in 450) carried 67 different cysteine-altering NOTCH3 variants. After adjustment for various covariates, NOTCH3 variant carriers had increased risk of stroke (OR: 2.33, p=0.0004) and vascular dementia (OR: 5.00, p=0.007), and increased white matter hyperintensity volume (standardised difference: 0.52, pConclusionsCysteine-changing NOTCH3 variants are more common in the general population than expected from CADASIL prevalence and are risk factors for apparently ‘sporadic’ stroke and vascular dementia. They are associated with MRI changes of small vessel disease, in a distribution similar to that seen in CADASIL.

Background Cerebral small vessel disease (SVD) leads to reduced quality of life (QOL), but the mechanisms underlying this relationship remain unknown. This study investigated multivariate relationships between radiological markers of SVD and domain‐specific QOL deficits, as well as potential mediators, in patients with SVD. Methods Clinical and neuroimaging measures were obtained from a pooled sample of 174 SVD patients from the St. George's Cognition and Neuroimaging in Stroke and PRESsure in established cERebral small VEssel disease studies. Lacunes, white matter hyperintensities, and microbleeds were defined as radiological markers of SVD and delineated using MRI. QOL was assessed using the Stroke‐Specific Quality of Life Scale. Multivariate linear regression was used to determine whether SVD markers were associated with domain‐specific QOL deficits. Significant associations were further investigated using mediation analysis to examine whether functional disability or cognition was potential mediators. Results Multivariate regression analyses revealed that lacunes were associated with total QOL score (β = −8.22, p = .02), as well as reductions in mobility (β = −1.41, p = .008) and language‐related subdomains (β = −0.69, p = .033). White matter hyperintensities and microbleeds showed univariate correlations with QOL, but these became nonsignificant during multivariate analyses. Mediation analyses revealed that functional disability, defined as reduced activities of daily living, and executive function, partially mediated the relationship between lacunes and total QOL, as well as mobility‐related QOL, but not language‐related QOL. Conclusions Lacunar infarcts have the most detrimental effect on QOL in SVD patients, particularly in the mobility and language‐related subdomains. These effects may be partially explained by a reduction in activities of daily living. These results may inform targeted interventions to improve QOL in patients with SVD., Fernando et al. investigate associations between radiological markers of cerebral small vessel disease (SVD) and subdomains of quality of life (QOL). In a pooled sample of SVD patients, they find that lacunes lead to reductions in total QOL, as well as mobility and language‐related QOL, and explore potential mediating variables. These results suggest the possibility of targeted interventions to improve QOL in SVD patients.

Background The effect of the COVID pandemic on stroke network performance is unclear, particularly with consideration of drip&ship vs. mothership models. Aims We systematically reviewed and meta-analyzed variations in stroke admissions, rate and timing of reperfusion treatments during the first wave COVID pandemic vs. the pre-pandemic timeframe depending on stroke network model adopted. Summary of findings The systematic review followed registered protocol (PROSPERO-CRD42020211535), PRISMA and MOOSE guidelines. We searched MEDLINE, EMBASE, and CENTRAL until 9 October 2020 for studies reporting variations in ischemic stroke admissions, treatment rates, and timing in COVID (first wave) vs. control-period. Primary outcome was the weekly admission incidence rate ratio (IRR = admissions during COVID-period/admissions during control-period). Secondary outcomes were (i) changes in rate of reperfusion treatments and (ii) time metrics for pre- and in-hospital phase. Data were pooled using random-effects models, comparing mothership vs. drip&ship model. Overall, 29 studies were included in quantitative synthesis (n = 212,960). COVID-period was associated with a significant reduction in stroke admission rates (IRR = 0.69, 95%CI = 0.61–0.79), with higher relative presentation of large vessel occlusion (risk ratio (RR) = 1.62, 95% confidence interval (CI) = 1.24–2.12). Proportions of patients treated with endovascular treatment increased (RR = 1.14, 95%CI = 1.02–1.28). Intravenous thrombolysis decreased overall (IRR = 0.72, 95%CI = 0.54–0.96) but not in the mothership model (IRR = 0.81, 95%CI = 0.43–1.52). Onset-to-door time was longer for the drip&ship in COVID-period compared to the control-period (+32 min, 95%CI = 0–64). Door-to-scan was longer in COVID-period (+5 min, 95%CI = 2–7). Door-to-needle and door-to-groin were similar in COVID-period and control-period. Conclusions Despite a 35% drop in stroke admissions during the first pandemic wave, proportions of patients receiving reperfusion and time-metrics were not inferior to control-period. Mothership preserved the weekly rate of intravenous thrombolysis and the onset-to-door timing to pre-pandemic standards.

RationaleType 2 diabetes mellitus (T2D) is an established risk factor for cerebrovascular disease but the mechanisms underlying this association remain elusive. Disentangling the causal effects of T2D, hyperglycemia, and pre-diabetic phenotypes (insulin resistance, β-cell dysfunction) on major etiological stroke subtypes (ischemic stroke, intracerebral hemorrhage, ischemic stroke subtypes) could inform the development of preventive strategies.ObjectiveWe employed Mendelian randomization (MR) to explore the effects of genetic predisposition to T2D, hyperglycemia, insulin resistance, and β-cell dysfunction on risk of stroke subtypes and related cerebrovascular phenotypes.Methods and ResultsWe selected instruments for genetic predisposition to T2D, HbA1c levels, fasting glucose levels, insulin resistance, and β-cell dysfunction (proxied by pro-insulin levels) based on published genome-wide association studies (up to 898,130 individuals). Applying two-sample MR, we examined associations with ischemic stroke, intracerebral hemorrhage, and ischemic stroke subtypes (large artery, cardioembolic, small vessel stroke; up to 60,341 cases and 454,450 controls). We further explored associations with the related phenotypes of carotid atherosclerosis, imaging markers of cerebral white matter integrity, and brain atrophy. Genetic predisposition to T2D and elevated HbA1c levels in the pre-diabetic range were associated with higher risk of any ischemic stroke, large artery stroke, carotid plaque and small vessel stroke. Independently of HbA1c levels, we further found genetic predisposition to insulin resistance to be associated with large artery and small vessel stroke, whereas predisposition to β-cell dysfunction was associated with small vessel stroke. Predisposition to β-cell dysfunction was further associated with intracerebral hemorrhage, lower grey matter volume, and total brain volume.ConclusionsThis study supports causal effects of T2D and hyperglycemia on large artery and small vessel stroke. We show differential effects of genetically determined insulin resistance and β-cell dysfunction on large artery and small vessel stroke that might have implications for anti-diabetic treatments targeting these mechanisms.

Cerebral small vessel disease (SVD) is a major cause of vascular cognitive impairment and dementia. There are few treatments, largely reflecting limited understanding of the underlying pathophysiology. Metabolomics can be used to identify novel risk factors in order to better understand pathogenesis and to predict disease progression and severity.We analysed data from 624 patients with symptomatic cerebral SVD from two prospective cohort studies. Serum samples were collected at baseline and patients underwent MRI scans and cognitive testing at regular intervals with up to 14 years of follow-up. Using ultra-performance liquid chromatography mass spectrometry and nuclear magnetic resonance spectroscopy, we obtained metabolic and lipidomic profiles from 369 annotated metabolites and 54,764 unannotated features and examined their association with respect to disease severity, assessed using MRI SVD markers, cognition, and future risk of all-cause dementia.Over 100 annotated metabolites were significantly associated with SVD imaging markers, cognition, and progression to dementia. Decreased levels of multiple glycerophospholipids, sphingolipids, and sterol lipids were associated with increased SVD load as evidenced by higher white matter hyperintensities (WMH) volume, lower mean diffusivity normalised peak height (MDNPH), greater brain atrophy, and impaired cognition. Higher levels of several amino acids and nucleotides were associated with higher WMH volume, greater atrophy, and lower MDNPH. Lower baseline levels of carnitines and creatinine were associated with higher annualised change in peak width of skeletonised mean diffusivity (PSMD), and several metabolites, including lower levels of valine, caffeine, and VLDL analytes, were associated with future dementia incidence. Additionally, we identified 1,362 unannotated features associated with lower MDNPH and 2,474 unannotated features associated with increased WMH volume.Our results show multiple distinct metabolic signatures that are associated with imaging markers of SVD, cognition, and conversion to dementia. Further research should assess causality and the use of metabolomic screening to improve the ability to predict future disease severity and dementia risk in SVD. The metabolomic profiles may also provide novel insights into disease pathogenesis and help identify novel treatment approaches.

BackgroundCysteine-altering NOTCH3 variants identical to those causing the rare monogenic form of stroke, CADASIL, have been reported more common than expected in the general population, but their clinical significance and contribution to stroke and dementia risk in the community remains unclear.MethodsCysteine-altering NOTCH3 variants were identified in UK Biobank whole-exome sequencing data (N=200,632). Frequency of stroke, dementia and other clinical features of CADASIL, and MRI white matter hyperintensity volume were compared between variant carriers and non-carriers. MRIs from those with variants were visually rated, each matched with three controls.ResultsOf 200,632 participants with exome sequencing data available, 443 (∼1 in 450) carried 67 different cysteine-altering NOTCH3 variants. After adjusting for age, sex, and ancestry principal components, NOTCH3 variant carriers had increased risk of stroke (OR: 2.33, p=0.0003), and vascular dementia (OR: 5.03, p=0.007), and increased WMH volume (standardised difference: 0.52, pConclusionsCysteine-changing NOTCH3 variants are common in the general population and are risk factors for apparently “sporadic” stroke and vascular dementia. They are associated with MRI changes of SVD, in a distribution similar to that seen in CADASIL.

Background and ObjectivesTo determine the prevalence of and risk factors for cerebral microbleeds (CMBs) at different locations in a large healthy community population.MethodsA total of 8,159 participants from the UK Biobank with MRI scans suitable for CMB analysis were included. Brain susceptibility-weighted imaging data were acquired on 2 identical 3.0T scanners. The Microbleed Anatomical Rating Scale was used to identify definite CMBs. Generalized linear models were used to determine independent associations with all CMBs and lobar, deep, and infratentorial CMBs.ResultsThe mean age at scan was 62.1 ± 7.4 years. One or more definite CMBs were detected in 572 (7.0%) participants. Of those with CMBs, 439 (76.7%) had lobar CMBs, 103 (18.0%) had deep CMBs, and 83 (14.5%) had infratentorial CMBs. Age was an independent risk factor for CMBs in all locations. APOE4 and male sex were positively associated and higher body mass index was negatively associated with lobar CMBs. Hypertension, smoking, and alcohol consumption were associated with deep CMBs, but not with lobar CMBs. Only age was associated with infratentorial CMBs. The associations were unchanged after controlling for white matter hyperintensity lesion volume as a marker of small vessel disease severity.DiscussionIn this large population-based study, CMB prevalence detected using a low sensitivity and high specificity system was 7%. There were distinct risk factor profiles for CMBs in lobar and deep locations consistent with different underlying pathophysiologic processes.Trial Registration InformationClinical Trial registration number: UK Biobank application number 19463.

Cerebral small vessel disease (SVD) and inflammation are increasingly recognized as key contributors to Alzheimer's disease (AD), although the timing, trajectory, and relation between them early in the disease process is unclear. Therefore, to investigate very early-stage changes, we compared 158 healthy midlife adults with and without inherited AD predisposition (APOE4 carriership (38% positive), parental family history (FH) of dementia (54% positive)) on markers of SVD (white matter hyperintensities (WMH), cerebral microbleeds), and inflammation (C-reactive protein (CRP), fibrinogen), cross-sectionally and longitudinally over two years. While WMH severity was comparable between groups at baseline, longitudinal progression of WMH was greater in at-risk groups (APOE4+ and FH+). Topographically, APOE4 was associated exclusively with deep, but not periventricular, WMH progression after adjusting for FH. Conversely, APOE4 carriers displayed lower CRP levels than noncarriers, but not fibrinogen. Furthermore, interaction analysis showed that FH moderated the effect of SVD and inflammation on reaction time, an early feature of SVD, but not episodic memory or executive function. Findings suggest that vascular and inflammatory changes could occur decades before dementia onset, and may be of relevance in predicting incipient clinical progression., Highlights • Heritable risk factors related to SVD progression, despite lower levels of inflammation. • SVD progression had more pronounced adverse effects on reaction time in at-risk individuals. • Association between SVD and inflammation was stronger in those at-risk.

Background: Coronavirus disease 2019 (COVID-19) has become a global pandemic, affecting millions of people. However, the relationship between COVID-19 and acute cerebrovascular diseases (CVD) is unclear. Aims: We aimed to characterize the incidence, risk factors, clinical-radiological manifestations and outcome of COVID-19-associated stroke. Methods: Three medical databases were systematically reviewed for published articles on acute CVD in COVID-19 (December 2019-September 2020). The review protocol was previously registered (PROSPERO ID=CRD42020185476). Data were extracted from articles reporting 5 stroke cases in COVID-19. We complied with the PRISMA guidelines, and used the Newcastle–Ottawa Scale to assess data quality. Data were pooled using a random-effects model. Summary of review: Of 2,277 initially identified articles, 61 (2.7%) were entered in the meta-analysis. Out of 108,571 patients with COVID-19, acute CVD occurred in 1.4% (95%CI: 1.0-1.9). The most common manifestation was acute ischemic stroke (87.4%); intracerebral haemorrhage was less common (11.6%). Patients with COVID-19 developing acute CVD, compared to those who did not, were older (pooled median difference=4.8 years; 95%CI:1.7-22.4), more likely to have hypertension (OR=7.35; 95%CI:1.94-27.87), diabetes mellitus (OR=5.56; 95%CI:3.34-9.24), coronary artery disease (OR=3.12; 95%CI:1.61-6.02), and severe infection (OR=5.10; 95%CI:2.72-9.54). Compared to individuals who experienced a stroke without the infection, patients with COVID-19 and stroke were younger (pooled median difference=-6.0 years; 95%CI:-12.3 to -1.4), had higher NIHSS (pooled median difference=5; 95%CI:3-9), higher frequency of large vessel occlusion (OR=2.73; 95%CI:1.63-4.57), and higher in-hospital mortality rate (OR=5.21; 95% CI:3.43-7.90). Conclusions: Acute CVD is not uncommon in COVID-19, especially in those whom are severely infected and have pre-existing vascular risk factors. The pattern of large vessel occlusion and multi-territory infarcts suggest that cerebral thrombosis and/or thromboembolism could be possible causative pathways for the disease., BHF

Approximately 20–40% of all ischaemic strokes occur in the posterior circulation, and about a quarter of these are caused by either vertebral or basilar artery stenosis. Despite its frequency, the optimal management for vertebrobasilar stenosis is not clear. This is in marked contrast to carotid stenosis for which large randomised controlled trials have provided robust evidence showing that removal of the stenosis by carotid endarterectomy improves outcome. A number of recent trials have examined the efficacy of stenting for symptomatic vertebral stenosis. These have reported a high peri-operative risk for intracranial stenosis but a low peri-operative risk for extracranial stenosis. Based on current evidence, there seemed to be no benefit of stenting over best medical therapy for intracranial vertebral stenosis. For extracranial stenosis, there was a non-significant trend towards benefit for stenting, but data from larger trials are required to determine whether or not stenting is the treatment of choice for extracranial stenosis.

IntroductionAssociations between cerebral small vessel disease (SVD) and inflammation have been largely examined using peripheral blood markers of inflammation, with few studies measuring inflammation within the brain. We investigated the cross-sectional relationship between SVD and in vivo neuroinflammation using [11C]PK11195 positron emission tomography (PET) imaging.MethodsForty-two participants were recruited (according to NIA-AA guidelines, 14 healthy controls, 14 mild Alzheimer’s disease, 14 amyloid-positive mild cognitive impairment). Neuroinflammation was assessed using [11C]PK11195 PET imaging, a marker of microglial activation. To quantify SVD, we assessed white matter hyperintensities (WMH), enlarged perivascular spaces, cerebral microbleeds and lacunes. Composite scores were calculated for global SVD burden, and SVD subtypes of hypertensive arteriopathy and cerebral amyloid angiopathy (CAA). General linear models examined associations between SVD and [11C]PK11195, adjusting for sex, age, education, cognition, scan interval, and corrected for multiple comparisons via false discovery rate (FDR). Dominance analysis directly compared the relative importance of hypertensive arteriopathy and CAA scores as predictors of [11C]PK11195.ResultsGlobal [11C]PK11195 binding was associated with SVD markers, particularly in regions typical of hypertensive arteriopathy: deep microbleeds (β=0.63, F(1,35)=35.24, p11C]PK11195 binding globally and in 28 out of 37 regions of interest, especially the medial temporal lobe (β=0.66–0.76, t=3.90–5.58, FDR-corrected p (pFDR)=FDR=0.001–0.004).ConclusionMicroglial activation is associated with SVD, particularly with the hypertensive arteriopathy subtype of SVD. Although further research is needed to determine causality, our study suggests that targeting neuroinflammation might represent a novel therapeutic strategy for SVD.

Background and Purpose: Stroke is a complex disease with multiple genetic and environmental risk factors. Blacks endure a nearly 2-fold greater risk of stroke and are 2× to 3× more likely to die from stroke than European Americans. Methods: The COMPASS (Consortium of Minority Population Genome-Wide Association Studies of Stroke) has conducted a genome-wide association meta-analysis of stroke in >22 000 individuals of African ancestry (3734 cases, 18 317 controls) from 13 cohorts. Results: In meta-analyses, we identified one single nucleotide polymorphism (rs55931441) near the HNF1A gene that reached genome-wide significance ( P =4.62×10 −8 ) and an additional 29 variants with suggestive evidence of association ( P −6 ), representing 24 unique loci. For validation, a look-up analysis for a 100 kb region flanking the COMPASS single nucleotide polymorphism was performed in SiGN (Stroke Genetics Network) Europeans, SiGN Hispanics, and METASTROKE (Europeans). Using a stringent Bonferroni correction P value of 2.08×10 −3 (0.05/24 unique loci), we were able to validate associations at the HNF1A locus in both SiGN ( P =8.18×10 −4 ) and METASTROKE ( P =1.72×10 −3 ) European populations. Overall, 16 of 24 loci showed evidence for validation across multiple populations. Previous studies have reported associations between variants in the HNF1A gene and lipids, C-reactive protein, and risk of coronary artery disease and stroke. Suggestive associations with variants in the SFXN4 and TMEM108 genes represent potential novel ischemic stroke loci. Conclusions: These findings represent the most thorough investigation of genetic determinants of stroke in individuals of African descent, to date.

ObjectiveTo characterize risk factors for spontaneous intracerebral hemorrhage (sICH) occurrence and severity among West Africans.MethodsThe Stroke Investigative Research and Educational Network (SIREN) study is a multicenter case-control study involving 15 sites in Ghana and Nigeria. Patients were adults ≥18 years old with CT-confirmed sICH with age-, sex-, and ethnicity-matched stroke-free community controls. Standard instruments were used to assess vascular, lifestyle, and psychosocial factors. Factors associated with sICH and its severity were assessed using conditional logistic regression to estimate odds ratios (ORs) and population-attributable risks (PARs) with 95% confidence intervals (CIs) for factors.ResultsOf 2,944 adjudicated stroke cases, 854 were intracerebral hemorrhage (ICH). Mean age of patients with ICH was 54.7 ± 13.9 years, with a male preponderance (63.1%), and 77.3% were nonlobar. Etiologic subtypes of sICH included hypertension (80.9%), structural vascular anomalies (4.0%), cerebral amyloid angiopathy (0.7%), systemic illnesses (0.5%), medication-related (0.4%), and undetermined (13.7%). Eight factors independently associated with sICH occurrence by decreasing order of PAR with their adjusted OR (95% CI) were hypertension, 66.63 (20.78–213.72); dyslipidemia, 2.95 (1.84–4.74); meat consumption, 1.55 (1.01–2.38); family history of CVD, 2.22 (1.41–3.50); nonconsumption of green vegetables, 3.61 (2.07–6.31); diabetes mellitus, 2.11 (1.29–3.46); stress, 1.68 (1.03–2.77); and current tobacco use, 14.27 (2.09–97.47). Factors associated with severe sICH using an NIH Stroke Scale score >15 with adjusted OR (95% CI) were nonconsumption of leafy green vegetables, 2.03 (1.43–2.88); systolic blood pressure for each mm Hg rise, 1.01 (1.00–1.01); presence of midline shift, 1.54 (1.11–2.13); lobar ICH, 1.72 (1.16–2.55); and supratentorial bleeds, 2.17 (1.06–4.46).ConclusionsPopulation-level control of the dominant factors will substantially mitigate the burden of sICH in West Africa.

CT perfusion images can be rapidly obtained on all modern CT scanners and easily incorporated into an acute stroke imaging protocol. Here we discuss the technique of CT perfusion imaging, how to interpret the data and how it can contribute to the diagnosis of acute stroke and selection of patients for treatment. Many patients with acute stroke are excluded from reperfusion therapy if the onset time is not known or if they present outside of traditional treatment time windows. There is a growing body of evidence supporting the use of perfusion imaging in these patients to identify patterns of brain perfusion that are favourable for recanalisation therapy.

Background and Purpose— Statin therapy is associated with a lower risk of ischemic stroke supporting a causal role of low-density lipoprotein (LDL) cholesterol. However, more evidence is needed to answer the question whether LDL cholesterol plays a causal role in ischemic stroke subtypes. In addition, it is unknown whether high-density lipoprotein cholesterol and triglycerides have a causal relationship to ischemic stroke and its subtypes. Our aim was to investigate the causal role of LDL cholesterol, high-density lipoprotein cholesterol, and triglycerides in ischemic stroke and its subtypes through Mendelian randomization (MR). Methods— Summary data on 185 genome-wide lipids-associated single nucleotide polymorphisms were obtained from the Global Lipids Genetics Consortium and the Stroke Genetics Network for their association with ischemic stroke (n=16 851 cases and 32 473 controls) and its subtypes, including large artery atherosclerosis (n=2410), small artery occlusion (n=3186), and cardioembolic (n=3427) stroke. Inverse-variance–weighted MR was used to obtain the causal estimates. Inverse-variance–weighted multivariable MR, MR-Egger, and sensitivity exclusion of pleiotropic single nucleotide polymorphisms after Steiger filtering and MR-Pleiotropy Residual Sum and Outlier test were used to adjust for pleiotropic bias. Results— A 1-SD genetically elevated LDL cholesterol was associated with an increased risk of ischemic stroke (odds ratio: 1.12; 95% confidence interval: 1.04–1.20) and large artery atherosclerosis stroke (odds ratio: 1.28; 95% confidence interval: 1.10–1.49) but not with small artery occlusion or cardioembolic stroke in multivariable MR. A 1-SD genetically elevated high-density lipoprotein cholesterol was associated with a decreased risk of small artery occlusion stroke (odds ratio: 0.79; 95% confidence interval: 0.67–0.90) in multivariable MR. MR-Egger indicated no pleiotropic bias, and results did not markedly change after sensitivity exclusion of pleiotropic single nucleotide polymorphisms. Genetically elevated triglycerides did not associate with ischemic stroke or its subtypes. Conclusions— LDL cholesterol lowering is likely to prevent large artery atherosclerosis but may not prevent small artery occlusion nor cardioembolic strokes. High-density lipoprotein cholesterol elevation may lead to benefits in small artery disease prevention. Finally, triglyceride lowering may not yield benefits in ischemic stroke and its subtypes.

Vertebrobasilar stenosis accounts for 20% of posterior circulation strokes and is associated with high risk of early stroke recurrence. We review data from randomized controlled trials examining whether stenting may reduce this risk, including the recently published Vertebral Artery Ischaemia Stenting Trial (VIST).VIST and VAST (Vertebral Artery Stenting Trial), having recruited both intracranial and extracranial vertebral stenosis and showed a low rate of perioperative stroke for extracranial (0 and 2%, respectively), but a higher rate for intracranial stenosis (15 and 22%, respectively). In VIST, the primary endpoint of stroke occurred in five patients in the stent group vs. 12 in the medical group (hazard ratio 0.40; 95% confidence interval 0.14-1.13, P = 0.08), although when days from last symptoms were adjusted for, the hazard ratio was 0.34 (95% confidence interval 0.12-0.98; P = 0.046). SAMMPRIS (Stenting and Aggressive Medical Management for the Prevention of Recurrent Stroke in Intracranial Stenosis) recruited only intracranial vertebral stenosis and showed a better outcome with intensive medical therapy than stenting.Stenting of extracranial stenosis can be performed with a low operative risk. VIST suggests it may reduce longer term stroke risk, but this needs confirming in larger trials. For intracranial stenosis, due to a higher operative risk, current evidence favours medical treatment. SAMMPRIS have emphasized the need for intensive medical therapy whether or not stenting is performed.

In the paper by Mok et al. (“Tackling challenges in care of Alzheimer's disease and other dementias amid the COVID-19 pandemic, now and in the future.”Alzheimer's Dement. 2020; 16: 1571-1581. https://doi.org/10.1002/alz.12143), an error occurred in the preparation of the paper for publication, requiring the following correction. In the initial publication of this article, Vorapun Senanarong, BSc, MD, was inadvertently omitted from the author group. The corrected author group and affiliations list appear above. We regret the error.

Background Coronavirus disease 2019 (COVID-19) has become a global pandemic, affecting millions of people. However, the relationship between COVID-19 and acute cerebrovascular diseases is unclear. Aims We aimed to characterize the incidence, risk factors, clinical–radiological manifestations, and outcome of COVID-19-associated stroke. Methods Three medical databases were systematically reviewed for published articles on acute cerebrovascular diseases in COVID-19 (December 2019–September 2020). The review protocol was previously registered (PROSPERO ID = CRD42020185476). Data were extracted from articles reporting ≥5 stroke cases in COVID-19. We complied with the PRISMA guidelines and used the Newcastle–Ottawa Scale to assess data quality. Data were pooled using a random-effect model. Summary of review Of 2277 initially identified articles, 61 (2.7%) were entered in the meta-analysis. Out of 108,571 patients with COVID-19, acute CVD occurred in 1.4% (95%CI: 1.0–1.9). The most common manifestation was acute ischemic stroke (87.4%); intracerebral hemorrhage was less common (11.6%). Patients with COVID-19 developing acute cerebrovascular diseases, compared to those who did not, were older (pooled median difference = 4.8 years; 95%CI: 1.7–22.4), more likely to have hypertension (OR = 7.35; 95%CI: 1.94–27.87), diabetes mellitus (OR = 5.56; 95%CI: 3.34–9.24), coronary artery disease (OR = 3.12; 95%CI: 1.61–6.02), and severe infection (OR = 5.10; 95%CI: 2.72–9.54). Compared to individuals who experienced a stroke without the infection, patients with COVID-19 and stroke were younger (pooled median difference = −6.0 years; 95%CI: −12.3 to −1.4), had higher NIHSS (pooled median difference = 5; 95%CI: 3–9), higher frequency of large vessel occlusion (OR = 2.73; 95%CI: 1.63–4.57), and higher in-hospital mortality rate (OR = 5.21; 95%CI: 3.43–7.90). Conclusions Acute cerebrovascular diseases are not uncommon in patients with COVID-19, especially in those whom are severely infected and have pre-existing vascular risk factors. The pattern of large vessel occlusion and multi-territory infarcts suggests that cerebral thrombosis and/or thromboembolism could be possible causative pathways for the disease.

Comment inThe yin and yang of magnesium and calcium: New genetic insights for stroke? [Neurology. 2019]; International audience; Objective To determine whether serum magnesium and calcium concentrations are causally associated with ischemic stroke or any of its subtypes using the mendelian randomization approach. Methods Analyses were conducted using summary statistics data for 13 single-nucleotide polymorphisms robustly associated with serum magnesium (n = 6) or serum calcium (n = 7) concentrations. The corresponding data for ischemic stroke were obtained from the MEGASTROKE consortium (34,217 cases and 404,630 noncases). Results In standard mendelian randomization analysis, the odds ratios for each 0.1 mmol/L (about 1 SD) increase in genetically predicted serum magnesium concentrations were 0.78 (95% confidence interval [CI] 0.69-0.89; p = 1.3 × 10 −4) for all ischemic stroke, 0.63 (95% CI 0.50-0.80; p = 1.6 × 10 −4) for cardioembolic stroke, and 0.60 (95% CI 0.44-0.82; p = 0.001) for large artery stroke; there was no association with small vessel stroke (odds ratio 0.90, 95% CI 0.67-1.20; p = 0.46). Only the association with cardioembolic stroke was robust in sensitivity analyses. There was no association of genetically predicted serum calcium concentrations with all ischemic stroke (per 0.5 mg/dL [about 1 SD] increase in serum calcium: odds ratio 1.03, 95% CI 0.88-1.21) or with any subtype. Conclusions This study found that genetically higher serum magnesium concentrations are associated with a reduced risk of cardioembolic stroke but found no significant association of genetically higher serum calcium concentrations with any ischemic stroke subtype.

BackgroundCerebral amyloid angiopathy associated with inflammation is an increasingly recognized condition, characterized by an inflammatory response to the vascular deposits of β-amyloid within the brain that are the hallmark of cerebral amyloid angiopathy. Two main patterns of this inflammatory response have been identified to date: one involving a perivascular inflammatory cell infiltrate (cerebral amyloid angiopathy-related inflammation); the other a transmural vasculitic process (A-beta related angiitis). Unlike cerebral amyloid angiopathy itself, which predisposes to intracerebral hemorrhage and has no known treatment, cerebral amyloid angiopathy associated with inflammation typically presents in diverse ways and diagnosis may be challenging and delayed.AimsWe sought to summarize the clinical features, imaging appearances and available data on outcome and treatment responses, using information derived from a systematic review of pathologically proven cases of cerebral amyloid angiopathy associated with inflammation.Summary of reviewWe identified 213 distinct pathologically proven cases of cerebral amyloid angiopathy-related inflammation/A-beta related angiitis, from 104 publications. The clinical presentation, imaging features, pathology, treatment, and outcomes of cerebral amyloid angiopathy associated with inflammation are described.ConclusionsCerebral amyloid angiopathy associated with inflammation is an important and increasingly recognized clinical condition, which affects the older patient population and presents most commonly with cognitive decline, seizures, and headaches. Future research is required to develop and validate diagnostic criteria and determine optimum treatment strategies.

Objective While there are several cognitive screening tests available for the detection of cortical dementias such as Alzheimer's disease (AD), these are rarely designed to be sensitive to vascular cognitive impairment (VCI). The Brief Memory and Executive Test (BMET) is a screening measure designed to be sensitive to the cognitive profile of both VCI and AD. This study investigated the ability of the BMET to detect AD, and to differentiate between VCI and AD. Methods This study included 150 patients, with either SVD, both with (n = 48) and without VCI (n = 51), or AD (N = 51) and 51 healthy controls. Participants were aged between 40 and 90 years of age and completed both the BMET and the MMSE. Results Receiver operator characteristic (ROC) curve analysis showed as before the BMET is a good predictor SVD. Additionally, the BMET was a good predictor of AD (AUC = 0.96) and performed at least as well as the MMSE (AUC = 0.92) when differentiating AD patients from healthy controls. The BMET had a sensitivity of 86% and specificity of 100% for detecting AD patients from control subjects. Using the difference in cognitive profile between the AD and VCI group, we developed an index score which correctly classified 76% of patients as either having VCI or AD. Conclusion The BMET is a brief and sensitive tool for the detection of cognitive impairment due to both SVD and AD and can be used to aid in the differentiation of the 2 diseases.