Strategic Lacunes Associated With Mild Cognitive Impairment in Rural Chinese Older Adults: A Population-Based Study

BACKGROUND

Lacunes are associated with cognitive impairment. We sought to identify strategic lacune locations associated with mild cognitive impairment (MCI) and subtypes of MCI among older adults, and further to examine the role of white matter hyperintensities and perivascular spaces in the association.

METHODS

This population-based cross-sectional study included 1230 dementia-free participants in the brain magnetic resonance imaging substudy (2018-2020) in MIND-China (Multimodal Interventions to Delay Dementia and Disability in Rural China). Lacunes were visually identified in frontal lobe, parieto-occipital lobe, temporal lobe, insula, basal ganglia, thalamus, cerebellum, and brainstem. MCI, amnestic MCI (aMCI), and nonamnestic MCI (naMCI) were defined following the Petersen's criteria. Data were analyzed using logistic regression models.

RESULTS

Of the 1230 participants (age, ≥60 years; mean age, 69.40; SD, 4.30 years; 58.5% women), lacunes were detected in 357 people and MCI was defined in 286 individuals, including 243 with aMCI and 43 with naMCI. Lacunes in the supratentorial area, internal capsula, putamen/pallidum, and insula was significantly associated with increased odds ratio of MCI (multivariable-adjusted odds ratio ranged 1.40-3.21; P<0.05) and aMCI (multivariable-adjusted odds ratio ranged 1.46-3.36; P<0.05), whereas lacunes in the infratentorial area and brainstem were significantly associated with naMCI (multivariable-adjusted odds ratio ranged 2.68-3.46; P<0.01). Furthermore, the associations of lacunes in insula and internal capsula with MCI and aMCI, as well as the associations of lacunes in infratentorial area and brainstem with naMCI were present independent of white matter hyperintensities volume and perivascular spaces number.

CONCLUSIONS

Lacunes in the internal capsula, putamen/pallidum, insula, and brainstem may represent the strategic lacunes that are independently associated with MCI, aMCI, or naMCI in Chinese older adults.

REGISTRATION

URL: https://www.chictr.org.cn; Unique identifier: ChiCTR1800017758.

Prevention of Vascular Contributions to Cognitive Impairment and Dementia: The Role of Physical Activity and Exercise

Vascular contributions to cognitive impairment and dementia, specifically cerebral small vessel disease (CSVD), are the second most common cause of dementia. Currently, there are no specific pharmacological treatments for CSVD, and the use of conventional antidementia drugs is not recommended. Exercise has the potential to prevent and mitigate CSVD-related brain damage and improve cognitive function. Mechanistic pathways underlying the neurocognitive benefits of exercise include the control of vascular risk factors, improving endothelial function, and upregulating exerkines. Notably, the therapeutic efficacy of exercise may vary by exercise type (ie, aerobic versus resistance training) and biological sex; thus, studies designed specifically to examine these moderating factors within a CSVD context are needed. Furthermore, future research should prioritize resistance training interventions, given their tremendous therapeutic potential. Addressing these knowledge gaps will help us refine exercise recommendations to maximize their therapeutic impact in the prevention and mitigation of CSVD.

Does Thrombosis Play a Causal Role in Lacunar Stroke and Cerebral Small Vessel Disease?

BACKGROUND

The importance of thromboembolism in the pathogenesis of lacunar stroke (LS), resulting from cerebral small vessel disease (cSVD), is debated, and although antiplatelets are widely used in secondary prevention after LS, there is limited trial evidence from well-subtyped patients to support this approach. We sought to evaluate whether altered anticoagulation plays a causal role in LS and cSVD using 2-sample Mendelian randomization.

METHODS

From a recent genome-wide association study (n=81 190), we used 119 genetic variants associated with venous thrombosis at genome-wide significance (P<5*10-8) and with a linkage disequilibrium r2<0.001 as instrumental variables. We also used genetic associations with stroke from the GIGASTROKE consortium (62 100 ischemic stroke cases: 10 804 cardioembolic stroke, 6399 large-artery stroke, and 6811 LS). In view of the lower specificity for LS with the CT-based phenotyping mainly used in GIGASTROKE, we also used data from patients with magnetic resonance imaging-confirmed LS (n=3199). We also investigated associations with more chronic magnetic resonance imaging features of cSVD, namely, white matter hyperintensities (n=37 355) and diffusion tensor imaging metrics (n=36 533).

RESULTS

Mendelian randomization analyses showed that genetic predisposition to venous thrombosis was associated with an increased odds of any ischemic stroke (odds ratio [OR], 1.19 [95% CI, 1.13-1.26]), cardioembolic stroke (OR, 1.32 [95% CI, 1.21-1.45]), and large-artery stroke (OR, 1.41 [95% CI, 1.26-1.57]) but not with LS (OR, 1.07 [95% CI, 0.99-1.17]) in GIGASTROKE. Similar results were found for magnetic resonance imaging-confirmed LS (OR, 0.94 [95% CI, 0.81-1.09]). Genetically predicted risk of venous thrombosis was not associated with imaging markers of cSVD.

CONCLUSIONS

These findings suggest that altered thrombosis plays a role in the risk of cardioembolic and large-artery stroke but is not a causal risk factor for LS or imaging markers of cSVD. This raises the possibility that antithrombotic medication may be less effective in cSVD and underscores the necessity for further trials in well-subtyped cohorts with LS to evaluate the efficacy of different antithrombotic regimens in LS.

Cardiovascular Management in Asymptomatic (Silent) Cerebral Microbleeds and Suspected Cerebral Amyloid Angiopathy

Cerebral microbleeds (CMBs) detected on blood-sensitive magnetic resonance imaging sequences are usually a sign of an underlying cerebral small vessel disease such as sporadic cerebral amyloid angiopathy or sporadic nonamyloid small vessel pathology (eg, arteriolosclerosis). Much of the enduring interest in CMBs relates to their high prevalence (partly due to the widespread use of magnetic resonance imaging) in the context of stroke, cognitive impairment and in healthy individuals, and the clinical uncertainties created about the safety of antithrombotic medications due to their association with both future hemorrhagic and ischemic stroke. Historically, the research literature overwhelmingly emphasized the future hemorrhagic risk associated with CMBs, potentially leading to unnecessary withholding of treatments proven effective at preventing thrombosis, such as anticoagulants in patients with atrial fibrillation who happened to have some microbleeds. The lack of strong guidelines in this area contributes to wide variation in clinical practice. In this article, we critically review and discuss the implications of silent CMBs and cortical superficial siderosis (ie, without symptomatic intracerebral hemorrhage) in different clinical settings: the general population, patients with ischemic stroke, and the memory clinic. Emerging evidence, albeit not from randomized controlled trials, suggests that in most patients, CMBs alone should not prevent the use of antithrombotics or anticoagulants for stroke prevention, when they are otherwise indicated. Where possible, we provide specific suggestions for clinical care grounded in both the limited available literature and our personal clinical practice.

Association of Mean Upper Cervical Spinal Cord Cross-Sectional Area With Cerebral Small Vessel Disease: A Community-Based Cohort Study

BACKGROUND

The purpose of this study was to investigate the association between the mean upper cervical spinal cord cross-sectional area (MUCCA) and the risk and severity of cerebral small vessel disease (CSVD).

METHODS

Community-dwelling residents in Lishui City, China, from the cross-sectional survey in the PRECISE cohort study (Polyvascular Evaluation for Cognitive Impairment and Vascular Events) conducted from 2017 to 2019. We included 1644 of 3067 community-dwelling adults in the PRECISE study after excluding those with incorrect, incomplete, insufficient, or missing clinical or imaging data. Total and modified total CSVD scores, as well as magnetic resonance imaging features, including white matter hyperintensity, lacunes, cerebral microbleeds, enlarged perivascular spaces, and brain atrophy, were assessed at the baseline. The Spinal Cord Toolbox was used to measure the upper cervical spinal cord cross-sectional area of the C1 to C3 segments of the spinal cord and its average value was taken as MUCCA. Participants were divided into 4 groups according to quartiles of MUCCA. Associations were analyzed using linear regression models adjusted for age, sex, current smoking and drinking, medical history, intracranial volume, and total cortical volume.

RESULTS

The means±SD age of the participants was 61.4±6.5 years, and 635 of 1644 participants (38.6%) were men. The MUCCA was smaller in patients with CSVD than those without CSVD. Using the total CSVD score as a criterion, the MUCCA was 61.78±6.12 cm2 in 504 of 1644 participants with CSVD and 62.74±5.94 cm2 in 1140 of 1644 participants without CSVD. Using the modified total CSVD score, the MUCCA was 61.81±6.04 cm2 in 699 of 1644 participants with CSVD and 62.91±5.94 cm2 in 945 of 1644 without CSVD. There were statistical differences between the 2 groups after adjusting for covariates in 3 models. The MUCCA was negatively associated with the total and modified total CSVD scores (adjusted β value, -0.009 [95% CI, -0.01 to -0.003] and -0.007 [95% CI, -0.01 to -0.0006]) after adjustment for covariates. Furthermore, the MUCCA was negatively associated with the white matter hyperintensity burden (adjusted β value, -0.01 [95% CI, -0.02 to -0.003]), enlarged perivascular spaces in the basal ganglia (adjusted β value, -0.005 [95% CI, -0.009 to -0.001]), lacunes (adjusted β value, -0.004 [95% CI, -0.007 to -0.0007]), and brain atrophy (adjusted β value, -0.009 [95% CI, -0.01 to -0.004]).

CONCLUSIONS

The MUCCA and CSVD were correlated. Spinal cord atrophy may serve as an imaging marker for CSVD; thus, small vessel disease may involve the spinal cord in addition to being intracranial.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

REGISTRATION

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

Sex Differences in the Association of Age at Hypertension Diagnosis With Brain Structure

BACKGROUND

Sex differences exist in the likelihood of cognitive decline. The age at hypertension diagnosis is a unique contributor to brain structural changes associated with cerebral small vessel disease. However, whether this relationship differs between sexes remains unclear. Therefore, our objective was to evaluate sex differences in the association between the age at hypertension diagnosis and cerebral small vessel disease-related brain structural changes.

METHODS

We used data from the UK Biobank to select participants with a known age at hypertension diagnosis and brain magnetic resonance imaging (n=9430) and stratified them by sex and age at hypertension diagnosis. Control participants with magnetic resonance imaging scans but no hypertension were chosen at random matched by using propensity score matching. For morphological brain structural changes, generalized linear models were used while adjusting for other vascular risk factors. For the assessment of white matter microstructure, principal component analysis led to a reduction in the number of fractional anisotropy variables, followed by regression analysis with major principal components as outcomes.

RESULTS

Males but not females with a younger age at hypertension diagnosis exhibited lower brain gray and white matter volume compared with normotensive controls. The volume of white matter hyperintensities was greater in both males and females with hypertension than normotensive controls, significantly higher in older females with hypertension. Compared with normotensive controls, white matter microstructural integrity was lower in individuals with hypertension, which became more prominent with increasing age.

CONCLUSIONS

Our study demonstrates that the effect of hypertension on cerebral small vessel disease-related brain structure differs by sex and by age at hypertension diagnosis.

Mediation of Regional Cerebral Blood Flow in the Relationship between Specific Gut Microbiota and Cognition in Vascular Cognitive Impairment

BACKGROUND

Gut microbiota could affect the onset and development of vascular cognitive impairment (VCI) through modulating metabolic and immune pathways. However, the vascular mechanisms involved remain unclear.

OBJECTIVE

To investigate the gut microbiota associated with VCI and examine the mediating effects of regional cerebral blood flow (CBF) to explore potential therapeutic targets for VCI.

METHODS

This prospective study enrolled patients with VCI (n = 16) and healthy controls (n = 18) from the Chinese Imaging, Biomarkers, and Lifestyle study between January 1 and June 30, 2022. The gut microbiota composition and diversity were determined by 16 S ribosomal RNA gene sequencing. The association between gut microbiota and Montreal Cognitive Assessment (MoCA) scores was determined using Spearman's correlation analysis. Regional CBF was calculated using pseudo-continuous arterial spin labeling. The mediating effects of regional CBF on the relationship between specific gut microbiota and cognition in VCI were investigated using mediation analysis.

RESULTS

Compared to healthy controls, patients with VCI had significantly greater abundance of Bifidobacterium, Veillonella, R uminococcus gnavus , Fusobacterium, and Erysipelatoclostridium and smaller abundance of Collinsella. The abundance of Ruminococcus gnavus was negatively associated with MoCA scores in patients with VCI, with the CBF in the left hypothalamus, right hypothalamus, and left amygdala accounting for 63.96%, 48.22%, and 36.51%, respectively, of this association after adjusting for confounders.

CONCLUSIONS

Ruminococcus gnavus is associated with cognition in VCI, which is strongly mediated by CBF in the bilateral hypothalamus and left amygdala. These findings highlight the potential regulatory roles of nutrition and metabolism-related areas of the brain in VCI.

White Matter Hyperintensity Volume and Poststroke Cognition: An Individual Patient Data Pooled Analysis of 9 Ischemic Stroke Cohort Studies

BACKGROUND

White matter hyperintensities (WMH) are associated with cognitive dysfunction after ischemic stroke. Yet, uncertainty remains about affected domains, the role of other preexisting brain injury, and infarct types in the relation between WMH burden and poststroke cognition. We aimed to disentangle these factors in a large sample of patients with ischemic stroke from different cohorts.

METHODS

We pooled and harmonized individual patient data (n=1568) from 9 cohorts, through the Meta VCI Map consortium (www.metavcimap.org). Included cohorts comprised patients with available magnetic resonance imaging and multidomain cognitive assessment <15 months poststroke. In this individual patient data meta-analysis, linear mixed models were used to determine the association between WMH volume and domain-specific cognitive functioning (Z scores; attention and executive functioning, processing speed, language and verbal memory) for the total sample and stratified by infarct type. Preexisting brain injury was accounted for in the multivariable models and all analyses were corrected for the study site as a random effect.

RESULTS

In the total sample (67 years [SD, 11.5], 40% female), we found a dose-dependent inverse relationship between WMH volume and poststroke cognitive functioning across all 4 cognitive domains (coefficients ranging from -0.09 [SE, 0.04, P=0.01] for verbal memory to -0.19 [SE, 0.03, P<0.001] for attention and executive functioning). This relation was independent of acute infarct volume and the presence of lacunes and old infarcts. In stratified analyses, the relation between WMH volume and domain-specific functioning was also largely independent of infarct type.

CONCLUSIONS

In patients with ischemic stroke, increasing WMH volume is independently associated with worse cognitive functioning across all major domains, regardless of old ischemic lesions and infarct type.

Mismatch of MRI White Matter Hyperintensities and Gait Function in Patients With Cerebral Small Vessel Disease

BACKGROUND

Cerebral small vessel disease (CSVD) is closely related to gait disorders. Previous studies have found a negative correlation between the severity of MRI white matter hyperintensities (WMH) and gait speed. However, not every individual with WMH experiences a gait disorder.

PURPOSE

To investigate the mechanisms underlying the mismatch between the severity of MRI WMH and gait impairment, in particular in subjects with severe WMH (Fazekas 3, scale 0-3) resulting from vascular disease.

STUDY TYPE

Cohort.

POPULATION

54 subjects with severe WMH and gait disorder (WMH-GD; 29 males) and 114 subjects with severe WMH with no gait disorder (WMH-nGD; 60 males).

FIELD STRENGTH/SEQUENCE

3T/diffusion tensor imaging (DTI), and T1-weighted, T2-weighted, FLAIR, DWI, SWI.

ASSESSMENT

Trace-based spatial statistics analysis (TBSS) approach (fractional anisotropy, FA; mean diffusivity; radial diffusivity; axial diffusivity); Cognitive assessment; Conventional MRI markers of CSVD (WMH, enlarged perivascular spaces, lacunae, and cerebral microbleeds); Gait parameters (gait speed; cadence; stride length; gait cycle duration; step duration; time-up-and-go test, TUG). Gait disorder was defined as a TUG time exceeding 12 sec.

STATISTICAL TESTS

The t-tests, Mann-Whitney U tests, Chi-square tests, and partial correlation analysis (Pearson or Spearman) were used. P < 0.05 with threshold-free cluster enhancement corrected was considered statistically significant for TBSS.

RESULTS

After adjusting for age, sex, height, and other conventional MRI markers of CSVD, the WMH-nGD group showed significantly decreased FA values in the corpus callosum, bilateral superior longitudinal fasciculus, left corona radiata, and left posterior thalamic radiation. There was a significant association between FA values and TUG time, gait speed, and stride length in multiple WM tracts, independent of other conventional CSVD markers.

DATA CONCLUSION

This study provides evidence for microstructural damage of specific fibers in WMH-GD subjects compared to WMH-nGD subjects. This may explain the mismatch between WMH and gait impairment in subjects with severe WMH.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 3.

Higher critical closing pressure is independently associated with enlarged basal ganglia perivascular spaces

Objective

This study aimed to explore the association between cerebral hemodynamic parameters focused on the critical closing pressure (CCP) and enlarged perivascular spaces (EPVS).

Methods

Cerebral blood velocity in the middle cerebral artery (MCAv) and non-invasive continuous blood pressure (NIBP) were measured using a transcranial Doppler (TCD) and Finometer, followed by the calculation of cerebral hemodynamic parameters including CCP, resistance area product (RAP), pulsatility index (PI), and pulse pressure (PP). EPVS were graded separately in the basal ganglia (BG) and centrum semiovale (CSO), using a visual semiquantitative ordinal scale. Patients with EPVS >10 were classified into the severe BG-EPVS group and severe CSO-EPVS group, and the remainder into the mild BG-EPVS group and the mild CSO-EPVS group. Spearman's correlation and binary logistic regression analysis were performed to analyze the relationship between hemodynamic parameters and BG-EPVS and CSO-EPVS, respectively.

Results

Overall, 107 patients were enrolled. The severe BG-EPVS group had higher CCP, mean arterial blood pressure (MABP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) than that in the mild BG-EPVS group (p < 0.05). There was no statistical difference in hemodynamic parameters between the severe CSO-EPVS group and the mild CSO-EPVS group. Spearman's correlation analysis showed that CCP was positively associated with BG-EPVS (rho = 0.331, p < 0.001) and CSO-EPVS (rho = 0.154, p = 0.044). The binary logistic regression analysis showed that CCP was independently associated with severe BG-EPVS (p < 0.05) and not with CSO-EPVS (p > 0.05) after adjusting for confounders.

Conclusion

CCP representing cerebrovascular tension was independently associated with BG-EPVS.

Enlarged Perivascular Spaces in Relation to Cumulative Blood Pressure Exposure and Cognitive Impairment

BACKGROUND

Hypertension and enlarged perivascular spaces (EPVS) are thought to be associated with cognitive impairment. However, the correlations among hypertension, EPVS, and cognitive impairment have not been studied yet. We aimed to investigate the relationships between cumulative blood pressure (cBP) exposure with EPVS and cognitive impairment and whether EPVS may mediate the relationship between cBP and cognitive impairment.

METHODS

A total of 1507 subjects from the Kailuan prospective cohort study were enrolled. cBP was calculated from 2006 to 2022. The effects of cBP, EPVS scores, and cognitive impairment were evaluated using a logistic regression model. The relationships among cBP, EPVS score, and cognitive impairment were analyzed using a mediation model.

RESULTS

An increase in cBP was positively correlated with an increase in EPVS score. For every SD increase in cBP, the odds ratios (95% CI) of increased EPVS score of the centrum semiovale were 1.67 (1.43-1.95), 1.63 (1.4-1.9), and 1.35 (1.17-1.56), respectively; the odds ratios (95% CI) of increased EPVS score of the basal ganglia were 1.83 (1.56-2.15), 2.01 (1.7-2.36), and 1.31 (1.13-1.52), respectively; and the odds ratios (95% CI) of developing cognitive impairment were 1.28 (1.06-1.53), 1.13 (0.95-1.34), and 1.28 (1.07-1.5), respectively. Basal ganglia-EPVS score accounted for 10.46% to 18.32% of the mediating effects on the relationships of cBP/SD with cognitive impairment.

CONCLUSIONS

High cBP exposure was an independent risk factor for EPVS, and basal ganglia-EPVS score mediated the effects of cBP on cognitive impairment.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: ChiCTR-TNRC-11001489.

Management of Inherited CNS Small Vessel Diseases: The CADASIL Example: A Scientific Statement From the American Heart Association

Lacunar infarcts and vascular dementia are important phenotypic characteristics of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, the most common inherited cerebral small vessel disease. Individuals with the disease show variability in the nature and onset of symptoms and rates of progression, which are only partially explained by differences in pathogenic mutations in the NOTCH3 gene. Recognizing the disease early in its course and securing a molecular diagnosis are important clinical goals, despite the lack of proven disease-modifying treatments. The purposes of this scientific statement are to review the clinical, genetic, and imaging aspects of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, contrasting it with other inherited small vessel diseases, and to provide key prevention, management, and therapeutic considerations with the intent of reducing practice variability and encouraging production of high-quality evidence to support future treatment recommendations.

[Neuroimaging Characteristics of Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) in Korean Based on Jeju Cohort: A Pictorial Essay]

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary small artery vasculopathy caused by mutations in the NOTCH3 gene on chromosome 19. Jeju Island has the highest reported prevalence of CADASIL patients in the world. Even though most studies on the neuroimaging characteristics of CADASIL have focused on Western populations, there are notable differences in Korean CADASIL patients compared to those in Western countries, which may impact their clinical manifestations and prognosis. Herein, this pictorial essay presents the neuroimaging patterns of CADASIL in patients in Korea, with an emphasis on the differences observed from previous reports based on a Western patient population.

Amlodipine limits microglia activation and cognitive dysfunction in aged hypertensive mice

BACKGROUND

SBP and blood pressure variability are independent risk factors for cerebral small vessel disease, a leading cause for stroke and dementia. Calcium-channel blockers are known to reduce blood pressure variability and may thus offer benefit against dementia. Beyond this effect, the impact of calcium-channel blockers on hypertension-induced neuroinflammation, and especially, microglial phenotype remains unknown. We aimed to study the ability of amlopidine to alleviate microglia inflammation, and slow down cognitive dysfunction in aged hypertensive mice.

METHODS

Hypertensive BPH/2J and normotensive BPN/3J mice were studied until 12 months of age. Hypertensive mice were untreated or received amlodipine (10 mg/kg per day). Blood pressure parameters were measured by telemetry and tail cuff plethysmography. Mice underwent repeated series of cognitive tasks. Brain immunohistochemistry was performed to study blood-brain barrier dysfunction and microglial pro-inflammatory phenotype (CD68 + Iba1 + cells; morphological analysis).

RESULTS

Amlodipine normalized SBP over the entire life span and decreased blood pressure variability. BPH/2J mice exhibited impaired short-term memory that was prevented by amlodipine at 12 months (discrimination index 0.41 ± 0.25 in amlodipine-treated vs. 0.14 ± 0.15 in untreated BPH/2J mice, P  = 0.02). Amlopidine treatment of BPH/2J did not prevent blood-brain barrier leakage, a measure of cerebral small vessel disease, but limited its size. Microglia's inflammatory phenotype in BPH/2J, characterized by an increased number of Iba1 + CD68 + cells, increased soma size and shortened processes, was partly reduced by amlodipine.

CONCLUSION

Amlodipine attenuated the short-term memory impairment in aged hypertensive mice. Beyond its blood pressure lowering capacity, amlodipine may be cerebroprotective by modulating neuroinflammation.

Resistance Training Maintains White Matter and Physical Function in Older Women with Cerebral Small Vessel Disease: An Exploratory Analysis of a Randomized Controlled Trial

Background

As the aging population grows, there is an increasing need to develop accessible interventions against risk factors for cognitive impairment and dementia, such as cerebral small vessel disease (CSVD). The progression of white matter hyperintensities (WMHs), a key hallmark of CSVD, can be slowed by resistance training (RT). We hypothesize RT preserves white matter integrity and that this preservation is associated with improved cognitive and physical function.

Objective

To determine if RT preserves regional white matter integrity and if any changes are associated with cognitive and physical outcomes.

Methods

Using magnetic resonance imaging data from a 12-month randomized controlled trial, we compared the effects of a twice-weekly 60-minute RT intervention versus active control on T1-weighted over T2-weighted ratio (T1w/T2w; a non-invasive proxy measure of white matter integrity) in a subset of study participants (N = 21 females, mean age = 69.7 years). We also examined the association between changes in T1w/T2w with two key outcomes of the parent study: (1) selective attention and conflict resolution, and (2) peak muscle power.

Results

Compared with an active control group, RT increased T1w/T2w in the external capsule (p = 0.024) and posterior thalamic radiations (p = 0.013) to a greater degree. Increased T1w/T2w in the external capsule was associated with an increase in peak muscle power (p = 0.043) in the RT group.

Conclusion

By maintaining white matter integrity, RT may be a promising intervention to counteract the pathological changes that accompany CSVD, while improving functional outcomes such as muscle power.

Elecsys Cerebrospinal Fluid Immunoassays Accurately Detect Alzheimer's Disease Regardless of Concomitant Small Vessel Disease

BACKGROUND

Differentiating dementia due to small vessel disease (SVD) from dementia due to Alzheimer's disease (AD) with concomitant SVD is challenging in clinical practice. Accurate and early diagnosis of AD is critical to delivering stratified patient care.

OBJECTIVE

We characterized the results of Elecsys ® cerebrospinal fluid (CSF) immunoassays (Roche Diagnostics International Ltd) in patients with early AD, diagnosed using core clinical criteria, with varying extent of SVD.

METHODS

Frozen CSF samples (n = 84) were measured using Elecsys β-Amyloid(1-42) (Aβ42), Phospho-Tau (181P) (pTau181), and Total-Tau (tTau) CSF immunoassays, adapted for use on the cobas ® e 411 analyzer (Roche Diagnostics International Ltd), and a robust prototype β-Amyloid(1-40) (Aβ40) CSF immunoassay. SVD was assessed by extent of white matter hyperintensities (WMH) using the lesion segmentation tool. Interrelations between WMH, biomarkers, fluorodeoxyglucose F18-positron emission tomography (FDG-PET), and other parameters (including age and Mini-Mental State examinations [MMSE]) were assessed using Spearman's correlation, sensitivity/specificity, and logistic/linear regression analyses.

RESULTS

The extent of WMH showed significant correlation with Aβ42/Aβ40 ratio (Rho=-0.250; p = 0.040), tTau (Rho = 0.292; p = 0.016), tTau/Aβ42 ratio (Rho = 0.247; p = 0.042), age (Rho = 0.373; p = 0.002), and MMSE (Rho=-0.410; p = 0.001). Sensitivity/specificity point estimates for Elecsys CSF immunoassays versus FDG-PET positivity for underlying AD pathophysiology were mostly comparable or greater in patients with high versus low WMH. WMH were not a significant predictor and did not interact with CSF biomarker positivity but modified the association between pTau181 and tTau.

CONCLUSION

Elecsys CSF immunoassays detect AD pathophysiology regardless of concomitant SVD and may help to identify patients with early dementia with underlying AD pathophysiology.

Early Subacute White Matter Hyperintensities and Recovery of Language After Stroke

BACKGROUND

White matter hyperintensities (WMH) are considered to contribute to diminished brain reserve, negatively impacting on stroke recovery. While WMH identified in the chronic phase after stroke have been associated with post-stroke aphasia, the contribution of premorbid WMH to the early recovery of language across production and comprehension has not been investigated.

OBJECTIVE

To investigate the relationship between premorbid WMH severity and longitudinal comprehension and production outcomes in aphasia, after controlling for stroke lesion variables.

METHODS

Longitudinal behavioral data from individuals with a left-hemisphere stroke were included at the early subacute (n = 37) and chronic (n = 28) stage. Spoken language comprehension and production abilities were assessed at both timepoints using word and sentence-level tasks. Magnetic resonance imaging (MRI) was performed at the early subacute stage to derive stroke lesion variables (volume and proportion damage to critical regions) and WMH severity rating.

RESULTS

The presence of severe WMH explained an additional 18% and 25% variance in early subacute (t = -3.00, p = .004) and chronic (t = -3.60, P = .001) language comprehension abilities respectively, after controlling for stroke lesion variables. WMH did not predict additional variance of language production scores.

CONCLUSIONS

Subacute clinical MRI can be used to improve prognoses of recovery of aphasia after stroke. We demonstrate that severe early subacute WMH add to the prediction of impaired longitudinal language recovery in comprehension, but not production. This emphasizes the need to consider different domains of language when investigating novel neurobiological predictors of aphasia recovery.

NOTCH2NLC GGC Repeat Expansion in Patients With Vascular Leukoencephalopathy

BACKGROUND

Neuronal intranuclear inclusion disease (NIID), caused by GGC (guanine-guanine-cytosine) repeat expansion in NOTCH2NLC, has several clinical and radiological features akin to cerebral small vessel disease (cSVD). The present study tested the hypothesis that NOTCH2NLC GGC expansion may contribute to cSVD.

METHODS

One hundred and ninety-seven unrelated patients with genetically unsolved vascular leukoencephalopathy without NOTCH3, HTRA1, and mitochondrial m.3243A>G mutations and 730 healthy individuals were screened for NOTCH2NLC GGC repeat expansion using repeat-primed polymerase chain reaction, fragment analysis, Southern blot analysis, or nanopore sequencing with Cas9 (CRISPR associated protein 9)-mediated enrichment. The clinical and neuroimaging features of the patients were compared between individuals with and without NOTCH2NLC GGC repeat expansion.

RESULTS

Six of the 197 (3.0%) patients with unsolved vascular leukoencephalopathy and none of the controls carried the GGC repeat expansion (P=0.00009). Skin biopsy of 1 patient revealed eosinophilic, ubiquitin-positive, and p62-positive intranuclear inclusions in the cells of sweat gland and capillary, providing pathologic evidence for the involvement of small vessels in NIID. For the 6 patients, gait disturbance and cognitive decline were common manifestations with a median onset age of 65 (59-69) years. They all had multiple neuroimaging features suggestive of cSVD, including diffuse white matter hyperintensities, lacunes, and enlarged perivascular space in all 6 patients, cerebral microbleeds in 5, and old intracerebral hemorrhage in 4. Four patients had linear hyperintensity in the corticomedullary junction on diffusion-weighted imaging-the characteristic neuroimaging feature of NIID. There was no difference in the severity of cSVD imaging features between the patients with and without the GGC expansion but more pronounced brain atrophy in the patients with the GGC expansion.

CONCLUSIONS

NOTCH2NLC GGC repeat expansion accounted for 3% of genetically unsolved Taiwanese vascular leukoencephalopathy cases after excluding participants with cerebral autosomal dominant arteriopathy with subcortical infarct and leukoencephalopathy (CADASIL), cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), and mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS). NIID should be considered in patients manifesting cSVD, especially in those with characteristic neuroimaging feature of NIID.

Neuroimaging biomarkers of small vessel disease in cerebral amyloid angiopathy-related intracerebral hemorrhage

AIMS

The significance of the correlation of computed tomography (CT)-based cerebral small vessel disease (SVD) markers with the clinical outcomes in patients with cerebral amyloid angiopathy (CAA)-related intracerebral hemorrhage (ICH) remains uncertain. Thus, this study aimed to explore the relationship between SVD markers and short-term outcomes of CAA-ICH.

METHODS

A total of 183 patients with CAA-ICH admitted to the Xuanwu Hospital, and Beijing Fengtai You'anmen Hospital, from 2014 to 2021 were included. The multivariate logistic regression analysis was performed to identify the correlation between SVD markers based on CT and clinical outcomes at 7-day and 90-day.

RESULTS

Of the 183 included patients, 66 (36%) were identified with severe SVD burden. The multivariate analysis showed that the total SVD burden, white matter lesion (WML) grade, and brain atrophy indicator were independent risk factors for unfavorable outcomes at 90-day. The brain atrophy indicator was independently associated with mortality at 90-day. Severe cortical atrophy was significantly associated with early neurological deterioration.

CONCLUSIONS

The neuroimaging profiles of SVD based on CT in patients with CAA-ICH might predict the short-term outcome more effectively. Further studies are required to validate these findings and identify modifiable factors for preventing CAA-ICH development.

Faulty TRPM4 channels underlie age-dependent cerebral vascular dysfunction in Gould syndrome

Gould syndrome is a rare multisystem disorder resulting from autosomal dominant mutations in the collagen-encoding genes COL4A1 and COL4A2. Human patients and Col4a1 mutant mice display brain pathology that typifies cerebral small vessel diseases (cSVDs), including white matter hyperintensities, dilated perivascular spaces, lacunar infarcts, microbleeds, and spontaneous intracerebral hemorrhage. The underlying pathogenic mechanisms are unknown. Using the Col4a1+/G394V mouse model, we found that vasoconstriction in response to internal pressure-the vascular myogenic response-is blunted in cerebral arteries from middle-aged (12 mo old) but not young adult (3 mo old) animals, revealing age-dependent cerebral vascular dysfunction. The defect in the myogenic response was associated with a significant decrease in depolarizing cation currents conducted by TRPM4 (transient receptor potential melastatin 4) channels in native cerebral artery smooth muscle cells (SMCs) isolated from mutant mice. The minor membrane phospholipid phosphatidylinositol 4,5 bisphosphate (PIP2) is necessary for TRPM4 activity. Dialyzing SMCs with PIP2 and selective blockade of phosphoinositide 3-kinase (PI3K), an enzyme that converts PIP2 to phosphatidylinositol (3, 4, 5)-trisphosphate (PIP3), restored TRPM4 currents. Acute inhibition of PI3K activity and blockade of transforming growth factor-beta (TGF-β) receptors also rescued the myogenic response, suggesting that hyperactivity of TGF-β signaling pathways stimulates PI3K to deplete PIP2 and impair TRPM4 channels. We conclude that age-related cerebral vascular dysfunction in Col4a1+/G394V mice is caused by the loss of depolarizing TRPM4 currents due to PIP2 depletion, revealing an age-dependent mechanism of cSVD.

Association of white matter lesions and brain atrophy with the development of dementia in a community: the Hisayama Study

AIM

To investigate the association of white matter lesions volume (WMLV) levels with dementia risk and the association between dementia risk and the combined measures of WMLV and either total brain atrophy or dementia-related gray matter atrophy in a general older population.

METHODS

One thousand one hundred fifty-eight Japanese dementia-free community-residents aged ≥65 years who underwent brain magnetic resonance imaging were followed for 5.0 years. WMLV were segmented using the Lesion Segmentation Toolbox. Total brain volume (TBV) and regional gray matter volume were estimated by voxel-based morphometry. The WMLV-to-intracranial brain volume ratio (WMLV/ICV) was calculated, and its association with dementia risk was estimated using Cox proportional hazard models. Total brain atrophy, defined as the TBV-to-ICV ratio (TBV/ICV), and dementia-related regional brain atrophy defined based on our previous report were calculated. The association between dementia risk and the combined measures of WMLV/ICV and either total brain atrophy or the number of atrophied regions was also tested.

RESULTS

During the follow-up, 113 participants developed dementia. The risks of dementia increased significantly with higher WMLV/ICV levels. In addition, dementia risk increased additively both in participants with higher WMLV/ICV levels and lower TBV/ICV levels and in those with higher WMLV/ICV levels and a higher number of dementia-related brain regional atrophy.

CONCLUSION

The risk of dementia increased significantly with higher WMLV/ICV levels. An additive increment in dementia risk was observed with higher WMLV/ICV levels and lower TBV/ICV levels or a higher number of dementia-related brain regional atrophy, suggesting the importance of prevention or control of cardiovascular risk factors.

Genetic considerations in cerebral small vessel diseases

Cerebral small vessel disease (CSVD) encompasses a broad clinical spectrum united by pathology of the small vessels of the brain. CSVD is commonly identified using brain magnetic resonance imaging with well characterized markers including covert infarcts, white matter hyperintensities, enlarged perivascular spaces, and cerebral microbleeds. The pathophysiology of CSVD is complex involving genetic determinants, environmental factors, and their interactions. While the role of vascular risk factors in CSVD is well known and its management is pivotal in mitigating the clinical effects, recent research has identified novel genetic factors involved in CSVD. Delineating genetic determinants can promote the understanding of the disease and suggest effective treatments and preventive measures of CSVD at the individual level. Here we review CSVD focusing on recent advances in the genetics of CSVD. The knowledge gained has advanced understanding of the pathophysiology of CSVD, offered promising early results that may improve subtype identification of small vessel strokes, has led to additional identification of mendelian forms of small vessel strokes, and is getting closer to influencing clinical care through pharmacogenetic studies.

Efficacy and safety of cilostazol in decreasing progression of cerebral white matter hyperintensities-A randomized controlled trial

Introduction

Cerebral small vessel disease (SVD) is an important cause of dementia that lacks effective treatment. We evaluated the efficacy and safety of cilostazol, an antiplatelet agent with potential neurovascular protective effects, in slowing the progression of white matter hyperintensities (WMHs) in stroke- and dementia-free subjects harboring confluent WMH on magnetic resonance imaging (MRI).

Methods

In this single-center, randomized, double-blind, placebo-controlled study, we randomized stroke- and dementia-free subjects with confluent WMHs to receive cilostazol or placebo for 2 years in a 1:1 ratio. The primary outcome was change in WMH volume over 2 years. Secondary outcomes were changes in brain volumes, lacunes, cerebral microbleeds, perivascular space, and alterations in white matter microstructural integrity, cognition, motor function, and mood.

Results

We recruited 120 subjects from October 27, 2014, to January 21, 2019. A total of 55 subjects in the cilostazol group and 54 subjects in the control group were included for intention-to-treat analysis. At 2-year follow-up, the changes in WMH volume were not statistically different between cilostazol treatment and placebo (0.3±1.0 mL vs -0.1±0.8 mL, p = 0.167). Secondary outcomes, bleeding and vascular events, were also not statistically different between the two groups.

Discussion

In this trial with stroke- and dementia-free subjects with confluent WMHs, cilostazol did not impact WMH progression but demonstrated an acceptable safety profile. Future studies should address the treatment effects of cilostazol on subjects at different clinical stages of SVD.

The association between white matter hyperintensity volume and cognitive/physical decline in older people with dementia: A one-year longitudinal study

OBJECTIVES

Understanding the relationship between white matter hyperintensities (WMHs) and cognitive and physical decline in people with dementia will assist in determining potential treatment strategies. Currently there is conflicting evidence describing the association between WMHs and cognitive decline and, WMHs association with declines in objective measures of physical function have not been examined. We examined the relationship between baseline WMH volume and physical/cognitive decline over one-year in older people with dementia.

METHODS

Twenty-six community-dwelling older people with dementia (mean age = 81 ± 8 years; 35% female) were assessed at baseline and follow-up (one-year) using the Addenbrooke's Cognitive Examination-Revised (including verbal fluency), Trail Making Test A, the Physiological Profile Assessment (PPA), timed-up-and-go (TUG) and gait speed. WMH volumes were quantified using a fully automated segmentation toolbox, UBO Detector.

RESULTS

In analyses adjusted for baseline performance, higher baseline WMH volume was associated with decline in executive function (verbal fluency), sensorimotor function (PPA) and mobility (TUG). Executive function (semantic/category fluency) was the only domain association that withstood adjustment for age, and additionally hippocampal volume.

CONCLUSIONS

In unadjusted analyses, WMH volume was associated with one-year declines in cognitive and physical function in older people with dementia. The association with executive function decline withstood adjustment for age. More research is needed to confirm these findings and explore whether vascular risk reduction strategies can reduce WMH volume and associated cognitive and physical impairments in this group.

Cerebral Small Vessel Diseases and Outcomes for Acute Ischemic Stroke Patients after Endovascular Therapy

The correlation between cerebral small vessel disease (CSVD) and the outcomes of acute ischemic stroke (AIS) patients after endovascular therapy (EVT) remains elusive. We aimed to investigate the effect of combined white matter hyperintensities (WMH) and enlarged perivascular spaces (EPVS) as detected in magnetic resonance imaging (MRI) at baseline on clinical outcomes in patients with AIS who underwent EVT. AIS patients that experienced EVT were retrospectively analyzed in this single-center study. Using MRIs taken prior to EVT, we rated WMH and EPVS as the burden of CSVD and dichotomized the population into two groups: absent-to-moderate and severe. Neurological outcome was assessed at day 90 with a modified Rankin Scale (mRS). Symptomatic intracerebral hemorrhage (sICH), early neurological deterioration (END), malignant cerebral edema (MCE), and hospital death were secondary outcomes. Of the 100 patients (64.0% male; mean age 63.71 ± 11.79 years), periventricular WMHs (28%), deep WMHs (41%), EPVS in basal ganglia (53%), and EPVS in centrum semiovale (73%) were observed. In addition, 69% had an absent-to-moderate total CSVD burden and 31.0% had a severe burden. The severe CSVD was not substantially linked to either the primary or secondary outcomes. Patients with AIS who underwent EVT had an elevated risk (OR: 7.89, 95% CI: 1.0, 62.53) of END if they also had EPVS. When considering WMH and EPVS together as a CSVD burden, there seemed to be no correlation between severe CSVD burden and sICH, END, or MCE following EVT for AIS patients. Further studies are warranted to clarify the relationship between CSVD burden and the occurrence, progression, and prognosis of AIS.

Long-term outcome of cerebral amyloid angiopathy-related hemorrhage

Object

The long‐term functional outcome of cerebral amyloid angiopathy‐related hemorrhage (CAAH) patients is unclear. We sought to assess the long‐term functional outcome of CAAH and determine the prognostic factors associated with unfavorable outcomes.

Methods

We enrolled consecutive CAAH patients from 2014 to 2020 in this observational study. Baseline characteristics and clinical outcomes were presented. Multivariable logistic regression analysis was performed to identify the prognostic factors associated with long‐term outcome.

Results

Among the 141 CAAH patients, 76 (53.9%) achieved favorable outcomes and 28 (19.9%) of them died at 1‐year follow‐up. For the longer‐term follow‐up with a median observation time of 19.0 (interquartile range, 12.0–26.5) months, 71 (50.4%) patients obtained favorable outcomes while 33 (23.4%) died. GCS on admission (OR, 0.109; 95% CI, 0.021–0.556; p = 0.008), recurrence of ICH (OR, 2923.687; 95% CI, 6.282–1360730.14; p = 0.011), WML grade 3–4 (OR, 31.007; 95% CI, 1.041–923.573; p = 0.047), severe central atrophy (OR, 4220.303; 95% CI, 9.135–1949674.84; p = 0.008) assessed by CT was identified as independent predictors for long‐term outcome.

Interpretation

Nearly 50% of CAAH patients achieved favorable outcomes at long‐term follow‐up. GCS, recurrence of ICH, WML grade and cerebral atrophy were identified as independent prognostic factors of long‐term outcome.

Idiopathic primary intraventricular hemorrhage and cerebral small vessel disease

BACKGROUND

Although primary intraventricular hemorrhage is frequently due to trauma or vascular lesions, the etiology of idiopathic primary intraventricular hemorrhage (IP-IVH) is not defined.

AIMS

Herein, we test the hypothesis that cerebral small vessel diseases (cSVD) including hypertensive cSVD (HTN-cSVD) and cerebral amyloid angiopathy are associated with IP-IVH.

METHODS

Brain magnetic resonance imaging from consecutive patients (January 2011 to September 2019) with non-traumatic intracerebral hemorrhage from a single referral center were reviewed for the presence of HTN-cSVD (defined by strictly deep or mixed-location intracerebral hemorrhage/cerebral microbleeds) and cerebral amyloid angiopathy (applying modified Boston criteria).

RESULTS

Forty-six (4%) out of 1276 patients were identified as having IP-IVH. Among these, the mean age was 74.4 ± 12.2 years and 18 (39%) were females. Forty (87%) had hypertension, and the mean initial blood pressure was 169.2 ± 40.4/88.8 ± 22.2 mmHg. Of the 35 (76%) patients who received a brain magnetic resonance imaging, two (6%) fulfilled the modified Boston criteria for possible cerebral amyloid angiopathy and 10 (29%) for probable cerebral amyloid angiopathy. Probable cerebral amyloid angiopathy was found at a similar frequency when comparing IP-IVH patients to the remaining patients with primary intraparenchymal hemorrhage (P-IPH) (27%, p = 0.85). Furthermore, imaging evidence for HTN-cSVD was found in 8 (24%) patients with IP-IVH compared to 209 (28%, p = 0.52) patients with P-IPH.

CONCLUSIONS

Among IP-IVH patients, cerebral amyloid angiopathy was found in approximately one-third of patients, whereas HTN-cSVD was detected in 23%-both similar rates to P-IPH patients. Our results suggest that both cSVD subtypes may be associated with IP-IVH.

Genetic analysis reveals novel variants for vascular cognitive impairment

OBJECTIVES

The genetic background of vascular cognitive impairment (VCI) is poorly understood compared to other dementia disorders. The aim of the study was to investigate the genetic background of VCI in a well-characterized Finnish cohort.

MATERIALS & METHODS

Whole-exome sequencing (WES) was applied in 45 Finnish VCI patients. Copy-number variant (CNV) analysis using a SNP array was performed in 80 VCI patients. This study also examined the prevalence of variants at the miR-29 binding site of COL4A1 in 73 Finnish VCI patients.

RESULTS

In 40% (18/45) of the cases, WES detected possibly causative variants in genes associated with cerebral small vessel disease (CSVD) or other neurological or stroke-related disorders. These variants included HTRA1:c.847G>A p.(Gly283Arg), TREX1:c.1079A>G, p.(Tyr360Cys), COLGALT1:c.1411C>T, p.(Arg471Trp), PRNP: c.713C>T, p.(Pro238Leu), and MTHFR:c.1061G>C, p.(Gly354Ala). Additionally, screening of variants in the 3'UTR of COL4A1 gene in a sub-cohort of 73 VCI patients identified a novel variant c.*36T>A. CNV analysis showed that pathogenic CNVs are uncommon in VCI.

CONCLUSIONS

These data support pathogenic roles of variants in HTRA1, TREX1 and in the 3'UTR of COL4A1 in CSVD and VCI, and suggest that vascular pathogenic mechanisms are linked to neurodegeneration, expanding the understanding of the genetic background of VCI.

A cluster of blood-based protein biomarkers reflecting coagulation relates to the burden of cerebral small vessel disease

Biological processes underlying cerebral small vessel disease (cSVD) are largely unknown. We hypothesized that identification of clusters of inter-related bood-based biomarkers that are associated with the burden of cSVD provides leads on underlying biological processes. In 494 participants (mean age 67.6 ± 8.7 years; 36% female; 75% cardiovascular diseases; 25% reference participants) we assessed the relation between 92 blood-based biomarkers from the OLINK cardiovascular III panel and cSVD, using cluster-based analyses. We focused particularly on white matter hyperintensities (WMH). Nineteen biomarkers individually correlated with WMH ratio (r range: 0.16-0.27, Bonferroni corrected p-values <0.05), of which sixteen biomarkers formed one biomarker cluster. Pathway analysis showed that this biomarker cluster predominantly reflected coagulation processes. This cluster related also significantly to other cSVD manifestations (lacunar infarcts, microbleeds, and enlarged perivascular spaces), which supports generalizability beyond WMHs. To study possible causal effects of biological processes reflected by the cluster we performed a mediation analysis that showed a mediation effect of the cluster on the relation between age and WMH ratio (proportion mediated 17%), and hypertension and WMH-volume (proportion mediated 21%). In conclusion, we identified a cluster of blood-based biomarkers reflecting coagulation, that is related to manifestations of cSVD, corroborating involvement of coagulation abnormalities in the etiology of cSVD.

The Association Between Standard Electrocardiography and Cerebral Small Vessel Disease in a Memory Clinic Study

BACKGROUND

P-wave terminal force in lead V1 (PTFV1) on electrocardiography has been associated with atrial fibrillation and ischemic stroke.

OBJECTIVE

To investigate whether PTFV1 is associated with cerebral small vessel disease (CSVD) markers and etiological subtypes of cognitive impairment and dementia.

METHODS

Participants were recruited from ongoing memory clinic study between August 2010 to January 2019. All participants underwent physical and medical evaluation along with an electrocardiography and 3 T brain magnetic resonance imaging. Participants were classified as no cognitive impairment, cognitive impairment no dementia, vascular cognitive impairment no dementia, and dementia subtypes (Alzheimer's disease and vascular dementia). Elevated PTFV1 was defined as >  4,000μV×ms and measured manually on ECG.

RESULTS

Of 408 participants, 78 (19.1%) had elevated PTFV1 (37 women [47%]; mean [SD] age, 73.8 [7.2] years). The participants with elevated PTFV1 had higher burden of lacunes, cerebral microbleeds (CMB), and cortical microinfarcts. As for the CMB location, persons with strictly deep CMB and mixed CMB had significantly higher PTFV1 than those with no CMB (p = 0.005, p = 0.007). Regardless of adjustment for cardiovascular risk factors and/or heart diseases, elevated PTFV1 was significantly associated with presence of CMB (odds ratio, 2.26; 95% CI,1.33-3.91).

CONCLUSION

Elevated PTFV1 was associated with CSVD, especially deep CMB. PTFV1 in vascular dementia was also higher compared to Alzheimer's disease. Thus, PTFV1 might be a potential surrogate marker of brain-heart connection and vascular brain damage.

Risk factors of cerebral small vessel disease: A systematic review and meta-analysis

BACKGROUND

Cerebral small vessel disease (CSVD) is a common neurological disease under the effect of multiple factors. Although some literature analyzes and summarizes the risk factors of CSVD, the conclusions are controversial. To determine the risk factors of CSVD, we conducted this meta-analysis.

METHODS

Five authoritative databases of PubMed, Embase, Cochrane Library, CNKI, and Wan Fang were searched to find related studies published before November 30, 2020. The literature was screened according to the inclusion and exclusion criteria. We used RevMan 5.4 software to analyze the data after extraction.

RESULTS

A total of 29 studies involving 16,587 participants were included. The meta-analysis showed that hypertension (odds ratio [OR] 3.16, 95% confidence interval [CI] 2.22-4.49), diabetes (OR 2.15, 95% CI 1.59-2.90), hyperlipidemia (OR 1.64, 95% CI 1.11-2.40), smoking (OR 1.47, 95% CI 1.15-1.89) were significantly related to the risk of lacune, while drinking (OR 1.03, 95% CI 0.87-1.23) was not. And hypertension (OR 3.31, 95% CI 2.65-4.14), diabetes (OR 1.66, 95% CI 2.65-1.84), hyperlipidemia (OR 1.88, 95% CI 1.08-3.25), smoking (OR 1.48, 95% CI 1.07-2.04) were significantly related to the risk of white matter hyperintensity, while drinking (OR 1.41, 95% CI 0.97-2.05) was not.

CONCLUSIONS

This study suggested that hypertension, diabetes, hyperlipidemia, and smoking are risk factors of CSVD, and we should take measures to control these risk factors for the purpose of preventing CSVD.

Oxygen Metabolic Stress and White Matter Injury in Patients With Cerebral Small Vessel Disease

BACKGROUND AND PURPOSE

Chronic hypoxia-ischemia is a putative mechanism underlying the development of white matter hyperintensities (WMH) and microstructural disruption in cerebral small vessel disease. WMH fall primarily within deep white matter (WM) watershed regions. We hypothesized that elevated oxygen extraction fraction (OEF), a signature of hypoxia-ischemia, would be detected in the watershed where WMH density is highest. We further hypothesized that OEF would be elevated in regions immediately surrounding WMH, at the leading edge of growth.

METHODS

In this cross-sectional study conducted from 2016 to 2019 at an academic medical center in St Louis, MO, participants (age >50) with a range of cerebrovascular risk factors underwent brain magnetic resonance imaging using pseudocontinuous arterial spin labeling, asymmetric spin echo, fluid-attenuated inversion recovery and diffusion tensor imaging to measure cerebral blood flow (CBF), OEF, WMH, and WM integrity, respectively. We defined the physiologic watershed as a region where CBF was below the 10th percentile of mean WM CBF in a young healthy cohort. We conducted linear regression to evaluate the relationship between CBF and OEF with structural and microstructural WM injury defined by fluid-attenuated inversion recovery WMH and diffusion tensor imaging, respectively. We conducted ANOVA to determine if OEF was increased in proximity to WMH lesions.

RESULTS

In a cohort of 42 participants (age 50-80), the physiologic watershed region spatially overlapped with regions of highest WMH lesion density. As CBF decreased and OEF increased, WMH density increased. Elevated watershed OEF was associated with greater WMH burden and microstructural disruption, after adjusting for vascular risk factors. In contrast, WM and watershed CBF were not associated with WMH burden or microstructural disruption. Moreover, OEF progressively increased while CBF decreased, in concentric contours approaching WMH lesions.

CONCLUSIONS

Chronic hypoxia-ischemia in the watershed region may contribute to cerebral small vessel disease pathogenesis and development of WMH. Watershed OEF may hold promise as an imaging biomarker to identify individuals at risk for cerebral small vessel disease progression.

Effects of Cilostazol and Isosorbide Mononitrate on Cerebral Hemodynamics in the LACI-1 Randomized Controlled Trial

Supplemental Digital Content is available in the text.

Cerebral small vessel disease—a major cause of stroke and dementia—is associated with cerebrovascular dysfunction. We investigated whether short-term isosorbide mononitrate (ISMN) and cilostazol, alone or in combination, improved magnetic resonance imaging–measured cerebrovascular function in patients with lacunar ischemic stroke.

Association of Blood Pressure, Its Treatment, and Treatment Efficacy With Volume of White Matter Hyperintensities in the Population-Based 1000BRAINS Study

[Figure: see text].

Rare NOTCH3 Variants in a Chinese Population-Based Cohort and Its Relationship With Cerebral Small Vessel Disease

BACKGROUND AND PURPOSE

Researches on rare variants of NOTCH3 in the general Chinese population are lacking. This study aims to describe the spectrum of rare NOTCH3 variants by whole-exome sequencing in a Chinese community-based cohort and to investigate the association between rare NOTCH3 variants and age-related cerebral small vessel disease.

METHODS

The cross-sectional study comprised 1065 participants who underwent whole-exome sequencing and brain magnetic resonance imaging. NOTCH3 variants with minor allele frequency<1% in all 4 public population databases (1000 Genomes, ESP6500siv2_ALL, GnomAD_ALL, and GnomAD_EAS) were defined as rare variants. Multivariable linear and logistic regressions were used to investigate the associations between rare NOTCH3 variants and volume of white matter hyperintensities and cerebral small vessel disease burden. Clinical and imaging characteristics of rare NOTCH3 variant carriers were summarized.

RESULTS

Sixty-five rare NOTCH3 variants were identified in 147 of 1065 (13.8%) participants, including 57 missense single nucleotide polymorphisms (SNPs), 5 SNPs in splice branching sites, and 3 frameshift deletions. A significantly higher volume of white matter hyperintensities and heavier burden of cerebral small vessel disease was found in carriers of rare NOTCH3 EGFr (epidermal growth factor-like repeats)-involving variants, but not in carriers of EGFr-sparing variants. The carrying rate of rare EGFr-involving NOTCH3 variants in participants with dementia or stroke was significantly higher than those without dementia or stroke (12.4% versus 6.6%, P=0.041). Magnetic resonance imaging signs suggestive of CADASIL were found in 3.4% (5/145) rare EGFr cysteine-sparing NOTCH3 variant carriers but not in 2 cysteine-altering NOTCH3 variant carriers.

CONCLUSIONS

Carriers of rare NOTCH3 variants involving the EGFr domain may be genetically predisposed to age-related cerebral small vessel disease in the general Chinese population.

Hereditary Cerebral Small Vessel Diseases and Stroke: A Guide for Diagnosis and Management

Cerebral small vessel diseases represent a frequent cause of stroke and cognitive or motor disability in adults. A small proportion of cerebral small vessel diseases is attributable to monogenic conditions. Since the characterization in the late 1990s of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, several other monogenic conditions leading to adult-onset ischemic or hemorrhagic stroke have been described. In this practical guide, we summarize the key features that should elicit the differential diagnosis of a hereditary cerebral small vessel diseases in adult stroke patients, describe the main clinical and imaging characteristics of the major hereditary cerebral small vessel diseases that can manifest as stroke, and provide general recommendations for the clinical management of affected patients and their relatives.

Prostaglandin E2 Dilates Intracerebral Arterioles When Applied to Capillaries: Implications for Small Vessel Diseases

Prostaglandin E2 (PGE2) has been widely proposed to mediate neurovascular coupling by dilating brain parenchymal arterioles through activation of prostanoid EP4 receptors. However, our previous report that direct application of PGE2 induces an EP1-mediated constriction strongly argues against its direct action on arterioles during neurovascular coupling, the mechanisms sustaining functional hyperemia. Recent advances have highlighted the role of capillaries in sensing neuronal activity and propagating vasodilatory signals to the upstream penetrating parenchymal arteriole. Here, we examined the effect of capillary stimulation with PGE2 on upstream arteriolar diameter using an ex vivo capillary-parenchymal arteriole preparation and in vivo cerebral blood flow measurements with two-photon laser-scanning microscopy. We found that PGE2 caused upstream arteriolar dilation when applied onto capillaries with an EC50 of 70 nM. The response was inhibited by EP1 receptor antagonist and was greatly reduced, but not abolished, by blocking the strong inward-rectifier K+ channel. We further observed a blunted dilatory response to capillary stimulation with PGE2 in a genetic mouse model of cerebral small vessel disease with impaired functional hyperemia. This evidence casts previous findings in a different light, indicating that capillaries are the locus of PGE2 action to induce upstream arteriolar dilation in the control of brain blood flow, thereby providing a paradigm-shifting view that nonetheless remains coherent with the broad contours of a substantial body of existing literature.

Cerebral Small Vessel Disease Associated With Atrial Fibrillation Among Older Adults: A Population-Based Study

[Figure: see text].

White Matter Lesions and Outcomes After Endovascular Treatment for Acute Ischemic Stroke: MR CLEAN Registry Results

Supplemental Digital Content is available in the text.

Background:

Cerebral white matter lesions (WMLs) have been associated with a greater risk of poor functional outcome after ischemic stroke. We assessed the relations between WML burden and radiological and clinical outcomes in patients treated with endovascular treatment in routine practice.

Methods:

We analyzed data from the MR CLEAN Registry (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischaemic Stroke in the Netherlands)—a prospective, multicenter, observational cohort study of patients treated with endovascular treatment in the Netherlands. WMLs were graded on baseline noncontrast computed tomography using a visual grading scale. The primary outcome was the score on the modified Rankin Scale at 90 days. Secondary outcomes included early neurological recovery, successful reperfusion (extended Thrombolysis in Cerebral Infarction ≥2b), futile recanalization (modified Rankin Scale score ≥3 despite successful reperfusion), and occurrence of symptomatic intracranial hemorrhage. We used multivariable logistic regression models to assess associations between WML severity and outcomes, taking the absence of WML on noncontrast computed tomography as the reference category.

Results:

Of 3180 patients included in the MR CLEAN Registry between March 2014 and November 2017, WMLs were graded for 3046 patients and categorized as none (n=1855; 61%), mild (n=608; 20%), or moderate to severe (n=588; 19%). Favorable outcome (modified Rankin Scale score, 0–2) was achieved in 838 patients (49%) without WML, 192 patients (34%) with mild WML, and 130 patients (24%) with moderate-to-severe WML. Increasing WML grades were associated with a shift toward poorer functional outcome in a dose-dependent manner (adjusted common odds ratio, 1.34 [95% CI, 1.13–1.60] for mild WML and 1.67 [95% CI, 1.39–2.01] for moderate-to-severe WML; P_trend, <0.001). Increasing WML grades were associated with futile recanalization (P_trend, <0.001) and were inversely associated with early neurological recovery (P_trend, 0.041) but not with the probability of successful reperfusion or symptomatic intracranial hemorrhage.

Conclusions:

An increasing burden of WML at baseline is associated with poorer clinical outcomes after endovascular treatment for acute ischemic stroke but not with the probability of successful reperfusion or symptomatic intracranial hemorrhage.

The Impact of Amyloid-β or Tau on Cognitive Change in the Presence of Severe Cerebrovascular Disease

BACKGROUND

As Alzheimer's disease (AD) and cerebral small vessel disease (CSVD) commonly coexist, the interaction between two has been of the considerable interest.

OBJECTIVE

We determined whether the association of Aβ and tau with cognitive decline differs by the presence of significant CSVD.

METHODS

We included 60 subcortical vascular cognitive impairment (SVCI) from Samsung Medical Center and 82 Alzheimer's disease-related cognitive impairment (ADCI) from ADNI, who underwent Aβ (florbetaben or florbetapir) and tau (flortaucipir, FTP) PET imaging. They were retrospectively assessed for 5.0±3.9 and 5.6±1.9 years with Clinical Dementia Rating-sum of boxes (CDR-SB)/Mini-Mental State Examination (MMSE). Mixed effects models were used to investigate the interaction between Aβ/tau and group on CDR-SB/MMSE changes.

RESULTS

The frequency of Aβ positivity (45% versus 54.9%, p = 0.556) and mean global FTP SUVR (1.17±0.21 versus 1.16±0.17, p = 0.702) were not different between the two groups. We found a significant interaction effect of Aβ positivity and SVCI group on CDR-SB increase/MMSE decrease (p = 0.013/p < 0.001), and a significant interaction effect of global FTP uptake and SVCI group on CDR-SB increase/MMSE decrease (p < 0.001 and p = 0.030). Finally, the interaction effects of regional tau and group were prominent in the Braak III/IV (p = 0.001) and V/VI (p = 0.003) not in Braak I/II region (p = 0.398).

CONCLUSION

The association between Aβ/tau and cognitive decline is stronger in SVCI than in ADCI. Therefore, our findings suggested that Aβ positivity or tau burden (particularly in the Braak III/IV or V/VI regions) and CSVD might synergistically affect cognitive decline.

PIP(2) corrects cerebral blood flow deficits in small vessel disease by rescuing capillary Kir2.1 activity

Cerebral small vessel diseases (SVDs) are a central link between stroke and dementia-two comorbidities without specific treatments. Despite the emerging consensus that SVDs are initiated in the endothelium, the early mechanisms remain largely unknown. Deficits in on-demand delivery of blood to active brain regions (functional hyperemia) are early manifestations of the underlying pathogenesis. The capillary endothelial cell strong inward-rectifier K⁺ channel Kir2.1, which senses neuronal activity and initiates a propagating electrical signal that dilates upstream arterioles, is a cornerstone of functional hyperemia. Here, using a genetic SVD mouse model, we show that impaired functional hyperemia is caused by diminished Kir2.1 channel activity. We link Kir2.1 deactivation to depletion of phosphatidylinositol 4,5-bisphosphate (PIP₂), a membrane phospholipid essential for Kir2.1 activity. Systemic injection of soluble PIP₂ rapidly restored functional hyperemia in SVD mice, suggesting a possible strategy for rescuing functional hyperemia in brain disorders in which blood flow is disturbed.

Brain Glucose Metabolism in Cerebral Amyloid Angiopathy: An FDG-PET Study

BACKGROUND AND PURPOSE

The in vivo diagnosis of cerebral amyloid angiopathy (CAA) is currently based on the Boston criteria, which largely rely on hemorrhagic features on brain magnetic resonance imaging. Adding to these criteria ¹⁸F-fluoro-deoxy-D-glucose (FDG) positron emission tomography, a widely available imaging modality, might improve their accuracy. Here we tested the hypothesis that FDG uptake is reduced in posterior cortical areas, particularly the primary occipital cortex, which pathologically bear the brunt of vascular Aβ deposition.

METHODS

From a large memory clinic database, we retrospectively included all patients in whom both brain magnetic resonance imaging and FDG positron emission tomography had been obtained as part of routine clinical care and who fulfilled the Boston criteria for probable CAA. None had a history of symptomatic intracerebral hemorrhage. FDG data processing involved (1) spatial normalization to the Montreal Neurology Institute/International Consortium for Brain Mapping 152 space and (2) generation of standardized FDG uptake (relative standardized uptake value; relative to the pons). The relative standardized uptake value data obtained in 13 regions of interest sampling key cortical areas and the cerebellum were compared between the CAA and age-matched control groups using 2 separate healthy subject databases and image-processing pipelines. The presence of significant hypometabolism (2-tailed P<0.05) was assessed for the bilaterally averaged regions-of-interest relative standardized uptake values.

RESULTS

Fourteen patients fulfilling the Boston criteria for probable CAA (≥2 exclusively lobar microbleeds) were identified. Significant hypometabolism (P range, 0.047 to <0.0001) consistently affected the posterior cortical areas, including the superior and inferior parietal, primary visual, lateral occipital, lateral temporal, precuneus, and posterior cingulate regions of interest. The anterior cortical areas were marginally or not significantly hypometabolic, and the cerebellum was spared.

CONCLUSIONS

Supporting our hypothesis, significant glucose hypometabolism predominantly affected posterior cortical regions, including the visual cortex. These findings from a small sample may have diagnostic implications but require replication in larger prospective studies. In addition, whether they generalize to CAA-related symptomatic intracerebral hemorrhage warrants specific studies.

Association of Plasma Neurofilament Light With Small Vessel Disease Burden in Nondemented Elderly: A Longitudinal Study

BACKGROUND AND PURPOSE

Neurofilament light chain (NfL) is a promising predictive biomarker of active axonal injury and neuronal degeneration diseases. We aimed to evaluate if an increase in plasma NfL levels could play a monitoring role in the progression of cerebral small vessel disease (CSVD) among the nondemented elders, which are highly prevalent in elderly individuals and associated with an increased risk of stroke and dementia.

METHODS

The study included 496 nondemented participants from the Alzheimer disease neuroimaging initiative database. All participants underwent plasma NfL measurements and 3.0-Tesla magnetic resonance imaging of the brain; 387 (78.0%) underwent longitudinal measurements. The number of cerebral microbleeds, lacunar infarcts, and volumetric white matter hyperintensities, as well as Fazekas scores, were measured. Cross-sectional and longitudinal associations between CSVD burden and NfL levels were evaluated using multivariable-adjusted models.

RESULTS

Plasma NfL was higher in the moderate-severe CSVD burden group (45.2±16.0 pg/mL) than in the nonburden group (34.3±15.1 pg/mL; odds ratio [OR]=1.71 [95% CI, 1.24-2.35]) at baseline. NfL was positively associated with the presence of cerebral microbleeds (OR=1.29 [95% CI, 1.01-1.64]), lacunar infarcts (OR=1.43 [95% CI, 1.06-1.93]), and moderate-severe white matter hyperintensities (OR=1.67 [95% CI, 1.24-2.25]). Longitudinally, a higher change rate of NfL could predict more progression of CSVD burden (OR=1.38 [95% CI, 1.08-1.76]), white matter hyperintensities (OR=1.41 [95% CI, 1.10-1.79]), and lacunar infarcts (OR=1.99 [95% CI, 1.42-2.77]).

CONCLUSIONS

Plasma NfL level is a valuable noninvasive biomarker that supplements magnetic resonance imaging scans and possibly reflects the severity of CSVD burden. Furthermore, high plasma NfL levels tend to represent an increased CSVD risk, and dynamic increases in NfL levels might predict a greater progression of CSVD.

Hypertensive Arteriopathy and Cerebral Amyloid Angiopathy in Patients with Cognitive Decline and Mixed Cerebral Microbleeds

BACKGROUND

Hypertensive arteriopathy (HA) and cerebral amyloid angiopathy (CAA) may contribute to the development of mixed cerebral microbleeds (CMBs). Recently, the total small vessel disease (SVD) scores for HA and CAA were proposed, which are determined by a combination of MRI markers to reflect overall severity of these microangiopathies.

OBJECTIVE

We investigated whether or not total HA-SVD and CAA-SVD scores could be used to predict overlap of HA and CAA in patients with mixed CMBs.

METHODS

Fifty-three subjects with mixed CMBs were retrospectively analyzed. MRI markers (CMBs, lacunes, perivascular space, white matter hyperintensity [WMH] and cortical superficial siderosis [cSS]) were assessed. The HA-SVD score and CAA-SVD score were obtained for each subject. Anterior or posterior WMH was also assessed using the age-related white matter changes scale.

RESULTS

The two scores were positively correlated (ρ= 0.449, p < 0.001). The prevalence of lobar dominant CMB distribution (p < 0.001) and lacunes in the centrum semiovale (p < 0.001) and the severity of WMH in the parieto-occipital lobes (p = 0.004) were significantly higher in the high CAA-SVD score group. cSS was found in four patients with high CAA-SVD score who showed lobar-dominant CMB distribution and severe posterior WMH.

CONCLUSION

Mixed CMBs are mainly due to HA. Assessing both two scores may predict the overlap of HA and CAA in individuals with mixed CMBs. Patients with a high CAA-SVD score may have some degree of advanced CAA, especially when lobar predominant CMBs, severe posterior WMH, lobar lacunes, or cSS are observed.