Whole-Genome Sequencing Association Analyses of Stroke and Its Subtypes in Ancestrally Diverse Populations From Trans-Omics for Precision Medicine Project.

BACKGROUND AND PURPOSE: Stroke is the leading cause of death and long-term disability worldwide. Previous genome-wide association studies identified 51 loci associated with stroke (mostly ischemic) and its subtypes among predominantly European populations. Using whole-genome sequencing in ancestrally diverse populations from the Trans-Omics for Precision Medicine (TOPMed) Program, we aimed to identify novel variants, especially low-frequency or ancestry-specific variants, associated with all stroke, ischemic stroke and its subtypes (large artery, cardioembolic, and small vessel), and hemorrhagic stroke and its subtypes (intracerebral and subarachnoid). METHODS: Whole-genome sequencing data were available for 6833 stroke cases and 27 116 controls, including 22 315 European, 7877 Black, 2616 Hispanic/Latino, 850 Asian, 54 Native American, and 237 other ancestry participants. In TOPMed, we performed single variant association analysis examining 40 million common variants and aggregated association analysis focusing on rare variants. We also combined TOPMed European populations with over 28 000 additional European participants from the UK BioBank genome-wide array data through meta-analysis. RESULTS: In the single variant association analysis in TOPMed, we identified one novel locus 13q33 for large artery at whole-genome-wide significance (P<5.00×10-9) and 4 novel loci at genome-wide significance (P<5.00×10-8), all of which need confirmation in independent studies. Lead variants in all 5 loci are low-frequency but are more common in non-European populations. An aggregation of synonymous rare variants within the gene C6orf26 demonstrated suggestive evidence of association for hemorrhagic stroke (P<3.11×10-6). By meta-analyzing European ancestry samples in TOPMed and UK BioBank, we replicated several previously reported stroke loci including PITX2, HDAC9, ZFHX3, and LRCH1. CONCLUSIONS: We represent the first association analysis for stroke and its subtypes using whole-genome sequencing data from ancestrally diverse populations. While our findings suggest the potential benefits of combining whole-genome sequencing data with populations of diverse genetic backgrounds to identify possible low-frequency or ancestry-specific variants, they also highlight the need to increase genome coverage and sample sizes.

Mendelian Randomization Study of Obesity and Cerebrovascular Disease.

OBJECTIVE: To systematically investigate causal relationships between obesity and cerebrovascular disease and the extent to which hypertension and hyperglycemia mediate the effect of obesity on cerebrovascular disease. METHODS: We used summary statistics from genome-wide association studies for body mass index (BMI), waist-to-hip ratio (WHR), and multiple cerebrovascular disease phenotypes. We explored causal associations with 2-sample Mendelian randomization (MR) accounting for genetic covariation between BMI and WHR, and we assessed what proportion of the association between obesity and cerebrovascular disease was mediated by systolic blood pressure (SBP) and blood glucose levels, respectively. RESULTS: Genetic predisposition to higher BMI did not increase the risk of cerebrovascular disease. In contrast, for each 10% increase in WHR there was a 75% increase (95% confidence interval [CI] = 44-113%) in risk for large artery ischemic stroke, a 57% (95% CI = 29-91%) increase in risk for small vessel ischemic stroke, a 197% increase (95% CI = 59-457%) in risk of intracerebral hemorrhage, and an increase in white matter hyperintensity volume (ß = 0.11, 95% CI = 0.01-0.21). These WHR associations persisted after adjusting for genetic determinants of BMI. Approximately one-tenth of the observed effect of WHR was mediated by SBP for ischemic stroke (proportion mediated: 12%, 95% CI = 4-20%), but no evidence of mediation was found for average blood glucose. INTERPRETATION: Abdominal adiposity may trigger causal pathological processes, partially independent from blood pressure and totally independent from glucose levels, that lead to cerebrovascular disease. Potential targets of these pathological processes could represent novel therapeutic opportunities for stroke. ANN NEUROL 2020;87:516-524.

Genetically Elevated LDL Associates with Lower Risk of Intracerebral Hemorrhage.

OBJECTIVE: Observational studies point to an inverse correlation between low-density lipoprotein (LDL) cholesterol levels and risk of intracerebral hemorrhage (ICH), but it remains unclear whether this association is causal. We tested the hypothesis that genetically elevated LDL is associated with reduced risk of ICH. METHODS: We constructed one polygenic risk score (PRS) per lipid trait (total cholesterol, LDL, high-density lipoprotein [HDL], and triglycerides) using independent genomewide significant single nucleotide polymorphisms (SNPs) for each trait. We used data from 316,428 individuals enrolled in the UK Biobank to estimate the effect of each PRS on its corresponding trait, and data from 1,286 ICH cases and 1,261 matched controls to estimate the effect of each PRS on ICH risk. We used these estimates to conduct Mendelian Randomization (MR) analyses. RESULTS: We identified 410, 339, 393, and 317 lipid-related SNPs for total cholesterol, LDL, HDL, and triglycerides, respectively. All four PRSs were strongly associated with their corresponding trait (all p < 1.00 × 10-100 ). While one SD increase in the PRSs for total cholesterol (odds ratio [OR] = 0.92; 95% confidence interval [CI] = 0.85-0.99; p = 0.03) and LDL cholesterol (OR = 0.88; 95% CI = 0.81-0.95; p = 0.002) were inversely associated with ICH risk, no significant associations were found for HDL and triglycerides (both p > 0.05). MR analyses indicated that 1mmol/L (38.67mg/dL) increase of genetically instrumented total and LDL cholesterol were associated with 23% (OR = 0.77; 95% CI = 0.65-0.98; p = 0.03) and 41% lower risks of ICH (OR = 0.59; 95% CI = 0.42-0.82; p = 0.002), respectively. INTERPRETATION: Genetically elevated LDL levels were associated with lower risk of ICH, providing support for a potential causal role of LDL cholesterol in ICH. ANN NEUROL 2020 ANN NEUROL 2020;88:56-66.

Genome-wide association study of cerebral small vessel disease reveals established and novel loci.

Intracerebral haemorrhage and small vessel ischaemic stroke (SVS) are the most acute manifestations of cerebral small vessel disease, with no established preventive approaches beyond hypertension management. Combined genome-wide association study (GWAS) of these two correlated diseases may improve statistical power to detect novel genetic factors for cerebral small vessel disease, elucidating underlying disease mechanisms that may form the basis for future treatments. Because intracerebral haemorrhage location is an adequate surrogate for distinct histopathological variants of cerebral small vessel disease (lobar for cerebral amyloid angiopathy and non-lobar for arteriolosclerosis), we performed GWAS of intracerebral haemorrhage by location in 1813 subjects (755 lobar and 1005 non-lobar) and 1711 stroke-free control subjects. Intracerebral haemorrhage GWAS results by location were meta-analysed with GWAS results for SVS from MEGASTROKE, using 'Multi-Trait Analysis of GWAS' (MTAG) to integrate summary data across traits and generate combined effect estimates. After combining intracerebral haemorrhage and SVS datasets, our sample size included 241 024 participants (6255 intracerebral haemorrhage or SVS cases and 233 058 control subjects). Genome-wide significant associations were observed for non-lobar intracerebral haemorrhage enhanced by SVS with rs2758605 [MTAG P-value (P) = 2.6 × 10-8] at 1q22; rs72932727 (P = 1.7 × 10-8) at 2q33; and rs9515201 (P = 5.3 × 10-10) at 13q34. In the GTEx gene expression library, rs2758605 (1q22), rs72932727 (2q33) and rs9515201 (13q34) are significant cis-eQTLs for PMF1 (P = 1 × 10-4 in tibial nerve), NBEAL1, FAM117B and CARF (P < 2.1 × 10-7 in arteries) and COL4A2 and COL4A1 (P < 0.01 in brain putamen), respectively. Leveraging S-PrediXcan for gene-based association testing with the predicted expression models in tissues related with nerve, artery, and non-lobar brain, we found that experiment-wide significant (P < 8.5 × 10-7) associations at three genes at 2q33 including NBEAL1, FAM117B and WDR12 and genome-wide significant associations at two genes including ICA1L at 2q33 and ZCCHC14 at 16q24. Brain cell-type specific expression profiling libraries reveal that SEMA4A, SLC25A44 and PMF1 at 1q22 and COL4A1 and COL4A2 at 13q34 were mainly expressed in endothelial cells, while the genes at 2q33 (FAM117B, CARF and NBEAL1) were expressed in various cell types including astrocytes, oligodendrocytes and neurons. Our cross-phenotype genetic study of intracerebral haemorrhage and SVS demonstrates novel genome-wide associations for non-lobar intracerebral haemorrhage at 2q33 and 13q34. Our replication of the 1q22 locus previous seen in traditional GWAS of intracerebral haemorrhage, as well as the rediscovery of 13q34, which had previously been reported in candidate gene studies with other cerebral small vessel disease-related traits strengthens the credibility of applying this novel genome-wide approach across intracerebral haemorrhage and SVS.

Association Between Perihematomal Perfusion and Intracerebral Hemorrhage Outcome.

BACKGROUND: The prognostic impact of perihematomal hypoperfusion in patients with acute intracerebral hemorrhage (ICH) remains unclear. We tested the hypothesis that perihematomal hypoperfusion predicts poor ICH outcome and explored whether hematoma growth (HG) is the pathophysiological mechanism behind this association. METHODS: A prospectively collected single-center cohort of consecutive ICH patients undergoing computed tomography perfusion on admission was analyzed. Cerebral blood flow (pCBF) was measured in the manually outlined perihematomal low-density area. pCBF was categorized into normal (40-55 mL/100 g/min), low (< 40 mL/100 g/min), and high (> 55 mL/100 g/min). HG was calculated as total volume increase from baseline to follow-up CT. A modified Rankin scale > 2 at three months was the outcome of interest. The association between cerebral perfusion and outcome was investigated with logistic regression, and potential mediators of this relationship were explored with mediation analysis. RESULTS: A total of 155 subjects were included, of whom 55 (35.5%) had poor outcome. The rates of normal pCBF, low pCBF, and high pCBF were 17.4%, 68.4%, and 14.2%, respectively. After adjustment for confounders and keeping subjects with normal pCBF as reference, the risk of poor outcome was increased in patients with pCBF < 40 mL/100 g/min (odds ratio 6.11, 95% confidence interval 1.09-34.35, p = 0.040). HG was inversely correlated with pCBF (R = -0.292, p < 0.001) and mediated part of the association between pCBF and outcome (proportion mediated: 82%, p = 0.014). CONCLUSION: Reduced pCBF is associated with poor ICH outcome in patients with mild-moderate severity. HG appears a plausible biological mediator but does not fully account for this association, and other mechanisms might be involved.

Associations of Radiographic Cerebral Small Vessel Disease with Acute Intracerebral Hemorrhage Volume, Hematoma Expansion, and Intraventricular Hemorrhage.

BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate the impact of radiographic cerebral small vessel disease (CSVD) on the severity of acute intracerebral hemorrhage (ICH) as measured by: ICH volume, hematoma expansion, and extension of intraventricular hemorrhage (IVH). METHODS: CSVD was determined on baseline computed tomography (CT) scans of patients from the Ethnic and Racial Variations of Intracerebral Hemorrhage study through the extent of leukoaraiosis and cerebral atrophy using visual rating scales. The associations of leukoaraiosis and atrophy with ICH volume, hematoma expansion, IVH presence, and severity of IVH were tested using multivariable regression models. Secondary analyses were stratified by hemorrhage location. Bonferroni correction was applied to correct for multiple testing. RESULTS: A total of 2579 patients (mean age 61.7 years, 59% male) met inclusion criteria. Median ICH volume was 10.5 (Interquartile range [IQR] 4.0-25.3) mL. IVH was detected in 971 patients (38%). Neither leukoaraiosis nor atrophy was associated with hematoma expansion. Increasing grades of leukoaraiosis were associated with increased risk of IVH in a dose-dependent manner, while cerebral atrophy was inversely associated with IVH (both P for trend < 0.001). Increasing grades of global atrophy were dose-dependently associated with lower ICH volumes (ß (95% Confidence Interval [CI]) - 0.30[- 0.46, - 0.14], - 0.33[- 0.49, - 0.17], - 0.40[- 0.60, - 0.20], and - 0.54[- 0.76, - 0.32], for grades 1, 2, 3 and 4 compared to 0; all P < 0.001). The associations of leukoaraiosis with ICH volume were consistent with those of atrophy, albeit not meeting statistical significance. CONCLUSIONS: Leukoaraiosis and cerebral atrophy appear to have opposing associations with ICH severity. Cerebral atrophy correlates with smaller ICH volume and decreased risk and severity of IVH, while leukoaraiosis is associated with increased risk of IVH. Whether these observations reflect overlapping or divergent underlying mechanisms requires further study.

Impact of Cerebral Small Vessel Disease on Functional Recovery After Intracerebral Hemorrhage.

Background and Purpose- In this study, we aim to investigate the association of computed tomography-based markers of cerebral small vessel disease with functional outcome and recovery after intracerebral hemorrhage. Methods- Computed tomographic scans of patients in the ERICH study (Ethnic and Racial Variations of Intracerebral Hemorrhage) were evaluated for the extent of leukoaraiosis and cerebral atrophy using visual rating scales. Poor functional outcome was defined as a modified Rankin Scale (mRS) of ≥3. Multivariable logistic and linear regression models were used to explore the associations of cerebral small vessel disease imaging markers with poor functional outcome at discharge and, as a measure of recovery, change in mRS from discharge to 90 days poststroke. Results- After excluding in-hospital deaths, data from 2344 patients, 583 (24.9%) with good functional outcome (mRS of 0-2) at discharge and 1761 (75.1%) with poor functional outcome (mRS of 3-5) at discharge, were included. Increasing extent of leukoaraiosis (P for trend, 0.01) and only severe (grade 4) global atrophy (odds ratio, 2.02; 95% CI, 1.22-3.39, P=0.007) were independently associated with poor functional outcome at discharge. Mean (SD) mRS change from discharge to 90-day follow-up was 0.57 (1.18). Increasing extent of leukoaraiosis (P for trend, 0.002) and severe global atrophy (ß [SE], -0.23 [0.115]; P=0.045) were independently associated with less improvement in mRS from discharge to 90 days poststroke. Conclusions- In intracerebral hemorrhage survivors, the extent of cerebral small vessel disease at the time of intracerebral hemorrhage is associated with poor functional outcome at hospital discharge and impaired functional recovery from discharge to 90 days poststroke.

Hypoxia promotes tau hyperphosphorylation with associated neuropathology in vascular dysfunction.

BACKGROUND: Hypertension-induced microvascular brain injury is a major vascular contributor to cognitive impairment and dementia. We hypothesized that chronic hypoxia promotes the hyperphosphorylation of tau and cell death in an accelerated spontaneously hypertensive stroke prone rat model of vascular cognitive impairment. METHODS: Hypertensive male rats (n = 13) were fed a high salt, low protein Japanese permissive diet and were compared to Wistar Kyoto control rats (n = 5). RESULTS: Using electron paramagnetic resonance oximetry to measure in vivo tissue oxygen levels and magnetic resonance imaging to assess structural brain damage, we found compromised gray (dorsolateral cortex: p = .018) and white matter (corpus callosum: p = .016; external capsule: p = .049) structural integrity, reduced cerebral blood flow (dorsolateral cortex: p = .005; hippocampus: p < .001; corpus callosum: p = .001; external capsule: p < .001) and a significant drop in cortical oxygen levels (p < .05). Consistently, we found reduced oxygen carrying neuronal neuroglobin (p = .008), suggestive of chronic cerebral hypoperfusion in high salt-fed rats. We also observed a corresponding increase in free radicals (NADPH oxidase: p = .013), p-Tau (pThr231) in dorsolateral cortex (p = .011) and hippocampus (p = .003), active interleukin-1ß (p < .001) and neurodegeneration (dorsolateral cortex: p = .043, hippocampus: p = .044). Human patients with subcortical ischemic vascular disease, a type of vascular dementia (n = 38; mean age = 68; male/female ratio = 23/15) showed reduced hippocampal volumes and cortical shrinking (p < .05) consistent with the neuronal cell death observed in our hypertensive rat model as compared to healthy controls (n = 47; mean age = 63; male/female ratio = 18/29). CONCLUSIONS: Our data support an association between hypertension-induced vascular dysfunction and the sporadic occurrence of phosphorylated tau and cell death in the rat model, correlating with patient brain atrophy, which is relevant to vascular disease.

Cerebellar Hematoma Location: Implications for the Underlying Microangiopathy.

BACKGROUND AND PURPOSE: Spontaneous cerebellar intracerebral hemorrhage (ICH) has been reported to be mainly associated with vascular changes secondary to hypertension. However, a subgroup of cerebellar ICH seems related to vascular amyloid deposition (cerebral amyloid angiopathy). We sought to determine whether location of hematoma in the cerebellum (deep and superficial regions) was suggestive of a particular hemorrhage-prone small-vessel disease pathology (cerebral amyloid angiopathy or hypertensive vasculopathy). METHODS: Consecutive patients with cerebellar ICH from a single tertiary care medical center were recruited. Based on data from pathological reports, patients were divided according to the location of the primary cerebellar hematoma (deep versus superficial). Location of cerebral microbleeds (CMBs; strictly lobar, strictly deep, and mixed CMB) was evaluated on magnetic resonance imaging. RESULTS: One-hundred and eight patients (84%) had a deep cerebellar hematoma, and 20 (16%) a superficial cerebellar hematoma. Hypertension was more prevalent in deep than in patients with superficial cerebellar ICH (89% versus 65%, respectively; P<0.05). Among patients who underwent magnetic resonance imaging, those with superficial cerebellar ICH had higher prevalence of strictly lobar CMB (43%) and lower prevalence of strictly deep or mixed CMB (0%) compared with those with deep superficial cerebellar ICH (6%, 17%, and 38%, respectively). In a multivariable model, presence of strictly lobar CMB was associated with superficial cerebellar ICH (odds ratio, 3.8; 95% confidence interval, 1.5-8.5; P=0.004). CONCLUSIONS: Our study showed that superficial cerebellar ICH is related to the presence of strictly lobar CMB-a pathologically proven marker of cerebral amyloid angiopathy. Cerebellar hematoma location may thus help to identify those patients likely to have cerebral amyloid angiopathy pathology.

17p12 Influences Hematoma Volume and Outcome in Spontaneous Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE: Hematoma volume is an important determinant of clinical outcome in spontaneous intracerebral hemorrhage (ICH). We performed a genome-wide association study (GWAS) of hematoma volume with the aim of identifying novel biological pathways involved in the pathophysiology of primary brain injury in ICH. METHODS: We conducted a 2-stage (discovery and replication) case-only genome-wide association study in patients with ICH of European ancestry. We utilized the admission head computed tomography to calculate hematoma volume via semiautomated computer-assisted technique. After quality control and imputation, 7 million genetic variants were available for association testing with ICH volume, which was performed separately in lobar and nonlobar ICH cases using linear regression. Signals with P<5×10-8 were pursued in replication and tested for association with admission Glasgow coma scale and 3-month post-ICH dichotomized (0-2 versus 3-6) modified Rankin Scale using ordinal and logistic regression, respectively. RESULTS: The discovery phase included 394 ICH cases (228 lobar and 166 nonlobar) and identified 2 susceptibility loci: a genomic region on 22q13 encompassing PARVB (top single-nucleotide polymorphism rs9614326: ß, 1.84; SE, 0.32; P=4.4×10-8) for lobar ICH volume and an intergenic region overlying numerous copy number variants on 17p12 (top single-nucleotide polymorphism rs11655160: ß, 0.95; SE, 0.17; P=4.3×10-8) for nonlobar ICH volume. The replication included 240 ICH cases (71 lobar and 169 nonlobar) and corroborated the association for 17p12 (P=0.04; meta-analysis P=2.5×10-9; heterogeneity, P=0.16) but not for 22q13 (P=0.49). In multivariable analysis, rs11655160 was also associated with lower admission Glasgow coma scale (odds ratio, 0.17; P=0.004) and increased risk of poor 3-month modified Rankin Scale (odds ratio, 1.94; P=0.045). CONCLUSIONS: We identified 17p12 as a novel susceptibility risk locus for hematoma volume, clinical severity, and functional outcome in nonlobar ICH. Replication in other ethnicities and follow-up translational studies are needed to elucidate the mechanism mediating the observed association.

Men Experience Higher Risk of Pneumonia and Death After Intracerebral Hemorrhage.

BACKGROUND: Infectious complications worsen outcome after intracerebral hemorrhage (ICH). We investigated the impact of sex on post-ICH infections and mortality. METHODS: Consecutive ICH patients (admitted to a single hospital between 1994 and 2015) were retrospectively assessed via chart review to ascertain the following in-hospital infections: urinary tract infection (UTI), pneumonia, and sepsis. Adjusted logistic regression was performed to identify associations between sex, infection, and mortality at 90 days. RESULTS: Two thousand and four patients were investigated, 1071 (53.7%) males. Men were more likely to develop pneumonia (21.9 vs 15.5% p < 0.001) and sepsis (3.4 vs 1.6%, p = 0.009), whereas women had higher risk of UTI (19.9 vs 11.7% p < 0.001). Multivariate analyses confirmed association between male sex and pneumonia (Odds Ratio (OR) 1.37, 95% confidence interval (CI) 1.08-1.74, p = 0.011). Male sex (OR 1.40; CI 1.07-1.85; p = 0.015) and infection (OR 1.56; CI 1.11-1.85; p = 0.011) were independently associated with higher 90-day mortality. CONCLUSIONS: Types and rates of infection following ICH differ by sex. Male sex independently increases pneumonia risk, which subsequently increases 90-day mortality. Sex-specific preventive strategies to reduce the risk of these complications may be one strategy to improve ICH outcomes.

Lymphopenia, Infectious Complications, and Outcome in Spontaneous Intracerebral Hemorrhage.

BACKGROUND: Lymphopenia is increasingly recognized as a consequence of acute illness and may predispose to infections. We investigated whether admission lymphopenia (AL) is associated with increased risk of infectious complications and poor outcome in patients with spontaneous intracerebral hemorrhage (ICH). METHODS: We retrospectively analyzed a prospectively collected cohort of ICH patients ascertained between 1994 and 2015. We identified subjects with lymphocyte count obtained within 24 h from onset, and AL was defined as lymphocyte count <1000/µL. Infectious complications were assessed through retrospective chart review. Association between AL, infections, and mortality was investigated using multivariable logistic regression. RESULTS: Of the 2014 patients meeting inclusion criteria, 548 (27.2%) had AL and 605 (30.0%) developed an infectious complication. Case-fatality at 90 days was 36.9%. Patients with AL had larger hematoma volumes, higher frequency of intraventricular hemorrhage, and lower Glasgow Coma Scale score on presentation (all p < 0.001). AL was independently associated with increased risk of pneumonia [odds ratio (OR) 1.97, 95% confidence interval (CI) 1.50-2.58, p < 0.001] and multiple infections (OR 1.84, 95% CI 1.24-2.71, p = 0.003). AL was also an independent predictor of 90-day mortality (OR 1.55, 95% CI 1.18-2.04, p = 0.002) after adjusting for confounders. CONCLUSIONS: AL is common in ICH patients and independently associated with increased risk of infectious complications and poor outcome. Further studies will be needed to determine whether prophylactic antibiotics in ICH patients with AL can improve outcome.

White matter microstructural damage and depressive symptoms in patients with mild cognitive impairment and cerebral small vessel disease: the VMCI-Tuscany Study.

BACKGROUND AND PURPOSE: Disruption of cortical-subcortical circuits related to small vessel disease (SVD) may predispose to depression in the elderly. We aimed to determine the independent association between white matter (WM) microstructural damage, evaluated with diffusion tensor imaging (DTI), and depressive symptoms in a cohort of elderly subjects with mild cognitive impairment (MCI) and SVD. METHODS: The vascular mild cognitive impairment (VMCI)-Tuscany Study is an observational multicentric longitudinal study that enrolled patients with MCI and moderate to severe degrees of WM hyperintensities on MRI. Lacunar infarcts, cortical atrophy, medial temporal lobe atrophy, microbleeds, and DTI-derived indices (mean diffusivity, MD and fractional anisotropy, FA) were evaluated on baseline MRI. Geriatric Depression Scale (GDS) (score 0-15) was used to assess depressive symptoms. An extensive neuropsychological battery, Instrumental Activities of Daily Living scale, and the Short Physical Performance Battery were used for cognitive, functional, and motor assessments, respectively. RESULTS: Seventy-six patients (mean age: 75.1 ± 6.8 years) were included. Univariate analyses showed a significant association between GDS score and both DTI-derived indices (MD: r = 0.307, p = 0.007; FA: r = -0.245; p = 0.033). The association remained significant after adjustment for age, WM hyperintensities severity, global cognitive, functional and motor performances, and antidepressant therapy (MD: r = 0.361, p = 0.002; FA: r = -0.277; p = 0.021). CONCLUSIONS: These results outline the presence of an association between WM microstructural damage and depressive symptoms in MCI patients with SVD. This relationship does not seem to be mediated by disability, cognitive, and motor impairment, thus supporting the vascular depression hypothesis.

Operationalizing mild cognitive impairment criteria in small vessel disease: the VMCI-Tuscany Study.

INTRODUCTION: Mild cognitive impairment (MCI) prodromic of vascular dementia is expected to have a multidomain profile. METHODS: In a sample of cerebral small vessel disease (SVD) patients, we assessed MCI subtypes distributions according to different operationalization of Winblad criteria and compared the neuroimaging features of single versus multidomain MCI. We applied three MCI diagnostic scenarios in which the cutoffs for objective impairment and the number of considered neuropsychological tests varied. RESULTS: Passing from a liberal to more conservative diagnostic scenarios, of 153 patients, 5% were no longer classified as MCI, amnestic multidomain frequency decreased, and nonamnestic single domain increased. Considering neuroimaging features, severe medial temporal lobe atrophy was more frequent in multidomain compared with single domain. DISCUSSION: Operationalizing MCI criteria changes the relative frequency of MCI subtypes. Nonamnestic single domain MCI may be a previously nonrecognized type of MCI associated with SVD.

White matter microstructural damage in small vessel disease is associated with Montreal cognitive assessment but not with mini mental state examination performances: vascular mild cognitive impairment Tuscany study.

BACKGROUND AND PURPOSE: Montreal Cognitive Assessment (MoCA) has been proposed as a screening tool in vascular cognitive impairment. Diffusion tensor imaging is sensitive to white matter microstructural damage. We investigated if diffusion tensor imaging-derived indices are more strongly associated with performances on MoCA or on the widely used mini mental state examination in patients with mild cognitive impairment and small vessel disease. METHODS: Mild cognitive impairment patients with moderate/severe degrees of white matter hyperintensities on MRI were enrolled. Lacunar infarcts, cortical atrophy, medial temporal lobe atrophy and median values of mean diffusivity and fractional anisotropy of the cerebral white matter were studied and correlated with cognitive tests performances. RESULTS: Seventy-six patients (mean age 75.1±6.8 years, mean years of education 8.0±4.3) were assessed. In univariate analyses, a significant association of both MoCA and mini mental state examination scores with age, education, cortical atrophy, and medial temporal lobe atrophy was found, whereas mean diffusivity and fractional anisotropy were associated with MoCA. In partial correlation analyses, adjusting for all demographic and neuroimaging variables, both mean diffusivity and fractional anisotropy were associated only with MoCA (mean diffusivity: r= -0.275, P=0.023; fractional anisotropy: r=0.246, P=0.043). CONCLUSIONS: In patients with mild cognitive impairment and small vessel disease, diffusion tensor imaging-measured white matter microstructural damage is more related to MoCA than mini mental state examination performances. MoCA is suited for the cognitive screening of patients with small vessel disease.

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.

Pleiotropy analysis between lobar intracerebral hemorrhage and CSF ß-amyloid highlights new and established associations.

BACKGROUND AND AIMS: Combining biologically related traits in genome-wide association studies (GWAS) increases the power for genetic discovery. Given the established relationship between lobar intracerebral hemorrhage (ICH) and cerebral amyloid angiopathy (CAA), and between the latter and levels of cerebrospinal fluid amyloid-ß 42 (CSF-Aß42), we leveraged genetic predisposition for lower CSF-Aß42 levels as a proxy phenotype for CAA to identify new genes associated with lobar ICH. METHODS: We used publicly available GWAS data for CSF-Aß42 levels (n = 3146) and for lobar ICH (n = 2094). First, we evaluated the association between lobar ICH risk and CSF-Aß42 in lobar ICH patients using a polygenic risk score (PRS) for CSF-Aß42. Next, we conducted multi-trait analysis of GWAS (MTAG) for pleiotropy analysis of lobar ICH and CSF-Aß42. MTAG results were further tested using Expression Quantitative Trait Locus and Differential Gene Expression Analyses. RESULTS: CSF-Aß42 PRS was associated with lobar ICH risk (p = 0.04). MTAG analysis identified a novel association within CDH9 (rs1007589; minor allele frequency = 0.09; MTAG p = 5.4 × 10-8; lobar ICH odds ratio = 1.4 and p = 2.4 × 10-3; CSF-Aß42 ß = -0.03 and p = 4.5 × 10-6). rs1007589 was significantly associated with the expression levels of CDH9 in temporal and occipital cortices, regions known to preferentially accumulate microhemorrhages in CAA. CONCLUSION: Our pleiotropy analysis suggested a variant possibly implicated with lobar ICH driven by amyloid-related mechanisms in CDH9 and associated with differential expression in brain regions characteristically affected by CAA. CDH9 is one subtype of the cadherin superfamily, which regulates intercellular adhesion, is involved in blood-brain barrier integrity, and is elevated in Alzheimer's disease patients. Further analyses are warranted to understand the effects of the variant on the pathogenesis of ICH and its clinical significance.

The predictive validity of a Brain Care Score for dementia and stroke: data from the UK Biobank cohort.

Introduction: The 21-point Brain Care Score (BCS) was developed through a modified Delphi process in partnership with practitioners and patients to promote behavior changes and lifestyle choices in order to sustainably reduce the risk of dementia and stroke. We aimed to assess the associations of the BCS with risk of incident dementia and stroke. Methods: The BCS was derived from the United Kingdom Biobank (UKB) baseline evaluation for participants aged 40-69 years, recruited between 2006-2010. Associations of BCS and risk of subsequent incident dementia and stroke were estimated using Cox proportional hazard regressions, adjusted for sex assigned at birth and stratified by age groups at baseline. Results: The BCS (median: 12; IQR:11-14) was derived for 398,990 UKB participants (mean age: 57; females: 54%). There were 5,354 incident cases of dementia and 7,259 incident cases of stroke recorded during a median follow-up of 12.5 years. A five-point higher BCS at baseline was associated with a 59% (95%CI: 40-72%) lower risk of dementia among participants aged <50. Among those aged 50-59, the figure was 32% (95%CI: 20-42%) and 8% (95%CI: 2-14%) for those aged >59 years. A five-point higher BCS was associated with a 48% (95%CI: 39-56%) lower risk of stroke among participants aged <50, 52% (95%CI, 47-56%) among those aged 50-59, and 33% (95%CI, 29-37%) among those aged >59. Discussion: The BCS has clinically relevant and statistically significant associations with risk of dementia and stroke in approximately 0.4 million UK people. Future research includes investigating the feasibility, adaptability and implementation of the BCS for patients and providers worldwide.