Project description:Background and purposeSerum neurofilament light (NfL)-chain is a circulating marker for neuroaxonal injury and is also associated with severity of cerebral small vessel disease (SVD) cross-sectionally. Here we explored the association of serum-NfL with imaging and cognitive measures in SVD longitudinally.MethodsFrom 503 subjects with SVD, baseline and follow-up magnetic resonance imaging (MRI) was available for 264 participants (follow-up 8.7±0.2 years). Baseline serum-NfL was measured by an ultrasensitive single-molecule-assay. SVD-MRI-markers including white matter hyperintensity (WMH)-volume, mean diffusivity (MD), lacunes, and microbleeds were assessed at both timepoints. Cognitive testing was performed in 336 participants, including SVD-related domains as well as global cognition and memory. Associations with NfL were assessed using linear regression analyses and analysis of covariance (ANCOVA).ResultsSerum-NfL was associated with baseline WMH-volume, MD-values and presence of lacunes and microbleeds. SVD-related MRI- and cognitive measures showed progression during follow-up. NfL-levels were associated with future MRI-markers of SVD, including WMH, MD and lacunes. For the latter, this association was independent of baseline lacunes. Furthermore, NfL was associated with incident lacunes during follow-up (P=0.040). NfL-levels were associated with future SVD-related cognitive impairment (processing speed: β=-0.159; 95% confidence interval [CI], -0.242 to -0.068; P=0.001; executive function β=-0.095; 95% CI, -0.170 to -0.007; P=0.033), adjusted for age, sex, education, and depression. Dementia-risk increased with higher NfL-levels (hazard ratio, 5.0; 95% CI, 2.6 to 9.4; P<0.001), however not after adjusting for age.ConclusionsLongitudinally, serum-NfL is associated with markers of SVD, especially with incident lacunes, and future cognitive impairment affecting various domains. NfL may potentially serve as an additional marker for disease monitoring and outcome in SVD, potentially capturing both vascular and neurodegenerative processes in the elderly.
Project description:ObjectiveTo evaluate whether the burden of deep and lobar lacunes differs between patients with intracerebral hemorrhage (ICH) with definite/probable cerebral amyloid angiopathy (CAA) per the Boston criteria and hypertensive small vessel disease (HTN-SVD; ICH in basal ganglia, thalami, brainstem).MethodsWe defined lobar and deep lacunes similar to the topographic distribution used for ICH and cerebral microbleeds (CMBs). We then compared their distribution between patients with CAA-ICH and those with strictly deep CMB and ICH (HTN-ICH). The independent associations of lacune location with the diagnosis of CAA-ICH and HTN-ICH were evaluated with multivariable models. The relationship between lobar lacunes and white matter hyperintensity (WMH) volume was evaluated by means of partial correlation analyses adjusted for age and a validated visual scale.ResultsIn our final cohort of 316 patients with ICH, lacunes were frequent (24.7%), with similar rates in 191 patients with CAA and 125 with HTN-ICH (23% vs 27.2%, p = 0.4). Lobar lacunes were more commonly present in CAA (20.4% vs 5.7%, p < 0.001), while deep lacunes were more frequent in HTN-ICH (15.2% vs 2.1%, p < 0.001). After correction for demographics and clinical and neuroimaging markers of SVD, lobar lacunes were associated with CAA (p = 0.003) and deep lacunes with HTN-ICH (p < 0.001). Lobar lacunes in 80% of the cases were at least in contact with WMH, and after adjustment for age, they were highly correlated to WMH volume (r = 0.42, p < 0.001).ConclusionsLobar lacunes are associated with CAA, whereas deep lacunes are more frequent in HTN-SVD. Lobar lacunes seem to have a close relationship with WMH, suggesting a possible common origin.
Project description:Lacunes are an important disease feature of cerebral small vessel disease (SVD) but their relationship to cognitive impairment is not fully understood. To investigate this we determined (1) the relationship between lacune count and total lacune volume with cognition, (2) the spatial distribution of lacunes and the cognitive impact of lacune location, and (3) the whole brain anatomical covariance associated with these strategically located regions of lacune damage.One hundred and twenty one patients with symptomatic lacunar stroke and radiological leukoaraiosis were recruited and multimodal MRI and neuropsychological data acquired. Lacunes were mapped semi-automatically and their volume calculated. Lacune location was automatically determined by projection onto atlases, including an atlas which segments the thalamus based on its connectivity to the cortex. Lacune locations were correlated with neuropsychological results. Voxel based morphometry was used to create anatomical covariance maps for these 'strategic' regions.Lacune number and lacune volume were positively associated with worse executive function (number p < 0.001; volume p < 0.001) and processing speed (number p < 0.001; volume p < 0.001). Thalamic lacunes, particularly those in regions with connectivity to the prefrontal cortex, were associated with impaired processing speed (Bonferroni corrected p = 0.016). Regions of associated anatomical covariance included the medial prefrontal, orbitofrontal, anterior insular cortex and the striatum.Lacunes are important predictors of cognitive impairment in SVD. We highlight the importance of spatial distribution, particularly of anteromedial thalamic lacunes which are associated with impaired information processing speed and may mediate cognitive impairment via disruption of connectivity to the prefrontal cortex.
Project description:Multiple sclerosis (MS) is a condition that affects the veins and small blood vessels. Previous research suggests that individuals with MS have an increased risk of vascular events and higher mortality rates. However, the relationship between MS and cerebral small vessel disease (CSVD) remains uncertain. This study aims to investigate the association between MS and lacunes. A prospective observational study was conducted, including a total of 112 participants, of which 46 had MS and 66 had CSVD. All participants underwent an MRI scan and a battery of neurological functional assessments. The presence of definite lacunes and black holes was determined through the analysis of T2-weighted, T1-weighted, and FLAIR images. The occurrence of lacunes in MS patients was found to be 19.6%. Notably, the duration of MS was identified as the sole risk factor for the development of lacune lesions in MS patients [odds ratio (OR) = 1.3, 95% confidence interval (CI) = 1.1-1.6, p = 0.008]. Comparatively, MS patients with lacunes exhibited a higher frequency of attacks and larger volumes of T2 lesions compared to MS patients without lacunes. Further analysis using receiver operating characteristic (ROC) curves showed that lacune lesions had limited ability to discriminate between MS and CSVD when disease duration exceeded 6 years. The presence of small arterial lesions in the brain of individuals with MS, along with the duration of the disease, contributes to the development of lacunes in MS patients.
Project description:ObjectiveTo investigate the relation between baseline cerebral small vessel disease (SVD) and the risk of incident parkinsonism using different MRI and diffusion tensor imaging (DTI) measures.MethodsIn the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort (RUN DMC) study, a prospective cohort study, 503 elderly participants with SVD and without parkinsonism were included in 2006. During follow-up (2011-2012), parkinsonism was diagnosed according to UK Brain Bank criteria. Cox regression analysis was used to investigate the association between baseline imaging measures and incident all-cause parkinsonism and vascular parkinsonism (VP). Tract-based spatial statistics analysis was used to identify differences in baseline DTI measures of white matter (WM) tracts between participants with VP and without parkinsonism.ResultsFollow-up was available from 501 participants (mean age 65.6 years; mean follow-up duration 5.2 years). Parkinsonism developed in 20 participants; 15 were diagnosed with VP. The 5-year risk of (any) parkinsonism was increased for those with a high white matter hyperintensity (WMH) volume (hazard ratio [HR] 1.8 per SD increase, 95% confidence interval [CI] 1.3-2.4) and a high number of lacunes (HR 1.4 per number increase, 95% CI 1.1-1.8) at baseline. For VP, this risk was also increased by the presence of microbleeds (HR 5.7, 95% CI 1.9-16.8) and a low gray matter volume (HR 0.4 per SD increase, 95% CI 0.2-0.8). Lower fractional anisotropy values in bifrontal WM tracts involved in movement control were observed in participants with VP compared to participants without parkinsonism.ConclusionsSVD at baseline, especially a high WMH volume and a high number of lacunes, is associated with incident parkinsonism. Our findings favor a role of SVD in the etiology of parkinsonism.
Project description:Cerebral microbleeds (CMBs) are MRI markers attributed to the most common cerebral angiopathies in the elderly and in patients with dementia: hypertensive and cerebral amyloid angiopathy. CMB detection in asymptomatic persons may help identify those at risk for dementia and may influence preventive strategies and design of clinical trials testing treatments for dementia. We studied the association of CMB with risk of incident dementia in community dwelling individuals. A total of 1296 dementia-free Framingham Heart Study participants (mean age 72 years; 54% women) with available brain MRI and incident dementia data during a mean follow-up period of 6.7 years were included. Using Cox proportional hazards models, we related CMB presence to incident dementia. Multivariable models were adjusted for age, sex, APOE status, and education, with additional models adjusting for vascular risk factors and MRI markers of ischemic brain injury. CMBs were observed in 10.8% and incident dementia in 85 participants (6.6% over study period). Participants with any CMB had 1.74 times higher risk of dementia (hazard ratio [HR] 1.74, 95% confidence interval [CI] 1.00-3.01), whereas those with deep and mixed CMB had a three-fold increased risk (HR 2.99, 95% CI 1.52-5.90). The associations were independent of vascular risk factors, and for deep and mixed CMB also independent of MRI markers of ischemia (HR 2.44, 95% CI 1.22-4.88). Purely lobar CMBs were not associated with incident dementia. Our findings support a role for hypertensive vasculopathy and the interplay of hypertensive and cerebral amyloid angiopathy in risk of dementia and suggest that CMB presence can identify individuals at risk of dementia.
Project description:MRI features of cerebral small vessel disease (CSVD), i.e. white matter hyperintensities, lacunes, microbleeds, perivascular spaces, and cerebral atrophy, may be associated with clinical events, but the strength of these associations remains unclear. We conducted a systematic review and meta-analysis on the association between these features and incident ischaemic and haemorrhagic stroke, all-cause dementia and depression, and all-cause mortality. For the association with stroke, 36 studies were identified (number of individuals/events [n] = 38,432/4,136), for dementia 28 (n = 16,458/1,709), for depression nine (n = 9,538/1,746), and for mortality 28 (n = 23,031/2,558). Only two studies evaluated perivascular spaces; these results were not pooled. Pooled analyses showed that all other features were associated with all outcomes (hazard ratios ranged 1.22-2.72). Combinations of two features were more strongly associated with stroke than any individual feature. Individual features and combinations of CSVD features are strongly associated with incident ischaemic and haemorrhagic stroke, all-cause dementia and depression, and all-cause mortality. If these associations are causal, the strength of these associations suggests that a substantial burden of disease is attributable to CSVD.
Project description:Background Cerebral small-vessel disease (cSVD) is an important cause of stroke and vascular dementia. Most cases are multifactorial, but an emerging minority have a monogenic cause. While NOTCH3 is the best-known gene, several others have been reported. We aimed to summarize the cerebral phenotypes associated with these more recent cSVD genes. Methods and Results We performed a systematic review (PROSPERO [International Prospective Register of Systematic Reviews]: CRD42020196720), searching Medline/Embase (conception to July 2020) for any language publications describing COL4A1/2, TREX1, HTRA1, ADA2, or CTSA pathogenic variant carriers. We extracted data about individuals' characteristics and clinical and vascular radiological cerebral phenotypes. We summarized phenotype frequencies per gene, comparing patterns across genes. We screened 6485 publications including 402, and extracted data on 390 individuals with COL4A1, 123 with TREX1, 44 with HTRA1 homozygous, 41 with COL4A2, 346 with ADA2, 82 with HTRA1 heterozygous, and 14 with CTSA. Mean age ranged from 15 (ADA2) to 59 years (HTRA1 heterozygotes). Clinical phenotype frequencies varied widely: stroke, 9% (TREX1) to 52% (HTRA1 heterozygotes); cognitive features, 0% (ADA2) to 64% (HTRA1 homozygotes); and psychiatric features, 0% (COL4A2; ADA2) to 57% (CTSA). Among individuals with neuroimaging, vascular radiological phenotypes appeared common, ranging from 62% (ADA2) to 100% (HTRA1 homozygotes; CTSA). White matter lesions were the most common pathology, except in ADA2 and COL4A2 cases, where ischemic and hemorrhagic lesions dominated, respectively. Conclusions There appear to be differences in cerebral manifestations across cSVD genes. Vascular radiological changes were more common than clinical neurological phenotypes, and present in the majority of individuals with reported neuroimaging. However, these results may be affected by age and biases inherent to case reports. In the future, better characterization of associated phenotypes, as well as insights from population-based studies, should improve our understanding of monogenic cSVD to inform genetic testing, guide clinical management, and help unravel underlying disease mechanisms.
Project description:Background: Somatic mutations in blood indicative of clonal hematopoiesis of indeterminate potential (CHIP), particularly in DNMT3A, TET2, and JAK2, are associated with an increased risk of hematologic malignancy, coronary artery disease, and all-cause mortality. However, whether CHIP is associated with increased risk of peripheral artery disease (PAD) remains unknown. In addition, chemotherapy frequently causes mutations in DNA Damage Repair (DDR) genes TP53 and PPM1D, and whether CHIP caused by somatic mutations in DDR genes results in increased risk of atherosclerosis is unclear. We sought to test whether CHIP, and CHIP caused by DDR genes, associates with incident peripheral artery disease (PAD) and atherosclerosis. Methods: We identified CHIP among 50,122 exome sequences in individuals from UK and Mass General Brigham Biobanks and tested CHIP status (N=2,851) with incident PAD and atherosclerosis across multiple arterial beds. To mimic the human scenario of clonal hematopoiesis and test whether the expansion of p53-deficient hematopoietic cells contributes to atherosclerosis, a competitive bone marrow transplantation (BMT) strategy was used to generate atherosclerosis-prone Ldlr-/- chimeric mice carrying 20% Trp53-/- hematopoietic cells (20% KO-BMT mice). We then evaluated aortic plaque burden and plaque macrophage accumulation 12 weeks after grafting. Results: CHIP associated with incident PAD (HR 1.7; P=2.2x10-5) and atherosclerosis in multiple beds (HR 1.3; P=9.7x10-5), with increased risk among individuals with DDR CHIP (HR 2.0; P=0.0084). Among atherosclerosis-prone Ldlr null mice, the p53 -/- 20% KO-BMT mice demonstrated increased aortic plaque size (p=0.013) and accumulation of p53-/- plaque macrophages (P<0.001), driven by an abundance of p53-deficient plaque macrophages. The expansion of p53-deficient cells did not affect the expression of the pro-inflammatory cytokines IL-6 and IL-1β in the atherosclerotic aortic wall. Conclusions: Our findings highlight the role of CHIP as a broad driver of atherosclerosis across the entire arterial system, with evidence of increased plaque among p53 -/- 20% KO-BMT mice via expansion of plaque macrophages. These observations provide new insight into the link between CHIP and cardiovascular disease, and lend human genetic support to the concept that post-cytotoxic chemotherapy patients may benefit from surveillance for atherosclerotic conditions in addition to therapy-related myeloid neoplasms.