Confluent Thalamic Hyperintensities in CADASIL

Background: CADASIL is responsible for diffuse hyperintensities in the white matter on FLAIR images. These lesions are often associated with focal lesions in the basal ganglia such as lacunar infarctions. The prevalence and significance of diffuse or confluent thalamic hyperintensities (CTH) remain unknown. Methods: The frequency of hyperintensities on FLAIR images in the thalamus was assessed in 147 CADASIL patients, and signal abnormalities on both FLAIR and T(1)-weighted images were categorized as focal/punctuate or diffuse/confluent by the same reader. The areas of increased diffusion were also analyzed on apparent diffusion coefficient maps. The association of CTH with vascular risk factors, the main clinical manifestations of the disease and MRI markers (brain parenchymal fraction, volume of white matter hyperintensities, volume of lacunar infarcts and number of microbleeds) was analyzed with generalized linear regression models. Results: CTH were detected in 12% of the CADASIL subjects in association with hypointensities on T(1)-weighted images. CTH corresponded to areas of increased diffusion apparent diffusion coefficient maps. CTH were found significantly associated with age and independently related to the volume of white matter hyperintensities but not to that of lacunar infarctions or to cerebral atrophy after adjustment for age and sex. No significant association was found between CTH and global cognitive performances. Conclusion: CTH are observed on FLAIR images in a sizeable proportion of CADASIL patients. They are mainly related to the extent of white matter hyperintensities and do not correlate with cognitive decline. Demyelination and/or loss of glial cells appear to be the most plausible cause of these confluent signal changes in the thalamus. Copyright (C) 2010 S. Karger AG, Base

Carotid Atherosclerotic Markers in CADASIL

Purpose: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a cerebral small vessel disease caused by mutations of the NOTCH3 gene. Marked variations in disease severity have raised the hypothesis that non-genetic factors may modulate the expressivity of the phenotype. The aim of the current study was to evaluate whether atherosclerosis, assessed by carotid duplex ultrasonography, is associated with variations in the clinical and MRI phenotype of CADASIL. Methods: Data from 144 consecutive patients enrolled in an ongoing prospective cohort study were collected. Degree of disability was assessed by the modified Rankin Scale, that of cognitive impairment by the Mattis Dementia Rating Scale (MDRS). The total volume of the brain, of lacunar lesions and of white matter hyperintensities, the number of cerebral microhemorrhages, and parameters derived from histograms of apparent diffusion coefficient were measured on cerebral MRI. Atherosclerosis was evaluated by B-mode ultrasonography of carotid arteries. Both the carotid intima-media thickness cIMT) and the presence of carotid plaques or stenosis were recorded. Results: Higher cIMT was found to be independently associated with lower MDRS scores when this score was less than the quartile limit (p = 0.02). Only a trend for a positive association was detected between cIMT and the Rankin score (p = 0.06). There was no significant association between carotid markers and the occurrence of stroke or MRI parameters except for diffusion data. The mean and peak values of MRI diffusion histograms were found positively associated with the presence of plaques (p < 0.01). Conclusion: The results suggest that the severity of atherosclerosis may relate to cognitive decline in CADASIL and that this effect is possibly related to the degree of microstructural cerebral tissue lesions. Longitudinal studies are needed to confirm these results. Copyright (C) 2010 S. Karger AG, Base

Boltzmann and Fokker-Planck equations modelling the Elo rating system with learning effects

In this paper we propose and study a new kinetic rating model for a large number of players, which is motivated by the well-known Elo rating system. Each player is characterised by an intrinsic strength and a rating, which are both updated after each game. We state and analyse the respective Boltzmann type equation and derive the corresponding nonlinear, nonlocal Fokker-Planck equation. We investigate the existence of solutions to the Fokker-Planck equation and discuss their behaviour in the long time limit. Furthermore, we illustrate the dynamics of the Boltzmann and Fokker-Planck equation with various numerical experiments

Cortical folding influences migraine aura symptoms in CADASIL

Migraine with aura is a hallmark of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). In contrast with the majority of CADASIL patients, some affected subjects never experience visual symptoms during their attacks of migraine with aura. The aim of this study was to determine whether specific morphology of the primary visual cortex is associated with the absence of visual symptoms during migraine aura in CADASIL

Age‐dependent amyloid deposition is associated with white matter alterations in cognitively normal adults during the adult life span

Introduction Both beta‐amyloid (Ab) deposition and decline in white matter integrity, are brain alterations observed in Alzheimer's disease (AD) and start to occur by the fourth and fifth decades. However, the association between both brain alterations in asymptomatic subjects is unclear. Methods Amyloid positron emission tomography (PET) and diffusion tensor imaging (DTI) were obtained in 282 cognitively normal subjects (age 30‐89 years). We assessed the interaction of age by abnormal amyloid PET status (Florbetapir F‐18 PET >1.2 standard uptake value ratio [SUVR]) on regional mean diffusivity (MD) and global white matter hyperintensity (WMH) volume, controlled for sex, education, and hypertension. Results Subjects with abnormal amyloid PET (n = 87) showed stronger age‐related increase in global WMH and regional MD, particularly within the posterior parietal regions of the white matter. Discussion Sporadic Aβ deposition is associated with white matter alterations in AD predilection areas in an age‐dependent manner in cognitively normal individuals

Arterial branching and basal ganglia lacunes: a study in pure small vessel disease

Introduction: Lacunes are defined morphologically by size and location, but radiological characteristics alone may be unable to distinguish small vessel disease aetiology from alternative mechanisms. We investigated the branching order of arterial vessels associated with basal ganglia lacunes in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), in order to improve the understanding of their pathogenesis in pure cerebral small vessel disease. Patients and methods: Adults with a confirmed diagnosis of CADASIL were included. A pilot study was conducted in a Scottish CADASIL cohort. The Paris–Munich CADASIL cohort was used for independent validation. Lacunes identified on T1-weighted magnetic resonance imaging scans were registered to a standard brain template. A microangiographic template of the basal ganglia vasculature was automatically overlaid onto coronal slices, and raters estimated the vessel branching order related to each lacune. Results: Of 179 lacunes, 150 (84%) were associated with third-order vessels. In 14 incident lacunes, 11 (79%) were associated with third-order vessels. In the pilot study, lacune volume was significantly lower in lacunes associated with third-order vessels (0.04 ml 0.04 ml) compared to second-order vessels (0.48 0.16 ml; p &lt; 0.001). Discussion: In this study of CADASIL patients, most lacunes were small and associated with third-order vessel disease. This suggests that these are the vessels primarily affected in cerebral small vessel disease. Microangiographic template techniques could be used to further investigate in a general stroke population whether finding large lacunes originating from higher order vessels indicates an alternative cause of stroke. Conclusion: Lacunes in pure small vessel disease are associated with the smallest vessels in the basal ganglia

Sex differences of vascular brain lesions in patients with atrial fibrillation.

OBJECTIVE To examine sex differences in prevalence, volume and distribution of vascular brain lesions on MRI among patients with atrial fibrillation (AF). METHODS In this cross-sectional analysis, we included 1743 patients with AF (27% women) from the multicentre Swiss Atrial Fibrillation study (SWISS-AF) with available baseline brain MRI. We compared presence and total volume of large non-cortical or cortical infarcts (LNCCIs), small non-cortical infarcts, microbleeds (MB) and white matter hyperintensities (WMH, Fazekas score ≥2 for moderate or severe degree) between men and women with multivariable logistic regression. We generated voxel-based probability maps to assess the anatomical distribution of lesions. RESULTS We found no strong evidence for an association of female sex with the prevalence of all ischaemic infarcts (LNCCI and SNCI combined; adjusted OR 0.86, 95% CI 0.67 to 1.09, p=0.22), MB (adjusted OR 0.91, 95% CI 0.68 to 1.21, p=0.52) and moderate or severe WMH (adjusted OR 1.15, 95% CI 0.90 to 1.48, p=0.27). However, total WMH volume was 17% larger among women than men (multivariable adjusted multiplicative effect 1.17, 95% CI 1.01 to 1.35; p=0.04). Lesion probability maps showed a right hemispheric preponderance of ischaemic infarcts in both men and women, while WMH were distributed symmetrically. CONCLUSION Women had higher white matter disease burden than men, while volume and prevalence of other lesions did not differ. Our findings highlight the importance of controlling risk factors for cerebral small vessel disease in patients with AF, especially among women

Investigating the origin and evolution of cerebral small vessel disease: The RUN DMC - InTENse study

Background Neuroimaging in older adults commonly reveals signs of cerebral small vessel disease (SVD). SVD is believed to be caused by chronic hypoperfusion based on animal models and longitudinal studies with inter-scan intervals of years. Recent imaging evidence, however, suggests a role for acute ischaemia, as indicated by incidental diffusion-weighted imaging lesions (DWI+ lesions), in the origin of SVD. Furthermore, it becomes increasingly recognised that focal SVD lesions likely affect the structure and function of brain areas remote from the original SVD lesion. However, the temporal dynamics of these events are largely unknown. Aims (1) To investigate the monthly incidence of DWI+ lesions in subjects with SVD;(2) to assess to which extent these lesions explain progression of SVD imaging markers;(3) to investigate their effects on cortical thickness, structural and functional connectivity and cognitive and motor performance;and (4) to investigate the potential role of the innate immune system in the pathophysiology of SVD. Design/methods The RUN DMC - InTENse study is a longitudinal observational study among 54 non-demented RUN DMC survivors with mild to severe SVD and no other presumed cause of ischaemia. We performed MRI assessments monthly during 10 consecutive months (totalling up to 10 scans per subject), complemented with clinical, motor and cognitive examinations. Discussion Our study will provide a better understanding of the role of DWI+ lesions in the pathophysiology of SVD and will further unravel the structural and functional consequences and clinical importance of these lesions, with an unprecedented temporal resolution. Understanding the role of acute, potentially ischaemic, processes in SVD may provide new strategies for therapies

METACOHORTS for the study of vascular disease and its contribution to cognitive decline and neurodegeneration: an initiative of the Joint Programme for Neurodegenerative Disease Research

Dementia is a global problem and major target for health care providers. Although up to 45% of cases are primarily or partly due to cerebrovascular disease, little is known of these mechanisms or treatments because most dementia research still focuses on pure Alzheimer's disease. An improved understanding of the vascular contributions to neurodegeneration and dementia, particularly by small vessel disease, is hampered by imprecise data, including the incidence and prevalence of symptomatic and clinically “silent” cerebrovascular disease, long-term outcomes (cognitive, stroke, or functional), and risk factors. New large collaborative studies with long follow-up are expensive and time consuming, yet substantial data to advance the field are available. In an initiative funded by the Joint Programme for Neurodegenerative Disease Research, 55 international experts surveyed and assessed available data, starting with European cohorts, to promote data sharing to advance understanding of how vascular disease affects brain structure and function, optimize methods for cerebrovascular disease in neurodegeneration research, and focus future research on gaps in knowledge. Here, we summarize the results and recommendations from this initiative. We identified data from over 90 studies, including over 660,000 participants, many being additional to neurodegeneration data initiatives. The enthusiastic response means that cohorts from North America, Australasia, and the Asia Pacific Region are included, creating a truly global, collaborative, data sharing platform, linked to major national dementia initiatives. Furthermore, the revised World Health Organization International Classification of Diseases version 11 should facilitate recognition of vascular-related brain damage by creating one category for all cerebrovascular disease presentations and thus accelerate identification of targets for dementia prevention