The clinical importance of white matter hyperintensities on brain magnetic resonance imaging: systematic review and meta-analysis

Objectives To review the evidence for an association of white matter hyperintensities with risk of stroke, cognitive decline, dementia, and death

Association of metabolic dysregulation with volumetric brain magnetic resonance imaging and cognitive markers of subclinical brain aging in middle-aged adults: the Framingham Offspring Study.

ObjectiveDiabetic and prediabtic states, including insulin resistance, fasting hyperglycemia, and hyperinsulinemia, are associated with metabolic dysregulation. These components have been individually linked to increased risks of cognitive decline and Alzheimer's disease. We aimed to comprehensively relate all of the components of metabolic dysregulation to cognitive function and brain magnetic resonance imaging (MRI) in middle-aged adults.Research design and methodsFramingham Offspring participants who underwent volumetric MRI and detailed cognitive testing and were free of clinical stroke and dementia during examination 7 (1998-2001) constituted our study sample (n = 2,439; 1,311 women; age 61 ± 9 years). We related diabetes, homeostasis model assessment of insulin resistance (HOMA-IR), fasting insulin, and glycohemoglobin levels to cross-sectional MRI measures of total cerebral brain volume (TCBV) and hippocampal volume and to verbal and visuospatial memory and executive function. We serially adjusted for age, sex, and education alone (model A), additionally for other vascular risk factors (model B), and finally, with the inclusion of apolipoprotein E-ε4, plasma homocysteine, C-reactive protein, and interleukin-6 (model C).ResultsWe observed an inverse association between all indices of metabolic dysfunction and TCBV in all models (P < 0.030). The observed difference in TCBV between participants with and without diabetes was equivalent to approximately 6 years of chronologic aging. Diabetes and elevated glycohemoglobin, HOMA-IR, and fasting insulin were related to poorer executive function scores (P < 0.038), whereas only HOMA-IR and fasting insulin were inversely related to visuospatial memory (P < 0.007).ConclusionsMetabolic dysregulation, especially insulin resistance, was associated with lower brain volumes and executive function in a large, relatively healthy, middle-aged, community-based cohort

Etude rétrospective de l'influence des polymorphismes génétiques de CYP3A4, CYP3A5 et ABCB1 des donneurs et des receveurs sur les effets des immunosuppresseurs en transplantation hépatique

Liver transplantation is now a well mastered surgery with standardized procedures, but the long-term clinical outcomes of the graft and the patient remain uncertain. The pharmacogenetic study of the calcineurin inhibitors (CNI) cyclosporine and tacrolimus should help to understand the variability of their pharmacokinetics and therapeutic or side effects. In the first part of this work, we reviewed the main pharmacogenetic studies of CNI in liver transplantation, focusing on the three polymorphisms mostly involved in CNI pharmacokinetics (CYP3A4*22, CYP3A5*3 et ABCB1 exons 12, 21, 26) and their possible associations with clinical outcomes. To date, the only pharmacogenetic test consensually recommended in organ transplantation is the CYP3A5*3 variant for a better selection of the initial tacrolimus dose in kidney transplantation. The second part of this work was a retrospective cohort study in liver transplantation to investigate the influence of the above mentioned donor’s and recipient’s genotypes, involved in the metabolism (CYP3A4*22, CYP3A5*3) and the membrane transport (ABCB1 exons 12, 21 and 26) of cyclosporine and tacrolimus. 170 patients were enrolled in this study with a mean follow-up of more than ten years. Our main results are that: the recipient CYP3A5*1 allele was associated with a higher risk of graft loss than the CYP3A5*3 allele; the recipient ABCB1 exon 12 TT genotype was associated with a lower risk of chronic rejection than the CC genotype; overexposure to CNI, initial renal function and recipient age were associated with a higher risk of post-transplantation renal dysfunction. No genetic factor was associated with patient survival, acute rejection, liver function tests, recurrence of viral or other initial liver disease, or nephrotoxicity. Prospective characterization of both recipient and donor CYP3A4, CYP3A5 and ABCB1 polymorphisms could help to optimize immunosuppressive therapy for each candidate to liver transplantation. Further studies (pharmacogenetics of calcineurin pathway, early biomarkers of graft dysfunction, ...), should help to define a personalized profile for each transplant patient in order to best adapt the immunosuppressive strategy on the long term.La transplantation hépatique est une technique chirurgicale maîtrisée, mais le devenir à long terme du greffon et de l’hôte doit encore être amélioré. L’étude pharmacogénétique des inhibiteurs de la calcineurine (CNI) devrait permettre de comprendre la variabilité de leurs effets thérapeutiques et toxiques. Dans un premier temps, nous avons réalisé une revue de la littérature concernant la pharmacogénétique des CNI en greffe d’organe et surtout hépatique en particulier les trois polymorphismes les plus impliqués dans la pharmacocinétique des CNI (CYP3A4*22, CYP3A5*3 et ABCB1 exons 12, 21, 26) et leurs éventuelles associations avec le devenir clinique du patient. L’état actuel des connaissances valide l’intérêt du génotype CYP3A5*3 pour adapter au mieux la posologie précoce de tacrolimus seulement en greffe rénale. Dans un second temps, nous avons mené une étude de cohorte rétrospective visant à étudier la pertinence et l’intérêt des génotypes du donneur et du receveur d’organe mentionnés précédemment, intervenant dans le métabolisme (CYP3A4*22, CYP3A5*3) et le transport membranaire (ABCB1 exons 12, 21 et 26) de la cyclosporine et du tacrolimus en transplantation hépatique. 170 patients avec un suivi de plus de 10 ans en moyenne ont été inclus. Les principaux résultats montrent que : l’allèle CYP3A5 *1 du receveur était associé significativement à un risque plus élevé de perte de greffon à long terme comparé à l’allèle CYP3A5 *3 ; l’allèle TT de l’exon 12 d’ABCB1 du receveur était associé à un risque moins élevé de rejet chronique ; et l’exposition à des doses élevées de CNI, la valeur initiale de la fonction rénale et l’âge du receveur étaient également indépendamment associés au risque d’altération de la fonction rénale. La caractérisation de ces marqueurs pharmacogénétiques en transplantation hépatique pourrait permettre d’adapter les traitements immunosuppresseurs pour chaque patient transplanté. D’autres voies de recherche (pharmacogénétique de la voie calcineurine, biomarqueurs précoces des lésions du greffon, ...) seront nécessaires pour identifier un profil personnalisé pour chaque greffé afin d’adapter au mieux la stratégie thérapeutique à long terme

Cervical Artery Dissection and Sports

Cervical artery dissection (CeAD) occurring in the context of sports is a matter of concern for CeAD patients. They seek advice on the role of sports in CeAD and on the safety of resuming sports after CeAD. The scarcity of studies and guidelines addressing these issues poses a challenge. We aimed at summarizing the current knowledge about CeAD and sports in order to provide an informed, comprehensive opinion for counseling CeAD patients. We took into account pathophysiological considerations, observations of cases reports, series, and registries, and conclusions by analogy from aortic dissection or inherited connective tissue syndromes. In summary, practicing active sports as the cause of CeAD seems uncommon. It seems recommendable to refrain from any kind of sports activities for at least 1 month, which can be extended in case of an unfavorable clinical or neurovascular course. We recommend starting with sport activities at low intensity-preferably with types of endurance sports-and to gradually increase the pace in an individually tailored manner, taking into circumstances of the occurrences of the CeAD in the individual patient (particularly in relation to sports), the meaning of sports activities for the individual well-being, the presence or absence of comorbidities and of neurological sequela, neurovascular findings, and whether there are signs of an underlying connective tissue alteration. Major limitations and several forms of bias are acknowledged. Still, in the absence of any better data, the summarized observations and considerations might help clinicians in advising and counseling patients with CeAD in clinical practice

Associations of NINJ2 sequence variants with incident ischemic stroke in the Cohorts for Heart and Aging in Genomic Epidemiology (CHARGE) consortium

Background<p></p> Stroke, the leading neurologic cause of death and disability, has a substantial genetic component. We previously conducted a genome-wide association study (GWAS) in four prospective studies from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium and demonstrated that sequence variants near the NINJ2 gene are associated with incident ischemic stroke. Here, we sought to fine-map functional variants in the region and evaluate the contribution of rare variants to ischemic stroke risk.<p></p> Methods and Results<p></p> We sequenced 196 kb around NINJ2 on chromosome 12p13 among 3,986 European ancestry participants, including 475 ischemic stroke cases, from the Atherosclerosis Risk in Communities Study, Cardiovascular Health Study, and Framingham Heart Study. Meta-analyses of single-variant tests for 425 common variants (minor allele frequency [MAF] ≥ 1%) confirmed the original GWAS results and identified an independent intronic variant, rs34166160 (MAF = 0.012), most significantly associated with incident ischemic stroke (HR = 1.80, p = 0.0003). Aggregating 278 putatively-functional variants with MAF≤ 1% using count statistics, we observed a nominally statistically significant association, with the burden of rare NINJ2 variants contributing to decreased ischemic stroke incidence (HR = 0.81; p = 0.026).<p></p> Conclusion<p></p> Common and rare variants in the NINJ2 region were nominally associated with incident ischemic stroke among a subset of CHARGE participants. Allelic heterogeneity at this locus, caused by multiple rare, low frequency, and common variants with disparate effects on risk, may explain the difficulties in replicating the original GWAS results. Additional studies that take into account the complex allelic architecture at this locus are needed to confirm these findings

Vascular contributions to cognitive impairment and dementia: Research consortia that focus on etiology and treatable targets to lessen the burden of dementia worldwide

The research into vascular contributions to cognitive impairment and dementia (VCID) aims to understand the importance of cerebrovascular biology in cognitive decline. Prevention and treatment of VCID is poised to have major impact on dementia-related disease burden and is thus a critical emerging objective in dementia research. This article presents VCID consortia focused on multidisciplinary approaches to identify key pathologic targets and develop diagnostic tools with the goal of bridging the divide between basic research and clinical trials. Members of these multi-institute, multidisciplinary consortia provide a prospective on the history and emerging science of VCID and how VCID consortia can address some of the more complex questions in VCID and drive the field forward. These consortia, and others like them, are uniquely suited to tackle some of the most difficult obstacles in translating research to the clinic

Migraine, Stroke, and Cervical Arterial Dissection Shared Genetics for a Triad of Brain Disorders With Vascular Involvement

Background and Objectives Migraine, stroke, and cervical artery dissection (CeAD) represent a triad of cerebrovascular disorders with pairwise comorbid relationships and vascular involvement. Larger samples and recent advances in methodology invite systematic exploration of their shared genetics. Methods Genetic analyses leveraged summary statistics from genome-wide association studies of the largest available samples of each disorder, including subtypes of stroke (ischemic stroke, large artery stroke, small vessel stroke, and cardioembolic stroke) and migraine (with aura and without aura). For each pair of disorders, genetic correlation was assessed both on a genome-wide basis and within independent segments across the genome including known specific loci for each disorder. A cross-trait meta-analysis was used to identify novel candidate loci. Finally, potential causality of migraine susceptibility on stroke and CeAD was assessed by Mendelian randomization. Results Among all pairs of disorders, genome-wide genetic correlation was observed only between CeAD and migraine, particularly MO. Local genetic correlations were more extensive between migraine and CeAD than those between migraine and stroke or CeAD and stroke and revealed evidence for novel CeAD associations at rs6693567 (ADAMTSL4/ECM1), rs11187838 (PLCE1), and rs7940646 (MRVI1) while strengthening prior subthreshold evidence at rs9486725 (FHLS) and rs650724 (LRP1). At known migraine loci, novel associations with stroke had concordant risk alleles for small vessel stroke at rs191602009 (CARP) and for cardioembolic stroke at rs55884259 (NKX2-5). Known migraine loci also revealed novel associations but with opposite risk alleles for all stroke, ischemic stroke, and small vessel stroke at rs55928386 (HTRA1), for large artery stroke at rs11172113 (LRP1), and for all stroke and ischemic stroke at rs1535791 and rs4942561 (both LRCH1), respectively. rs182923402 (near PTCH1) was a novel concordant locus for migraine and cardioembolic stroke. Mendelian randomization supported potential causal influences of migraine on CeAD (odds ratio [95% confidence interval] per doubling migraine prevalence = 1.69 [1.24-2.3], p = 0.0009) with concordant risk, but with opposite risk on large artery stroke (0.86 [0.76-0.96], p = 0.0067). Discussion The findings emphasize shared genetic risk between migraine and CeAD while identifying loci with likely vascular function in migraine and shared but opposite genetic risk between migraine and stroke subtypes, and a central role of LRP1 in all 3 cerebrovascular disorders.Peer reviewe

Association of Metabolic Dysregulation With Volumetric Brain Magnetic Resonance Imaging and Cognitive Markers of Subclinical Brain Aging in Middle-Aged Adults

Objective: Diabetic and prediabtic states, including insulin resistance, fasting hyperglycemia, and hyperinsulinemia, are associated with metabolic dysregulation. These components have been individually linked to increased risks of cognitive decline and Alzheimer’s disease. We aimed to comprehensively relate all of the components of metabolic dysregulation to cognitive function and brain magnetic resonance imaging (MRI) in middle-aged adults. Research Design and Methods: Framingham Offspring participants who underwent volumetric MRI and detailed cognitive testing and were free of clinical stroke and dementia during examination 7 (1998–2001) constituted our study sample (n = 2,439; 1,311 women; age 61 ± 9 years). We related diabetes, homeostasis model assessment of insulin resistance (HOMA-IR), fasting insulin, and glycohemoglobin levels to cross-sectional MRI measures of total cerebral brain volume (TCBV) and hippocampal volume and to verbal and visuospatial memory and executive function. We serially adjusted for age, sex, and education alone (model A), additionally for other vascular risk factors (model B), and finally, with the inclusion of apolipoprotein E-ε4, plasma homocysteine, C-reactive protein, and interleukin-6 (model C). Results: We observed an inverse association between all indices of metabolic dysfunction and TCBV in all models (P < 0.030). The observed difference in TCBV between participants with and without diabetes was equivalent to approximately 6 years of chronologic aging. Diabetes and elevated glycohemoglobin, HOMA-IR, and fasting insulin were related to poorer executive function scores (P < 0.038), whereas only HOMA-IR and fasting insulin were inversely related to visuospatial memory (P < 0.007). Conclusions: Metabolic dysregulation, especially insulin resistance, was associated with lower brain volumes and executive function in a large, relatively healthy, middle-aged, community-based cohort

Early Life Socioeconomic Circumstance and Late Life Brain Hyperintensities : A Population Based Cohort Study

Funding: Image acquisition and image analysis for this study was funded by the Alzheimer's Research Trust (now Alzheimer's Research UK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments The authors would like to thank the participants of the Aberdeen 1936 Birth Cohort (ABC36), without whom this research would not have been possible.Peer reviewedPublisher PD

Fish Intake and MRI Burden of Cerebrovascular Disease in Older Adults

BACKGROUND AND OBJECTIVE: Fish intake may prevent cerebrovascular disease (CVD), yet the mechanisms are unclear, especially regarding its impact on subclinical damage. Assuming that fish may have pleiotropic effect on cerebrovascular health, we investigated the association of fish intake with global CVD burden based on brain MRI markers. METHODS: This cross-sectional analysis included participants from the Three-City Dijon population-based cohort (aged >/=65 years) without dementia, stroke, or history of hospitalized cardiovascular disease, who underwent brain MRI with automated assessment of white matter hyperintensities, visual detection of covert infarcts, and grading of dilated perivascular spaces. Fish intake was assessed through a frequency questionnaire and the primary outcome measure was defined as the first component of a factor analysis of mixed data applied to MRI markers. The association of fish intake with the CVD burden indicator was studied using linear regressions. RESULTS: In total, 1,623 participants (mean age, 72.3 years; 63% women) were included. The first component of factor analysis (32.4% of explained variance) was associated with higher levels of all three MRI markers. Higher fish intake was associated with lower CVD burden. In a model adjusted for total intracranial volume, compared to participants consuming fish /=4 times per week had a beta = -0.19 (95% CI, -0.37; -0.01) and beta = -0.30 (-0.57; -0.03) lower indicator of CVD burden, respectively (P trend /=75 years. For comparison, in the younger age group, consuming fish 2-3 times a week was roughly equivalent (in opposite direction) to the effect of hypertension. DISCUSSION: In this large population-based study, higher frequency of fish intake was associated with lower CVD burden, especially among participants younger than 75 years, suggesting a beneficial effect on brain vascular health before manifestation of overt brain disease. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in individuals without stroke or dementia, higher fish intake is associated with lower subclinical CVD at MRI