Diagnostic challenge of Creutzfeldt-Jakob disease in a patient with multimorbidity: a case-report.

BACKGROUND: Creutzfeldt-Jakob disease (CJD) is a rapidly progressive and ultimately fatal neurodegenerative condition caused by prions. The clinical symptoms of CJD vary with its subtype, and may include dementia, visual hallucinations, myoclonus, ataxia, (extra)pyramidal signs and akinetic mutism. In the early course of disease however, several clinical symptoms of CJD may mimic those of co-existing morbidities. CASE PRESENTATION: We report a male in his 60s with a history of situs inversus totalis and Churg Strauss syndrome, who presented with speech fluency disturbances, neuropsychiatric symptoms and allodynia, a few months after becoming a widower. Initially presumed a bereavement disorder along with a flare-up of Churg Strauss, his symptoms gradually worsened with apraxia, myoclonic jerks and eventually, akinetic mutism. MRI revealed hyperintensities at the caudate nucleus and thalami, while the cerebrospinal fluid was positive for the 14-3-3 protein and the real-time quick test, making the diagnosis of CJD highly probable. This case illustrates the complexities that may arise in diagnosing CJD when pre-existing multimorbidity may cloud the clinical presentation. We also discuss the potential mechanisms underlying the co-occurrence of three rare conditions (situs inversus totalis, Churg Strauss syndrome, CJD) in one patient, taking into consideration the possibility of coincidence as well as common underlying factors. CONCLUSIONS: The diagnosis of CJD may be easily missed when its clinical symptoms are obscured by those of pre-existing (rare) multimorbidity. This case highlights that when the multimorbidity has neurological manifestations, an extensive evaluation remains crucial to establish the diagnosis, minimize the risk of prion-transmission and provide appropriate guidance to patients and their caregivers.

Subcortical brain structures and the risk of dementia in the Rotterdam Study.

INTRODUCTION: Volumetric and morphological changes in subcortical brain structures are present in persons with dementia, but it is unknown if these changes occur prior to diagnosis. METHODS: Between 2005 and 2016, 5522 Rotterdam Study participants (mean age: 64.4) underwent cerebral magnetic resonance imaging (MRI) and were followed for development of dementia until 2018. Volume and shape measures were obtained for seven subcortical structures. RESULTS: During 12 years of follow-up, 272 dementia cases occurred. Mean volumes of thalamus (hazard ratio [HR] per standard deviation [SD] decrease 1.94, 95% confidence interval [CI]: 1.55-2.43), amygdala (HR 1.66, 95% CI: 1.44-1.92), and hippocampus (HR 1.64, 95% CI: 1.43-1.88) were strongly associated with dementia risk. Associations for accumbens, pallidum, and caudate volumes were less pronounced. Shape analyses identified regional surface changes in the amygdala, limbic thalamus, and caudate. DISCUSSION: Structure of the amygdala, thalamus, hippocampus, and caudate is associated with risk of dementia in a large population-based cohort of older adults.

Genome-wide profiling of circulatory microRNAs associated with cognition and dementia.

INTRODUCTION: MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression. Their role in the pathophysiology of dementia and potential as biomarkers remains undetermined. METHODS: We conducted a single- (one-by-one) and multi-marker (joint) analysis to identify well-expressed circulating miRNAs in plasma (total = 591) associated with general cognition and incident dementia, for 1615 participants of the population-based Rotterdam Study. RESULTS: During single-marker analysis, 47 miRNAs were nominally (P ≤ .05) associated with cognition and 18 miRNAs were nominally associated with incident dementia, after adjustment for potential confounders. Three miRNAs were common between cognition and dementia (miR-4539, miR-372-3p, and miR-566), with multi-marker analysis revealing another common miRNA (miR-7106-5p). In silico analysis of these four common miRNAs led to several putative target genes expressed in the brain, highlighting the mitogen-activated protein kinase signaling pathway. DISCUSSION: We provide population-based evidence on the relationship between circulatory miRNAs with cognition and dementia, including four common miRNAs that may elucidate downstream mechanisms. HIGHLIGHTS: MicroRNAs (miRNAs) are involved in the (dys)function of the central nervous system. Four circulating miRNAs in plasma are associated with cognition and incident dementia. Several predicted target genes of these four miRNAs are expressed in the brain. These four miRNAs may be linked to pathways underlying dementia. Although miRNAs are promising biomarkers, experimental validation remains essential.

Risk factors, neuroimaging correlates and prognosis of the motoric cognitive risk syndrome: A population-based comparison with mild cognitive impairment.

BACKGROUND AND PURPOSE: This study was undertaken to compare risk factors, neuroimaging characteristics and prognosis between two clinical prodromes of dementia, namely, the motoric cognitive risk syndrome (MCRS) and mild cognitive impairment (MCI). METHODS: Between 2009 and 2015, dementia-free participants of the population-based Rotterdam Study were classified with a dementia prodrome if they had subjective cognitive complaints and scored >1 SD below the population mean of gait speed (MCRS) or >1.5 SD below the population mean of cognitive test scores (MCI). Using multinomial logistic regression models, we determined cross-sectional associations of risk factors and structural neuroimaging markers with MCRS and MCI, followed by subdistribution hazard models, to determine risk of incident dementia until 2016. RESULTS: Of 3025 included participants (mean age = 70.4 years, 54.7% women), 231 had MCRS (7.6%), 132 had MCI (4.4%), and 62 (2.0%) fulfilled criteria for both. Although many risk factors were shared, a higher body mass index predisposed to MCRS, whereas male sex and hypercholesterolemia were associated with MCI only. Gray matter volumes, hippocampal volumes, white matter hyperintensities, and structural white matter integrity were worse in both MCRS and MCI. During a mean follow-up of 3.9 years, 71 individuals developed dementia and 200 died. Five-year cumulative risk of dementia was 7.0% (2.5%-11.5%) for individuals with MCRS, versus 13.3% (5.8%-20.8%) with MCI and only 2.3% (1.5%-3.1%) in unaffected individuals. CONCLUSIONS: MCRS is associated with imaging markers of neurodegeneration and risk of dementia, even in the absence of MCI, highlighting the potential of motor function assessment in early risk stratification for dementia.

Season of birth and the risk of dementia in the population-based Rotterdam Study.

Early-life environmental factors have been suggested in the pathophysiology of dementia. Season of birth has previously been used as a proxy for these external exposures. We investigated the link between season of birth and the risk of dementia and further explored underlying pathways by studying structural brain changes on MRI. From the Dutch, population-based Rotterdam Study, 12,964 participants born between 1887 and 1960 were followed between 1990 and 2018 for dementia. Cox regression was conducted to assess the association between season of birth and dementia. In addition, we distinguished between mild and cold winters. The association of season of birth with structural brain markers on MRI was examined in 5237 participants. The risk of dementia in participants born in winter and fall was higher than of those born in summer (hazard ratio (HR) 1.15 [95% confidence interval (CI) 1.01-1.31] for winter and HR 1.17 [95% CI 1.01-1.33] for fall), especially for Alzheimer's disease (HR 1.23 [1.06-1.43] for winter and HR 1.15 [95% CI 0.99-1.35] for fall). The risk was particularly increased for participants born in a cold winter. Except for slightly lower hippocampus in fall born participants (ß - 0.03; 95% CI - 0.06 to 0.00), we did not find associations with brain imaging markers. In conclusion, winter and fall births were associated with a higher incidence of dementia, especially of AD. We did not find evidence for structural brain changes as an underlying mechanism.

Influence of cerebrovascular disease on brain networks in prodromal and clinical Alzheimer's disease.

Network-sensitive neuroimaging methods have been used to characterize large-scale brain network degeneration in Alzheimer's disease and its prodrome. However, few studies have investigated the combined effect of Alzheimer's disease and cerebrovascular disease on brain network degeneration. Our study sought to examine the intrinsic functional connectivity and structural covariance network changes in 235 prodromal and clinical Alzheimer's disease patients with and without cerebrovascular disease. We focused particularly on two higher-order cognitive networks-the default mode network and the executive control network. We found divergent functional connectivity and structural covariance patterns in Alzheimer's disease patients with and without cerebrovascular disease. Alzheimer's disease patients without cerebrovascular disease, but not Alzheimer's disease patients with cerebrovascular disease, showed reductions in posterior default mode network functional connectivity. By comparison, while both groups exhibited parietal reductions in executive control network functional connectivity, only Alzheimer's disease patients with cerebrovascular disease showed increases in frontal executive control network connectivity. Importantly, these distinct executive control network changes were recapitulated in prodromal Alzheimer's disease patients with and without cerebrovascular disease. Across Alzheimer's disease patients with and without cerebrovascular disease, higher default mode network functional connectivity z-scores correlated with greater hippocampal volumes while higher executive control network functional connectivity z-scores correlated with greater white matter changes. In parallel, only Alzheimer's disease patients without cerebrovascular disease showed increased default mode network structural covariance, while only Alzheimer's disease patients with cerebrovascular disease showed increased executive control network structural covariance compared to controls. Our findings demonstrate the differential neural network structural and functional changes in Alzheimer's disease with and without cerebrovascular disease, suggesting that the underlying pathology of Alzheimer's disease patients with cerebrovascular disease might differ from those without cerebrovascular disease and reflect a combination of more severe cerebrovascular disease and less severe Alzheimer's disease network degeneration phenotype.

Global cerebrovascular burden and long-term clinical outcomes in Asian elderly across the spectrum of cognitive impairment.

ABSTRACTBackground/Aim:To investigate the predictive ability of the previously established global cerebrovascular disease (CeVD) burden scale on long-term clinical outcomes in a longitudinal study of Asian elderly participants across the spectrum of cognitive impairment. METHODS: A case-control study was conducted over a 2-year period involving participants with no cognitive impairment, cognitive impairment-no dementia (CIND), and Alzheimer's disease (AD). Annually, cognitive function was assessed with a comprehensive neuropsychological battery and the clinical dementia rating (CDR) scale was used to stage disease severity. RESULTS: Of 314 participants, 102 had none/very mild CeVD, 31 mild CeVD, 94 moderate CeVD, and 87 severe CeVD at baseline. There was a 1.14 and 1.42 units decline per year on global cognitive z-scores in moderate and severe CeVD groups, respectively, compared to none/very mild CeVD. Moderate-severe CeVD predicted significant functional deterioration at year 2 (HR = 2.0, 95% CI = 1.2-3.4), and conversion to AD (HR = 6.3, 95% CI = 1.7-22.5), independent of medial temporal atrophy. CONCLUSION: The global CeVD burden scale predicts poor long-term clinical outcome independent of neurodegenerative markers. Furthermore, CeVD severity affects the rate of cognitive and functional deterioration. Hence, cerebrovascular burden, which is potentially preventable, is a strong prognostic indicator, both at preclinical and clinical stages of AD, independent of neurodegenerative processes.

Meta-analysis of genome-wide association studies of adult height in East Asians identifies 17 novel loci.

Human height is associated with risk of multiple diseases and is profoundly determined by an individual's genetic makeup and shows a high degree of ethnic heterogeneity. Large-scale genome-wide association (GWA) analyses of adult height in Europeans have identified nearly 180 genetic loci. A recent study showed high replicability of results from Europeans-based GWA studies in Asians; however, population-specific loci may exist due to distinct linkage disequilibrium patterns. We carried out a GWA meta-analysis in 93 926 individuals from East Asia. We identified 98 loci, including 17 novel and 81 previously reported loci, associated with height at P < 5 × 10(-8), together explaining 8.89% of phenotypic variance. Among the newly identified variants, 10 are commonly distributed (minor allele frequency, MAF > 5%) in Europeans, with comparable frequencies with in Asians, and 7 single-nucleotide polymorphisms are with low frequency (MAF < 5%) in Europeans. In addition, our data suggest that novel biological pathway such as the protein tyrosine phosphatase family is involved in regulation of height. The findings from this study considerably expand our knowledge of the genetic architecture of human height in Asians.

Prevalence, risk factors and consequences of cerebral small vessel diseases: data from three Asian countries.

BACKGROUND: Cerebral small vessel disease (SVD) has been suggested to be more common in Asians compared with Caucasians. However, data from population-based studies in Asia are lacking. We report on the prevalence, risk factors and consequences of SVD from contemporary studies in three Asian countries using 3-Tesla MRI for the evaluation of SVD. METHODS: Clinical, cognitive and 3-Tesla brain MRI assessments were performed among participants of three studies from Singapore, Hong Kong and Korea. SVD markers include white matter hyperintensities (WMHs) using the modified Fazekas scale, lacunes and microbleeds. Cognition was assessed using the Mini Mental Status Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Adjustments were made for age, sex and cardiovascular risk factors. RESULTS: A total of 1797 subjects were available for analysis (mean age: 70.1±6.3 years and 57% women). The prevalence of confluent WMH was 36.6%, lacunes, 24.6% and microbleeds, 26.9%. Presence of all three SVD markers showed a steeper increase with increasing age rising from 1.9% in the lowest to 46.2% in the highest 5-year age strata. The major risk factors for the increased severity of SVD markers were advancing age and hypertension. Moreover, increasing severity of SVD markers was independently associated with worse performance on MMSE and MoCA. CONCLUSION: Elderly Asians have a high burden of SVD which was associated with cognitive dysfunction. This suggests that SVD markers should be a potential target for treatment in clinical trials so as to delay progression of cerebrovascular disease and potentially cognitive decline.

Cerebral microbleeds and neuropsychiatric symptoms in an elderly Asian cohort.

OBJECTIVES: Neuropsychiatric symptoms (NPS) are commonly found in patients with cerebral small vessel disease such as white matter hyperintensities and lacunar infarcts. However, the association between cerebral microbleeds (CMBs) and NPS has not been examined. Hence the present study sought to investigate the relation between CMBs and NPS in an elderly population. METHODS: This is a cross-sectional study of elderly Asians living in the community, who were assessed on a comprehensive neuropsychological battery and underwent clinical examinations as well as brain MRI scans. The 12-item neuropsychiatric inventory (NPI) was administered to a reliable informant. Total scores for individual symptoms and for NPI global performance were calculated and compared across three groups: no CMB, presence of 1 CMB and presence of multiple CMBs, controlling for demographics, vascular risk factors and other MRI markers. RESULTS: A total of 802 participants were included in the analysis. Participants with multiple CMBs had higher NPI total score compared to those with no CMB (1.06 vs 2.66, p=0.03). On individual symptom scores, higher score on depression (0.16 vs 0.53, p=0.02) and disinhibition (0.01 vs 0.14, p=0.04) was found in those elderly with multiple CMBs, independent of demographic and vascular risk factors, history of stroke, and other small vessel and large vessel disease markers. CONCLUSIONS: The presence of multiple CMBs is associated with high global neuropsychiatric disorder burden, in particular symptoms of depression and disinhibition. Future studies are recommended to investigate the importance of CMBs in the pathogenesis and longitudinal progression of neuropsychiatric disorders in the general elderly population.

Retinal vascular imaging in early life: insights into processes and risk of cardiovascular disease.

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. In recent years, studies have shown that the origins of CVD may be traced to vascular and metabolic processes in early life. Retinal vascular imaging is a new technology that allows detailed non-invasive in vivo assessment and monitoring of the microvasculature. In this systematic review, we described the application of retinal vascular imaging in children and adolescents, and we examined the use of retinal vascular imaging in understanding CVD risk in early life. We reviewed all publications with quantitative retinal vascular assessment in two databases: PubMed and Scopus. Early life CVD risk factors were classified into four groups: birth risk factors, environmental risk factors, systemic risk factors and conditions linked to future CVD development. Retinal vascular changes were associated with lower birth weight, shorter gestational age, low-fibre and high-sugar diet, lesser physical activity, parental hypertension history, childhood hypertension, childhood overweight/obesity, childhood depression/anxiety and childhood type 1 diabetes mellitus. In summary, there is increasing evidence supporting the view that structural changes in the retinal microvasculature are associated with CVD risk factors in early life. Thus, the retina is a useful site for pre-clinical assessment of microvascular processes that may underlie the future development of CVD in adulthood.

Influence of Maternal Gestational Hypertensive Disorders on Microvasculature in School-Age Children: The Generation R Study.

Gestational hypertensive disorders may lead to vascular changes in the offspring. We examined the associations of maternal blood pressure development and hypertensive disorders during pregnancy with microvasculature adaptations in the offspring in childhood. This study was performed as part of the Generation R Study in Rotterdam, the Netherlands (2002-2012), among 3,748 pregnant mothers and their children for whom information was available on maternal blood pressure in different periods of pregnancy and gestational hypertensive disorders. Childhood retinal arteriolar and venular calibers were assessed at the age of 6 years. We found that higher maternal systolic and diastolic blood pressures in early pregnancy were associated with childhood retinal arteriolar narrowing (P < 0.05). Higher maternal systolic blood pressure in late pregnancy, but not in middle pregnancy, was associated with childhood narrower retinal venular caliber (standard deviation score per standardized residual increase in systolic blood pressure: -0.05; 95% confidence interval: -0.08, -0.01). Paternal blood pressure was not associated with childhood retinal vessel calibers. Children of mothers with gestational hypertensive disorders tended to have narrower retinal arteriolar caliber (standard deviation score: -0.13, 95% confidence interval: -0.27, 0.01). Our results suggest that higher maternal blood pressure during pregnancy is associated with persistent microvasculature adaptations in their children. Further studies are needed to replicate these observations.

Is there a link between passive smoke exposure and early-onset myopia in preschool Asian children?

PURPOSE: To investigate the association of passive tobacco smoke exposure with early-onset myopia among three-year-old children in Singapore. METHODS: Pregnant mothers who attended their first trimester clinic at two major maternity units were recruited into the GUSTO birth cohort. The current analysis comprised 572 three-year-old children, who underwent cycloplegic autorefraction and axial length (AL) measurements. Myopia was defined as spherical equivalent (SE) of ≤-0.50 dioptres (D). Either parent completed questionnaires describing their child's exposure to passive smoke at six months, one and two years of age. RESULTS: There were 197 children (36.2%) who were exposed to passive smoke from birth to before six months. Compared to non-exposed children, children exposed to any passive smoke from birth to before six months experienced greater myopia prevalence (adjusted OR = 2.79; 95% CI: 1.24-6.29; p = 0.01). The odds of myopia in a child was greater if a smoker smokes at home, in the family car, or in the presence of the child (adjusted OR = 3.95; 95% CI: 1.41-11.09; p < 0.01) compared to non-exposed child. In contrast to myopia, childhood exposure to passive smoke did not systematically shift mean values for SE or AL. CONCLUSIONS: In this prospective birth cohort study, we found that childhood exposure to passive smoke from birth to before six months slightly increased the risk of early-onset myopia. This may indicate a delayed response to passive smoke exposure before six months and the development of myopia at three years of age. Our study is limited by the small number of myopic children at this young age. Thus, larger prospective studies using more objective cotinine level measures are required to fully establish and understand the influence of tobacco smoke on refractive development in older children.

Association of Magnetic Resonance Imaging Markers of Cerebrovascular Disease Burden and Cognition.

BACKGROUND AND PURPOSE: The present study sought to examine the association between the burden of cerebrovascular disease (CeVD) as assessed by multimodal magnetic resonance imaging and neurocognitive function. METHODS: Cognitively impaired patients and controls were tested on an extensive neuropsychological battery and underwent multimodal brain magnetic resonance imaging. CeVD markers determined from magnetic resonance imaging included the presence of multiple lacunes, multiple cerebral microbleeds, and moderate or severe white matter hyperintensities as markers for small-vessel disease and cortical stroke and intracranial stenosis as markers for large-vessel disease. A weighted CeVD burden score was constructed, and its association with global and domain-specific cognitive performance was investigated. RESULTS: A total of 305 cases and 94 controls were included in the analysis. A graded association of CeVD burden with neurocognitive function was found. Moreover, a clear threshold of CeVD burden was associated with severe impairment. White matter hyperintensities was associated with global neurocognitive deficits, whereas microbleeds were associated with domain-specific impairments. CONCLUSIONS: The weighted CeVD burden score comprising markers of both small- and large-vessel diseases were associated with deficits in both global and domain-specific neurocognitive function. Additional studies are needed to validate the use of this CeVD burden score for the prediction of dementia.

Genome-wide association study for refractive astigmatism reveals genetic co-determination with spherical equivalent refractive error: the CREAM consortium.

To identify genetic variants associated with refractive astigmatism in the general population, meta-analyses of genome-wide association studies were performed for: White Europeans aged at least 25 years (20 cohorts, N = 31,968); Asian subjects aged at least 25 years (7 cohorts, N = 9,295); White Europeans aged <25 years (4 cohorts, N = 5,640); and all independent individuals from the above three samples combined with a sample of Chinese subjects aged <25 years (N = 45,931). Participants were classified as cases with refractive astigmatism if the average cylinder power in their two eyes was at least 1.00 diopter and as controls otherwise. Genome-wide association analysis was carried out for each cohort separately using logistic regression. Meta-analysis was conducted using a fixed effects model. In the older European group the most strongly associated marker was downstream of the neurexin-1 (NRXN1) gene (rs1401327, P = 3.92E-8). No other region reached genome-wide significance, and association signals were lower for the younger European group and Asian group. In the meta-analysis of all cohorts, no marker reached genome-wide significance: The most strongly associated regions were, NRXN1 (rs1401327, P = 2.93E-07), TOX (rs7823467, P = 3.47E-07) and LINC00340 (rs12212674, P = 1.49E-06). For 34 markers identified in prior GWAS for spherical equivalent refractive error, the beta coefficients for genotype versus spherical equivalent, and genotype versus refractive astigmatism, were highly correlated (r = -0.59, P = 2.10E-04). This work revealed no consistent or strong genetic signals for refractive astigmatism; however, the TOX gene region previously identified in GWAS for spherical equivalent refractive error was the second most strongly associated region. Analysis of additional markers provided evidence supporting widespread genetic co-susceptibility for spherical and astigmatic refractive errors.

Association of neuropsychiatric symptoms and sub-syndromes with cognitive impairment in community-dwelling Asian elderly.

OBJECTIVES: To investigate the presence of neuropsychiatric symptoms (NPS) and sub-syndromes in elderly community-dwelling Asians with varying severity of cognitive impairment. METHODS: Chinese and Malay participants (n = 613) from the Epidemiology of Dementia in Singapore (EDIS) Study aged ≥ 60 years underwent clinical examination, neuropsychological testing, and NPS assessment using the Neuropsychiatric Inventory (NPI). Diagnosis of no cognitive impairment (NCI), cognitive impairment-no dementia (CIND), including CIND-mild and CIND-moderate, and dementia were made using established criteria. RESULTS: A significant increase in the numbers of NPS was observed accompanying with increasing severity of cognitive impairment (p < 0.001). Compared to those with NCI/CIND-mild, participants with CIND-moderate [Odds ratio (OR): 4.2, 95% confidence interval (CI): 1.8-10.0] or dementia [OR: 9.2, 95% CI: 2.3-36.0] were more likely to have two or more neuropsychiatric sub-syndromes. Participants with CIND-moderate were more likely to have hyperactivity [OR: 2.0, 95% CI: 1.0-3.8] and apathy [OR: 2.9, 95% CI: 1.0-8.4] sub-syndromes, whereas patients with dementia were more likely to have psychosis [OR: 6.9, 95% CI: 2.4-20.1], affective (OR: 8.7, 95% CI: 1.8-42.9), and hyperactivity (OR: 5.4, 95% CI: 1.8-16.1). Furthermore, executive dysfunction and visual memory impairment were associated with the presence of three neuropsychiatric sub-syndromes; whist language and visuomotor speed impairment were related to the presence of two sub-syndromes. By contrast, impairment in attention, verbal memory, and visuoconstruction were not associated with any of the sub-syndromes. CONCLUSIONS: The presence of NPS and sub-syndromes increase with increasing severities of cognitive impairment, and different neuropsychiatric syndromes are associated with specific impairment on cognitive domains in community-dwelling Asian elderly.

Cortical microinfarcts on 3T MRI: Clinical correlates in memory-clinic patients.

INTRODUCTION: This is the first study to assess cerebral microinfarcts (CMIs) on 3 tesla (3T) magnetic resonance imaging (MRI) in a memory clinic population. METHODS: We included 238 consecutive patients (aged 72.5 ± 9.1 years) from a memory clinic in Singapore. All patients underwent extensive neurological and neuropsychological testing and 3T MRI on the same day. Cortical CMI rating criteria were adapted from a previous study on 7T MRI. We analyzed the frequency and association of cortical CMIs with demographic, clinical, cognition, and other MRI findings. RESULTS: Seventy-five patients (32%) had cortical CMIs (median 1, range 1-43). Patients with CMIs showed worse cognitive functioning on MMSE, and in the domains of language and visuoconstruction. The presence of CMIs was related to other markers of small vessel disease, but most strongly larger cortical infarcts. Patients with CMIs were more often diagnosed with vascular dementia. DISCUSSION: Cortical CMIs on 3T MRI are a novel marker of cerebrovascular disease in dementia.

Ankle-brachial index, cognitive impairment and cerebrovascular disease in a Chinese population.

BACKGROUND: Previous studies have assessed the association between ankle-brachial index (ABI) and cognition, mainly using brief cognitive tests. We investigated whether ABI was associated with cognition independent of neuroimaging markers of cerebrovascular disease. METHODS: Chinese subjects (n = 278, aged ≥60 years) were recruited from the ongoing Epidemiology of Dementia in Singapore (EDIS) Study. Ankle and brachial blood pressures were measured, and low ABI was defined as ≤0.9. A neuropsychological battery was utilized to determine cognition. Cognitive impairment no dementia (CIND) and dementia were diagnosed according to standard diagnostic criteria. Magnetic resonance imaging (MRI) was used to obtain semiquantitative and quantitative markers of cerebrovascular disease and atrophy. RESULTS: A low ABI was related to the presence of intracranial stenosis (odds ratio, OR = 1.71; 95% confidence interval, CI: 1.13-2.59), but not with the presence of infarcts, microbleeds or grey matter, white matter and white matter lesion volumes. Furthermore, a low ABI was associated with poorer overall cognitive function and CIND-moderate/dementia (OR = 2.26; 95% CI: 1.11-4.59), independent of cardiovascular risk factors, and the MRI markers related to cerebrovascular disease and atrophy. CONCLUSION: We found an association between a low ABI and cognitive impairment, independent of any MRI marker of cerebral small vessel disease or large artery atherosclerotic disease.

Genome-wide meta-analysis of five Asian cohorts identifies PDGFRA as a susceptibility locus for corneal astigmatism.

Corneal astigmatism refers to refractive abnormalities and irregularities in the curvature of the cornea, and this interferes with light being accurately focused at a single point in the eye. This ametropic condition is highly prevalent, influences visual acuity, and is a highly heritable trait. There is currently a paucity of research in the genetic etiology of corneal astigmatism. Here we report the results from five genome-wide association studies of corneal astigmatism across three Asian populations, with an initial discovery set of 4,254 Chinese and Malay individuals consisting of 2,249 cases and 2,005 controls. Replication was obtained from three surveys comprising of 2,139 Indians, an additional 929 Chinese children, and an independent 397 Chinese family trios. Variants in PDGFRA on chromosome 4q12 (lead SNP: rs7677751, allelic odds ratio = 1.26 (95% CI: 1.16-1.36), P(meta) = 7.87×10(-9)) were identified to be significantly associated with corneal astigmatism, exhibiting consistent effect sizes across all five cohorts. This highlights the potential role of variants in PDGFRA in the genetic etiology of corneal astigmatism across diverse Asian populations.

Microvascular structure and network in the retina of patients with ischemic stroke.

BACKGROUND AND PURPOSE: Microvascular disease has been implicated in the pathogenesis of stroke. The retina provides a window to assess microcirculation noninvasively. We studied the association between quantitatively measured retinal microvascular characteristics and acute ischemic stroke. METHODS: We conducted a case-control study with acute ischemic stroke patients recruited from a tertiary hospital in Singapore and controls from the Singapore Epidemiology of Eye Disease program matched by 10-year age strata, sex, and race. Strokes were classified using modified Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. Retinal vascular parameters were measured from retinal fundus photographs using a computer program. Logistic regression models for stroke were constructed adjusting for age, sex, race, and additionally for smoking, hypertension, diabetes mellitus, and hypercholesterolemia. RESULTS: We included 557 ischemic stroke cases (261 lacunar, 185 large artery, and 54 cardioembolic stroke) and 557 controls. After adjusting for vascular risk factors, decreased arteriolar fractal dimension (odds ratio [OR] per standard deviation [SD] decrease, 2.28; 95% confidence interval [CI], 1.80-2.87) and venular fractal dimension (OR per SD decrease, 1.80; 95% CI, 1.46-2.23), increased arteriolar tortuosity (OR per SD increase, 1.56; 95% CI, 1.25-1.95), and venular tortuosity (OR per SD increase, 1.49; 95% CI, 1.27-1.76), narrower arteriolar caliber (OR per SD decrease, 2.79; 95% CI, 2.21-3.53), and wider venular caliber (OR per SD increase, 1.57; 95% CI, 1.27-1.95) were associated with stroke. Stratification by stroke subtypes and further adjustment for retinopathy signs revealed similar results. CONCLUSIONS: Patients with ischemic stroke have a sparser and more tortuous microvascular network in the retina. These findings provide insight into the structure and pattern of microcirculation changes in stroke.