Global White Matter Hyperintensities Research Articles

White Matter Hyperintensities Contribute to Language Deficits in Primary Progressive Aphasia.

To determine the contribution of white matter hyperintensities (WMH) to language deficits while accounting for cortical atrophy in individuals with primary progressive aphasia (PPA). Forty-three individuals with PPA completed neuropsychological assessments of nonverbal semantics, naming, and sentence repetition plus T2-weighted and fluid-attenuated inversion recovery scans. Using three visual scales, we rated WMH and cerebral ventricle size for both scan types. We used Spearman correlations to evaluate associations between the scales and scans. To test whether visual ratings-particularly of WMH-are associated with language, we compared a base model (including gray matter component scores obtained via principal component analysis, age, and days between assessment and MRI as independent variables) with full models (ie, the base model plus visual ratings) for each language variable. Visual ratings were significantly associated within and between scans and were significantly correlated with age but not with other vascular risk factors. Only the T2 scan ratings were associated with language abilities. Specifically, controlling for other variables, poorer naming was significantly related to larger ventricles (P = 0.033) and greater global (P = 0.033) and periventricular (P = 0.049) WMH. High global WMH (P = 0.034) were also correlated with worse sentence repetition skills. Visual ratings of global brain health were associated with language deficits in PPA independent of cortical atrophy and age. While WMH are not unique to PPA, measuring WMH in conjunction with cortical atrophy may elucidate more accurate brain structure-behavior relationships in PPA than cortical atrophy measures alone.

White matter hyperintensities are associated with subthreshold amyloid accumulation

The association between white matter hyperintensities (WMH) and amyloid accumulation over time in cognitively normal, amyloid-negative elderly people remains largely unexplored. In order to study whether baseline WMH were associated with longitudinal subthreshold amyloid accumulation, 159 cognitively normal participants from the Alzheimer’s Disease Neuroimaging Initiative who were amyloid-negative at baseline were examined. All the participants underwent a T1 and a Fluid-Attenuated Inversion Recovery MRI scan at baseline. Amyloid PET imaging was performed at baseline and follow-up visits in 2-year intervals for up to 8 years. Partial volume correction was applied for quantifying cortical Standardised Uptake Value Ratios (SUVR). The associations between global and regional WMH burden and amyloid accumulation were assessed using linear mixed models adjusted by demographic characteristics and baseline SUVR. Partial volume correction increased the measured annual rate of change (+2.4%) compared to that obtained from non-corrected data (+0.5%). There were no significant correlations between baseline WMHs and baseline subthreshold cortical amyloid uptake. In a longitudinal analysis, increased baseline cortical SUVR and increased baseline burden of global (p ​= ​0.006), frontal (p ​= ​0.006), and parietal WMH (p ​= ​0.003) were associated with faster amyloid accumulation. WMH-related amyloid accumulation occurred in parietal, frontal, and, to a lesser extent, cingulate cortices. These results remained unchanged after a sensitivity analysis excluding participants with the highest cortical SUVRs. This is the first study to identify a specific spatial distribution of WMH which is associated with future amyloid accumulation in cognitively normal elderly subjects without PET-detectable amyloid pathology. These findings may have important implications in prevention trials for the early identification of amyloid accumulation.

Optimized prediction of cognition based on brain morphometry across the adult life span

We mapped out the combined and unique contributions of 5 different biomarkers for 2 cognitive outcomes in cognitively healthy adults. Beside associations of biomarkers with cognition in the full experimental sample, we focused on how well any such associations would persist in held-out data. Three hundred thirty-five cognitively normal participants, 20–80 years older, were included in the study. Z-scores were computed for fluid reasoning and vocabulary. The following imaging data were included: regional brain volume, regional thickness, fractional anisotropy of white-matter tracts, volumes of select deep gray-matter regions, and global white-matter hyperintensity. Volume accounted for most of the variance in both cognitive domains. In out-of-sample data, fluid reasoning was best predicted by volumes, but vocabulary by the combination of all modalities. Although the predictive utility was better overall for older participants, the information gleaned relative to null models was less for older participants. An optimized set of brain biomarkers can thus predict cognition in out-of-sample data, to various degrees, for both fluid and crystallized intelligence.

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

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. 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. 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. Sporadic Aβ deposition is associated with white matter alterations in AD predilection areas in an age-dependent manner in cognitively normal individuals.

White matter hyperintensities are not associated with cognitive decline in early Parkinson's disease – The DeNoPa cohort

BackgroundSmall vessel disease and white matter hyperintensities (WMH) as its surrogate marker are known to predict cognitive decline in the elderly. However, the influence of vascular lesions on cognitive impairment in Parkinson's disease (PD) has been discussed controversial so far. The Aim of this study was to evaluate the predictive role of volume and location of white matter hyperintensities (WMH) on cognitive decline in de novo PD patients. Methods108 diagnosed drug-naïve PD patients (64 ± 9 years, 38% women) from the DeNoPa Cohort underwent extensive neuropsychological testing with re-testing in 24-month later. Movement Disorder Society criteria for the classification of mild cognitive impairment (MCI) and dementia in PD were applied. Participants that declined from normal cognition or MCI at baseline to MCI or dementia at 24-month follow-up (FU) or from MCI to dementia at 24-month FU were defined as “converters”. Subjects with stable cognitive level or improved cognitive status were classified as “non-converters”. Magnetic resonance imaging (MRI) was performed, and the extent of WMH was assessed as global volume and as WMH load within cholinergic pathways using the Cholinergic Pathways Hyperintensities Scale. We compared Parkinson's disease subjects with age-matched, neurologically healthy controls. ResultsAt total of 29 (27%) patients met the criteria for MCI at baseline, whereas 79 (73%) patients had no cognitive impairment. During the 24-month FU 33 patients showed cognitive decline (“converter”) compared to 75 “non-converters”. Multivariable logistic regression revealed no significant differences between “cognitively impaired” and “cognitively non-impaired” patients and participants of the control group at baseline or between “converter” and “non-converter” regarding the extent of WMH globally or within cholinergic pathways. ConclusionsWe could not identify global or localized WMH load as predictive markers of cognitive decline in de novo PD patients indicating that cerebral small vessel disease is not a critical modifier of cognitive function in early PD.

Hippocampal subfield volumes and pre-clinical Alzheimer's disease in 408 cognitively normal adults born in 1946.

The human hippocampus comprises a number of interconnected histologically and functionally distinct subfields, which may be differentially influenced by cerebral pathology. Automated techniques are now available that estimate hippocampal subfield volumes using in vivo structural MRI data. To date, research investigating the influence of cerebral β-amyloid deposition-one of the earliest hypothesised changes in the pathophysiological continuum of Alzheimer's disease-on hippocampal subfield volumes in cognitively normal older individuals, has been limited. Using cross-sectional data from 408 cognitively normal individuals born in mainland Britain (age range at time of assessment = 69.2-71.9 years) who underwent cognitive assessment, 18F-Florbetapir PET and structural MRI on the same 3 Tesla PET/MR unit (spatial resolution 1.1 x 1.1 x 1.1. mm), we investigated the influences of β-amyloid status, age at scan, and global white matter hyperintensity volume on: CA1, CA2/3, CA4, dentate gyrus, presubiculum and subiculum volumes, adjusting for sex and total intracranial volume. Compared to β-amyloid negative participants (n = 334), β-amyloid positive participants (n = 74) had lower volume of the presubiculum (3.4% smaller, p = 0.012). Despite an age range at scanning of just 2.7 years, older age at time of scanning was associated with lower CA1 (p = 0.007), CA4 (p = 0.004), dentate gyrus (p = 0.002), and subiculum (p = 0.035) volumes. There was no evidence that white matter hyperintensity volume was associated with any subfield volumes. These data provide evidence of differential associations in cognitively normal older adults between hippocampal subfield volumes and β-amyloid deposition and, increasing age at time of scan. The relatively selective effect of lower presubiculum volume in the β-amyloid positive group potentially suggest that the presubiculum may be an area of early and relatively specific volume loss in the pathophysiological continuum of Alzheimer's disease. Future work using higher resolution imaging will be key to exploring these findings further.

Patterns of white matter hyperintensities associated with cognition in middle-aged cognitively healthy individuals

White matter hyperintensities (WMH) are commonly detected in the brain of elderly individuals and have been associated with a negative impact on multiple cognitive domains. We aim to investigate the impact of global and regional distribution of WMH on episodic memory and executive function in middle-aged cognitively unimpaired participants [N = 561 (45–75 years)] enriched for Alzheimer’s disease risk factors. WMH were automatically segmented from FLAIR, T1 and FSE MR images. WMH load was calculated both globally and regionally. At each cerebral lobe, regional WMH load was measured at four equidistant layers extending from the lateral ventricles to juxtacortical areas. Cognition was measured by The Memory Binding Test (MBT) and WAIS-IV subtests. Global composite z-scores were calculated for the two cognitive domains. Association between global and regional WMH measurements were sought against cognitive measures, both in global composite scores and in individual subtests. We adjusted cognition and WMH burden for the main sociodemographic (age, sex and education) and genetic factors (APOE-ε4). Memory and executive function were significantly associated with global WMH load. Regionally, lower executive performance was mainly associated with higher deep WMH load in frontal areas and, to a lower degree, in occipital, parietal and temporal regions. Lower episodic memory performance was correlated with higher WMH burden in deep frontal and occipital areas. Our novel methodological approach of regional analysis allowed us to reveal the association between cognition and WMH in strategic brain locations. Our results suggest that, even a small WMH load can impact cognition in cognitively unimpaired middle-aged subjects.

P2‐410: A RISK FACTOR PROFILE OF INCREASED WHITE MATTER HYPERINTENSITY BURDEN IN THE ABERDEEN CHILDREN OF THE NINETEEN FIFTIES COHORT

The Aberdeen Children of the Nineteen Fifties (ACONF) is a well-characterised cohort of healthy, community-dwelling individuals, born in Aberdeen, Scotland (UK) between 1950 and 1956. This rich source of data allows us to investigate early- and mid-life risk factors for poor health in later life. Recently, subgroup of this cohort underwent brain magnetic resonance imaging (MRI), as well as health and neuropsychological assessments. Here, we aimed to utilise these life-course data to identify risk-factors for increased brain white matter hyperintensity (WMH) burden: a common MRI finding in older adults, associated with cognitive decline, dementia, stroke and death. We calculated the relative risk (RR) of certain factors on increased global WMH burden in 277 cognitively healthy ACONF participants (mean age = 62.3). Global WMH burden was measured as total WMH volume (ml) using an automated WMH segmentation algorithm. We investigated potential risk factors within the domains of demographics, early-life, medical history, socioeconomic circumstance, late-life objective health, and late-life cognition. We identified elevated risk factors for increased global WMH burden among each domain mentioned above. The most significant risk factors for increased WMH burden in this cohort included medical histories of stroke (RR = 2.642, 95% CI = 1.59 – 4.39), heart disease (RR = 1.864, 95% CI = 1.098 – 3.165), diabetes (RR = 1.903, 95% CI = 1.194 – 3.032), and high cholesterol (RR = 1.566, 95% CI = 1.077 – 2.277). Notable early- and mid-life risk factors approaching significance included birth weight of less than 5.5lbs (RR = 1.697, 95% CI = .913 – 3.153) and working in lower-income occupations (RR = 1.049, 95% CI = .715 – 1.538). We were able to confirm age and cardiometabolic risk factors for increased WMH burden in a relatively young cohort of older adults, and add contributions of emerging early and mid-life risk factors. Many of these cardiometabolic risk factors have their origins in early life and are greatest in those with the least resilience. Future work will involve developing a robust model of risk- and protective determinants of WMH burden.

Cross-sectional and longitudinal associations between total and regional white matter hyperintensity volume and cognitive and motor function in Parkinson's disease.

BackgroundWhite matter hyperintensities (WMH) are frequently observed on T2-weighted brain magnetic resonance imaging studies of healthy older adults and have been linked with impairments in balance, gait, and cognition. Nonetheless, few studies have investigated the longitudinal effects of comorbid WMH on cognition and motor function in Parkinson's disease.MethodsThe Lesion Segmentation Tool for Statistical Parametric Mapping was used to obtain total lesion volume and map regional WMH probabilities in 29 PD and 42 control participants at two study visits 18 months apart. Both cross-sectional and longitudinal comparisons were made between composite scores in the domains of executive function, memory, and language, and Unified Parkinson's Disease Rating Scale (UPDRS) scores.ResultsWe found no difference between disease and control groups in total WMH volume or progression during the study. Greater regional and global WMH at baseline was more strongly associated with lower executive function in PD subjects than in controls. Increased regional WMH was also more strongly associated with impaired memory performance in PD relative to controls. Longitudinally, no associations between cognitive change and total or regional WMH progression were detected in either group. A positive relationship between baseline regional WMH and total UPDRS scores was present in the control group, but not PD. However, greater WMH increase was associated with a greater increase in UPDRS motor sub-scores in PD.ConclusionsThese findings suggest that although PD patients do not experience greater mean WMH load than normal aged adults, comorbid WMH do exacerbate cognitive and motor symptoms in PD.

Subcortical Brain Involvement Is Associated With Impaired Performance on the Psychomotor Vigilance Task After Minor Stroke

Objective. Impaired attentional processes have been linked with poor outcomes after stroke, but their radiographical correlates have been infrequently studied. Our objective was to assess the relationship between stroke location and vigilant attention. Methods. A total of 39 patients presenting within 2 weeks of a minor stroke were prospectively recruited. Vigilant attention was assessed using the psychomotor vigilance task (PVT), and neuroimaging was used to assess stroke location, white matter hyperintensity (WMH) burden, and ischemic stroke involvement within lateral cholinergic projections. Correlational analyses and linear regression models tested the association between PVT performance and our neuroimaging parameters of interest. Subtractions of lesion overlays were used to identify brain regions of acute stroke patients who performed most poorly on the PVT. Results. Subcortical stroke location was a predictor of PVT performance in this cohort of acute stroke patients. Patients who performed most poorly on the PVT had lesions in the corona radiata, internal capsule, globus pallidus, and thalamus. Global WMH burden and cerebrovascular disease in lateral cholinergic pathways were not significant predictors of PVT performance. Interpretation. Subcortical stroke location was associated with impaired vigilant attention. The poorest PVT performers had stroke lesions involving the corona radiata, internal capsule, globus pallidus, and thalamus, suggesting that vigilance depends on the integrity of subcortical structures and their connections with cortical brain regions.

The association of sleep-disordered breathing and white matter hyperintensities in heart failure patients.

Heart failure patients often manifest white matter hyperintensites on brain magnetic resonance imaging (MRI). White matter hyperintnsities have also been linked with cognitive problems in patients with heart failure. Sleep disordered breathing may contribute to structural brain changes in heart failure. The purpose of this study was to test the extent to which the apnea hypopnea index is associated with global and regional white matter hyperintensities, and is a moderating factor in the relationship between age and white matter hyperintensites. A total of 28 HF patients [mean age (SD) = 67.89 (5.8)] underwent T1-weighted and T2FLAIR MRI and a home sleep monitoring study. The apnea hypopnea index cut off of 10 was used to compare between higher and lower risks of sleep disordered breathing. Regression analysis was used to test the association between apnea hypopnea index and both global and regional white matter hyperintensities. The interaction term was entered to identify the moderation effect. Apnea hypopnea index was associated with higher regional white matter hyperintensities but not global white matter hyperintensities. There was a significant interaction between the apnea hypopnea index and age, such that older participants with the apnea hypopnea index ≥10 showed greater regional white matter hyperintensities than those with the apnea hypopnea index <10. The results of this preliminary study indicate that a higher apnea hypopnea index is associated with more white matter hyperintensities. The age-related white matter hyperintensities appear to be exacerbated by apnea hypopnea index in our individuals with heart failure. Future studies are needed to further investigate the underlying mechanisms.

The neural correlates of perceived energy levels in older adults with late-life depression

Late-life depression is common among older adults. Although white-matter abnormality is highly implicated, the extent to which the corticospinal tract is associated with the pathophysiology of late-life depression is unclear. The current study aims to investigate the white-matter structural integrity of the corticospinal tract and determine its cognitive and functional correlates in older adults with late-life depression. Twenty-eight older adults with clinical depression and 23 healthy age-matched older adults participated in the study. The white matter volume and the white matter hyperintensities (WMHs) of the corticospinal tract, as well as the global WMHs, were measured. Psychomotor processing speed, severity of depression, perceived levels of energy and physical functioning were measured to examine the relationships among the correlates in the depressed participants. The right corticospinal tract volume was significantly higher in depressed older adults relative to healthy controls. Moreover, the right corticospinal tract volume was significantly associated with the overall severity of depression and accounted for 17% of its variance. It further attenuated the relationship between the severity of depression and perceived levels of energy. Our findings suggested that higher volume in the right corticospinal tract is implicated in LLD and may relate to lower perceived levels of energy experienced by older adults with depression.

Ethnoracial differences in brain structure change and cognitive change.

The purpose of this study was to examine longitudinal associations between structural MRI and cognition in a diverse sample. Older adults (n = 444; Mage = 74.5)-121 African Americans, 212 Whites, and 111 Hispanics-underwent an average of 5.3 annual study visits. Approximately half were cognitively normal at baseline (global Clinical Dementia Rating M = 0.5). Of the patients with dementia, most (79%) were diagnosed with Alzheimer's disease (AD). MRI measures of gray matter volume (baseline and change), and hippocampal and white matter hyperintensity (WMH) volumes (baseline), were used to predict change in global cognition. Multilevel latent variable modeling was used to test the hypothesis that brain effects on cognitive change differed across ethnoracial groups. In a multivariable model, global gray matter change was the strongest predictor of cognitive decline in Whites and African Americans and specific temporal lobe change added incremental explanatory power in Whites. Baseline WMH volume was the strongest predictor of cognitive decline in Hispanics and made an incremental contribution in Whites. We found ethnoracial group differences in associations of brain variables with cognitive decline. The unique patterns in Whites appeared to suggest a greater influence of AD in this group. In contrast, cognitive decline in African Americans and Hispanics was most uniquely attributable to global gray matter change and baseline WMH, respectively. Brain changes underlying cognitive decline in older adults are heterogeneous and depend on fixed and modifiable risk factors that differ based on ethnicity and race. (PsycINFO Database Record

Bullseye's representation of cerebral white matter hyperintensities

Background and purposeVisual rating scales have limited capacities to depict the regional distribution of cerebral white matter hyperintensities (WMH). We present a regional-zonal volumetric analysis alongside a visualization tool to compare and deconstruct visual rating scales. Materials and methods3D T1-weighted, T2-weighted spin-echo and FLAIR images were acquired on a 3T system, from 82 elderly participants in a population-based study. Images were automatically segmented for WMH. Lobar boundaries and distance to ventricular surface were used to define white matter regions. Regional-zonal WMH loads were displayed using bullseye plots. Four raters assessed all images applying three scales. Correlations between visual scales and regional WMH as well as inter and intra-rater variability were assessed. A multinomial ordinal regression model was used to predict scores based on regional volumes and global WMH burdens. ResultsOn average, the bullseye plot depicted a right-left symmetry in the distribution and concentration of damage in the periventricular zone, especially in frontal regions. WMH loads correlated well with the average visual rating scores (e.g. Kendall's tau [Volume, Scheltens]=0.59 CI=[0.53 0.62]). Local correlations allowed comparison of loading patterns between scales and between raters. Regional measurements had more predictive power than global WMH burden (e.g. frontal caps prediction with local features: ICC=0.67 CI=[0.53 0.77], global volume=0.50 CI=[0.32 0.65], intra-rater=0.44 CI=[0.23 0.60]). ConclusionRegional-zonal representation of WMH burden highlights similarities and differences between visual rating scales and raters. The bullseye infographic tool provides a simple visual representation of regional lesion load that can be used for rater calibration and training.

COMPUTED RATING SCALES FOR COGNITIVE DISORDERS FROM MRI

Magnetic resonance imaging (MRI) is an important tool in the clinical diagnosis of cognitive disorders. In addition to visual reading of images, visual rating scales are used to evaluate images in clinical practice. The objective of this study is to assess whether widely used visual rating scales, medial temporal lobe atrophy (MTA)1, global cortical atrophy (GCA)2 and white matter hyperintensities (WMHs) measured by the Fazekas scale3, could be estimated automatically. Images and visual ratings from the Amsterdam Dementia Cohort4 (Table 1) were used to develop the models. A set of imaging biomarkers were extracted from T1-weighted and FLAIR images using methods similar to 5, and corrected for age, gender and head size. The biomarkers tested included: volumes for hippocampus (MTA), inferior lateral ventricle (MTA), cortical gray matter (GCA), global WMHs (Fazekas) and deep WMHs (Fazekas), and gray matter concentrations from voxel-based morphometry6 for hippocampus (MTA) and cortex (GCA). A regression model was developed for estimating the visual rating scale values from the imaging biomarkers. Cross-validation was used. The Mann-Whitney U-test was used to test statistical differences. Correlation coefficient between the visual and computed rating scale values was 0.86 (MTA-Left), 0.85 (MTA-Right), 0.67 (GCA) and 0.80 (WMHs). In classifying cognitively normal subjects and Alzheimer's disease patients, the area under the curve (AUC) for the visual scales was 0.82 (MTA-left), 0.79 (MTA-right) and 0.76 (GCA), and for the computed scales 0.88 (MTA-Left), 0.89 (MTA-Right) and 0.90 (GCA). The corresponding AUC values for classifying cases with vascular cognitive impairment and other etiologies were 0.88 (visual) and 0.96 (computed). The differences between the visual and computed scales were statistically significant. Figure 1 shows ROC curves for the left MTA, GCA and Fazekas. MTA, GCA and WMHs can be reliably measured automatically. The computed ratings performed better than current visual ratings in classification. Age correction was not used for visual ratings which may partly explain the result. 1 Scheltens J Neurol 1995; 2 Pasquier Eur Neurol 1996; 3 Fazekas Am J Roentgenol 1987; 6 van der Flier J Alzheimers Dis 2014; 5 Koikkalainen NeuroImage Clinical 2016; 6 Ashburner NeuroImage 2000. ROC curves for the visual and computed MTA-L, GCA and Fazekas rating scales. Two curves are shown for the computed scales: the original scalar scale and the scale rounded to an integer value corresponding to the range of values in the visual scales.

Lesion location and cognitive impact of cerebral small vessel disease.

Cerebral small vessel disease (SVD) is an important cause of cognitive impairment. Important MRI manifestations of SVD include white matter hyperintensities (WMH) and lacunes. This narrative review addresses the role of anatomical lesion location in the impact of SVD on cognition, integrating findings from early autopsy studies with emerging findings from recent studies with advanced image analysis techniques. Early autopsy and imaging studies of small case series indicate that single lacunar infarcts in, for example the thalamus, caudate nucleus or internal capsule can cause marked cognitive impairment. However, the findings of such case studies may not be generalizable. Emerging location-based image analysis approaches are now being applied to large cohorts. Recent studies show that WMH burden in strategic white matter tracts, such as the forceps minor or anterior thalamic radiation (ATR), is more relevant in explaining variance in cognitive functioning than global WMH volume. These findings suggest that the future diagnostic work-up of memory clinic patients could potentially be improved by shifting from a global assessment of WMH and lacune burden towards a quantitative assessment of lesion volumes within strategic brain regions. In this review, a summary of currently known strategic regions for SVD-related cognitive impairment is provided, highlighting recent technical developments in SVD research. The potential and challenges of location-based approaches for diagnostic purposes in clinical practice are discussed, along with their potential prognostic and therapeutic applications.

Cognitive decline in metabolic syndrome is linked to microstructural white matter abnormalities

Subjects with metabolic syndrome (MetS) often show worse cognitive performance compared with the healthy population. We investigated whether microstructural white matter abnormalities are associated with cognitive performance in adults with MetS using diffusion tensor MR imaging. A total of 32 subjects with MetS (age 64.8±7.8, 56.25% female) and 23 age-, gender-, and education-matched healthy controls completed a battery of neuropsychological tests and diffusion tensor imaging (DTI) at 3-T MRI. Brain global and regional volumes, white matter fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (LD) were calculated. The least-square models adjusted for age, sex, HbA1c, hypertension, body mass index, hyperlipidemia, and white matter hyperintensities were used to evaluate the relationship between cognitive function and DTI. The MetS group had worse performance in verbal fluency (VF) and learning and memory function (total VF: T score (p=0.01), VF: animals T score (p=0.0001), Hopkins Verbal Learning Test (HVLT): Total recall T score (p=0.0001), and HVLT: delayed recall T score (p=0.002), as compared with controls. In the MetS group, abnormalities in diffusivity measures were associated with worse cognitive performance [VF: animals T score and left post-central gyrus-LD (p=0.0007, r adj 0.4), R angular gyrus-RD (p=0.0008, r adj 0.3), L supra-marginal gyrus-RD (p=0.009, r adj 0.2) after adjusting for age, sex, HbA1c, 24h mean BP, presence of hyperlipidemia, and global white matter hyperintensities]. Microstructural white matter abnormalities in the MetS group might be the underlying mechanisms of worse verbal learning and memory performance.

Stroke: Highlights of Selected Articles

<i>Stroke:</i> Highlights of Selected Articles

Posterior Atrophy and Medial Temporal Atrophy Scores Are Associated with Different Symptoms in Patients with Alzheimer's Disease and Mild Cognitive Impairment.

BackgroundWhether the occurrence of posterior atrophy (PA) and medial temporal lobe atrophy (MTA) was correlated with cognitive and non-cognitive symptoms in Alzheimer’s disease (AD) and mild cognitive impairment (MCI) patients are unclear.MethodsPatients with probable AD and MCI from a medical center outpatient clinic received attention, memory, language, executive function evaluation and Mini-Mental Status Examination (MMSE). The severity of dementia was rated by the Clinical Dementia Rating (CDR) Sum of Box (CDR-SB). The neuropsychiatric inventory (NPI) subscale of agitation/aggression and mood symptoms was also applied. Magnetic resonance imaging (MRI) was scored visually for the MTA, PA and white matter hyperintensity (WMH) scores.ResultsWe recruited 129 AD and 31 MCI (mean age 78.8 years, 48% female) patients. MMSE scores, memory, language and executive function were all significantly decreased in individuals with AD than those with MCI (p < 0.01). MTA and PA scores reflected significant atrophy in AD compared to MCI; however, the WMH scores did not differ. The MTA scores were significantly correlated with the frontal, parieto-occipital and global WMH scores (p < 0.01) while the PA scores showed a correlation with the parieto-occipital and temporal WMH scores (p < 0.01). After adjusting for age, education, APOE4 gene and diagnostic group covariates, the MTA scores showed a significant association with MMSE and CDR-SB, while the right side PA scores were significantly associated with NPI-agitation/aggression subscales (p < 0.01).ConclusionRegional atrophy is related to different symptoms in patients with AD or MCI. PA score is useful as a complementary measure for non-cognitive symptom.

Automated quantification of white matter hyperintensities to support dementia diagnosis

White matter hyperintensities (WMH) are present in various dementia types, but are particularly associated with vascular dementia (VaD). A WMH load 25% total white matter is used as a diagnostic criterion. The load and location of WMH provide useful information for dementia diagnosis, and differentiation between dementia types. We present an automated tool that provides a summary report based on quantitative assessment of global and regional WMH. This tool is incorporated in the Assessa ®