Posterior White Matter Hyperintensities Research Articles

6 Posterior cerebral artery-defined white matter hyperintensities are associated with object domain memory and transentorhinal volume independently of global beta-amyloid burden

Objective:White matter hyperintensities (WMH) are a radiological marker of small vessel cerebrovascular disease that are related to cognition and memory decline in aging and Alzheimer’s disease (AD). However, the mechanisms that link WMH to memory impairment and whether they interact with or act independently of AD pathophysiology are unclear. The transentorhinal cortex (BA35) is among the earliest anatomical regions to show tau deposition and subsequent atrophy, and baseline posterior WMH is related to longitudinal cortical thinning of the entorhinal cortex. However, it is unclear whether regional WMH are related to BA35 volume specifically, and whether this relationship is influenced by amyloid-β (Aβ) burden. We hypothesized that WMH in the vascular territory of the posterior cerebral artery (PCA), which perfuses both posterior and medial temporal lobe regions, would be associated with reduced BA35 volume and with lower memory in older adults independently of Aβ.Participants and Methods:114 older adults without dementia, aged 60 to 98 years (mean (SD) = 78.31 (11.02), 71 (62.8%) women), were included. Regional WMH volumes were derived from T2-FLAIR images using ANTs, a vascular territory atlas and manual editing. Global Aβ was assessed with 18F-florbetapir PET, using SUVR of a cortical composite region (FBP mean SUVR) with a cerebellar reference region. Total transentorhinal (BA35) volume was derived using T1 and T2-weighted images using ASHS. To assess hippocampal pattern separation ability, an index of episodic memory, participants completed both object (MDT-O) and spatial (MDT-S) versions of a mnemonic discrimination task, with the lure discrimination index as the outcome. Using linear regressions, we first tested for associations among PCA-defined WMH, Aβ, BA35 volume, and MDT-S and MDT-O scores. We then tested whether the relationship between PCA-defined WMH and MDT-O performance was mediated by BA35 volume and whether this mediation was moderated by Aβ. All models adjusted for age, sex, and education.Results:PCA-defined WMH were related to higher FBP mean SUVR (b=0.287, p=0.042) and lower BA35 volume (b=-0.222, p=0.038). PCA-defined WMH were also negatively related to MDT-O performance (b=-0.229, p=0.044), but not to MDT-S (b=-0.171, p=0.118). FBP mean SUVR was not related to BA35 volume (b=-0.131, p=0.344) or MDT performance (MDT-S: b=-0.138, p=0.348; MDT-O: b=0.059, p=0.690). Furthermore, FBP mean SUVR did not interact with PCA-defined WMH to predict memory performance (interaction b=-0.039, p=0.973), nor BA35 volume (interaction b=-0.140, p=0.894). The association of PCA-defined WMH to MDT-O was fully mediated by BA35 volume (indirect effect b=-0.0005, 95% CI (-0.0014, -0.0003)). This mediation was not moderated by FBP mean SUVR (indirect effect b=-0.00001, 95% CI (-0.001, 0.001)).Conclusions:We found that PCA-defined WMH were related to memory performance in older adults, and this association is fully mediated by transentorhinal volume. While PCA-defined WMH are related to higher global Aβ burden, there is no interaction between PCA-defined WMH and Aβ on BA35 volume. These findings point to an amyloid-independent vascular pathway towards memory decline in aging and AD. Future work should examine whether the pathway linking PCA-defined WMH to transentorhinal cortex atrophy and subsequent memory decline is mediated by regional tau pathology.

White matter hyperintensity longitudinal morphometric analysis in association with Alzheimer disease.

Vascular damage in Alzheimer's disease (AD) has shown conflicting findings particularly when analyzing longitudinal data. We introduce white matter hyperintensity (WMH) longitudinal morphometric analysis (WLMA) that quantifies WMH expansion as the distance from lesion voxels to a region of interest boundary. WMH segmentation maps were derived from 270 longitudinal fluid-attenuated inversion recovery (FLAIR) ADNI images. WLMA was performed on five data-driven WMH patterns with distinct spatial distributions. Amyloid accumulation was evaluated with WMH expansion across the five WMH patterns. The preclinical group had significantly greater expansion in the posterior ventricular WM compared to controls. Amyloid significantly associated with frontal WMH expansion primarily within AD individuals. WLMA outperformed WMH volume changes for classifying AD from controls primarily in periventricular and posterior WMH. These data support the concept that localized WMH expansion continues to proliferate with amyloid accumulation throughout the entirety of the disease in distinct spatial locations.

Arterial hypertension and β-amyloid accumulation have spatially overlapping effects on posterior white matter hyperintensity volume: a cross-sectional study

BackgroundWhite matter hyperintensities (WMH) in subjects across the Alzheimer’s disease (AD) spectrum with minimal vascular pathology suggests that amyloid pathology—not just arterial hypertension—impacts WMH, which in turn adversely influences cognition. Here we seek to determine the effect of both hypertension and Aβ positivity on WMH, and their impact on cognition.MethodsWe analysed data from subjects with a low vascular profile and normal cognition (NC), subjective cognitive decline (SCD), and amnestic mild cognitive impairment (MCI) enrolled in the ongoing observational multicentre DZNE Longitudinal Cognitive Impairment and Dementia Study (n = 375, median age 70.0 [IQR 66.0, 74.4] years; 178 female; NC/SCD/MCI 127/162/86). All subjects underwent a rich neuropsychological assessment. We focused on baseline memory and executive function—derived from multiple neuropsychological tests using confirmatory factor analysis—, baseline preclinical Alzheimer’s cognitive composite 5 (PACC5) scores, and changes in PACC5 scores over the course of three years (ΔPACC5).ResultsSubjects with hypertension or Aβ positivity presented the largest WMH volumes (pFDR < 0.05), with spatial overlap in the frontal (hypertension: 0.42 ± 0.17; Aβ: 0.46 ± 0.18), occipital (hypertension: 0.50 ± 0.16; Aβ: 0.50 ± 0.16), parietal lobes (hypertension: 0.57 ± 0.18; Aβ: 0.56 ± 0.20), corona radiata (hypertension: 0.45 ± 0.17; Aβ: 0.40 ± 0.13), optic radiation (hypertension: 0.39 ± 0.18; Aβ: 0.74 ± 0.19), and splenium of the corpus callosum (hypertension: 0.36 ± 0.12; Aβ: 0.28 ± 0.12). Elevated global and regional WMH volumes coincided with worse cognitive performance at baseline and over 3 years (pFDR < 0.05). Aβ positivity was negatively associated with cognitive performance (direct effect—memory: − 0.33 ± 0.08, pFDR < 0.001; executive: − 0.21 ± 0.08, pFDR < 0.001; PACC5: − 0.29 ± 0.09, pFDR = 0.006; ΔPACC5: − 0.34 ± 0.04, pFDR < 0.05). Splenial WMH mediated the relationship between hypertension and cognitive performance (indirect-only effect—memory: − 0.05 ± 0.02, pFDR = 0.029; executive: − 0.04 ± 0.02, pFDR = 0.067; PACC5: − 0.05 ± 0.02, pFDR = 0.030; ΔPACC5: − 0.09 ± 0.03, pFDR = 0.043) and WMH in the optic radiation partially mediated that between Aβ positivity and memory (indirect effect—memory: − 0.05 ± 0.02, pFDR = 0.029).ConclusionsPosterior white matter is susceptible to hypertension and Aβ accumulation. Posterior WMH mediate the association between these pathologies and cognitive dysfunction, making them a promising target to tackle the downstream damage related to the potentially interacting and potentiating effects of the two pathologies.Trial registrationGerman Clinical Trials Register (DRKS00007966, 04/05/2015).

Posterior white matter hyperintensities are associated with reduced medial temporal lobe subregional integrity and long-term memory in older adults

White matter hyperintensities are a marker of small vessel cerebrovascular disease that are strongly related to cognition in older adults. Similarly, medial temporal lobe atrophy is well-documented in aging and Alzheimer’s disease and is associated with memory decline. Here, we assessed the relationship between lobar white matter hyperintensities, medial temporal lobe subregional volumes, and hippocampal memory in older adults.We collected MRI scans in a sample of 139 older adults without dementia (88 females, mean age (SD) = 76.95 (10.61)). Participants were administered the Rey Auditory Verbal Learning Test (RAVLT). Regression analyses tested for associations among medial temporal lobe subregional volumes, regional white matter hyperintensities and memory, while adjusting for age, sex, and education and correcting for multiple comparisons.Increased occipital white matter hyperintensities were related to worse RAVLT delayed recall performance, and to reduced CA1, dentate gyrus, perirhinal cortex (Brodmann area 36), and parahippocampal cortex volumes. These medial temporal lobe subregional volumes were related to delayed recall performance. The association of occipital white matter hyperintensities with delayed recall performance was fully mediated statistically only by perirhinal cortex volume.These results suggest that white matter hyperintensities may be associated with memory decline through their impact on medial temporal lobe atrophy. These findings provide new insights into the role of vascular pathologies in memory loss in older adults and suggest that future studies should further examine the neural mechanisms of these relationships in longitudinal samples.

Association of Data-Driven White Matter Hyperintensity Spatial Signatures With Distinct Cerebral Small Vessel Disease Etiologies.

Topographical distribution of white matter hyperintensities (WMH) are hypothesized to vary by cerebrovascular risk factors. We used an unbiased pattern discovery approach to identify distinct WMH spatial patterns and investigate their association with different WMH etiologies. We performed a cross-sectional study on participants of the Alzheimer's Disease Neuroimaging Initiative (ADNI) to identify spatially distinct WMH distribution patterns using voxel-based spectral clustering analysis of aligned WMH probability maps. We included all participants from the ADNI Grand Opportunity/ADNI 2 study with available baseline 2D-FLAIR MRI scans, without history of stroke or presence of infarction on imaging. We evaluated the associations of these WMH spatial patterns with vascular risk factors, amyloid-β PET, and imaging biomarkers of cerebral amyloid angiopathy (CAA), characterizing different forms of cerebral small vessel disease (CSVD) using multivariable regression. We also used linear regression models to investigate whether WMH spatial distribution influenced cognitive impairment. We analyzed MRI scans of 1,046 ADNI participants with mixed vascular and amyloid-related risk factors (mean age 72.9, 47.7% female, 31.4% hypertensive, 48.3% with abnormal amyloid PET). We observed unbiased partitioning of WMH into 5 unique spatial patterns: deep frontal, periventricular, juxtacortical, parietal, and posterior. Juxtacortical WMH were independently associated with probable CAA, deep frontal WMH were associated with risk factors for arteriolosclerosis (hypertension and diabetes), and parietal WMH were associated with brain amyloid accumulation, consistent with an Alzheimer disease (AD) phenotype. Juxtacortical, deep frontal, and parietal WMH spatial patterns were associated with cognitive impairment. Periventricular and posterior WMH spatial patterns were unrelated to any disease phenotype or cognitive decline. Data-driven WMH spatial patterns reflect discrete underlying etiologies including arteriolosclerosis, CAA, AD, and normal aging. Global measures of WMH volume may miss important spatial distinctions. WMH spatial signatures may serve as etiology-specific imaging markers, helping to resolve WMH heterogeneity, identify the dominant underlying pathologic process, and improve prediction of clinical-relevant trajectories that influence cognitive decline.

Arterial Spin-Labeling Parameters and Their Associations with Risk Factors, Cerebral Small-Vessel Disease, and Etiologic Subtypes of Cognitive Impairment and Dementia.

Cerebral small-vessel disease may alter cerebral blood flow (CBF) leading to brain changes and, hence, cognitive impairment and dementia. CBF and the spatial coefficient of variation can be measured quantitatively by arterial spin-labeling. We aimed to investigate the associations of demographics, vascular risk factors, location, and severity of cerebral small-vessel disease as well as the etiologic subtypes of cognitive impairment and dementia with CBF and the spatial coefficient of variation. Three hundred ninety patients with a diagnosis of no cognitive impairment, cognitive impairment no dementia, vascular cognitive impairment no dementia, Alzheimer disease, and vascular dementia were recruited from the memory clinic. Cerebral microbleeds and lacunes were categorized into strictly lobar, strictly deep, and mixed-location and enlarged perivascular spaces into the centrum semiovale and basal ganglia. Total and region-specific white matter hyperintensity volumes were segmented using FreeSurfer. CBF (n = 333) and the spatial coefficient of variation (n = 390) were analyzed with ExploreASL from 2D-EPI pseudocontinuous arterial spin-labeling images in white matter (WM) and gray matter (GM). To analyze the effect of demographic and vascular risk factors as well as the location and severity of cerebral small-vessel disease markers on arterial spin-labeling parameters, we constructed linear regression models, whereas logistic regression models were used to determine the association between arterial spin-labeling parameters and cognitive impairment no dementia, vascular cognitive impairment no dementia, Alzheimer disease, and vascular dementia. Increasing age, male sex, hypertension, hyperlipidemia, history of heart disease, and smoking were associated with lower CBF and a higher spatial coefficient of variation. Higher numbers of lacunes and cerebral microbleeds were associated with lower CBF and a higher spatial coefficient of variation. Location-specific analysis showed mixed-location lacunes and cerebral microbleeds were associated with lower CBF. Higher total, anterior, and posterior white matter hyperintensity volumes were associated with a higher spatial coefficient of variation. No association was observed between enlarged perivascular spaces and arterial spin-labeling parameters. A higher spatial coefficient of variation was associated with the diagnosis of vascular cognitive impairment no dementia, Alzheimer's disease, and vascular dementia. Reduced CBF and an increased spatial coefficient of variation were associated with cerebral small-vessel disease, and more specifically lacunes, whereas cerebral microbleeds and white matter hyperintensities were associated with WM-CBF and GM spatial coefficient of variation. The spatial coefficient of variation was associated with cognitive impairment and dementia, suggesting that hypoperfusion might be the key underlying mechanism for vascular brain damage.

NEUROLOGICALLY ASYMPTOMATIC PATIENTS FREQUENTLY PRESENT CEREBRAL INJURIES DURING MALIGNANT HYPERTENSION: A MRI STUDY

Objective: Acute and diffuse microvascular damage characterizes malignant hypertension (MHT), the deadliest form of hypertension. Although its ophthalmological, renal and cardiological repercussions are well known, brain involvement is considered rare with few descriptions, although it is one of the main causes of death. We aim to describe brain MRI abnormalities in patients admitted for MHT crisis but without objective neurological signs. Design and method: This single-center, cross-sectionnal observational study recruited patients with malignant Hypertension (MHT). MHT was defined by severe hypertension and severe hypertensive retinopathy OR subacute damage of three among the target organs: heart, kidney, brain, vessels (thrombotic microangiopathy). Patients under 18 years old, under chronic dialysis and not willing to participate were excluded. Brain MRI was performed within 21 days following diagnosis and was reviewed by a stroke neurologist who recorded the following markers: acute ischemic stroke(DWI and FLAIR positive), acute intracerebral hemorrhage (T2* and FLAIR positive), acute brain edema with extensive posterior white matter hyperintensity suggesting a PRES, and small vessel disease including old lacunar infarct, white matter hyperintensities (WMH), presence of dilated perivascular spaces. Results: We included 58 patients without neurological signs, 66% were men, and mean age was 45.6+/-11.3 years. Brain MRI were normal in 26% of patients but we found at least one acute abnormality on brain MRI in 29% and an Small Vessel Disease score (SVD score) of two or higher in 52%.In patients with neurological signs, these findings were 9, 53 and 70%, respectively. A PRES was found in 16% of asymptomatic patients and 31% had an ischemic stroke and/or a cerebral hematoma. Conclusions: PRES, recent hematoma, ischemic stroke and severe cerebral microangiopathy are common findings in MHT patients without neurological signs on admission. The impact of these findings on patient management, and their cerebrovascular and cognitive prognostic value, should be established. Brain MRI might need to become systematic in patients suffering from MHT episodes.

IS HEADACHE AT ADMISSION ASSOCIATED WITH HIGHER RATE OF RECENT BRAIN MRI INJURY DURING MALIGNANT HYPERTENSION CRISIS?

Objective: Reliable clinical signs associated with recent brain injuries in neurologically asymptomatic patients during malignant hypertension crisis are lacking. We aimed to compare the prevalence of brain MRI injuries between fully asymptomatic patients and those with isolated headache. Design and method: This single-center, cross-sectionnal observational study recruited patients with malignant Hypertension (MHT). MHT was defined by severe hypertension and severe hypertensive retinopathy OR subacute damage of three among the target organs: heart, kidney, brain, vessels (thrombotic microangiopathy). Patients under 18 years old, under chronic dialysis and not willing to participate were excluded. IBrain MRI was performed within 21 days following diagnosis and was reviewed by a stroke neurologist who recorded the following markers: acute ischemic stroke(DWI and FLAIR positive), acute intracerebral hemorrhage (T2* and FLAIR positive), acute brain edema with extensive posterior white matter hyperintensity suggesting a PRES, and small vessel disease including old lacunar infarct, white matter hyperintensities (WMH), presence of dilated perivascular spaces. Primary endpoint was the prevalence of recent brain injury in both group. Results: 92 patients were included. Among them, the average age was 47.8 years, 67 % were men, average admission systolic blood pressure and diastolic blood pressure were respectively 213 +/- 31 mmHg and 119 +/- 19 mmHg, 73 % had severe hypertensive retinopathy, median(IQR) creatininemia was 115 (92–180) mol/l and 11 % had systemic Hemolysis. Patients with no clinical symptoms or isolated headache presented respectively 39.5 % and 40 % of recent brain MRI abnormalities (cerebral Hematoma, ischemic stroke or PRES, p = 0.96). Patients with neurological signs on admission tended to have a higher frequency of recent brain injury than patients with isolated headaches (64,5%, p = 0,06), and a higher prevalence of chronic lacunar infarct (70,5% vs 44%, p = 0,04). We found no difference regarding cerebral microangiopathy in the 3 groups. Conclusions: Prevalence of recent brain injuries among patients with isolated headache and fully asymptomatic patients at admission of malignant hypertensive patients are similar and high. This raises the question of systematically performing brain MRI in patients with malignant hypertensive crisis.

Regional associations of white matter hyperintensities and early cortical amyloid pathology.

White matter hyperintensities (WMHs) have a heterogeneous aetiology, associated with both vascular risk factors and amyloidosis due to Alzheimer’s disease. While spatial distribution of both amyloid and WM lesions carry important information for the underlying pathogenic mechanisms, the regional relationship between these two pathologies and their joint contribution to early cognitive deterioration remains largely unexplored.We included 662 non-demented participants from three Amyloid Imaging to Prevent Alzheimer’s disease (AMYPAD)-affiliated cohorts: EPAD-LCS (N = 176), ALFA+ (N = 310), and EMIF-AD PreclinAD Twin60++ (N = 176). Using PET imaging, cortical amyloid burden was assessed regionally within early accumulating regions (medial orbitofrontal, precuneus, and cuneus) and globally, using the Centiloid method. Regional WMH volume was computed using Bayesian Model Selection. Global associations between WMH, amyloid, and cardiovascular risk scores (Framingham and CAIDE) were assessed using linear models. Partial least square (PLS) regression was used to identify regional associations. Models were adjusted for age, sex, and APOE-e4 status. Individual PLS scores were then related to cognitive performance in 4 domains (attention, memory, executive functioning, and language).While no significant global association was found, the PLS model yielded two components of interest. In the first PLS component, a fronto-parietal WMH pattern was associated with medial orbitofrontal–precuneal amyloid, vascular risk, and age. Component 2 showed a posterior WMH pattern associated with precuneus-cuneus amyloid, less related to age or vascular risk. Component 1 was associated with lower performance in all cognitive domains, while component 2 only with worse memory.In a large pre-dementia population, we observed two distinct patterns of regional associations between WMH and amyloid burden, and demonstrated their joint influence on cognitive processes. These two components could reflect the existence of vascular-dependent and -independent manifestations of WMH-amyloid regional association that might be related to distinct primary pathophysiology.

Determinants of arterial spin labeling parameters and its association with cerebral small vessel disease and diagnostic groups

AbstractBackgroundCerebral small vessel disease (SVD) may alter cerebral blood flow (CBF) leading to brain changes and hence cognitive impairment and dementia in elderly. CBF and spatial coefficient of variation (sCoV) can be measured quantitatively by Arterial Spin Labelling (ASL). CBF and sCoV have been related to age and systemic vascular risk factors. The relation of CBF and sCoV with location and severity of SVD and etiologic subtypes of cognitive impairment and dementia have not been explored in detail. We aim to investigate the association of demographic, vascular risk factors, location and severity of SVD with ASL parameters. We further investigate the association of ASL parameters with etiologic subtypes of cognitive impairment and dementia in a memory clinic population.MethodWe included 390 subjects (median: 73 11years, women = 52.3%) from an ongoing memory‐clinic based case‐control study. Patients were classified as no cognitive impairment, cognitive impairment no dementia (CIND), vascular CIND (VCIND) and dementia [Alzheimer’s disease (AD) and Vascular Dementia (VaD)]. Cerebral microbleeds (CMBs) and lacunes were categorized into strictly lobar, strictly deep and mixed‐location; ePVS into centrum semiovale and basal ganglia. Total and region‐specific white matter hyperintensities (WMH) volumes were automatically segmented using a validated pipeline. sCoV and CBF were analyzed with ExploreASL from 2D‐EPI pseudo‐continuous ASL images.ResultIncreasing age, male sex, hypertension, hyperlipidemia, history of heart disease and smoking were associated with CBF and sCoV. Increasing numbers of lacunes and CMBs were associated with reduced CBF and increased sCoV. Location‐specific analysis showed mixed‐location lacunes and CMBs were associated with hypoperfusion. Total WMH volume was associated with associated with increased sCoV. Region specific analysis with anterior and posterior WMH volumes showed similar results. No association was observed between ePVS and ASL parameters. Increased sCoV was associated with the diagnosis of VCIND, AD and VaD.ConclusionIncreased sCoV in ASL is associated with SVD, cognitive impairment and dementia, suggesting that SVD may induce brain changes via vascular insufficiency. Thus future research aimed to elucidate the pathophysiology of SVD and vascular insufficiency in elderly may help in developing prevention and treatment strategies.

Cerebral Microbleeds and White Matter Hyperintensities are Associated with Cognitive Decline in an Asian Memory Clinic Study.

Cerebral Small Vessel Disease (SVD); lacunes, Cerebral Microbleeds (CMBs), and White Matter Hyperintensities (WMH) have a vital role in cognitive impairment and dementia. SVD in lobar location is related to cerebral amyloid angiopathy, whereas SVD in a deep location with hypertensive arteriopathy. It remains unclear how different locations of SVD affect long-term cognitive decline. The present study aimed to analyse the association between different locations and severity of SVD with global and domain-specific cognitive decline over the follow-up interval of 3 years. We studied 428 participants who had performed MRI scans at baseline and at least 3 neuropsychological assessments. Locations of lacunes and CMBs were categorized into strictly lobar, strictly deep and mixed-location, WMH volume into anterior and posterior. The National Institute of Neurological Disorders and Stroke-Canadian Stroke Network Harmonization Neuropsychological Battery was used to assess cognitive function. To analyse the association between baseline location and severity of SVD with cognitive decline, linear regression models with generalized estimated equations were constructed to calculate the mean difference, 95% confidence interval and two-way interaction factor between time and SVD. Increased numbers of baseline CMBs were associated with a decline in global cognition as well as a decline in executive function and memory domains. Location-specific analysis showed similar results with strictly lobar CMBs. There was no association with strictly deep and mixed-location CMBs with cognitive decline. Baseline WMH volume was associated with a decline in global cognition, executive function and memory. Similar results were obtained with anterior and posterior WMH volumes. Lacunes and their locations were not associated with cognitive decline. Strictly lobar CMBs, as well as WMH volume in anterior and posterior regions, were associated with cognitive decline. Future research focuses are warranted to evaluate interventions that may prevent cognitive decline related to SVD.

Insights in the pathophysiology of haemorrhagic strokes in a sub-Sahara African country, an epidemiological and MRI study.

Intra-cerebral Haemorrhage (ICH) seems more prevalent in sub-Saharan Africa (SSA) than in High-Income Countries (HIC) with poorer clinical outcome. Higher impact of hypertension and/or amyloid angiopathy could account for this disproportion. Here, we sought to (i) retrospectively compare ICH clinical and imaging patterns in Belgium and Guinea and in a subsequent cohort (ii) prospectively compare brain MRI characteristics to seek evidence for a different proportion of amyloid angiopathy patterns. Ninety one consecutive patients admitted for spontaneous ICH at Brussels Erasme-ULB Hospital and at Conakry Ignace Deen-UGANC were retrospectively compared in terms of ICH volume estimated with the ABC/2 method, clinical characteristics and modified ranking (mRS) score at 30days. mRS was dichotomised as good outcomes (≤3) and poor outcomes (>3). A prospective cohort of 30 consecutive patients with ICH admitted at CHU Conakry Ignace Deen-UGANC was prospectively included to undergo brain MRI. Results of the Guinean MRI were compared to 30 patients randomly selected from Brussels' initial cohort. Paired Student's t-test and Mann-Whitney u-test were used for group comparisons. Age of ICH onset was higher in Belgium (68±17years vs. 56±14years, P<0.01) while ICH volume and 30-day mortality rate were higher in Guinea (20ml vs. 11ml, P<0.01 and mortality 33% vs. 10 %, P<0.01). ICH burden in survivors in Conakry and Brussels showed respectively good outcomes in 56.7% and 60.4% (P=0.09) and poor outcomes in 10.3% vs. 29.6% (P<0.001). MRI analysis of the prospective cohort failed to disclose significant differences regarding brain MRI characteristics. Intra-cerebral Haemorrhage affected patients 15years younger in Guinea with larger haematoma volumes and higher mortality than in Belgium. MRI findings did not show more prevalent amyloid angiopathy pathology suggesting that better primary prevention of hypertension could positively impact ICH epidemiology in Guinea.

Brain amyloid and vascular risk are related to distinct white matter hyperintensity patterns

White matter hyperintensities (WMHs) are associated with vascular risk and Alzheimer’s disease. In this study, we examined relations between WMH load and distribution, amyloid pathology and vascular risk in 339 controls and cases with either subjective (SCD) or mild cognitive impairment (MCI). Regional deep (DWMH) and periventricular (PWMH) WMH loads were determined using an automated algorithm. We stratified on Aβ1-42 pathology (Aβ+/−) and analyzed group differences, as well as associations with Framingham Risk Score for cardiovascular disease (FRS-CVD) and age. Occipital PWMH (p = 0.001) and occipital DWMH (p = 0.003) loads were increased in SCD-Aβ+ compared with Aβ− controls. In MCI-Aβ+ compared with Aβ− controls, there were differences in global WMH (p = 0.003), as well as occipital DWMH (p = 0.001) and temporal DWMH (p = 0.002) loads. FRS-CVD was associated with frontal PWMHs (p = 0.003) and frontal DWMHs (p = 0.005), after adjusting for age. There were associations between global and all regional WMH loads and age. In summary, posterior WMH loads were increased in SCD-Aβ+ and MCI-Aβ+ cases, whereas frontal WMHs were associated with vascular risk. The differences in WMH topography support the use of regional WMH load as an early-stage marker of etiology.

Clinical Relevance of Cerebral Small Vessel Diseases.

Clinical Relevance of Cerebral Small Vessel Diseases.

Associations between low circulatory low-density lipoprotein cholesterol level and brain health in non-stroke non-demented subjects

Low-density lipoprotein cholesterol (LDL-C) and hypertension have independent and synergistic effects on atherosclerotic cardiovascular disease. However, the role of circulatory LDL-C and its possible interactions with hypertension in brain health have been poorly investigated. The study aimed to investigate the relationship between the circulatory LDL-C level and (1) brain structures, grey-matter volume (GMV) and white matter hyperintensity (WMH) and (2) cognitive functions, and whether hypertension plays a role in these relationships. Subjects who were non-stroke and non-demented were prospectively recruited from the community-based I-Lan Longitudinal Aging Study. High-resolution 3T MRI was performed with GM and WMH segmentation. GMVs, total and regional including Alzheimer's disease-susceptible area, and WMH volumes were measured. Neurological tests including verbal memory, visuospatial, and verbal executive functions were assessed. Eight-hundred-and-two participants (59.2 ± 5.7 years; 44% men) were included. Multivariate linear regression analyses showed that low circulatory LDL-C levels (<98 mg/dL) were significantly associated with reduced GMVs in frontal (standardized β = −0.130; p = 0.003) and posterior cingulate (β = −0.113; p = 0.032) regions in hypertensive but not normotensive subjects. In addition, low circulatory LDL-C levels, combined with hypertension, had the lowest posterior cingulate GMV (β = −0.073; p = 0.021), highest periventricular WMH (β = 0.089; p = 0.011) and lowest verbal memory test scores (β = −0.088; p = 0.035) compared with neither low circulatory LDL-C level nor hypertension, and either hypertension or low circulatory LDL-C level. Age, sex, total intracranial volume, vascular risk factors, level of other circulatory lipids, and the taking of anti-hypertensive and lipid-lowering medications were adjusted. In conclusion, the role of circulatory LDL-C level and its interactive effect with hypertension on brain health are firstly demonstrated. A low circulatory LDL-C level was associated with reduced regional brain GMVs in hypertensive but not normotensive subjects. In addition, there seems a combined detrimental-effect of low circulatory LDL-C levels with hypertension on posterior cingulate GMV, WMH, and verbal memory.

Rubinstein-Taybi syndrome: New neuroradiological and neuropsychiatric insights from a multidisciplinary approach.

Rubinstein-Taybi syndrome is a rare, autosomal dominant, plurimalformative disorder that is clinically characterized by intellectual disability and a wide spectrum of congenital anomalies; facial dysmorphisms are typical, and broad thumbs and great toes are particularly distinctive. Its genetic basis is only partially known, with a detection rate of approximately 65-70%; specifically, microdeletions or mutations in the CREBBP or EP300 genes can be found. Much is known about its clinical features and health-care protocols, but some areas of clinical knowledge are currently unsolved. In particular, few efforts have been made until now to understand the variability in the neuropsychological and neurobehavioral profile and to deepen knowledge of the neuroradiological malformative pattern. Consequently, little is known about the possible genotype-phenotype correlations of these issues. Here, we report clinical and genetic data from a cohort of 23 RSTS Italian patients. The most common features in brain magnetic resonance imaging (MRI) were dysmorphic aspects of the corpus callosum (73.6%) with or without minor dysmorphisms of cerebellar vermis, periventricular posterior white matter hyperintensity, and other less common anomalies. The most interesting feature on the whole spine MRI scans was the tendency for a low-lying conus medullaris without terminal filum thickening. These data will help to improve neuropsychiatric and neuroradiological knowledge and highlight specific genotype-phenotype correlations.

Prediction of Cognitive Decline from White Matter Hyperintensity and Single-Photon Emission Computed Tomography in Alzheimer's Disease.

While several studies support an association of white matter hyperintensity (WMH) volume and regional cerebral blood flow (rCBF) with cognitive decline in Alzheimer's disease (AD), no reports have simultaneously considered the effects of both factors on cognitive decline. The purpose of the present study was to compare WMH volume and rCBF in relation to cognitive function by developing a new software program to fuse magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) data. We used MRI, SPECT, and neuropsychological data from 182 serial outpatients treated at the memory clinic of our hospital. Twenty-nine AD patients fulfilled the inclusion criteria (18 females, mean age: 73.1 ± 7.9 years, mean Mini-Mental State Examination: 23.1 ± 3.0). Analysis of variance revealed that posterior deep WMH (DWMH) volume was significantly larger than both anterior periventricular hyperintensity (PVH) and DWMH, and posterior PVH volumes. Multivariate regression analysis showed that increased volumes of the anterior PVH and the posterior DWMH and decreased rCBF of the parietal cortex negatively affected cognitive function. The other areas had no significant negative effects on cognitive function. Our findings show that the volume of the posterior WMH was significantly larger than that of other areas, and the increased posterior WMH volume and decreased rCBF of the parietal cortex negatively affected cognitive function. Therefore, the posterior WMH volume and the parietal rCBF are key parameters of cognitive decline in AD patients.

Total Magnetic Resonance Imaging Burden of Small Vessel Disease in Cerebral Amyloid Angiopathy: An Imaging-Pathologic Study of Concept Validation.

Cerebral amyloid angiopathy (CAA) is characteristically associated with magnetic resonance imaging (MRI) biomarkers of small vessel brain injury, including strictly lobar cerebral microbleeds, cortical superficial siderosis, centrum semiovale perivascular spaces, and white matter hyperintensities. Although these neuroimaging markers reflect distinct pathophysiologic aspects in CAA, no studies to date have combined these structural imaging features to gauge total brain small vessel disease burden in CAA. To investigate whether a composite score can be developed to capture the total brain MRI burden of small vessel disease in CAA and to explore whether this score contributes independent and complementary information about CAA severity, defined as intracerebral hemorrhage during life or bleeding-related neuropathologic changes. This retrospective, cross-sectional study examined a single-center neuropathologic CAA cohort of eligible patients from the Massachusetts General Hospital from January 1, 1997, through December 31, 2012. Data analysis was performed from January 2, 2015, to January 9, 2016. Patients with pathologic evidence of CAA (ie, any presence of CAA from routinely collected brain biopsy specimen, biopsy specimen at hematoma evacuation, or autopsy) and available brain MRI sequences of adequate quality, including T2-weighted, T2*-weighted gradient-recalled echo, and/or susceptibility-weighted imaging and fluid-attenuated inversion recovery sequences, were considered for the study. Brain MRIs were rated for lobar cerebral microbleeds, cortical superficial siderosis, centrum semiovale perivascular spaces, and white matter hyperintensities. All 4 MRI lesions were incorporated into a prespecified ordinal total small vessel disease score, ranging from 0 to 6 points. Associations with severity of CAA-associated vasculopathic changes (fibrinoid necrosis and concentric splitting of the wall), clinical presentation, number of intracerebral hemorrhages, and other imaging markers not included in the score were explored using logistic and ordinal regression. In total, 105 patients with pathologically defined CAA were included: 52 with autopsies, 22 with brain biopsy specimens, and 31 with pathologic samples from hematoma evacuations. The mean (range) age of the patients was 73 (71-74) years, and 55 (52.4%) were women. In multivariable ordinal regression analysis, severity of CAA-associated vasculopathic changes (odds ratio, 2.40; 95% CI, 1.06-5.45; P = .04) and CAA presentation with symptomatic intracerebral hemorrhage (odds ratio, 2.23; 95% CI, 1.07-4.64; P = .03) were independently associated with the total MRI small vessel disease score. The score was associated with small, acute, diffusion-weighted imaging lesions and posterior white matter hyperintensities in adjusted analyses. This study provides evidence of concept validity of a total MRI small vessel disease score in CAA. After further validation, this approach can be potentially used in prospective clinical studies.

White matter deterioration in 15 months: latent growth curve models in healthy adults

The goal of the study was to examine the differences in trajectories of change in the volume of white matter hyperintensities (WMH) in healthy adults within a relatively short period. We measured volumes of periventricular and deep WMH in frontal, temporal, parietal, and occipital lobes of healthy volunteers (age 49-83) on 3 occasions, approximately 15 months apart. At baseline, 40 participants underwent magnetic resonance imaging (MRI), 37 returned for the first and 30 for the second follow-up. Latent growth curve models estimated the variance and mean change in WMH volume and examined their associations with age, sex, education, and hypertension. In both regions and for both WMH types, the positive association between volume and age was stronger among the middle-aged adults and became weaker in older ages, as a logarithmic function of age. Individual variations were present in initial WMH volume but not in WMH volume progression. Frontal deep WMH volume was greater in hypertensive participants, whereas lower education was associated with greater posterior deep WMH volume. Thus, white matter of healthy middle-aged and older adults undergoes significant regional deterioration in a relatively short period, and is negatively affected by vascular risk and lower educational level.

Differential Patterns of Cognitive Decline in Anterior and Posterior White Matter Hyperintensity Progression

White matter hyperintensities (WMHs) found on brain MRI in elderly individuals are largely thought to be due to microvascular disease, and its progression has been associated with cognitive decline. The present study sought to determine patterns of cognitive decline associated with anterior and posterior WMH progression. Subjects included 110 normal controls, aged >or=60 years, who were participants in the Duke Neurocognitive Outcomes of Depression in the Elderly study. All subjects had comprehensive cognitive evaluations and MRI scans at baseline and after 2 years. Cognitive composites were created in 5 domains: complex processing speed, working memory, general memory, visual-constructional skills, and language. Change in cognition was calculated using standard regression-based models accounting for variables known to impact serial testing. A semiautomated segmentation method was used to measure WMH extent in anterior and posterior brain regions. Hierarchical multiple linear regression models were used to evaluate which of the 5 measured cognitive domains was most strongly associated with regional (anterior and posterior) and total WMH progression after adjusting for demographics (age, sex, and education). Decline in complex processing speed was independently associated with both anterior (r(2)=0.06, P=0.02) and total WMH progression (r(2)=0.05, P=0.04). In contrast, decline in visual-constructional skills was uniquely associated with posterior progression (r(2)=0.05, P<0.05). Distinct cognitive profiles are associated with anterior and posterior WMH progression among normal elders. These differing profiles need to be considered when evaluating the cognitive correlates of WMHs.