Small vessel cerebrovascular disease, visualized as white matter hyperintensities on T2-weighted MRI, contributes to the clinical presentation of Alzheimer’s disease. However, the extent to which cerebrovascular disease represents an independent pathognomonic feature of Alzheimer's disease or directly promotes Alzheimer’s pathology is unclear. The purpose of this study was to examine the association between white matter hyperintensities and plasma levels of tau and to determine if white matter hyperintensities and tau levels interact to predict Alzheimer’s disease diagnosis. To confirm that cerebrovascular disease promotes tau pathology, we examined tau fluid biomarker concentrations and pathology in a mouse model of ischemic injury. Three hundred ninety-one participants from the Alzheimer’s Disease Neuroimaging Initiative (ADNI; 74.5 ± 7.1 years of age) were included in this cross-sectional analysis. Participants had measurements of plasma total-tau, CSF beta amyloid, and white matter hyperintensities, and were diagnosed clinically as Alzheimer’s disease (n = 97), mild cognitive impairment (n = 186), or cognitively normal control (n = 108). We tested the relationship between plasma tau concentration and white matter hyperintensity volume across diagnostic groups. We also examined the extent to which white matter hyperintensity volume, plasma tau, amyloid positivity status, and the interaction between white matter hyperintensities and plasma tau correctly classifies diagnostic category. Increased white matter hyperintensity volume was associated with higher plasma tau concentration, particularly among those diagnosed clinically with Alzheimer’s disease. Presence of brain amyloid and the interaction between plasma tau and white matter hyperintensity volume distinguished Alzheimer’s disease and mild cognitive impairment participants from controls with 77.6% and 63.3% accuracy, respectively. In 63 ADNI participants who came to autopsy (82.33 ± 7.18 age at death) we found that higher degrees of arteriosclerosis were associated with higher Braak staging, indicating a positive relationship between cerebrovascular disease and neurofibrillary pathology. In a transient middle cerebral artery occlusion (tMCAo) mouse model, aged mice that received tMCAo, but not sham surgery, had increased plasma and CSF tau concentrations, induced myelin loss, and hyperphosphorylated tau pathology in the ipsilateral hippocampus and cerebral hemisphere. These findings demonstrate a relationship between cerebrovascular disease, operationalized as white matter hyperintensities, and tau levels, indexed in the plasma, suggesting that hypoperfusive injury promotes tau pathology. This potential causal association is supported by the demonstration that transient cerebral artery occlusion induces white matter damage, increases biofluidic markers of tau, and promotes cerebral tau hyperphosphorylation in older adult mice.

Introduction: We examined whether educational attainment differentially contributes to cognitive reserve (CR) across race/ethnicity. Methods: A total of 1553 non-Hispanic Whites (Whites), non-Hispanic Blacks (Blacks), and Hispanics in the Washington Heights-Inwood Columbia Aging Project (WHICAP) completed structural magnetic resonance imaging. Mixture growth curve modeling was used to examine whether the effect of brain integrity indicators (hippocampal 70

Objective: Adults with Down syndrome (DS) develop Alzheimer disease (AD) pathology by their 5th decade. Compared with the general population, traditional vascular risks in adults with DS are rare, allowing examination of cerebrovascular disease in this population and insight into its role in AD without the confound of vascular risk factors. We examined in vivo magnetic resonance imaging (MRI)-based biomarkers of cerebrovascular pathology in adults with DS, and determined their cross-sectional relationship with age, beta-amyloid pathology, and mild cognitive impairment or clinical AD diagnostic status. Methods: Participants from the Biomarkers of Alzheimer's Disease in Down Syndrome study (n = 138, 50 ± 7 years, 39% women) with MRI data and a subset (n = 90) with amyloid positron emission tomography (PET) were included. We derived MRI-based biomarkers of cerebrovascular pathology, including white matter hyperintensities (WMH), infarcts, cerebral microbleeds, and enlarged perivascular spaces (PVS), as well as PET-based biomarkers of amyloid burden. Participants were characterized as cognitively stable (CS), mild cognitive impairment-DS (MCI-DS), possible AD dementia, or definite AD dementia based on in-depth assessments of cognition, function, and health status. Results: There were detectable WMH, enlarged PVS, infarcts, and microbleeds as early as the 5th decade of life. There was a monotonic increase in WMH volume, enlarged PVS, and presence of infarcts across diagnostic groups (CS < MCI-DS < possible AD dementia < definite AD dementia). Higher amyloid burden was associated with a higher likelihood of an infarct. Interpretation: The findings highlight the prevalence of cerebrovascular disease in adults with DS and add to a growing body of evidence that implicates cerebrovascular disease as a core feature of AD and not simply a comorbidity.

HighlightsWhite matter hyperintensity volume in association and projection tracts was related to memory in older adults.The relationship of WMH volumes in association and projection tracts with cognition was specific to memory, and not to a global cognition measure that excluded memory.Within projection tracts, WMH volumes affecting the anterior thalamic and the corticospinal tracts were most reliably associated with poorer memory.Within association tracts, WMH volume affecting the inferior fronto-occipital fasciculus, the superior longitudinal fasciculus, and the uncinate fasciculus were most reliably associated with poorer memory.

ObjectiveTo test the hypotheses that hypertension and nocturnal blood pressure are related to white matter hyperintensity (WMH) volume, an MRI marker of small vessel cerebrovascular disease, and that WMH burden statistically mediates the association of hypertension and dipping status with memory functioning, we examined the relationship of hypertension and dipping status on WMH volume and neuropsychological test scores in middle-aged and older adults.MethodsParticipants from the community-based Maracaibo Aging Study received ambulatory 24-hour blood pressure monitoring, structural MRI, and neuropsychological assessment. Four hundred thirty-five participants (mean ± SD age 59 ± 13 years, 71% women) with available ambulatory blood pressure, MRI, and neuropsychological data were included in the analyses. Ambulatory blood pressure was used to define hypertension and dipping status (i.e., dipper, nondipper, and reverse dipper based on night/day blood pressure ratio <0.9, 0.9–1, and >1, respectively). Outcome measures included regional WMH and memory functioning derived from a neuropsychological test battery.ResultsThe majority of the participants (59%) were hypertensive. Ten percent were reverse dippers, and 40% were nondippers. Reverse dipping in the presence of hypertension was associated with particularly elevated periventricular WMH volume (F2,423 = 3.78, p = 0.024) and with lowered memory scores (F2,423 = 3.911, p = 0.021). Periventricular WMH volume mediated the effect of dipping status and hypertension on memory (β = −4.1, 95% confidence interval −8.7 to −0.2, p < 0.05).ConclusionReverse dipping in the presence of hypertension is associated with small vessel cerebrovascular disease, which, in turn, mediates memory functioning. These results point toward reverse dipping as a marker of poor nocturnal blood pressure control, particularly among hypertensive individuals, with potentially pernicious effects on cerebrovascular health and associated cognitive function.

Introduction Positron emission tomography (PET) imaging for neurofibrillary tau allows investigation of the in vivo spatiotemporal progression of Alzheimer's disease (AD) pathology. We evaluated the suitability of 18F‐MK‐6240 in a clinical sample and determined the relationships among 18F‐MK‐6240 binding, age, cognition, and cerebrospinal fluid (CSF)‐based AD biomarkers. Methods Participants (n = 101, 72 ± 9 years, 52% women) underwent amyloid PET, tau PET, structural T1‐weighted magnetic resonance imaging, and neuropsychological evaluation. Twenty‐one participants had lumbar puncture for CSF measurement of amyloid beta (Aβ)42, tau, and phosphorylated tau (p‐tau). Results 18F‐MK‐6240 recapitulated Braak staging and correlated with CSF tau and p‐tau, normalized to Aβ42. 18F‐MK‐6240 negatively correlated with age across Braak regions in amyloid‐positive participants, consistent with greater tau pathology in earlier onset AD. Domain‐specific, regional patterns of 18F‐MK‐6240 binding were associated with reduced memory, executive, and language performance, but only in amyloid‐positive participants. Discussion 18F‐MK‐6240 can approximate Braak staging across the AD continuum and provide region‐dependent insights into biomarker‐based AD models.

BACKGROUND AND PURPOSE: White matter hyperintensities on T2-weighted MR imaging are typical in older adults and have been linked to several poor health outcomes, including cognitive impairment and Alzheimer disease. The presence and severity of white matter hyperintensities have traditionally been attributed to occlusive arteriopathy, but recent evidence also implicates deep medullary venule collagenosis and associated vasogenic edema. Historically, postmortem analyses have been the sole way to analyze cerebral veins, but SWI can be now used to examine cortical veins in vivo. The aim of the current study was to determine whether there is an association between the diameters of the large draining cerebral veins/sinuses and white matter hyperintensity volume.MATERIALS AND METHODS: T2-weighted FLAIR and SWI were performed in 682 older adults without dementia (mean age, 73.9 6 5.9 years; 59.1% women). Total and regional white matter hyperintensity volume was derived. We measured the diameters of 5 regions of the cerebral venous draining system: internal cerebral veins, basal veins of Rosenthal, superior sagittal sinus, vein of Galen, and straight sinus terminus. RESULTS:Increased diameter of the internal cerebral veins was associated with greater total white matter hyperintensity volume (b = 0.09, P = .02) and regionally in the parietal (b = 0.10, P = .006), frontal (b = 0.09, P = .02), and temporal (b = 0.09, P = .02) lobes. Increased diameter of the basal veins of Rosenthal was associated with greater total (b = 0.10, P = .01), frontal (b = 0.11, P = .003), and temporal (b = 0.09, P = .02) white matter hyperintensity volume. CONCLUSIONS:Our results suggest that the caliber of the internal cerebral veins and of the basal veins of Rosenthal relates to regional white matter disease. ABBREVIATIONS: AD¼ Alzheimer disease; WHICAP ¼ Washington Heights-Inwood Columbia Aging Project; WMH ¼ white matter hyperintensity; ICC ¼ intraclass correlation coefficient C hronic ischemia of the white matter of the brain can result in Indicates open access to non-subscribers at www.ajnr.org http://dx.

Objective: To build a model to predict cognitive status reflecting structural, functional, and white matter integrity changes in early multiple sclerosis (MS). Methods: Based on Symbol Digit Modalities Test (SDMT) performance, 183 early MS patients were assigned “lower” or “higher” performance groups. Three-dimensional (3D)-T2, T1, diffusion weighted, and resting-state magnetic resonance imaging (MRI) data were acquired in 3T. Using Random Forest, five models were trained to classify patients into two groups based on 1—demographic/clinical, 2—lesion volume/location, 3—local/global tissue volume, 4—local/global diffusion tensor imaging, and 5—whole-brain resting-state-functional-connectivity measures. In a final model, all important features from previous models were concatenated. Area under the receiver operating characteristic curve (AUC) values were calculated to evaluate classifier performance. Results: The highest AUC value (0.90) was achieved by concatenating all important features from neuroimaging models. The top 10 contributing variables included volumes of bilateral nucleus accumbens and right thalamus, mean diffusivity of left cingulum-angular bundle, and functional connectivity among hubs of seven large-scale networks. Conclusion: These results provide an indication of a non-random brain pattern mostly compromising areas involved in attentional processes specific to patients who perform worse in SDMT. High accuracy of the final model supports this pattern as a potential neuroimaging biomarker of subtle cognitive changes in early MS.