Discussion: Strictly lobar MBs strongly predict CAA in non-ICH individuals when found in a hospital context. However, their diagnostic accuracy in the general population appears limited. (C) 2015... Show moreDiscussion: Strictly lobar MBs strongly predict CAA in non-ICH individuals when found in a hospital context. However, their diagnostic accuracy in the general population appears limited. (C) 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved. Show less
Conclusions-Detecting even a single DWI lesion suggests an annual incidence of hundreds of new CMI. The cumulative effects of these lesions may directly contribute to small-vessel-related vascular... Show moreConclusions-Detecting even a single DWI lesion suggests an annual incidence of hundreds of new CMI. The cumulative effects of these lesions may directly contribute to small-vessel-related vascular cognitive impairment. Show less
Objective We hypothesized that vascular amyloid contributes to chronic brain ischemia, therefore amyloid burden measured by Pittsburgh compound B retention on positron emission tomography (PiB PET)... Show moreObjective We hypothesized that vascular amyloid contributes to chronic brain ischemia, therefore amyloid burden measured by Pittsburgh compound B retention on positron emission tomography (PiB PET) would correlate with the extent of magnetic resonance imaging (MRI) white matter hyperintensities (WMH; or leukoaraiosis) in patients with high vascular amyloid deposition (cerebral amyloid angiopathy [CAA]) but not in patients with high parenchymal amyloid deposition (Alzheimer disease [AD]; mild cognitive impairment [MCI]) or in healthy elderly (HE) subjects. Methods Forty-two nondemented CAA patients, 50 HE subjects, and 43 AD/MCI patients had brain MRI and PiB PET. Multivariate linear regression was used to assess the independent association between PiB retention and white matter disease volume, controlling for age, gender, apolipoprotein E genotype, and vascular risk factors within each group. Results CAA patients were younger than HE and AD subjects (68 +/- 10 vs 73.3 +/- 7 and 74 +/- 7.4, p < 0.01) but had higher amounts of WMH (median = 21 vs 3.2 and 10.8 ml, respectively, p < 0.05 for both comparisons). Global PiB retention and WMH showed strong correlation (rho = 0.52, p < 0.001) in the CAA group but not in HE or AD. These associations did not change in the multivariate models. Lobar microbleed count, another marker of CAA severity, also remained as an independent predictor of WMH volume. Interpretation Our results indicate that amyloid burden in CAA subjects (with primarily vascular amyloid) but not AD subjects (with primarily parenchymal amyloid) independently correlates with WMH volume. These findings support the idea that vascular amyloid burden directly contributes to chronic cerebral ischemia and highlights the possible utility of amyloid imaging as a marker of CAA severity. Ann Neurol 2013;73:529-536 Show less
