Focal atrophy on MRI and neuropathologic classification of dementia with Lewy bodies

Abstract

Objective: To determine the association between the focal atrophy measures on antemortem MRI and postmortem neuropathologic classification of dementia with Lewy bodies (DLB) using the Third Report of the DLB Consortium criteria. Methods:We retrospectively identified 56 subjects who underwent antemortem MRI and had Lewy body (LB) pathology at autopsy. Subjects were pathologically classified as high (n ϭ 25), intermediate (n ϭ 22), and low likelihood DLB (n ϭ 9) according to the Third Report of the DLB Consortium criteria. We included 2 additional pathologic comparison groups without LBs: one with low likelihood Alzheimer disease (AD) (control; n ϭ 27) and one with high likelihood AD (n ϭ 33). The associations between MRI-based volumetric measurements and the pathologic classification of DLB were tested with analysis of covariance by adjusting for age, sex, and MRI-to-death interval. Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia after Alzheimer disease (AD); however, many patients with DLB also have AD pathology. [1][2][3][4][5] Imaging markers that predict the contribution of AD to the dementia syndrome in DLB would have an important role in treatment decisions and assessing responsiveness to treatments targeting disease-specific pathologies. Results:According to the Third Report of the DLB Consortium criteria, 6 the pathologic diagnosis of DLB is made by considering both AD and Lewy body (LB) pathologies. For example, patients with limbic LBs are diagnosed as high likelihood DLB if they have low likelihood AD, but diagnosed as low likelihood DLB if they have high likelihood AD. Therefore, in vivo identification of AD and LB pathology is critical for the differential diagnosis of DLB.