A multiparametric MRI study of structural brain damage in dementia with lewy bodies: A comparison with Alzheimer's disease.

Differential diagnosis between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) is crucial for an adequate patients' management but might be challenging. We investigated with advanced MRI techniques gray (GM) and white matter (WM) damage in DLB patients compared to those with AD. 24 DLB patients, 26 age- and disease severity-matched AD patients, and 20 age and sex-matched controls performed clinical and neuropsychological assessment, and brain structural and diffusion-tensor MRI. We measured GM atrophy using voxel-based morphometry, WM hyperintensities (WMH) using a local thresholding segmentation technique, and normal-appearing WM (NAWM) damage using tract-based spatial statistic. DLB and AD patients exhibited mild-to-moderate-stage dementia. Compared to controls, GM damage was diffuse in AD, while limited to bilateral thalamus and temporal regions in DLB. Compared to DLB, AD patients exhibited GM atrophy in bilateral fronto-temporal and occipital regions. DLB and AD patients showed higher WMH load than controls, with no differences among each other. WMH in DLB were diffuse with relative prevalence in posterior parietal-occipital regions. Compared to controls, both DLB and AD patients showed reduced microstructural integrity of the main supratentorial and infratentorial NAWM tracts. AD patients exhibited greater posterior NAWM damage than DLB. DLB showed prominent WM degeneration compared to the limited GM atrophy, while in AD both tissue compartments were severely involved. In DLB, NAWM microstructural degeneration was independent of WMH, thus revealing two possible underlying processes. Different pathophysiological mechanisms are likely to drive GM and WM damage distribution in DLB and AD.

Caso F ，Agosta F ，Scamarcia PG ，Basaia S ，Canu E ，Magnani G ，Volontè MA ，Filippi M ... -  《-》

Gray matter atrophy in dementia with Lewy bodies with and without concomitant Alzheimer's disease pathology.

We aimed to study if patients with dementia with Lewy bodies (DLB) who have concomitant Alzheimer's disease (AD) pathology (detected antemortem by cerebrospinal fluid [CSF] biomarkers) have additional loss of gray matter volume. Ninety-eight DLB patients were divided into a "pure DLB" (DLB/AD-, n = 62) and a "mixed DLB" group (DLB/AD+, n = 36) and matched for age and symptom duration to 84 AD patients and 75 controls. We compared visual atrophy ratings, and in a subset, we analyzed cortical thickness and subcortical gray matter volumes. DLB/AD+ patients had more pronounced medial temporal lobe atrophy (MTA) compared to DLB/AD- (mean [total] MTA score 2.5 vs. 1.3, p = 0.02). Global and parietal atrophy scores were comparable between the 3 dementia groups and differed from controls. MTA score was associated with CSF Aβ-42, while posterior cortical and global atrophy scores were associated with CSF tau. Cortical thinning was found in DLB/AD-, DLB/AD+, and AD compared to controls. Concomitant AD pathology seems to cause additional (hippocampal) atrophy in DLB, and this may contribute to a more devastating disease course in DLB/AD+ patients.

van der Zande JJ ，Steenwijk MD ，Ten Kate M ，Wattjes MP ，Scheltens P ，Lemstra AW ... -  《-》

White matter hyperintensities on MRI in dementia with Lewy bodies, Parkinson's disease with dementia, and Alzheimer's disease.

In dementia with Lewy bodies (DLB) and Parkinson's disease with dementia (PDD), it is still debated whether white matter hyperintensities (WMH) on MRI reflect atherosclerotic cerebrovascular changes or Alzheimer's disease (AD)-related pathology such as cerebral amyloid angiopathy. To examine AD-related pathology in DLB and PDD, we compared the severity of WMH and medial temporal lobe atrophy among patients with DLB, PDD, non-demented PD (PDND), and AD. We retrospectively studied sex- and age-matched outpatients with AD, DLB, PDD, and PDND, as well as subjects without central nervous system disorders as normal controls (n=50 each). All subjects underwent 1.5-T MRI examinations, and WMH detected by T2-weighted images or fluid-attenuated inversion recovery images were semiquantified according to the Fazekas method. Medial temporal lobe atrophy (MTA) was visually assessed by the MTA score. WMH were more prominent in AD, DLB, and PDD patients than in PDND patients and normal controls (NCs). DLB as well as AD showed more severe WMH than PDD. Visual assessment of medial temporal lobe atrophy showed that AD patients had the most severe atrophy, followed by DLB, PDD, and PDND patients, and NC subjects in that order. MTA scores showed significant correlations with WMH severity. Our results indicated that DLB was more similar to AD than to PDD in terms of MRI findings, suggesting that WMH in DLB may reflect mainly AD-related pathology rather than atherosclerotic cerebrovascular changes.

Joki H ，Higashiyama Y ，Nakae Y ，Kugimoto C ，Doi H ，Kimura K ，Kishida H ，Ueda N ，Nakano T ，Takahashi T ，Koyano S ，Takeuchi H ，Tanaka F ... -  《-》

Following the Spreading of Brain Structural Changes in Alzheimer's Disease: A Longitudinal, Multimodal MRI Study.

Weiler M ，Agosta F ，Canu E ，Copetti M ，Magnani G ，Marcone A ，Pagani E ，Balthazar ML ，Comi G ，Falini A ，Filippi M ... -  《-》

An investigation of cerebrovascular lesions in dementia with Lewy bodies compared to Alzheimer's disease.

Cerebrovascular lesions on MRI are common in Alzheimer's disease (AD) dementia, but less is known about their frequency and impact on dementia with Lewy bodies (DLB). White-matter hyperintensities (WMHs) and infarcts on MRI were assessed in consecutive DLB (n = 81) and AD dementia (n = 240) patients and compared to age-matched and sex-matched cognitively normal subjects (CN) from a population-based cohort. DLB had higher WMH volume compared to CN, and WMH volume was higher in the occipital and posterior periventricular regions in DLB compared to AD. Higher WMH volume was associated with history of cardiovascular disease and diabetes but not with clinical disease severity in DLB. Frequency of infarcts in DLB was not different from CN and AD dementia. In DLB, WMH volume is higher than AD and CN and appears to be primarily associated with history of vascular disease.

Sarro L ，Tosakulwong N ，Schwarz CG ，Graff-Radford J ，Przybelski SA ，Lesnick TG ，Zuk SM ，Reid RI ，Raman MR ，Boeve BF ，Ferman TJ ，Knopman DS ，Comi G ，Filippi M ，Murray ME ，Parisi JE ，Dickson DW ，Petersen RC ，Jack CR Jr ，Kantarci K ... -  《-》