Selective reduction of diffusion anisotropy in white matter of Alzheimer disease brains measured by 3.0 Tesla magnetic resonance imaging

Takahashi, Satoshi; Yonezawa, Hisashi; Takahashi, Jun; Kudo, Momonari; Inoue, Takashi; Tohgi, Hideo

doi:10.1016/s0304-3940(02)00914-x

Cited by 208 publications

(167 citation statements)

References 25 publications

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“…Studies utilizing [ 18 F] fluorodeoxyglucose (FDG) positron emission tomography (PET) have shown that patients with AD have significantly reduced temporoparietal metabolism compared to healthy controls [1,15]. Also, studies using diffusion tensor imaging (DTI) have found a significant reduction in the structural integrity of the white matter tracts in the splenium of AD patients [30,33]. Our posterior callosal findings complement the results from those studies.…”

Section: Discussionsupporting

confidence: 77%

Regionally specific atrophy of the corpus callosum in AD, MCI and cognitive complaints

Wang

Saykin

Flashman

et al. 2006

Neurobiology of Aging

102

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The goal of the present study was to determine if there are global or regionally specific decreases in callosal area in early Alzheimer's disease (AD) and mild cognitive impairment (MCI). In addition, this study examined the corpus callosum of healthy older adults who have subjective cognitive complaints (CC) but perform within normal limits on neuropsychological tests. We used a semi-automated procedure to examine the total and regional areas of the corpus callosum in 22 patients with early AD, 28 patients with amnestic MCI, 28 healthy older adults with cognitive complaints, and 50 demographically matched healthy controls (HC). The AD, MCI, and CC groups all showed a significant reduction of the posterior region (isthmus and splenium) relative to healthy controls. The AD group also had a significantly smaller overall callosum than the controls. The demonstration of callosal atrophy in older adults with cognitive complaints suggests that callosal changes occur very early in the dementing process, and that these earliest changes may be too subtle for detection by neuropsychological assessments, including memory tests.

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Section: Discussionsupporting

confidence: 77%

Regionally specific atrophy of the corpus callosum in AD, MCI and cognitive complaints

Wang

Saykin

Flashman

et al. 2006

Neurobiology of Aging

102

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“…39,40 FA is an imaging marker commonly used to study microstructural white matter abnormalities in various pathologic states. 3,[8][9][10][11][12][13][14][15][16][17] Results of decreased FA in the present study suggest microstructural degradation of cerebral white matter in AD and MCI. The observed differences in FA follow a clear regional gradient, with the greatest changes seen in the temporal lobe, followed by the parietal lobe, then the frontal lobe, and no changes compared with controls in the occipital lobe.…”

Section: Discussionmentioning

confidence: 89%

“…Collectively, these studies suggest that the distribution of white matter abnormalities in AD and MCI is inhomogeneous, showing concentrations in regions connected with association cortices (posterior cingulum fibers, corpus callosum, and temporal, frontal, and parietal lobe white matter) and largely sparing regions serving motor (internal capsule) or visual (optic radiation) functions. 3,[11][12][13][14][15][16][17] Because FA is a relatively simple descriptor of water diffusivity, it provides limited information useful for determining specific brain pathologies underlying changes in water diffusion. We, therefore, further studied changes in directional diffusivities (DA and DR) in the NAWM of AD and MCI subjects.…”

Section: Discussionmentioning

confidence: 99%

“…10 A few investigations using DTI have reported anisotropic diffusion changes in different white matter regions in AD and MCI as measured by fractional anisotropy (FA) and mean diffusivity (MD). 3,[11][12][13][14][15][16][17] Unfortunately, FA and MD permit only a simplified description of water diffusion, and neither is particularly well suited for elucidating the pathologies underlying observed changes in water diffusion. 18 Results from recent human studies and from experimental studies in animal models now permit a more analytic approach to interpreting white matter pathologies from DTI data.…”

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confidence: 99%

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Diffusion Tensor Imaging of Normal-Appearing White Matter in Mild Cognitive Impairment and Early Alzheimer Disease: Preliminary Evidence of Axonal Degeneration in the Temporal Lobe

Huang

Friedland²,

Auchus³

2007

American Journal of Neuroradiology

204

138

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“…In fact, the main result mentioned above, that is atrophy mainly in the callosal anterior and posterior subregions, comes from studies of AD groups that included patients in different illness stages, ranging from mild to severe dementia [7,8,[10][11][12][14][15][16][17][18][19][23][24][25][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] and sometimes selected using different diagnostic criteria [10,14].…”

Section: Introductionmentioning

confidence: 99%

In Vivo Structural Neuroanatomy of Corpus Callosum in Alzheimer's Disease and Mild Cognitive Impairment Using Different MRI Techniques: A Review

Paola

Spalletta

Caltagirone

2010

JAD

128

103

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Abstract. The corpus callosum (CC), which connects the two cerebral hemispheres, is the largest white matter fiber bundle in the human brain. This structure presents a peculiar myelination pattern: it has small diameter fibers, located in the genu, which myelinate much later in normal development, and large diameter fibers of the splenium, which myelinate early in development. Although the pathology of AD mainly involves the cerebral gray matter structure, there is evidence that white matter may also be involved. To illustrate callosal white matter changes in AD pathology, in this review we summarize in vivo imaging studies in humans, focusing on region of interest, voxel-based morphometry, diffusion-weighted imaging, and diffusion tensor imaging techniques. Our aims were to identify where in the CC, when in the different stages of AD, and how callosal changes can be detected with different MRI techniques. Results showed that changes in the anterior (genu and anterior body) as well as in the posterior (isthmus and splenum) portions of the CC might already be present in the early stages of AD. These findings support the hypothesis that two mechanisms, Wallerian degeneration and myelin breakdown, might be responsible for the region-specific changes detected in AD patients. Wallerian degeneration affects the posterior CC subregion, which receives axons directly from those brain areas (temporo-parietal lobe regions) primarily affected by the AD pathology. Instead, the myelin breakdown process affects the later-myelinating CC subregion and explains the earlier involvement of the genu in CC atrophy.

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Selective reduction of diffusion anisotropy in white matter of Alzheimer disease brains measured by 3.0 Tesla magnetic resonance imaging

Cited by 208 publications

References 25 publications

Regionally specific atrophy of the corpus callosum in AD, MCI and cognitive complaints

Regionally specific atrophy of the corpus callosum in AD, MCI and cognitive complaints

Diffusion Tensor Imaging of Normal-Appearing White Matter in Mild Cognitive Impairment and Early Alzheimer Disease: Preliminary Evidence of Axonal Degeneration in the Temporal Lobe

In Vivo Structural Neuroanatomy of Corpus Callosum in Alzheimer's Disease and Mild Cognitive Impairment Using Different MRI Techniques: A Review

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