White matter imaging changes in subjective and mild cognitive impairment

Selnes, Per; Fjell, Anders M.; Gjerstad, Leif; Bjørnerud, Atle; Wallin, Anders; Due‐Tønnessen, Paulina; Grambaitė, Ramunė; Stenset, Vidar; Fladby, Tormod

doi:10.1016/j.jalz.2011.07.001

Cited by 87 publications

(104 citation statements)

References 47 publications

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“…Interestingly, these microstructural changes were evident in the absence of obvious GM macrostructural changes. Our DTI findings in SMI are in line with previous studies that showed DTI changes as a sensitive marker of neurodegeneration in the early stage of AD prior to GM macrostructural changes [4,16,17]. We additionally highlighted variable degrees of WM microstructural changes in SMI subjects stratified to risk profiles, which could provide a better clinical relevance.…”

Section: Discussionsupporting

confidence: 90%

“…This can be explained by different characteristics of the two DTI parameters; decreased FA represents disrupted directionality of fibers, whereas increased MD represents increased water diffusivity [4]. Intriguingly, MD values correlate more with AD-associated GM changes than FA values, which was compatible with a previous report demonstrating MD as a better discriminating factor of early neurodegenerative changes in GM [4]. …”

Section: Discussionsupporting

confidence: 83%

“…Several studies suggested that individuals with SMI may be at an increased risk of developing Alzheimer disease (AD) [1] or other future cognitive decline [2,3,4,5]. There still remain, however, some controversies about its natural history because SMI is a heterogeneous condition ranging from normal aging to AD spectrum disorder [3,4]. Therefore, it is important to provide neuroimaging clues of neurodegenerative changes in SMI which herald the progression to AD spectrum disorders.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

White Matter Changes May Precede Gray Matter Loss in Elderly with Subjective Memory Impairment

Hong

Kim

Jang

et al. 2016

Dement Geriatr Cogn Disord

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Background/Aims: A limited number of studies addressed MRI-based neurodegenerative changes in subjective memory impairment (SMI). We investigated changes in white matter (WM) microstructures as well as gray matter (GM) macrostructures in subjects with SMI of high and low risk for progression. Methods: A modeling scale (score range, 0-6) developed for prediction of SMI progression was used to divide SMI subjects (n = 46) into two groups: a high risk of progression (score ≥3; n = 19) and a low risk of progression (score ≤2; n = 27). Cross-sectional comparisons were performed using a region-of-interest-based diffusion tensor imaging (DTI) analysis, cortical thickness analysis, and hippocampal volumetry. Results: The high-risk group had more microstructural disruption shown by lower fractional anisotropy in the hippocampus, parahippocampal gyrus, supramarginal gyrus, and parts of frontotemporal lobes. On the other hand, GM macrostructural changes did not differ between the groups and were not associated with modeling scale scores. Conclusion: SMI subjects with a high risk of progression had more WM microstructural disruption than those with a low risk, and the changes were not explained by GM atrophy. Our findings suggest that the degree of microstructural alterations in SMI may be distinctive according to the risk factors and may precede GM atrophy.

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Section: Discussionsupporting

confidence: 90%

Section: Discussionsupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

White Matter Changes May Precede Gray Matter Loss in Elderly with Subjective Memory Impairment

Hong

Kim

Jang

et al. 2016

Dement Geriatr Cogn Disord

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“…human and animal models (Desai et al, 2009;Selnes et al, 2012). Perhaps most important, is the fact that at least some of the WM damage is related to the vascular changes, which are often represented as WM hyperintensities (Zhuang et al, 2010).…”

Section: Functional Organization and White Matter Integrity In MCImentioning

confidence: 99%

White Matter Damage Disorganizes Brain Functional Networks in Amnestic Mild Cognitive Impairment

et al. 2014

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Although progressive functional brain network disruption has been one of the hallmarks of Alzheimer's Disease, little is known about the origin of this functional impairment that underlies cognitive symptoms. We investigated how the loss of white matter (WM) integrity disrupts the organization of the functional networks at different frequency bands. The analyses were performed in a sample of healthy elders and mild cognitive impairment (MCI) subjects. Spontaneous brain magnetic activity (measured with magnetoencephalography) was characterized with phase synchronization analysis, and graph theory was applied to the functional networks. We identified WM areas (using diffusion weighted magnetic resonance imaging) that showed a statistical dependence between the fractional anisotropy and the graph metrics. These regions are part of an episodic memory network and were also related to cognitive functions. Our data support the hypothesis that disruption of the anatomical networks influences the organization at the functional level resulting in the prodromal dementia syndrome of MCI.

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“…In these findings, the loss of WM volume or microstructural integrity, in key structures, appears to be measurable before gray matter differences. Similarly, in groups of subjects with and without subjective memory complaints, but scoring normally on all cognitive tests – thus encompassing very subtle differences – WM diffusivity of the posterior cingulate, retrosplenial cortex (RSC), and precuneus (Selnes et al, 2012) and parahippocampal WM (Wang et al, 2012) was significantly different for those with memory complaints, while gray matter thickness was not. Recent results such as these have been taken to suggest that early WM deterioration may be at least partially separate (Agosta et al, 2011; Selnes et al, 2012) from the β-amyloid and tau pathologies of gray matter, whose evolution is known to characterize Alzheimer’s disease (AD) (Braak and Braak, 1996), and have even raised the question whether Alzheimer’s should be considered a disease of the WM (Sachdev et al, 2013).…”

Section: Introductionmentioning

confidence: 98%

Early Brain Loss in Circuits Affected by Alzheimerâ€™s Disease is Predicted by Fornix Microstructure but may be Independent of Gray Matter

Fletcher

Carmichael

Pasternak

et al. 2014

Front. Aging Neurosci.

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In a cohort of community-recruited elderly subjects with normal cognition at initial evaluation, we found that baseline fornix white matter (WM) microstructure was significantly correlated with early volumetric longitudinal tissue change across a region of interest (called fornix significant ROI, fSROI), which overlaps circuits known to be selectively vulnerable to Alzheimer’s dementia pathology. Other WM and gray matter regions had much weaker or non-existent associations with longitudinal tissue change. Tissue loss in fSROI was in turn a significant factor in a survival model of cognitive decline, as was baseline fornix microstructure. These findings suggest that WM deterioration in the fornix and tissue loss in fSROI may be the early beginnings of posterior limbic circuit and default mode network degeneration. We also found that gray matter baseline volumes in the entorhinal cortex and hippocampus predicted cognitive decline in survival models. But since GM regions did not also significantly predict brain-tissue loss, our results may imply a view in which early, prodromal deterioration appears as two quasi independent processes in white and gray matter regions of the limbic circuit crucial to memory.

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White matter imaging changes in subjective and mild cognitive impairment

Abstract: WM tract degeneration is prominent in SCI and MCI patients, and is at least in part independent of overlying gray matter atrophy.

Cited by 87 publications

References 47 publications

White Matter Changes May Precede Gray Matter Loss in Elderly with Subjective Memory Impairment

White Matter Changes May Precede Gray Matter Loss in Elderly with Subjective Memory Impairment

White Matter Damage Disorganizes Brain Functional Networks in Amnestic Mild Cognitive Impairment

Early Brain Loss in Circuits Affected by Alzheimerâ€™s Disease is Predicted by Fornix Microstructure but may be Independent of Gray Matter

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