Functional implications of hippocampal volume and diffusivity in mild cognitive impairment

Müller, Matthias J.; Greverus, Dirk; Dellani, Paulo R.; Weibrich, Carsten; Wille, Paulo Roberto; Scheurich, Armin; Stoeter, P.; Fellgiebel, Andreas

doi:10.1016/j.neuroimage.2005.06.029

Cited by 179 publications

(174 citation statements)

References 75 publications

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“…These deficits are associated with poor verbal memory performance, and the data further suggest that a combination of macro-and microstructural parameters can enhance the early detection of neurodegenerative processes [80] . Subsequently, this research group compared the diagnostic accuracy of stru ctural MRI and DTI techniques and reported that the left and right hippocampus have different predictive power in these techniques [38] .…”

Section: Mri and Functional Mri Approaches In The Hippocampus Of Amcmentioning

confidence: 83%

Can multi-modal neuroimaging evidence from hippocampus provide biomarkers for the progression of amnestic mild cognitive impairment?

Chen

Zhang

2015

Neurosci. Bull.

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Impaired structure and function of the hippocampus is a valuable predictor of progression from amnestic mild cognitive impairment (aMCI) to Alzheimer's disease (AD). As a part of the medial temporal lobe memory system, the hippocampus is one of the brain regions affected earliest by AD neuropathology, and shows progressive degeneration as aMCI progresses to AD. Currently, no validated biomarkers can precisely predict the conversion from aMCI to AD. Therefore, there is a great need of sensitive tools for the early detection of AD progression. In this review, we summarize the specifi c structural and functional changes in the hippocampus from recent aMCI studies using neurophysiological and neuroimaging data. We suggest that a combination of advanced multi-modal neuroimaging measures in discovering biomarkers will provide more precise and sensitive measures of hippocampal changes than using only one of them. These will potentially affect early diagnosis and disease-modifying treatments. We propose a new sequential and progressive framework in which the impairment spreads from the integrity of fibers to volume and then to function in hippocampal subregions. Meanwhile, this is likely to be accompanied by progressive impairment of behavioral and neuropsychological performance in the progression of aMCI to AD.

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Section: Mri and Functional Mri Approaches In The Hippocampus Of Amcmentioning

confidence: 83%

Can multi-modal neuroimaging evidence from hippocampus provide biomarkers for the progression of amnestic mild cognitive impairment?

Chen

Zhang

2015

Neurosci. Bull.

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“…The assumption, arising out of experiments on animal models, is that significantly reduced DR in WM without differences in DA might represent specifically compromised integrity of myelin in the absence of axonal structural irregularities. With respect to structural MRI (ROI and VBM), DWI and DTI techniques have the advantage of being very sensitive in detecting microstructural abnormalities not revealed by other volumetric measures [28,76]. In fact, structural MRI techniques, which reflect macrostructural changes, may not be sensitive to the degeneration of myelin and axons in the WM microstructure [28,46].…”

Section: Diffusion-weighted Imaging and Diffusion Tensor Imaging Studiesmentioning

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

125

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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“…and volume. However, other studies on GM MD in MCI that did not use PVE correction found no significant correlations between regional volumes and MD values (Eustache et al, 2016;Müller et al, 2005). Unfortunately, these studies did not report the correlation sizes because of nonsignificant p-values.…”

Section: Discussionmentioning

confidence: 90%

“…Previous studies on GM MD in AD reported increases of hippocampal MD and whole brain GM MD in subjects with mild cognitive impairment (MCI) as compared to healthy controls Eustache et al, 2016;Fellgiebel et al, 2004;Müller et al, 2005;Scola et al, 2010), as well as in MCI patients that converted to AD compared to MCI subjects that remained stable over a period of several years (Douaud et al, 2013;Fellgiebel et al, 2006;Scola et al, 2010;van Uden et al, 2016). In some studies, hippocampal diffusivity even demonstrated a higher diagnostic and prognostic accuracy than hippocampal volume (Fellgiebel et al, 2006;Kantarci et al, 2005;Müller et al, 2007).…”

Section: Introductionmentioning

confidence: 98%

[IC‐P‐161]: MEAN DIFFUSIVITY IN CORTICAL GRAY MATTER IN ALZHEIMER's DISEASE: THE IMPORTANCE OF PARTIAL VOLUME CORRECTION

Henf

Grothe

Teipel

et al. 2017

Alzheimer's & Dementia

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Mean diffusivity (MD) measured by diffusion tensor imaging can reflect microstructural alterations of the brain's gray matter (GM). Therefore, GM MD may be a sensitive marker of neurodegeneration related to Alzheimer's Disease (AD). However, due to partial volume effects (PVE), differences in MD may be overestimated because of a higher degree of brain atrophy in AD patients and in cases with mild cognitive impairment (MCI). Here, we evaluated GM MD changes in AD and MCI compared with healthy controls, and the effect of partial volume correction (PVC) on diagnostic utility of MD.We determined region of interest (ROI) and voxel-wise group differences and diagnostic accuracy of MD and volume measures between matched samples of 39 AD, 39 MCI and 39 healthy subjects before and after PVC. Additionally, we assessed whether effects of GM MD values on diagnosis were mediated by volume.ROI and voxel-wise group differences were reduced after PVC. When using these ROIs for predicting group separation in logistic models, both PVE corrected and uncorrected GM MD values yielded a poorer diagnostic accuracy in single predictor models than regional volume. For the discrimination of AD patients and healthy controls, the effect of GM MD on diagnosis was significantly mediated by volume of hippocampus and posterior cingulate ROIs.Our results suggest that GM MD measurements are strongly confounded by PVE in the presence of brain atrophy, underlining the necessity of PVC when using these measurements as specific metrics of microstructural tissue degeneration. Independently of PVC, regional MD was not superior to regional volume in separating prodromal and clinical stages of AD from healthy controls.

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Functional implications of hippocampal volume and diffusivity in mild cognitive impairment

Cited by 179 publications

References 75 publications

Can multi-modal neuroimaging evidence from hippocampus provide biomarkers for the progression of amnestic mild cognitive impairment?

Can multi-modal neuroimaging evidence from hippocampus provide biomarkers for the progression of amnestic mild cognitive impairment?

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

[IC‐P‐161]: MEAN DIFFUSIVITY IN CORTICAL GRAY MATTER IN ALZHEIMER's DISEASE: THE IMPORTANCE OF PARTIAL VOLUME CORRECTION

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