Diffusion tensor imaging in early Alzheimer's disease

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

“…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.…”

“…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.…”

“…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.…”

Feeling, learning from and being aware of inner states: interoceptive dimensions in neurodegeneration and stroke

“…B 371: 20160006 AD patients were diagnosed following NINCDS-ADRDA criteria [35,40]. They presented memory and language deficits and early atrophy in the temporal lobes, parietal regions [41,42], and, in some cases, in the IC [43]. Patients with logopenic progressive aphasia and atypical forms of AD (e.g.…”

Predicting White Matter Integrity from Multiple Common Genetic Variants

“…By mapping the diffusion of water through the brain's fibers, DTI can recover major fiber pathways in the brain, and patterns of anatomical connectivity, with broad applications in psychiatry, neurology, and brain mapping (Thomason and Thompson, 2011). DTI-based white matter abnormalities are widely reported in developmental and degenerative brain diseases including Alzheimer's disease and mild cognitive impairment (Fellgiebel et al, 2004;Naggara et al, 2006;Oishi et al, 2011), schizophrenia (White et al, 2008;Ellison-Wright and Bullmore, 2009;Patel et al, 2011), bipolar disorder (Sussmann et al, 2009;Heng et al, 2010), attention-deficit/hyperactivity disorder (Konrad and Eickhoff, 2010), and autism (Alexander et al, 2007;Ke et al, 2009). These studies show the utility of DTI in neuropsychiatric research.…”