BACKGROUND: Different clinical syndromes can arise from Alzheimer's disease (AD) neuropathology, including dementia of the Alzheimer's type (DAT), logopenic primary progressive aphasia (lvPPA), and posterior cortical atrophy (PCA). OBJECTIVE: To assess similarities and differences in patterns of white matter tract degeneration across these syndromic variants of AD. METHODS: Sixty-four subjects (22 DAT, 24 lvPPA, and 18 PCA) that had diffusion tensor imaging and showed amyloid-β deposition on PET were assessed in this case-control study. A whole-brain voxel-based analysis was performed to assess differences in fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity across groups. RESULTS: All three groups showed overlapping diffusion abnormalities in a network of tracts, including fornix, corpus callosum, posterior thalamic radiations, superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and uncinate fasciculus. Subtle regional differences were also observed across groups, with DAT particularly associated with degeneration of fornix and cingulum, lvPPA with left inferior fronto-occipital fasciculus and uncinate fasciculus, and PCA with posterior thalamic radiations, superior longitudinal fasciculus, posterior cingulate, and splenium of the corpus callosum. CONCLUSION: These findings show that while each AD phenotype is associated with degeneration of a specific structural network of white matter tracts, striking spatial overlap exists among the three network patterns that may be related to AD pathology.
BACKGROUND: Different clinical syndromes can arise from Alzheimer's disease (AD) neuropathology, including dementia of the Alzheimer's type (DAT), logopenic primary progressive aphasia (lvPPA), and posterior cortical atrophy (PCA). OBJECTIVE: To assess similarities and differences in patterns of white matter tract degeneration across these syndromic variants of AD. METHODS: Sixty-four subjects (22 DAT, 24 lvPPA, and 18 PCA) that had diffusion tensor imaging and showed amyloid-β deposition on PET were assessed in this case-control study. A whole-brain voxel-based analysis was performed to assess differences in fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity across groups. RESULTS: All three groups showed overlapping diffusion abnormalities in a network of tracts, including fornix, corpus callosum, posterior thalamic radiations, superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and uncinate fasciculus. Subtle regional differences were also observed across groups, with DAT particularly associated with degeneration of fornix and cingulum, lvPPA with left inferior fronto-occipital fasciculus and uncinate fasciculus, and PCA with posterior thalamic radiations, superior longitudinal fasciculus, posterior cingulate, and splenium of the corpus callosum. CONCLUSION: These findings show that while each AD phenotype is associated with degeneration of a specific structural network of white matter tracts, striking spatial overlap exists among the three network patterns that may be related to AD pathology.
Authors: Irene Sintini; Christopher G Schwarz; Peter R Martin; Jonathan Graff-Radford; Mary M Machulda; Matthew L Senjem; Robert I Reid; Anthony J Spychalla; Daniel A Drubach; Val J Lowe; Clifford R Jack; Keith A Josephs; Jennifer L Whitwell Journal: Hum Brain Mapp Date: 2018-12-13 Impact factor: 5.038
Authors: Adam Odolil; Amy E Wright; Lynsey M Keator; Shannon M Sheppard; Bonnie Breining; Donna C Tippett; Argye E Hillis Journal: Aphasiology Date: 2019-03-23 Impact factor: 2.773
Authors: Qing Wang; Yong Wang; Jingxia Liu; Courtney L Sutphen; Carlos Cruchaga; Tyler Blazey; Brian A Gordon; Yi Su; Charlie Chen; Joshua S Shimony; Beau M Ances; Nigel J Cairns; Anne M Fagan; John C Morris; Tammie L S Benzinger Journal: Neuroimage Clin Date: 2019-03-13 Impact factor: 4.881
Authors: Catherine F Slattery; Jiaying Zhang; Ross W Paterson; Alexander J M Foulkes; Amelia Carton; Kirsty Macpherson; Laura Mancini; David L Thomas; Marc Modat; Nicolas Toussaint; David M Cash; John S Thornton; Susie M D Henley; Sebastian J Crutch; Daniel C Alexander; Sebastien Ourselin; Nick C Fox; Hui Zhang; Jonathan M Schott Journal: Neurobiol Aging Date: 2017-05-03 Impact factor: 4.673