Gwenaelle Douaud1, Saad Jbabdi1,
Timothy Edward Behrens1, Ricarda Menke1, Achim Gass2,
Andreas Monsch3, Anil Rao4,
1FMRIB Centre, University of Oxford, Oxford, Oxfordshire, United Kingdom; 2Departments of Neurology and Neuroradiology, University Hospital, Basel, Switzerland; 3Memory Clinic, Basel, Switzerland; 4GSK, CIC Hammersmith Hospital, London, United Kingdom; 5Department of Computer Science and Computation Institute, University of Chicago, Chicago, IL, United States
Using TBSS, we investigated white matter abnormalities in the largest diffusion study including healthy elderly, mild cognitive impairment and Alzheimers disease. We also used the mode of anisotropy which specifies the shape of anisotropy. All diffusion tensor indices converged to show that the uncinate fasciculus, cingulum bundle, corpus callosum, anterior commissure and superior longitudinal fasciculus were affected. We found a regional increase of mode and fractional anisotropy, often considered atypical for a degenerative disorder. Using tractography, we directly and quantitatively showed that these local increases were related to the neuropathological sparing of the motor-related pathways compared with the superior longitudinal fasciculus.