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.