DTT parameters in white matter tracts.

Fractional anisotropy (FA), mean and radial diffusivity (MD, RD, 10?−3 mmˆ2/s) and apparent area coefficient (AAC) values in major white matter tracts. The medians of diffusion parameters are presented. For paired structures (CG, cingulum, CST, corticospinal tract, MCP, middle cerebellar peduncles), all values are estimated medians from the left and right tracts; values in parenthesis indicate 25–75 percentiles. aCTR/PSP, P≤0.008; bIPD/PSP, P≤0.002; cCTR/IPD, P = 0,002; dIPD/MSA, P = 0.007, Mann-Whitney U test. eIPD/PSP, P<0.05, binary logistic regression analysis, age/sex adjusted. Abbreviations: IPD, idiopathic Parkinson’s disease; PSP, progressive supranuclear palsy; MSA-P, multiple system atrophy, parkinsonian variant; CTR, healthy controls.