Correlation between functional changes in multiple sclerosis and diffusion tensor imaging parameters

Introduction: diffusion tensor imaging (DTI) is an advanced magnetic resonance imaging (MRI) technique that provides information on microscopic structural damage in white matter tracts and fibers, enabling the calculation of several parameters, including fractional anisotropy (FA), radial diffusivity [(RD, related to axonal damage)] and axial diffusivity [(AD, related to demyelinating damage)]. Objectives: to evaluate 12-year longitudinal changes in functional tests and DTI parameters. Methods: 42 patients were selected from a previous cohort. Clinical variables evaluated were the EDSS, 9HPT and T25FW. The DTI images were acquired on a 3-T device and analyzed using MRtrix3 (https://www.mrtrix.org). We selected the corpus callosum (CC) and the cingulum (Cg). Results: We found a moderate and significant correlation between the T25 test and the following DTI parameters: AF Cg right (r= .421*) and RD Cg right (r = -.442*) and, moderate and significant relationship of 9HPT in the following parameters AF left Cg (r= -.371*), DR Cg right (r= .380*), RD Cg left (r= .414*) , FA CC (r= -.374*) and RD CC (r=.373*). Conclusion: In the 12 years of follow-up, Cg and CC alterations were related with worse outcomes in the T25FW and 9HPT.