Integrity of the cortico-spinal tract is associated with physical activity.

Background and purpose: Despite the primary motor efferent role of the cortico-spinal tract (CST), it is hardly understood whether the amount of physical activity is associated with the integrity of the CST.Materials and methods: We examined the association between the amount of physical activity and the integrity of the CST, using Diffusion Tensor Imaging (DTI) data from 465 individuals. The CST was segmented by probabilistic tractography and the association of the fractional anisotropy (FA) within was tested against physical activity (PA) assessed by moderate-intensity physical activity of the International Physical Activity Questionnaire.Results: The FA and PA showed a positive association. Post-hoc analyses showed that the radial diffusivity (RD) of the CST was negatively associated with PA, suggesting a potential association with preserved myelination with PA.Conclusion: This study shows that the integrity of the CST is associated with its traffic in the general population.