Neural network related to hand movement: A combined study of diffusion tensor tractography and functional MRI

Abstract

[Purpose] Little is known about the detailed anatomical connections of the neural network related to hand movement in the human brain. We investigated the neural network using diffusion tensor tractography (DTT) data analyzed in conjunction with functional MRI (fMRI) activation results. [Subjects and Method] We recruited 19 healthy volunteers for this study. Probabilistic tractography was used to analyze diffusion tensor imaging (DTI) data that were collected using fMRI activation induced by grasp-release movements of the hand at a rate of 1 Hz. [Results] The brain areas connected to the primary sensorimotor cortex (SM1), which is activated by hand movements, were the premotor cortex (100%), superior parietal lobule (100%), intraparietal sulcus (100%), supramarginal gyrus (97.37%), supplementary motor area (89.47%), thalamus (86.84%), putamen (81.58%), pars opercularis (81.58%), pars triangularis (68.42%), angular gyrus (65.79%), and cerebellum (60.53%) in the same hemisphere and the contralateral primary motor cortex (60.53%) in the opposite hemisphere. No significant difference was observed in the total incidence of connected tracts between hemispheres. [Conclusion] These results reveal that more brain areas are involved in hand movements than were previously thought necessary for motor planning and execution in the human brain.