The study of mechanism on the completely paralyzed hands of chronic stroke patients by voxel-based morphometry

Objective: In order to explore Wallerian degeneration in the whole brain and reveal the mechanism on the completely paralyzed hands of chronic stroke patients, we perform this study using voxel-based morphometry (VBM). Method: Twenty-three chronic stroke patients were divided into two groups: the CPH group (completely paralyzed hands, 11 patients) and the PPH group (partially paralyzed hands, 12 patients). Twelve healthy people were included in the HC group (healthy control). All the subjects underwent diffusion tensor imaging by 3.0T MRI. The VBM analysis was performed by the software SPM. The regions with significant differences of FA map were made as binary masks, which were applied to all participants respectively. Then, individual ROI value of each region was obtained by averaging FA value of all voxels within each mask. The procedure of processing M D, AD and RD was the same as FA. Result: Compared with the PPH group, it was found that in the CPH group there were significant decreases of the FA in the ipsilateral brainstem, sub-lobar, precentral gyrus, medial frontal gyrus (MFG), supplementary motor area (SMA), superior temporal gyrus, parietal lobe and occipital lobe, and the contralateral postcentral gyrus. There were significant increases of the MD and AD in the ipsilateral sub-lobar. In addition, there were significant increases of the RD in the ipsilateral sub-lobar and brainstem. Compared with the HC group, the range of the regions with significant differences of DTI parameters in the CPH group were significantly wider than in the PPH group. Conclusion: The Wallerian degeneration of the ipsilateral brainstem, sub-lobar, precentral gyrus, MFG, SMA, superior temporal gyrus, parietal lobe, occipital lobe and the contralateral postcentral gyrus played an important role in the completely paralyzed hands after stroke.