Injury of the corticobulbar tract in patients with dysarthria following cerebral infarct: diffusion tensor tractography study

摘要

Objectives: Little is known about injury of the corticobulbar tract (CBT) in stroke patients. We attempted to investigate injury of the CBT in patients with dysarthria following cerebral infarct, using diffusion tensor tractography (DTT). Methods: Eight patients with dysarthria following a corona radiata infarct and 12 control subjects were recruited for this study. Diffusion tensor imaging was performed at 14.3days after onset and reconstruction of the CBT was performed using the probabilistic tractography method. Fractional anisotropy, mean diffusivity, and tract volume of the CBT were measured. Results: Reconstructed CBTs in the affected hemisphere of the patient group were thinner than those of the unaffected hemisphere of the patient group and the control group. Regarding the DTT parameters of the CBTs, fractional anisotropy and tract volume were significantly lower in the affected hemisphere of the patient group than in the unaffected hemisphere of the patient group and the control group (p<0.05). However, we did not observe any difference in the mean diffusivity value (p>0.05). Conclusions: We demonstrated injury of the CBT in patients with dysarthria following cerebral infarct in the corona radiata using DTT. This result indicates the importance of CBT evaluation for dysarthria in patients with cerebral infarct. Therefore, we suggest that evaluations of the CBT using DTT would be useful for patients with dysarthria following cerebral infarct.