Effect Of Repetitive Transcranial Magnetic Stimulation On Mild Cognitive Impairment Patients:A DTI Study

Objective: To investigate the curative effect of repetitive transcranial magnetic stimulation(rTMS)on mild cognitive impairment(MCI)patients and observe the microstructural alteration in cognition related brain regions by using diffusion tensor imaging(DTI)and cognitive functional scales.Methods: Twenty-nine identified MCI patients in Nanchong City were included and divided into two groups: real stimulation group(rTMS group,17)and sham stimulation group(Sham group,12).The rTMS group received a high-frequency rTMS(10Hz)over the right dorsolateral prefrontal cortex(DLPFC)for 10 days,the Sham group received sham stimulation with the same parameters.Both groups received Montreal Cognitive Assessment Score(MoCA),Mini-mental State Examination Score(MMSE),and DTI images at the baseline and after the final treatment.The changes and differences of MoCA,MMSE score and Fractional Anisotropy(FA)between rTMS group and Sham group before and after treatment were compared.The correlation between the amount of change in MoCA,MMSE score and the amount of change in FA were calculated.Results:(1)Compared to the baseline,the scores of MoCA and MMSE in the two groups were improved after the treatment,but there was no significant difference in MMSE before and after treatment in Sham group;the difference was no significant in MoCA and MMSE between the rTMS group and Sham group after treatment.(2)Compared to the baseline,the FA values of the right precuneus,bilateral superior frontal gyrus,and bilateral middle frontal gyrus were significantly increased in the rTMS group after treatment,but FA value showed no significant change in brain areas of Sham group after treatment.Compared with the Sham group,the FA values of the right middle frontal gyrus,the right occipital lobe,the right parietal lobe,the bilateral superior frontal gyrus,and the bilateral precuneus were significantly increased in the rTMS group,while the FA value of the left thalamus,the left hippocampus,the left middle temporal gyrus and the left lingual gyrus were significantly decreased.(3)The FA value of the left occipital lobe and the left hippocampus was negatively correlated with the MMSE score after treatment in the rTMS group.The changes of FA of the left occipital lobe was negatively correlated with the change of the MoCA score.Conclusion: High-frequency rTMS can effectively improve the cognitive function of MCI patients,which may be achieved by regulating the diffusion microstructure parameters of the gray matter region related to cognitive function...