Parietal-hippocampal rTMS improves cognitive function in Alzheimer's disease and increases dynamic functional connectivity of default mode network

• Published in: Psychiatry research Vol. 315; p. 114721
• Main Authors: Wei, Lili, Zhang, Yingchun, Wang, Jintao, Xu, Luoyi, Yang, Kehua, Lv, Xinghui, Zhu, Zhenwei, Gong, Qian, Hu, Weiming, Li, Xia, Qian, Mincai, Shen, Yuedi, Chen, Wei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2022
• Subjects: Alzheimer's disease; Default mode network; Dynamic functional connectivity; Mini Mental State Examination; Parietal lobe; Repetitive transcranial magnetic stimulation; Default mode network; Repetitive transcranial magnetic stimulation; Parietal lobe; Dynamic functional connectivity; Mini Mental State Examination; Alzheimer's disease
• ISSN: 0165-1781; 1872-7123; 1872-7123
• DOI: 10.1016/j.psychres.2022.114721

•A double-blind, randomized, sham-controlled, fMRI-guided rTMS trial.•Individualized rTMS over the parietal region is effective in treating Alzheimer's disease.•fMRI-guided rTMS treatment improves patients’ cognitive performance.•fMRI-guided rTMS treatment enhances functional connectivity of DMN.•IMPROVED cognitive function is related to enhanced DMN functional connectivity. Parietal-hippocampal repetitive transcranial magnetic stimulation (rTMS) improves cognitive function in Alzheimer's disease (AD), however, the underlying therapeutic mechanism has not been elucidated. A double-blind, randomized, sham-controlled parietal-hippocampal rTMS trial (five sessions/week for a total of 10 sessions) of mild-to-moderate AD patients was conducted in the study. High-frequency rTMS was applied to a subject-specific left lateral parietal region with the highest functional connectivity with the hippocampus based on resting-state fMRI. A multimodal MRI scan and a complete neuropsychological battery of tests were conducted at baseline, immediately after the intervention and 12-week follow-up after the rTMS treatment. Compared to sham treatment (n = 27), patients undergoing active rTMS treatment (n = 29) showed higher Mini Mental State Examination (MMSE) score and dynamic functional connectivity (dFC) magnitude of the default mode network (DMN) after two weeks of rTMS treatment, but not at 12-week follow-up. A significant positive correlation was observed between changes in MMSE and changes in the dFC magnitude of DMN in patients who underwent active-rTMS treatment, but not in those who received sham-rTMS treatment. The findings of the current study indicate that fMRI-guided rTMS treatment improves cognitive function of AD patients in the short term, and DMN functional connectivity contributes to therapeutic effectiveness of rTMS.