Department of Neurology & Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Department of Psychiatry, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
J Alzheimers Dis. 2019;69(4):1137-1151. doi: 10.3233/JAD-181296.
Repetitive transcranial magnetic stimulation (rTMS) is thought to be effective in alleviating cognitive symptoms in patients with amnestic mild cognitive impairment (aMCI), but the mechanisms related to network modification are poorly understood.
Here we tested rTMS efficacy and explored the effect of rTMS-induced changes in the default mode network (DMN) and their predictive value for treatment response.
Twenty-one subjects clinically diagnosed with aMCI were recruited to complete a 10-session randomized and sham-controlled rTMS treatment targeting the right dorsolateral prefrontal cortex. Resting-state functional magnetic resonance imaging in tandem with neuropsychological assessments were administered before and after the intervention. Changes in functional connectivity of the DMN and relevant brain regions, as well as the correlations between baseline functional connectivity and clinical rating scales were calculated in order to elucidate the mechanism of treatment response to rTMS therapy.
Compared to the sham group, the rTMS group achieved improvement of neuropsychological performance and significant functional connectivity changes within the DMN. Group×Time interactions were found between posterior cingulate gyrus and right fusiform gyrus (F (1,19) = 17.154, p = 0.001), and also left anterior cingulate gyrus (F (1,19) = 3.908, p = 0.063), showing an rTMS-induced deactivation of functional connectivity within the DMN. Baseline functional connectivity analysis of seeds within the DMN in the rTMS group revealed negative correlation with AVLT-Recognition score changes.
rTMS-induced hypoconnectivity within DMN is associated with clinical cognitive improvements in patients with aMCI. Further, pre-rTMS baseline activity of the DMN at rest may be a predictor for favorable rTMS treatment response.
重复经颅磁刺激（rTMS）被认为可以有效缓解遗忘型轻度认知障碍（aMCI）患者的认知症状，但与网络改变相关的机制仍知之甚少。
本研究旨在检验 rTMS 的疗效，并探讨 rTMS 诱导的默认模式网络（DMN）改变及其对治疗反应的预测价值。
本研究共纳入 21 例临床诊断为 aMCI 的患者，完成了为期 10 次的右侧背外侧前额叶皮层随机对照 rTMS 治疗。在干预前后进行了静息态功能磁共振成像和神经心理学评估。计算 DMN 及其相关脑区的功能连接变化，以及基线功能连接与临床评分量表之间的相关性，以阐明 rTMS 治疗对治疗反应的机制。
与 sham 组相比，rTMS 组的神经心理学表现得到改善，DMN 内的功能连接发生了显著变化。rTMS 组与 sham 组之间在后扣带回和右侧梭状回（F(1,19) = 17.154，p = 0.001）以及左侧前扣带回（F(1,19) = 3.908，p = 0.063）之间存在组间×时间交互作用，表现为 DMN 内功能连接的去激活。rTMS 组 DMN 内种子点的基线功能连接分析显示与 AVLT-Recognition 评分变化呈负相关。
rTMS 诱导的 DMN 内功能连接减少与 aMCI 患者的临床认知改善有关。此外，rTMS 治疗前 DMN 的静息状态下的基线活动可能是预测 rTMS 治疗反应的指标。
