Prior studies have reported increased cortical excitability in people with Alzheimer's disease (AD), but findings have been inconsistent, and how excitability relates to dementia severity remains incompletely understood. The objective of this study was to investigate the association between a transcranial magnetic stimulation (TMS) measure of motor cortical excitability and measures of cognition in AD. A retrospective cross-sectional analysis tested the relationship between resting motor threshold (RMT) and the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog) across two independent samples of AD participants (a discovery cohort, n=22 and a larger validation cohort, n=129) and a control cohort of cognitively normal adults (n=26). RMT was correlated with ADAS-Cog in the discovery-AD cohort (n=22, β=-.70, p<0.001) but not in the control cohort (n=26, β=-0.13, p=0.513). This relationship was confirmed in the validation-AD cohort (n=129, β=-.35, p<0.001). RMT can be a useful neurophysiological marker of progressive global cognitive dysfunction in AD. Future translational research should focus on the potential of RMT to predict and track individual pathophysiological trajectories of aging.

先前的研究报告了阿尔茨海默病 (AD) 患者的皮质兴奋性增加，但研究结果不一致，兴奋性与痴呆严重程度的关系仍未完全了解。本研究的目的是调查运动皮层兴奋性的经颅磁刺激 (TMS) 测量与 AD 认知测量之间的关联。一项回顾性横断面分析测试了两个独立的 AD 参与者样本（一个发现队列，n=22 和一个更大的验证队列）之间的静息运动阈值 (RMT) 和阿尔茨海默氏病评估量表 - 认知分量表 (ADAS-Cog) 之间的关系, n=129) 和认知正常成年人的对照组 (n=26)。RMT 在发现-AD 队列中与 ADAS-Cog 相关（n=22，β=-.70，p <0.001) 但在对照组中没有 (n=26, β=-0.13, p =0.513)。这种关系在验证-AD 队列中得到证实（n=129，β=-.35，p <0.001）。RMT 可以作为 AD 进行性整体认知功能障碍的有用神经生理学标志物。未来的转化研究应侧重于 RMT 预测和跟踪衰老的个体病理生理轨迹的潜力。