International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Tokyo, Japan.
Department of Neurology, Far Eastern Memorial Hospital, New Taipei City, Taiwan.
Aging Clin Exp Res. 2024 Jul 30;36(1):154. doi: 10.1007/s40520-024-02805-8.
Mild cognitive impairment (MCI) is recognized as the prodromal phase of dementia, a condition that can be either maintained or reversed through timely medical interventions to prevent cognitive decline. Considerable studies using functional magnetic resonance imaging (fMRI) have indicated that altered activity in the medial prefrontal cortex (mPFC) serves as an indicator of various cognitive stages of aging. However, the impacts of intrinsic functional connectivity in the mPFC as a mediator on cognitive performance in individuals with and without MCI have not been fully understood. In this study, we recruited 42 MCI patients and 57 healthy controls, assessing their cognitive abilities and functional brain connectivity patterns through neuropsychological evaluations and resting-state fMRI, respectively. The MCI patients exhibited poorer performance on multiple neuropsychological tests compared to the healthy controls. At the neural level, functional connectivity between the mPFC and the anterior cingulate cortex (ACC) was significantly weaker in the MCI group and correlated with multiple neuropsychological test scores. The result of the mediation analysis further demonstrated that functional connectivity between the mPFC and ACC notably mediated the relationship between the MCI and semantic fluency performance. These findings suggest that altered mPFC-ACC connectivity may have a plausible causal influence on cognitive decline and provide implications for early identifications of neurodegenerative diseases and precise monitoring of disease progression.
轻度认知障碍（MCI）被认为是痴呆症的前驱阶段，通过及时的医疗干预可以维持或逆转这种状态，从而预防认知能力下降。大量使用功能磁共振成像（fMRI）的研究表明，内侧前额叶皮层（mPFC）的活动改变可以作为各种认知衰老阶段的指标。然而，mPFC 内在功能连接作为中介对 MCI 患者和非 MCI 患者认知表现的影响尚未得到充分理解。在这项研究中，我们招募了 42 名 MCI 患者和 57 名健康对照组，分别通过神经心理学评估和静息态 fMRI 评估他们的认知能力和功能脑连接模式。与健康对照组相比，MCI 患者在多项神经心理学测试中的表现较差。在神经水平上，MCI 组 mPFC 与前扣带皮层（ACC）之间的功能连接明显较弱，与多项神经心理学测试分数相关。中介分析的结果进一步表明，mPFC-ACC 之间的功能连接显著中介了 MCI 与语义流畅性表现之间的关系。这些发现表明，mPFC-ACC 连接的改变可能对认知能力下降有合理的因果影响，并为神经退行性疾病的早期识别和疾病进展的精确监测提供了依据。
