BackgroundPatients with Parkinson's disease (PD) experience changes in behavior, personality, and cognition that can manifest even in the initial stages of the disease. Previous studies have suggested that mild behavioral impairment (MBI) should be considered an early marker of cognitive decline. However, the precise neurostructural underpinnings of MBI in early‐ to mid‐stage PD remain poorly understood.ObjectiveThe aim was to explore the changes in white matter microstructure linked to MBI and mild cognitive impairment (MCI) in early‐ to mid‐stage PD using diffusion magnetic resonance imaging (dMRI).MethodsA total of 91 PD patients and 36 healthy participants were recruited and underwent anatomical MRI and dMRI, a comprehensive neuropsychological battery, and the completion of the Mild Behavioral Impairment‐Checklist. Metrics of white matter integrity included tissue fractional anisotropy (FAt) and radial diffusivity (RDt), free water (FW), and fixel‐based apparent fiber density (AFD).ResultsThe connection between the left amygdala and the putamen was disrupted when comparing PD patients with MBI (PD‐MBI) to PD‐non‐MBI, as evidenced by increased RDt (η2 = 0.09, P = 0.004) and both decreased AFD (η2 = 0.05, P = 0.048) and FAt (η2 = 0.12, P = 0.014). Compared to controls, PD patients with both MBI and MCI demonstrated increased FW for the connection between the left orbitofrontal gyrus (OrG) and the hippocampus (η2 = 0.22, P = 0.008), augmented RDt between the right OrG and the amygdala (η2 = 0.14, P = 0.008), and increased RDt (η2 = 0.25, P = 0.028) with decreased AFD (η2 = 0.10, P = 0.046) between the right OrG and the caudate nucleus.ConclusionMBI is associated with abnormal microstructure of connections involving the orbitofrontal cortex, putamen, and amygdala. To our knowledge, this is the first assessment of the white matter microstructure in PD‐MBI using dMRI. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

中文翻译：

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帕金森病轻度行为障碍的白质微观结构基础

背景帕金森病 (PD) 患者会经历行为、性格和认知的变化，即使在疾病的初始阶段也会出现这种变化。先前的研究表明，轻度行为障碍（MBI）应被视为认知能力下降的早期标志。然而，对于早中期PD中MBI的精确神经结构基础仍然知之甚少。目的：目的是利用MBI和轻度认知障碍（MCI）在早中期PD中探索与MBI和轻度认知障碍（MCI）相关的白质微结构的变化。方法 总共招募了 91 名 PD 患者和 36 名健康参与者，并接受了解剖 MRI 和 dMRI、全面的神经心理学电池，并完成了轻度行为障碍检查表。白质完整性指标包括组织分数各向异性 (FAt) 和径向扩散率 (RDt)、自由水 (FW) 和基于固定素的表观纤维密度 (AFD)。结果在比较 PD 时，左侧杏仁核和壳核之间的连接被破坏MBI (PD-MBI) 患者转变为 PD-非 MBI，如 RDt 增加所证明（η2= 0.09,磷= 0.004) 并且 AFD 均下降 (η2= 0.05,磷= 0.048) 和 FAt (η2= 0.12,磷= 0.014）。与对照组相比，同时患有 MBI 和 MCI 的 PD 患者左眶额回 (OrG) 和海马体之间的连接 FW 增加。η2= 0.22,磷= 0.008), 右侧 OrG 和杏仁核之间的增强 RDt (η2= 0.14,磷= 0.008)，并增加 RDt (η2= 0.25,磷= 0.028），AFD 降低（η2= 0.10,磷= 0.046) 右侧 OrG 和尾状核之间。 结论 MBI 与涉及眶额皮质、壳核和杏仁核的连接微观结构异常有关。据我们所知，这是首次使用 dMRI 对 PD-MBI 中的白质微观结构进行评估。 © 2024 作者。运动障碍由 Wiley periodicals LLC 代表国际帕金森和运动障碍协会出版。