BackgroundEvidence regarding cortical atrophy patterns in Parkinson's disease (PD) with probable rapid eye movement sleep behavior disorder (RBD) (PD‐pRBD) remains scarce. Cortical mean diffusivity (cMD), as a novel imaging biomarker highly sensitive to detecting cortical microstructural changes in different neurodegenerative diseases, has not been investigated in PD‐pRBD yet.ObjectivesThe aim was to investigate cMD as a sensitive measure to identify subtle cortical microstructural changes in PD‐pRBD and its relationship with cortical thickness (CTh).MethodsTwenty‐two PD‐pRBD, 31 PD without probable RBD (PD‐nonpRBD), and 28 healthy controls (HC) were assessed using 3D T1‐weighted and diffusion‐weighted magnetic resonance imaging on a 3‐T scanner and neuropsychological testing. Measures of cortical brain changes were obtained through cMD and CTh. Two‐class group comparisons of a general linear model were performed (P < 0.05). Cohen's d effect size for both approaches was computed.ResultsPD‐pRBD patients showed higher cMD than PD‐nonpRBD patients in the left superior temporal, superior frontal, and precentral gyri, precuneus cortex, as well as in the right middle frontal and postcentral gyri and paracentral lobule (d > 0.8), whereas CTh did not detect significant differences. PD‐pRBD patients also showed increased bilateral posterior cMD in comparison with HCs (d > 0.8). These results partially overlapped with CTh results (0.5 < d < 0.8). PD‐nonpRBD patients showed no differences in cMD when compared with HCs but showed cortical thinning in the left fusiform gyrus and lateral occipital cortex bilaterally (d > 0.5).ConclusionscMD may be more sensitive than CTh displaying significant cortico‐structural differences between PD subgroups, indicating this imaging biomarker's utility in studying early cortical changes in PD. © 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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帕金森病可能伴有快速眼动睡眠行为障碍的皮质宏观和微观结构变化

背景有关帕金森病 (PD) 可能伴有快速动眼睡眠行为障碍 (RBD) (PD-pRBD) 的皮质萎缩模式的证据仍然很少。皮质平均扩散率（cMD）作为一种新型成像生物标志物，对检测不同神经退行性疾病的皮质微结构变化高度敏感，尚未在 PD-pRBD 中进行研究。 目的：研究 cMD 作为识别细微皮质微结构变化的敏感指标PD-pRBD 及其与皮质厚度 (CTh) 的关系。方法使用 3D T1 加权和扩散加权对 22 名 PD-pRBD、31 名无可能 RBD 的 PD (PD-nonpRBD) 和 28 名健康对照 (HC) 进行评估3-T 扫描仪上的磁共振成像和神经心理学测试。通过 cMD 和 CTh 获得大脑皮层变化的测量结果。对一般线性模型进行了两类组比较（磷< 0.05）。科恩的d计算两种方法的效应大小。结果PD-pRBD 患者在左侧颞上、额上、中央前回、楔前叶皮质以及右侧额中、中央后回和旁中央小叶中表现出比 PD-nonpRBD 患者更高的 cMD （d> 0.8），而 CTh 没有检测到显着差异。与 HC 相比，PD-pRBD 患者的双侧后部 cMD 也有所增加（d> 0.8）。这些结果与 CTh 结果部分重叠 (0.5 <d< 0.8）。PD-nonpRBD 患者与 HC 相比，cMD 没有差异，但左侧梭状回和双侧枕叶皮质出现皮质变薄（d> 0.5)。结论scMD 可能比 CTh 更敏感，显示 PD 亚组之间显着的皮质结构差异，表明该成像生物标志物在研究 PD 早期皮质变化中的实用性。© 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。