Supplementary Material for: Functional Disconnectivity during Inter-Task Resting State in Dementia with Lewy Bodies

Aims: Limited research has been done on the functional connectivity in visuoperceptual regions in dementia with Lewy bodies (DLB) patients. This study aimed to investigate the functional connectivity differences between a task condition and an inter-task resting state condition within a visuoperceptual paradigm, in DLB patients compared with Alzheimer disease (AD) patients and healthy elderly control subjects. Methods: Twenty-six DLB, 29 AD, and 22 healthy subjects underwent a detailed clinical and neuropsychological examination along with a functional MRI during the different conditions of a visuoperceptual paradigm. Functional images were analyzed using group-level spatial independent component analysis and seed-based connectivity analyses. Results: While the DLB patients scored well and did not differ from the control and AD groups in terms of functional activity and connectivity during the task conditions, they showed decreased functional connectivity in visuoperceptual regions during the resting state condition, along with a temporal impairment of the default-mode network activity. Functional connectivity disturbances were also found within two attentional-executive networks and between these networks and visuoperceptual regions. Conclusion: We found a specific functional profile in the switching between task and resting state conditions in DLB patients. This result could help better characterize functional impairments in DLB and their contribution to several core symptoms of this pathology such as visual hallucinations and cognitive fluctuations.

目的：关于路易体痴呆（DLB）患者视知觉区域的功能连通性的研究尚显不足。本研究旨在探究在视知觉范式下，DLB患者与阿尔茨海默病（AD）患者及健康老年对照组相比，任务条件与任务间休息状态条件之间的功能连通性差异。方法：26名DLB患者、29名AD患者和22名健康受试者接受了详细的临床和神经心理学检查，并在视知觉范式的不同条件下进行了功能性核磁共振成像扫描。使用组内空间独立成分分析和基于种子的连通性分析对功能图像进行了分析。结果：尽管DLB患者在任务条件下的功能活动和连通性得分良好，与对照和AD组无显著差异，但在休息状态条件下，他们在视知觉区域表现出功能连通性的下降，同时伴随默认模式网络活动的时间性损害。在两个注意力-执行网络内以及这些网络与视知觉区域之间也发现了功能连通性的紊乱。结论：我们发现在DLB患者任务与休息状态条件之间的切换存在特定的功能特征。这一结果有助于更好地描述DLB的功能障碍，及其对多种核心症状，如视觉幻觉和认知波动等方面的贡献。