Background:A proper explanation for perceptual symptoms in neurodegenerative disorders including Alzheimer’s disease and Parkinson’s disease (PD) is still lacking. Objective:This study aimed at investigating the imbalance between ‘bottom-up’ and ‘top-down’ information flow (IF) and processing in PDin relation with visual hallucination symptoms. Methods:Here, we looked at bottom-up and top-down IF markers using resting state electroencephalographic (EEG) data from PD patients analyzed through three different IF measures (direct Directed Transfer Function (dDTF), full frequency Directed Transfer Function (ff-DTF), and renormalized Partial Directed Coherence (rPDC). Results:We observed an increased gamma band IF and a reduced beta band IF in PD patients compared to healthy controls. Additionally, we noticed a reduced theta band IF in PD patients using dDTF as a measure of IF. By source localizing the EEG activity of the PD patients and healthy controls, we looked at the alterations of IF in the prefrontal cortex of PD patients as well. Conclusion:In line with previous studies, our results suggest that the delicate balance between bottom-up and top-down IF is disrupted in Parkinson’s disease potentially contributing to the cognitive symptoms of PD patients.

中文翻译：

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神经退行性疾病中自下而上和自上而下的神经信息流改变的研究。

背景：仍然缺乏对包括阿尔茨海默病和帕金森病 (PD) 在内的神经退行性疾病的知觉症状的正确解释。目的：本研究旨在调查 PD 中“自下而上”和“自上而下”信息流 (IF) 和处理之间的不平衡与幻视症状的相关性。方法：在这里，我们使用来自 PD 患者的静息状态脑电图 (EEG) 数据查看自下而上和自上而下的 IF 标记，这些数据通过三种不同的 IF 测量（直接定向传递函数 (dDTF)、全频定向传递函数 (ff- DTF) 和重整化部分定向相干 (rPDC)。结果：与健康对照相比，我们观察到 PD 患者的 γ 带 IF 增加，β 带 IF 降低。此外，我们注意到使用 dDTF 作为 IF 的量度的 PD 患者的 theta 波段 IF 降低。通过对 PD 患者和健康对照的 EEG 活动进行源定位，我们还研究了 PD 患者前额叶皮层中 IF 的变化。结论：与之前的研究一致，我们的结果表明自下而上和自上而下 IF 之间的微妙平衡在帕金森病中被破坏，可能导致 PD 患者的认知症状。