Neuroscience Laboratory, NSL (Brain, Cognition and Behavior), Department of Neuroscience, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran.
Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA.
J Alzheimers Dis. 2020;78(1):169-183. doi: 10.3233/JAD-200590.
A proper explanation for perceptual symptoms in neurodegenerative disorders including Alzheimer's disease and Parkinson's disease (PD) is still lacking.
This study aimed at investigating the imbalance between 'bottom-up' and 'top-down' information flow (IF) and processing in PD in relation with visual hallucination symptoms.
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).
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.
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.
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仍然缺乏合理的解释。
本研究旨在探讨 PD 中与视觉幻觉症状相关的“下传”和“上传”信息流（IF）及其处理之间的失衡。
在这里，我们使用 PD 患者的静息状态脑电图（EEG）数据，通过三种不同的 IF 测量方法（直接有向传递函数（dDTF）、全频有向传递函数（ff-DTF）和重归一化部分定向相干性（rPDC）来研究下传和上传 IF 标志物。
与健康对照组相比，我们观察到 PD 患者的伽马频带 IF 增加，β频带 IF 减少。此外，我们还注意到 PD 患者使用 dDTF 作为 IF 测量方法时，θ频带 IF 减少。通过对 PD 患者和健康对照组的 EEG 活动进行源定位，我们还观察了 PD 患者前额叶皮层 IF 的改变。
与之前的研究一致，我们的结果表明，帕金森病中下传和上传 IF 之间的微妙平衡被打破，这可能导致 PD 患者的认知症状。
