PDF(Pubmed)
Abstract：
The role of brain asymmetries of dopaminergic neurons in motor symptoms of Parkinson\'s disease is still undefined. Local field recordings from the subthalamic nucleus revealed some neurophysiological biomarkers of the disease: increased beta activity, increased low-frequency activity and high-frequency oscillations. Phase-amplitude coupling coordinates the timing of neuronal activity and allows determining the mechanism for communication within distinct regions of the brain. In this study, we discuss the use of phase-amplitude coupling to assess the differences between the two hemispheres in a cohort of 24 patients with Parkinson\'s disease before and after levodopa administration. Subthalamic low- (12-20 Hz) and high-beta (20-30 Hz) oscillations were compared with low- (30-45 Hz), medium- (70-100 Hz) and high-frequency (260-360 Hz) bands. We found a significant beta-phase-amplitude coupling asymmetry between left and right and an opposite-side-dependent effect of the pharmacological treatment, which is associated with the reduction of motor symptoms. In particular, high coupling between high frequencies and high-beta oscillations was found during the OFF condition (P < 0.01) and a low coupling during the ON state (P < 0.0001) when the right subthalamus was assessed; exactly the opposite happened when the left subthalamus was considered in the analysis, showing a lower coupling between high frequencies and high-beta oscillations during the OFF condition (P < 0.01), followed by a higher one during the ON state (P < 0.01). Interestingly, these asymmetries are independent of the motor onset side, either left or right. These findings have important implications for neural signals that may be used to trigger adaptive deep brain stimulation in Parkinson\'s and could provide more exhaustive insights into subthalamic dynamics.
摘要：
多巴胺能神经元的脑不对称性在帕金森病运动症状中的作用尚不明确。来自丘脑底核的局部现场记录揭示了该疾病的一些神经生理学生物标志物：增加的β活性，增加了低频活动和高频振荡。相位-振幅耦合协调神经元活动的定时，并允许确定大脑不同区域内的通信机制。在这项研究中,我们讨论了使用相位-振幅耦合评估左旋多巴给药前后24例帕金森病患者的两个半球之间的差异。将丘脑低（12-20Hz）和高β（20-30Hz）振荡与低（30-45Hz）振荡进行了比较，中（70-100赫兹）和高频（260-360赫兹）频段。我们发现左右之间存在明显的β相位-振幅耦合不对称性，并且药物治疗具有相反的依赖性作用，这与运动症状的减少有关。特别是,当评估右下丘脑时，在OFF条件（P<0.01）和ON状态（P<0.0001）期间发现高频和高β振荡之间的高耦合，而在分析中考虑左下丘脑时，情况正好相反，在OFF条件下，高频和高β振荡之间的耦合较低（P<0.01），其次是较高的一个在ON状态(P<0.01)。有趣的是,这些不对称性独立于运动开始侧，左或右。这些发现对神经信号具有重要意义，这些神经信号可用于在帕金森氏症中触发自适应深部脑刺激，并可以提供对丘脑下动力学的更详尽的见解。
