Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, London, WC1N 3BG UK.
Neuroscience. 2010 Nov 24;171(1):245-57. doi: 10.1016/j.neuroscience.2010.08.068. Epub 2010 Sep 9.
The local strength of pathological synchronization in the region of the subthalamic nucleus (STN) is emerging as a possible factor in the motor impairment of Parkinson's Disease (PD). In particular, correlations have been repeatedly demonstrated between treatment-induced suppressions of local oscillatory activity in the beta frequency band and improvements in motor performance. However, a mechanistic role for beta activity is brought into question by the difficulty in showing a correlation between such activity at rest and the motor deficit in patients withdrawn from medication. Here we recorded local field potential (LFP) activity from 36 subthalamic regions in 18 patients undergoing functional neurosurgery for the treatment of PD. We recorded directly from the contacts of the deep brain stimulation (DBS) electrodes as they were introduced in successive 2 mm steps, and assessed phase coherence as a measure of spatially extended, rather than local, oscillatory synchronization. We found that phase coherence in the beta frequency band correlated with the severity of Parkinsonian bradykinesia and rigidity, both in the limbs and axial body. Such correlations were frequency and site specific in so far as they were reduced when the lowermost contact of the DBS electrode was above the dorsal STN. Correlations with limb tremor occurred at sub-beta band frequencies and were more lateralized than those between beta activity and limb bradykinesia and rigidity. Phase coherence could account for up to ∼25% of the variance in motor scores between sides and patients. These new data suggest that the strength of spatially extended oscillatory synchronization, as well as the strength of local synchronization, may be worthwhile incorporating into modelling studies designed to inform surgical targeting, post-operative stimulation parameter selection and closed-loop stimulation regimes in PD. In addition, they strengthen the link between pathological synchronization and the different motor features of Parkinsonism.
局部的亚核区（STN）病理性同步现象的强度可能是帕金森病（PD）运动障碍的一个因素。特别是，在β频带的局部振荡活动的治疗诱导抑制与运动表现的改善之间，已经反复显示出相关性。然而，β活动的机制作用受到以下事实的质疑，即在停止药物治疗的患者中，很难显示静息状态下的这种活动与运动缺陷之间的相关性。在这里，我们记录了 18 名接受功能性神经外科手术治疗 PD 的患者的 36 个 STN 区域的局部场电位（LFP）活动。我们直接记录深部脑刺激（DBS）电极接触的局部场电位（LFP）活动，这些电极在逐步推进的 2mm 步长中被引入，并评估相位相干性作为衡量空间扩展而非局部振荡同步性的指标。我们发现，β频带中的相位相干性与帕金森病性运动徐缓和僵硬的严重程度相关，无论是在肢体还是轴向身体中。这些相关性在频率和部位上都是特定的，因为当 DBS 电极的最下部接触位于 STN 背侧上方时，它们会降低。与肢体震颤相关的相关性发生在亚β频带频率，并且比β活动与肢体运动徐缓和僵硬之间的相关性更偏向于一侧。相位相干性可以解释运动评分在侧面和患者之间的变化高达 25%。这些新数据表明，空间扩展振荡同步的强度以及局部同步的强度可能值得纳入旨在为手术靶点、术后刺激参数选择和 PD 闭环刺激方案提供信息的建模研究中。此外，它们加强了病理性同步与帕金森病不同运动特征之间的联系。
