A direct relationship between oscillatory subthalamic nucleus-cortex coupling and rest tremor in Parkinson's disease
A direct relationship between oscillatory subthalamic nucleus-cortex coupling and rest tremor in Parkinson's disease
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DOI：
10.1093/brain/awt271
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发表时间：
2013-12-01
期刊：
影响因子：
14.5
通讯作者：
Schnitzler, Alfons
中科院分区：
文献类型：
--
作者：
Hirschmann, Jan;Hartmann, Christian J.;Schnitzler, Alfons
电生理学研究表明，帕金森病的静止性震颤与振荡活动的改变有关。尽管众所周知，震颤依赖于皮质肌肉耦合，但尚不清楚大脑区域内和之间的同步是否与震颤的存在和严重程度具体相关。为了解决这个长期存在的问题，我们利用自然发生的自发性震颤波动，研究了存在和不存在静止性震颤时的大脑同步性。我们同时记录了11名帕金森病患者（均为男性，年龄：52-74岁）的丘脑底核局部场电位、脑磁图和前臂肌电图。录音是在停止抗帕金森病药物后进行深部脑刺激手术后的第二天进行的。我们分别选择包含自发性静止性震颤和无震颤的时期，并比较不同条件下丘脑核、皮层和肌肉之间的功率和一致性。通过相干源动态成像来定位与震颤相关的脑肌肉相干性变化。随后，通过计算相干性的虚部（一种对体积传导不敏感的耦合测量）来分析皮质-皮质耦合。震颤发作后，局部场电位功率在个别震颤频率下增加，而皮层功率在 β 频段（13-30 Hz）下降。震颤期间，传感器水平的丘脑核-皮质、皮质-肌肉和丘脑核-肌肉的一致性增加，特别是在震颤频率下。丘脑底核-皮质一致性的增加与肌电图功率的增加相关。在源水平上，我们观察到与震颤相关的初级运动皮层、前运动皮层和震颤肢体对侧的后顶叶皮层的皮质肌肉一致性增加。对相干性虚部的分析揭示了这些皮质区域在震颤频率和双震颤频率下的震颤依赖性耦合。我们的研究结果证明了大脑振荡的同步性与震颤表现之间的直接关系。此外，他们提出了基于局部场电位的震颤检测的可行性，因此可能与闭环刺激系统的设计相关。
Electrophysiological studies suggest that rest tremor in Parkinson's disease is associated with an alteration of oscillatory activity. Although it is well known that tremor depends on cortico-muscular coupling, it is unclear whether synchronization within and between brain areas is specifically related to the presence and severity of tremor. To tackle this longstanding issue, we took advantage of naturally occurring spontaneous tremor fluctuations and investigated cerebral synchronization in the presence and absence of rest tremor. We simultaneously recorded local field potentials from the subthalamic nucleus, the magnetoencephalogram and the electromyogram of forearm muscles in 11 patients with Parkinson's disease (all male, age: 52-74 years). Recordings took place the day after surgery for deep brain stimulation, after withdrawal of anti-parkinsonian medication. We selected epochs containing spontaneous rest tremor and tremor-free epochs, respectively, and compared power and coherence between subthalamic nucleus, cortex and muscle across conditions. Tremor-associated changes in cerebro-muscular coherence were localized by Dynamic Imaging of Coherent Sources. Subsequently, cortico-cortical coupling was analysed by computation of the imaginary part of coherency, a coupling measure insensitive to volume conduction. After tremor onset, local field potential power increased at individual tremor frequency and cortical power decreased in the beta band (13-30 Hz). Sensor level subthalamic nucleus-cortex, cortico-muscular and subthalamic nucleus-muscle coherence increased during tremor specifically at tremor frequency. The increase in subthalamic nucleus-cortex coherence correlated with the increase in electromyogram power. On the source level, we observed tremor-associated increases in cortico-muscular coherence in primary motor cortex, premotor cortex and posterior parietal cortex contralateral to the tremulous limb. Analysis of the imaginary part of coherency revealed tremor-dependent coupling between these cortical areas at tremor frequency and double tremor frequency. Our findings demonstrate a direct relationship between the synchronization of cerebral oscillations and tremor manifestation. Furthermore, they suggest the feasibility of tremor detection based on local field potentials and might thus become relevant for the design of closed-loop stimulation systems.