The cerebral oscillatory network of parkinsonian resting tremor
The cerebral oscillatory network of parkinsonian resting tremor
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DOI：
10.1093/brain/awg022
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发表时间：
2003-01-01
期刊：
影响因子：
14.5
通讯作者：
Schnitzler, A
中科院分区：
文献类型：
--
作者：
Timmermann, L;Gross, J;Schnitzler, A
来自MPTP猴实验以及来自帕金森病患者的侵入性和非侵入性记录的数据表明，帕金森病中静息震颤产生中神经元活动的异常同步。在6例震颤为主的特发性帕金森病患者中，我们同时记录了手部肌肉的表面肌电图（EMG）和全头脑磁图（MEG）系统的大脑活动。使用最近开发的分析工具（相干源的动态成像; DICS），我们确定了脑-肌肉和脑-大脑的相干性以及大脑区域和肌肉之间的部分相干性，并在单独的MRI扫描中定位相干源。EMG和大脑活动之间的相位滞后通过两个信号的希尔伯特变换来确定。停药过夜后，患者表现出典型的帕金森病静息震颤（4-6 Hz）。这种震颤与前臂肌肉的EMG和对侧初级运动皮层（M1）在震颤频率和双震颤频率下的活动之间的强相干性有关。M1活动和EMG之间的相位滞后在15和25毫秒之间（M1活动领先），在单一的，但也在双震颤频率，以及对应的皮质肌传导时间。此外，在单次震颤时，M1与内侧壁区（扣带/辅助运动区; CMA/SMA）、外侧运动前皮层（PM）、间脑、次级体感皮层（SII）、后顶叶皮层（PPC）和对侧小脑之间观察到显著的一致性，在双次震颤频率时甚至更强。丘脑活动和小脑以及几个大脑区域之间的相干性光谱显示了20 Hz附近的额外宽峰。功率谱分析表明，在所有中心地区的活动最强的频率成分在双震颤频率。部分相干分析和相移的计算显示，EMG和间脑活动之间的双向耦合和EMG和SII和PPC之间的直接传入耦合。相比之下，小脑、SMA/CMA和PM与外周EMG直接耦合的证据很少，但似乎通过其他大脑区域（例如M1）与外周相连。总而言之，我们的结果表明，大脑网络内存在与震颤相关的振荡活动，其中小脑-间脑-皮质环路以及对侧的皮质运动（M1、SMA/CMA、PM）和感觉（SII、PPC）区域存在异常耦合震颤手。脑-脑耦合的主要频率对应于震颤频率的两倍。
Data from experiments in MPTP monkeys as well as from invasive and non-invasive recordings in patients with Parkinson's disease suggest an abnormal synchronization of neuronal activity in the generation of resting tremor in Parkinson's disease. In six patients with tremor-dominant idiopathic Parkinson's disease, we recorded simultaneously surface electromyograms (EMGs) of hand muscles, and brain activity with a whole-head magnetoencephalography (MEG) system. Using a recently developed analysis tool (Dynamic Imaging of Coherent Sources; DICS), we determined cerebro-muscular and cerebro-cerebral coherence as well as the partial coherence between cerebral areas and muscle, and localized coherent sources within the individual MRI scans. The phase lag between the EMG and cerebral activity was determined by means of a Hilbert transform of both signals. After overnight withdrawal from medication, patients showed typical Parkinson's disease resting tremor (4-6 Hz). This tremor was associated with strong coherence between the EMG of forearm muscles and activity in the contralateral primary motor cortex (M1) at tremor frequency but also at double tremor frequency. Phase lags between M1 activity and EMG were between 15 and 25 ms (M1 activity leading) at single, but also at double tremor frequency, corresponding well to the corticomuscular conduction time. Furthermore, significant coherence was observed between M1 and medial wall areas (cingulate/supplementary motor area; CMA/SMA), lateral premotor cortex (PM), diencephalon, secondary somatosensory cortex (SII), posterior parietal cortex (PPC) and the contralateral cerebellum at single tremor and, even stronger at double tremor frequency. Spectra of coherence between thalamic activity and cerebellum as well as several brain areas revealed additional broad peaks around 20 Hz. Power spectral analysis of activity in all central areas indicated the strongest frequency components at double tremor frequency. Partial coherence analysis and the calculation of phase shifts revealed a strong bidirectional coupling between the EMG and diencephalic activity and a direct afferent coupling between the EMG and SII and the PPC. In contrast, the cerebellum, SMA/CMA and PM show little evidence for direct coupling with the peripheral EMG but seem to be connected with the periphery via other cerebral areas (e.g. M1). In summary, our results demonstrate tremor-related oscillatory activity within a cerebral network, with abnormal coupling in a cerebello-diencephalic-cortical loop and cortical motor (M1, SMA/CMA, PM) and sensory (SII, PPC) areas contralateral to the tremor hand. The main frequency of cerebro-cerebral coupling corresponds to double the tremor frequency.