Beudel Martijn, Little Simon, Pogosyan Alek, Ashkan Keyoumars, Foltynie Thomas, Limousin Patricia, Zrinzo Ludvic, Hariz Marwan, Bogdanovic Marko, Cheeran Binith, Green Alexander L, Aziz Tipu, Thevathasan Wesley, Brown Peter
Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK.
Department of Neurology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands.
Neuromodulation. 2015 Jul;18(5):349-54. doi: 10.1111/ner.12297. Epub 2015 Apr 16.
Rest tremor is a cardinal symptom of Parkinson's disease (PD), and is readily suppressed by deep brain stimulation (DBS) of the subthalamic nucleus (STN). The therapeutic effect of the latter on bradykinesia and rigidity has been associated with the suppression of exaggerated beta (13-30 Hz) band synchronization in the vicinity of the stimulating electrode, but there is no correlation between beta suppression and tremor amplitude. In the present study, we investigate whether tremor suppression is related to suppression of activities at other frequencies.
We recorded hand tremor and contralateral local field potential (LFP) activity from DBS electrodes during stimulation of the STN in 15 hemispheres in 11 patients with PD. DBS was applied with increasing voltages starting at 0.5 V until tremor suppression was achieved or until 4.5 V was reached.
Tremor was reduced to 48.9% ± 10.9% of that without DBS once stimulation reached 2.5-3 V (t14 = -4.667, p < 0.001). There was a parallel suppression of low gamma (31-45 Hz) power to 92.5% ± 3% (t14 = -2.348, p = 0.034). This was not seen over a band containing tremor frequencies and their harmonic (4-12 Hz), or over the beta band. Moreover, low gamma power correlated with tremor severity (mean r = 0.43 ± 0.14, p = 0.008) within subjects. This was not the case for LFP power in the other two bands.
Our findings support a relationship between low gamma oscillations and PD tremor, and reinforce the principle that the subthalamic LFP is a rich signal that may contain information about the severity of multiple different Parkinsonian features.
静止性震颤是帕金森病（PD）的主要症状，可通过丘脑底核（STN）的深部脑刺激（DBS）轻易抑制。后者对运动迟缓及强直的治疗效果与刺激电极附近过度的β（13 - 30Hz）频段同步性的抑制有关，但β抑制与震颤幅度之间并无关联。在本研究中，我们探究震颤抑制是否与其他频率活动的抑制有关。
我们记录了11例PD患者15个脑半球在STN刺激期间，DBS电极处的手部震颤及对侧局部场电位（LFP）活动。从0.5V开始逐渐增加电压进行DBS，直至震颤被抑制或达到4.5V。
一旦刺激达到2.5 - 3V，震颤降至无DBS时的48.9%±10.9%（t14 = -4.667，p < 0.001）。同时，低γ（31 - 45Hz）功率平行抑制至92.5%±3%（t14 = -2.348，p = 0.034）。在包含震颤频率及其谐波（4 - 12Hz）的频段或β频段上未观察到这种情况。此外，在个体内部，低γ功率与震颤严重程度相关（平均r = 0.43±0.14，p = 0.008）。其他两个频段的LFP功率则并非如此。
我们的研究结果支持低γ振荡与PD震颤之间的关系，并强化了丘脑底核LFP是一个丰富信号的原则，该信号可能包含有关多种不同帕金森特征严重程度的信息。
