Compta Yaroslau, Valls-Solé Josep, Valldeoriola Francesc, Kumru Hatice, Rumià Jordi
Department of Neurology, Hospital Clínic, Universitat de Barcelona, IDIBAPS (Institut d'Investigació Biomèdica August Pi i Sunyer), Barcelona, Spain.
Clin Neurophysiol. 2006 Nov;117(11):2512-20. doi: 10.1016/j.clinph.2006.08.005. Epub 2006 Sep 27.
We aimed at characterizing the silent period induced in hand muscles by subcortical stimulation through electrodes implanted on the subthalamic nucleus for deep brain stimulation (STN-DBS).
In 10 patients with Parkinson's disease, we analyzed the inhibitory effects induced in the contralateral and ipsilateral thenar muscles by STN-DBS of varying stimulus intensity and strength of muscle contraction.
Both, the contralateral silent period (CSP) and the ipsilateral silent period (ISP) were induced by stimuli at an intensity subthreshold for eliciting a contralateral motor evoked potential (MEP) and were composed of two phases. With a stimulus intensity of 120% of active threshold and a strength of 20%, the first CSP had a mean onset latency of 38.0 +/- 2.9 ms and a mean duration of 37.7 ms +/- 2.8 ms, and the second CSP had a mean onset latency of 90.6 +/- 18.5 ms and a mean duration of 53.4 +/- 6.3 ms. The first ISP had a mean onset latency of 34.9 +/- 4.3 ms and a mean duration of 12.5 +/- 3.4 ms, and the second ISP had a mean onset latency of 76.3 +/- 10.1 ms and a mean duration of 23.1 +/- 9.0 ms. The duration of both phases of the CSP increased with increasing the stimulus intensity and the burst separating the two phases of the CSP increased in size with increasing the strength of muscle contraction or the stimulus intensity. No ipsilateral MEP was observed in any patient at any strength or stimulus intensity.
Our results indicate that the silent period induced by STN-DBS has specific physiological mechanisms that differ from those of the silent period induced by cortical transcranial magnetic stimulation.
The induction of ISP by stimulation of the motor tract at a point caudal to the corpus callosum indicates that non-callosal pathways are capable of generating ISP.
我们旨在通过植入丘脑底核的电极进行皮层下刺激以用于深部脑刺激（STN - DBS），来表征手部肌肉中诱发的静息期。
在10例帕金森病患者中，我们分析了不同刺激强度和肌肉收缩强度的STN - DBS对同侧和对侧鱼际肌诱发的抑制作用。
对侧静息期（CSP）和同侧静息期（ISP）均由低于引发对侧运动诱发电位（MEP）阈值的刺激诱发，且均由两个阶段组成。在刺激强度为激活阈值的120%且强度为20%时，首个CSP的平均起始潜伏期为38.0±2.9毫秒，平均持续时间为37.7毫秒±2.8毫秒，第二个CSP的平均起始潜伏期为90.6±18.5毫秒，平均持续时间为53.4±6.3毫秒。首个ISP的平均起始潜伏期为34.9±4.3毫秒，平均持续时间为12.5±3.4毫秒，第二个ISP的平均起始潜伏期为76.3±10.1毫秒，平均持续时间为23.1±9.0毫秒。CSP两个阶段的持续时间均随刺激强度增加而增加，且分隔CSP两个阶段的爆发波大小随肌肉收缩强度或刺激强度增加而增大。在任何强度或刺激强度下，均未在任何患者中观察到同侧MEP。
我们的结果表明，STN - DBS诱发的静息期具有与皮层经颅磁刺激诱发的静息期不同的特定生理机制。
在胼胝体尾侧一点刺激运动通路诱发ISP表明，非胼胝体通路能够产生ISP。
