II Neurological Department and Multiple Sclerosis Center, San Luigi Hospital, Orbassano, Turin, Italy.
Clin Neurophysiol. 2011 Oct;122(10):2071-80. doi: 10.1016/j.clinph.2011.03.002. Epub 2011 Mar 31.
To describe a neurophysiological method to locate the optimal stimulation site (OSS) over the vertebral column, customized to the individual subject, to achieve maximal activation of lumbosacral roots by means of non-invasive high voltage electrical stimulation (HVES).
OSS was located in 30 volunteers by testing different stimulation points of a surface multi-electrode array placed over the dorso-lumbar junction of the vertebral column. The dorso-ventral stimulating montage was used (Troni et al., 1996). Motor responses to root stimulation (rCMAPs) were bilaterally recorded from Vastus Medialis (VM), Tibialis Anterior (TA), Soleus (SL) and Flexor Hallucis Brevis (FHB) muscles. The direct nature of rCMAPs was tested by delivering two maximal stimuli 50 ms apart.
Except for a few subjects with large girth, maximal rCMAPs could be obtained from all muscles with a stimulating current intensity up to 550 V (1050 mA). Maximal double HVES excluded any reflex component in the recorded rCMAPs. The procedure was well tolerated and no side effects were observed.
A single maximal electric shock delivered at the proper vertebral level by means of the dorso-ventral montage is able to safely achieve synchronous, bilateral maximal activation of several roots, from L3 to S1.
Maximal activation of lumbosacral roots at their origin, unattainable with magnetic stimulation, is the essential requirement for direct detection of proximal nerve conduction slowing and block in lower limbs.
描述一种神经生理学方法，通过非侵入性高压电刺激（HVES），针对个体受试者，定位位于脊柱上的最佳刺激部位（OSS），以实现对腰骶神经根的最大激活。
通过测试放置在脊柱背-腰部交界处的表面多电极阵列的不同刺激点，对 30 名志愿者进行 OSS 定位。使用背-腹刺激模式（Troni 等人，1996 年）。通过从股四头肌（VM）、胫骨前肌（TA）、比目鱼肌（SL）和腓肠肌短肌（FHB）双侧记录神经根刺激的运动反应（rCMAPs）来定位。通过相隔 50 毫秒施加两次最大刺激来测试 rCMAPs 的直接性质。
除了少数腰围较大的受试者外，通过施加高达 550 V（1050 mA）的刺激电流强度，所有肌肉都可以获得最大的 rCMAPs。最大的双 HVES 排除了记录的 rCMAPs 中的任何反射成分。该程序耐受性良好，未观察到副作用。
通过背-腹模式在适当的椎骨水平施加单次最大电击，能够安全地同步激活 L3 到 S1 的多个神经根，达到双侧最大激活。
在磁刺激无法达到的神经根起源处实现最大激活，是直接检测下肢近端神经传导减慢和阻滞的基本要求。
