Patil Parag G, Carmena Jose M, Nicolelis Miguel A L, Turner Dennis A
Division of Neurosurgery, Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Neurosurgery. 2004 Jul;55(1):27-35; discussion 35-8.
Patients with severe neurological injury, such as quadriplegics, might benefit greatly from a brain-machine interface that uses neuronal activity from motor centers to control a neuroprosthetic device. Here, we report an implementation of this strategy in the human intraoperative setting to assess the feasibility of using neurons in subcortical motor areas to drive a human brain-machine interface.
Acute ensemble recordings from subthalamic nucleus and thalamic motor areas (ventralis oralis posterior [VOP]/ventralis intermediate nucleus [VIM]) were obtained in 11 awake patients during deep brain stimulator surgery by use of a 32-microwire array. During extracellular neuronal recordings, patients simultaneously performed a visual feedback hand-gripping force task. Offline analysis was then used to explore the relationship between neuronal modulation and gripping force.
Individual neurons (n = 28 VOP/VIM, n = 119 subthalamic nucleus) demonstrated a variety of modulation responses both before and after onset of changes in gripping force of the contralateral hand. Overall, 61% of subthalamic nucleus neurons and 81% of VOP/VIM neurons modulated with gripping force. Remarkably, ensembles of 3 to 55 simultaneously recorded neurons were sufficiently information-rich to predict gripping force during 30-second test periods with considerable accuracy (up to R = 0.82, R(2) = 0.68) after short training periods. Longer training periods and larger neuronal ensembles were associated with improved predictive accuracy.
This initial feasibility study bridges the gap between the nonhuman primate laboratory and the human intraoperative setting to suggest that neuronal ensembles from human subcortical motor regions may be able to provide informative control signals to a future brain-machine interface.
患有严重神经损伤的患者，如四肢瘫痪者，可能会从一种脑机接口中大大受益，该接口利用运动中枢的神经元活动来控制神经假体装置。在此，我们报告了这一策略在人体术中环境中的实施情况，以评估利用皮质下运动区域的神经元来驱动人脑机接口的可行性。
在11名清醒患者进行脑深部刺激器手术期间，使用32微丝阵列从丘脑底核和丘脑运动区域（腹后外侧核[VOP]/腹中间核[VIM]）获取急性群体记录。在细胞外神经元记录期间，患者同时执行视觉反馈手握力任务。然后进行离线分析，以探索神经元调制与握力之间的关系。
单个神经元（n = 28个VOP/VIM，n = 119个丘脑底核）在对侧手握力变化开始之前和之后均表现出多种调制反应。总体而言，61%的丘脑底核神经元和81%的VOP/VIM神经元随握力调制。值得注意的是，在短训练期后，3至55个同时记录的神经元群体在30秒测试期内具有足够丰富的信息，能够以相当高的准确度预测握力（相关系数高达R = 0.82，决定系数R(2) = 0.68）。更长的训练期和更大的神经元群体与更高的预测准确度相关。
这项初步可行性研究弥合了非人灵长类动物实验室与人体术中环境之间的差距，表明来自人类皮质下运动区域的神经元群体或许能够为未来的脑机接口提供信息丰富的控制信号。
