Gallasch Eugen, Golaszewski Stefan M, Fend Martin, Siedentopf Christian M, Koppelstaetter Florian, Eisner Wilhelm, Gerstenbrand Franz, Felber Stephan R
Department of Physiology, Medical University Graz, Graz, Austria.
J Magn Reson Imaging. 2006 Nov;24(5):1177-82. doi: 10.1002/jmri.20742.
To study cerebral responses evoked from mechanoreceptors in the human foot sole using a computer-controlled vibrotactile stimulation system.
The stimulation system consisted of two stationary moving magnet actuators with indentors to gently contact and vibrate the foot sole during functional MRI (fMRI) experiments. To allow independent settings of contact force (0-20 N) and intensity of vibration (frequency range=20-100 Hz) the actuators were controlled by a digital servo loop. For fMRI experiments with complex stimulus protocols, both vibrating probes were further operated under supervisory control.
The MR compatibility of this electromagnetic system was tested in a 1.5T scanner with an actively shielded magnet (Siemens Magnetom Sonata). Blood oxygenation level-dependent (BOLD) responses were detected in the contralateral left pre- and postcentral gyrus, bilaterally within the secondary somatosensory cortex, bilaterally within the supplementary motor cortex, and bilaterally within the anterior cingular gyrus.
This stimulation device provides a new tool for identifying cerebral structures that convey sensory information from the foot region, which is of promising diagnostic value, particularly for assessing sensorimotor deficits resulting from brain lesions.
使用计算机控制的振动触觉刺激系统研究人类足底机械感受器诱发的大脑反应。
刺激系统由两个带有压头的固定移动磁体致动器组成，在功能磁共振成像（fMRI）实验期间，压头可轻轻接触并振动足底。为了能够独立设置接触力（0 - 20 N）和振动强度（频率范围 = 20 - 100 Hz），致动器由数字伺服回路控制。对于采用复杂刺激方案的fMRI实验，两个振动探头在监控下进一步操作。
该电磁系统的磁共振兼容性在配备有源屏蔽磁体的1.5T扫描仪（西门子Magnetom Sonata）中进行了测试。在对侧左中央前回和中央后回、双侧次级体感皮层、双侧辅助运动皮层以及双侧前扣带回中检测到了血氧水平依赖（BOLD）反应。
该刺激装置为识别从足部区域传递感觉信息的脑结构提供了一种新工具，具有广阔的诊断价值，特别是对于评估脑损伤导致的感觉运动缺陷。
