Evaluation of cortical activation area responsible for changes in orofacial function: An fMRI study

血氧水平依赖(BOLD)-功能磁共振成像（fMRI）被认为是研究人类大脑功能的一种无创技术。本研究将上述方法应用于8名正常的右撇子志愿者，目的是确定负责产生舌头运动的大脑区域及其与个体咀嚼侧偏好的关系。所有受试者均给予书面知情同意，并经当地伦理批准进行研究，实验结束后进行咀嚼侧偏好访谈。在磁共振成像前，所有受试者都接受了舌运动训练，并通过口面部肌肉的肌电图活动进行视觉反馈，以最大限度地减少口面部运动对所获得图像的伪影。使用ASiemens Vision 1.5T MRI仪进行图像采集。采用SPM99软件对数据进行分析。在组间分析中，舌动过程中主要感觉运动皮层、辅助运动区和小脑的BOLD信号明显高于静息状态；在所有的例子中，两个半球的这些大脑区域都在舌头向左右两侧的所有突出运动中被激活。通过对6名咀嚼侧边偏好明显的被试不同舌头运动时BOLD信号的个体分析，初级感觉运动皮层和小脑的信号强度分别在咀嚼侧边偏好的对侧和同侧有较大的趋势。结果表明，在负责舌头运动的初级感觉运动皮层中，存在半球优势和咀嚼侧偏好之间的关系。

Blood oxygenation level dependent (BOLD)-functional magnetic resonance imaging (fMRI) is known to be a noninvasive technique for studying human brain function. The purpose of this study, applying the above method to 8 normal right-handed volunteers, was to identify brain areas responsible for producing tongue movements and their relations with the individual chewing side preference. All subjects gave written informed consentand were studied with local ethical approval, and the chewing side preference was interviewed after the experiment. All subjects were trained, before the MR imaging, to perform tongue movements with visual feedback of electromyographic activities of orofacial muscles in order to minimize the artifacts onto the acquired images by motion of orofacial area. ASiemens Vision 1.5T MRI apparatus was used for image acquisition. The data were analyzed by SPM99. In the group analysis, marked increase of BOLD signals compared with the rest conditions was detected during tongue movements in primary sensorimotor cortices, supplementary motor area and cerebellum ; in all instances were these brain areas of both hemispheres activated upon all of protrusion, rignt and leftward tongue movements. By the individual-based analysis of BOLD signals during various tongue movements in 6 subjects with evident chewing side preference, the signal intensity of the primary sensorimotor cortex and the cerebellum tended to be greater in the contralateral and ipsilateral side of the chewing side preference, respectively. The results suggest that, in primary sensorimotor cortices responsible for tongue movements, there is a relationship between hemispheric dominance and chewing side preference across subjects.