Functional MRI study of thalamic and cortical activations evoked by cutaneous heat, cold, and tactile stimuli
Functional MRI study of thalamic and cortical activations evoked by cutaneous heat, cold, and tactile stimuli
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DOI：
10.1152/jn.1998.80.3.1533
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发表时间：
1998-09-01
影响因子：
2.5
通讯作者：
Mikulis, DJ
中科院分区：
文献类型：
--
作者：
Davis, KD;Kwan, CL;Mikulis, DJ
正电子发射断层扫描的研究提供了证据，丘脑和皮层参与疼痛和温度的感知。然而，这些结构的参与，在疼痛和温度感知的个别科目还没有详细研究与高空间分辨率成像。作为实现这一目标的第一步，我们已经使用功能性磁共振成像（fMRI）来定位丘脑，丘脑和第二体感皮层（S2）在无害和有害的热刺激调制的离散区域。结果进行了比较，在手掌的触觉刺激。在1.5T回波速度GE MR系统上获得高分辨率功能图像，面内分辨率为1.7mm。使用改良的Peltier型热刺激器对正常男性和女性志愿者的鱼际隆起进行40-60 s的无害冷、温和有害冷、热刺激。实验范式包括四个重复的交错控制和任务刺激。在每个任务与对照期间获得的图像的逐像素统计分析（例如，有害热vs.，温暖，温暖vs.中性温度等）用于确定与任务相关的激活。疼痛性热刺激激活了外侧和内侧丘脑内的离散区域，和丘脑，主要是在大多数受试者的前丘脑，50%的受试者的对侧S2。无害的热刺激没有激活任何受试者的S2，但激活了50%的受试者的丘脑和后丘脑。相比之下，无害的触觉刺激始终激活双侧S2和对侧外侧丘脑。这些数据还表明，有毒的热和无害的燃烧相关的激活重叠在S2。这些数据还表明，无害和有毒相关的激活可能在丘脑内重叠，但可能位于丘脑的不同区域。因此，我们提供了支持的作用，前丘脑，S2，丘脑在感知疼痛，而后丘脑似乎参与触觉和无害的温度感知。这些数据表明，使用功能磁共振成像的疼痛，温度和机械刺激的研究在个别科目的可行性，甚至在小区域，如丘脑核。然而，在未来的单个受试者成像研究和依赖于平均组反应的研究中，应考虑受试者间的变异性。
Positron emission tomography studies have provided evidence for the involvement of the thalamus and cortex in pain and temperature perception. However, the involvement of these structures in pain and temperature perception of individual subjects has not been studied in detail with high spatial resolution imaging. As a first step toward this goal, we have used functional magnetic resonance imaging (fMRI) to locate discrete regions of the thalamus, insula, and second somatosensory cortex (S2) modulated during innocuous and noxious thermal stimulation. Results were compared with those obtained during tactile stimulation of the palm. High resolution functional images were acquired on a 1.5 T echospeed GE MR system with an in-plane resolution of 1.7 mm. A modified peltier-type thermal stimulator was used to deliver innocuous cool and warm and noxious cold and hot stimuli for 40-60 s to the thenar eminence of normal male and female volunteers. Experimental paradigms consisted of four repetitions of interleaved control and task stimuli. A pixel by pixel statistical analysis of images obtained during each task versus control (e.g., noxious heat vs, warm, warm vs. neutral temperature, etc.) was used to determine task-related activations. Painful thermal stimuli activated discrete regions within the lateral and medial thalamus, and insula, predominantly in the anterior insula in most subjects, and the contralateral S2 in 50% of subjects. The innocuous thermal stimuli did not activate the S2 in any of the subjects but activated the thalamus and posterior insula in 50% of subjects. By comparison, innocuous tactile stimulation consistently activated S2 bilaterally and the contralateral lateral thalamus. These data also demonstrate that noxious thermal and innocuous tactile-related activations overlap in S2. The data also suggest that innocuous and noxious-related activations may overlap within the thalamus but may be located in different regions of the insula. Therefore, we provide support for a role of the anterior insula, S2, and thalamus in the perception of pain; whereas the posterior insula appears to be involved in tactile and innocuous temperature perception. These data demonstrate the feasibility of using fMRI for studies of pain, temperature, and mechanical stimuli in individual subjects, even in small regions such as thalamic nuclei. However, the intersubject variability should be considered in future single subject imaging studies and studies that rely on averaged group responses.