Reproducibility of human brain activity evoked by esophageal stimulation using functional magnetic resonance imaging
Reproducibility of human brain activity evoked by esophageal stimulation using functional magnetic resonance imaging
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DOI：
10.1152/ajpgi.00461.2006
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发表时间：
2007-07-01
影响因子：
4.5
通讯作者：
Aziz, Qasim
中科院分区：
文献类型：
--
作者：
Coen, Steven J.;Gregory, Lloyd J.;Aziz, Qasim
功能性磁共振成像是一种流行的工具，用于研究内脏疼痛的中枢加工在健康和临床人群。尽管如此，功能性核磁共振成像对内脏感觉的神经相关性的再现性仍不清楚。本研究的目的就是要解决这个问题。7名健康的右撇子志愿者参加了这项研究。在1.5 T时获得血氧水平相关的对比图像，同时受试者接受无疼痛和疼痛的相位球囊扩张（“开-关”块设计，每“开”期10次刺激，0.3 Hz）到食管远端。这一过程又重复了两次，以调查再现性。疼痛刺激在前岛、初级体感皮层和前扣带皮层的三个扫描过程中产生高度可重复的激活。从第1阶段到第3阶段，前扣带皮层、初级体感皮层和辅助运动皮层的激活强度显著降低，这可以用疼痛等级的类似降低来解释。非疼痛刺激激活的大脑区域与疼痛刺激相似，但信号强度和扫描之间激活区域的差异更大。对食道的疼痛刺激会在大脑的许多区域产生强烈的激活。从第一次扫描到最后一次扫描，主观痛觉和大脑活动的减少表明，连续的脑成像研究可能受到习惯化的影响。这些发现表明，对于需要连续扫描的脑成像研究，开发控制习惯效应的实验范式是必要的。
Functional MRI is a popular tool for investigating central processing of visceral pain in healthy and clinical populations. Despite this, the reproducibility of the neural correlates of visceral sensation by use of functional MRI remains unclear. The aim of the present study was to address this issue. Seven healthy right-handed volunteers participated in the study. Blood oxygen level-dependent contrast images were acquired at 1.5 T while subjects received nonpainful and painful phasic balloon distensions ("on-off" block design, 10 stimuli per "on" period, 0.3 Hz) to the distal esophagus. This procedure was repeated on two further occasions to investigate reproducibility. Painful stimulation resulted in highly reproducible activation over three scanning sessions in the anterior insula, primary somatosensory cortex, and anterior cingulate cortex. A significant decrease in strength of activation occurred from session 1 to session 3 in the anterior cingulate cortex, primary somatosensory cortex, and supplementary motor cortex, which may be explained by an analogous decrease in pain ratings. Nonpainful stimulation activated similar brain regions to painful stimulation, but with greater variability in signal strength and regions of activation between scans. Painful stimulation of the esophagus produces robust activation in many brain regions. A decrease in subjective perception of pain and brain activity from the first to the final scan suggests that serial brain imaging studies may be affected by habituation. These findings indicate that for brain imaging studies that require serial scanning, development of experimental paradigms that control for the effect of habituation is necessary.