fMRI观察电刺激麻木感对正常人中枢神经系统的影响

Task-state fMRI observation on impact of electrical stimulation numbness to central nervous system in normal people

目的观察电刺激麻木感对正常人中枢神经系统的影响。方法对22名健康受试者以电刺激仪于右侧脚踝上方建立低频率及高频率电刺激麻木感模型,记录其对不同电刺激的麻木感评分和情绪效价评分;采集任务态血氧水平依赖fMRI(BOLD-fMRI),比较低频率及高频率电刺激下麻木感及情绪效价评分的差异,经分析获得不同频率电刺激下脑激活强度显著差异的脑区,比较不同强度电刺激下脑激活区激活效应值差异,分析高频电刺激下麻木感与情绪效价评分的关系。结果不同频率电刺激下,受试者麻木感评分(t=13.18)及情绪效价评分(t=10.77)差异均有统计学意义(P均<0.01)。高频电刺激下,麻木感与效价评分呈负相关(r=-0.53,P=0.01)。不同电刺激下脑激活强度存在差异显著脑区包括左侧岛叶顶盖、左侧中扣带回、左侧颞叶、右侧顶叶岛盖、左侧中央后回、右侧中央岛盖、右侧岛叶后部及左侧丘脑,其激活效应值差异均有统计学意义(P均<0.05)。结论电刺激麻木感可激活正常人左侧岛叶顶盖、左侧中扣带回、左侧颞叶、右侧顶叶岛盖、左侧中央后回、右侧中央岛盖、右侧岛叶后部及左侧丘脑;组块设计BOLD-fMRI可用于检测麻木感相关脑区活动。

Objective To investigate the impact of electrical stimulation numbness to central nervous system in normal people.Methods Electric stimulator was used to establish low-frequency,high-frequency numbness models with 22 healthy subjects.Scores for numbness and emotional valence for different electrical stimulations were recorded,and data of functional MRI(fMRI)in task state were also collected.The differences of numbness and emotional valence score of subjects under low frequency and high frequency electrical stimulation were compared,respectively.Then brain regions with significant differences in brain activation intensity under different frequencies of electrical stimulation were obtained,and the differences of activation effect values of activated brain regions under different electrical stimulations intensity were compared,respectively.The relationship of numbness and emotional valence scores under high frequency electrical stimulation were analyzed.Results There were statistical differences of numbness(t=13.18)and valence score(t=10.77)under different electrical stimulations(both P<0.05).There was negative correlation between numbness and valence scores under high-frequency electrical stimulation(r=-0.53,P=0.01).The brain areas with significant differences of activation intensity under different electrical stimulation included left parietal operculum,left middle cingulate gyrus,left temporal gyrus,right parietal operculum,left postcentral gyrus,right central operculum,right posterior insula and left thalamus(all P<0.05).Conclusion The activated brain regions under different electrical stimulations caused numbness include left parietal operculum,left middle cingulate gyrus,left temporal gyrus,right parietal operculum,left postcentral gyrus,right central operculum,right posterior insula and left thalamus in normal people.Block-designed BOLD-fMRI can be used to detect activity of brain areas associated with numbness.