基于分数低频振幅观察长时程电刺激诱发健康人肢体麻木后脑功能变化

Fractional amplitude low frequency fluctuation for observing brain function changes accompanying limb numbness induced by long-term electrical stimulation in healthy subjects

目的利用静息态功能MRI(rs-fMRI)分数低频振幅(fALFF)观察长时程电刺激(LTES)诱发健康人肢体麻木感后不同脑区功能变化。方法前瞻性对27名健康人以LTES诱发单侧肢体麻木感,每日1次、每次30 min,持续1周;分别于开始刺激前日及末次刺激次日采集脑rs-fMRI,并于予5 min短时程电刺激后要求受试者采用视觉模拟评分法(VAS)对麻木感进行评分。比较LTES前、后各脑区fALFF,针对存在显著差异脑区分析其fALFF值变化及其差值与VAS评分差值的相关性。结果LTES后双侧顶上小叶、右侧颞中回、左侧海马旁回及右侧缘上回fALFF值降低,而双侧伏隔核、右侧中央后回、左侧小脑及右侧壳核fALFF值升高(P均<0.05)。LTES前、后左侧顶上小叶fALFF差值与VAS评分差值呈负相关(r=-0.422,P=0.029)。结论LTES所诱发的肢体麻木感涉及感觉运动皮层及情绪等相关脑区,尤以左侧顶上小叶最为重要。

Objective To explore brain function changes in different regions after limb numbness induced by long-term electrical stimulation(LTES)in healthy subjects with fractional amplitude of low frequency fluctuation(fALFF)based on resting-state functional MRI(rs-fMRI).Methods A total of 27 healthy subjects were prospectively recruited.LTES once a day,30 min per day,over 1 week was administered to induce unilateral limb numbness.Brain rs-fMRI were acquired,and scoring of the numbness after 5 min short-term electrical stimulation was performed according to visual analogue scale(VAS)on the day before LTES and the day after LTES,respectively.Then brain regions with fALFF being significantly different before and after LTES were collected,changes of fALFF values were assessed,and the correlations of the difference of fALFF values with that of VAS scores in the corresponding brain regions were analyzed.Results After LTES,fALFF values decreased in the bilateral superior parietal lobule,the right middle temporal gyrus,the left parahippocampal gyrus and right supra marginal gyrus,but increased in bilateral nucleus accumbens,the right postcentral gyrus,the left cerebellum and the right putamen compared with those before LTES(all P<0.05).The difference of fALFF values in left superior parietal lobule before and after LTES was negatively correlated with the difference of VAS scores(r=-0.422,P=0.029).Conclusion Limb numbness induced by LTES involved various brain regions related to sensorimotor cortex and emotion,especially the left superior parietal lobule.