针刺太冲穴得气及疼痛激发相对抗的脑功能网络效应fMRI研究

Deqi and Sharp pain during acupuncture at Taichong eliciting the opposite functional brain network effects——an fMRI study

目的:采用磁共振脑功能成像技术,比较针刺太冲穴得气及针刺疼痛时所激发的脑功能网络效应异同。方法:47例初次接受针刺的志愿者参加手针右侧太冲穴fMRI实验。针刺时脑fMRI扫描10min,共2次捻针,各2min,间隔3min。其中17例接受体表触觉刺激作为针刺对照,分为3组:①针刺得气组;②针刺得气合并尖锐性疼痛组(简称针刺疼痛组);③触觉对照组。采用Fisher’s精确检验和t检验分析感觉频率及强度;用AFNI处理fMRI数据,得到激活、负激活脑区;用种子相关分析法,以前扣带回膝部为种子点,分析其与全脑的功能网络联系图谱,并比较得气与疼痛组之间的差异。结果:针刺2组的酸痛、酸感、压感、麻感、钝痛等得气感觉的频率和强度均明显强于触觉刺激组;针刺2组间除尖锐性疼痛及酸痛外,各种感觉差异无统计学意义。针刺得气及疼痛2组均激活了体感及丘脑岛叶皮层,重要的是,针刺得气时在大脑边缘叶-旁边缘叶-新皮层系统(LPNN)产生了较强而广泛的负激活区,加强了负激活区之间的脑功能网络联系。此网络包括杏仁核、海马、旁海马、颞极、前额叶腹内侧回、前扣带回膝及下部、前楔叶内侧回和后扣带回(BA31,23_腹侧核,29,30),另外,小脑蚓部、导水管周围灰质及脑干网状结构也见负激活现象。然而,在针刺疼痛时,这些脑区负激活程度减低且区域缩小,大部分脑区fMRI信号逆转为激活信号,被疼痛激活的脑区之间功能网络明显增强。这些脑区参与了疼痛、镇痛(如感觉、情感、认知、自主性、内源性镇痛)功能调制环路。结合既往研究表明,负激活与脑血氧消耗及血流量下降呈正相关。本结果支持针刺通过调制LPNN和疼痛中枢网络的活动,产生其镇痛、抗焦虑和其他调节效应的假说。结论:针刺得气及针刺得气伴随疼痛产生了相对抗的脑功能网络效应。针刺得气对LPNN及疼痛脑中枢网络(Pain matrix)的负激活效应,可能与针刺镇痛脑中枢机制相关。LPNN和静息态默认网络(Default mode)之间的相似性,提示针刺需通过这一内在脑功能网络系统发挥其广泛的调制作用。

Objective.. To investigate the needling sensations（deqi and sharp pain）coupling with fMRI signal change in the brain functional network upon acupuncture at Taichong（LV3）. Methods Forty seven acupuncture-nave normal subjects received man- ual acupuncture at Taichong（LV3, right）during fMRI scan, and 17 of them received superficial tactile stimulation at LV3 prior to acupuncture procedures as control. Right after acupuncture or tactile stimulation procedures,all subjects were interviewed by our researchers with a sensation questionnaire. The collected data were then divided into the following three groups.-1）acupunc- ture deqi. 2）acupuncture pain：acupuncture deqi mixed with sharp pain. 3）sensory control：tactile stimulation. Results：The deqi sensations such as aching,soreness,pressure,numbness and dull pain experienced by the subjects were significantly more fre- quent and the intensity ratings were significantly higher in acupuncture than in sensory control. Activation of the somatosensory cortex was observed in all groups, but significantly more marked in subjects who experienced sharp pain during acupuncture. Importantly, the majority of the cohort who experienced deqi without sharp pain demonstrated prominent signal de- creases in the limbic-paralimbic-neocortical network（LPNN）widely spread across the brain,including the amygdala,hippocam- pus, parahippocampus, temporal pole, pregenual and subgenual cingulate, ventromedial prefrontal cortex, precuneus and posterior cingulate（BA31,23 ventral, 29,30）, cerebellar vermis, the periaqueductal gray and reticular formation in the brainstem. A large subset of these regions is involved in the affective and cognitive dimensions of pain. The decreases of the signal intensity in these areas were significantly attenuated or changed to signal increases with the development of sharp pain in acupuncture. Major regions in the LPNN were found overlapped with the De- fault mode network in the resting Brain. Conclusions：The find- ings provide support for the hypothesis that acupuncture modu- lates the limbie-paralimbic-neocortical network and pain neu-romatrix activity to produce its anti-pain, anti-stress and other modulatory effects. The similarity of LPNN and default mode network in the resting brain suggests that acupuncture may mobilize the important brain intrinsic network for its multiple mod- ulation effects.