The Sustained Brain Effects After Needling At Fengchi(GB20) Measured By FMRI

Objective:To investigate the sustained brain effects after needling at Feng chi(GB20),Measured by functional magnetic resonance imaging(fMRI).Background:Acupuncture is a treatment method that has been used in ancient China for thousands of years.Nowadays,the therapeutic effect of acupuncture is gradually recognized in the western world as an alternative and complementary treatment.Based on traditional Chinese medicine(TCM),each acupoint has functional specificity,so stimulation of a specific acupoint will treat specific types of diseases.It is believed that the therapeutic effects of acupoints are conducted through the meridian;that is to say,acupuncture stimulation at acupoints on the same meridian might evoke certain similar activation patterns.In spite of acupuncture's long history and public acceptance for medical management,the exact physiological underlying mechanisms of acupuncture therapy remain unclear and need further investigation.Today,functional magnetic resonance imaging functional magnetic resonance imaging(fMRI)has been used extensively because it can indirectly measure the brain's activity and the functional changes in the brain's state as well as discover connectivity patterns,in response to acupuncture without radiation or invasive procedures.Fengchi(GB 20)translation of Wind Pool is regarded as a major point for treatment and prevention of some diseases in acupuncture therapy such as stiff neck,epilepsy,migraine,eye disorders.However,a large number of clinical studies have reported its significant curative effects,its mechanism of action is still not clear.Although,by using fMRI and neuroscience,researchers demonstrate that stimulation of specific acupuncture points induces hemodynamic changes in relative specific brain networks,it is not explored what the sustained changes in the cortical connectivity are happened after needling at Fengchi(GB20).In the present study,11 healthy subjects underwent fMRI represents imaging of the brain before and after acupuncture at GB20.It is observed both of the activity changes in the brain fMRI and the needle sensations.Method:This study was performed in the Department of Radiology,Guang An Men Hospital,China Academy of Chinese Medical Sciences in Beijing.The study design included 11 healthy subjects(6 men and 5 women).When a subject was determined to be fit for participation based on inclusion and exclusion criteria,was prohibited from taking any medications,drinking coffee or alcohol or using smoke and nicotine for 24 hours before the study.Needling method in Acupuncture group:Disposable sterile stainless steel filiform needles 0.25 mm × 40 mm were used.The needle was inserted toward the tip of the nose till 1 can deep into the left GB20 acupoint,then did lift,thrust and rotate manually clockwise and counterclockwise for 30 seconds,then the needle was drawn out.Tactile stimulation in Control group:The skin over the acupoint was tapped gently with a 5.88 Von Frey monofilament(bending force of 588 mN)at 90 degrees to the skin surface of GB20 for 30 seconds.fMRI Acquisitions:fMRI was performed in subjects for 4 sessions in one day:before and after acupuncture or tactile stimulation(sham acupuncture)at acupoint GB20 on the head.First resting-state scan started with 15 minutes of rest,followed by 30 seconds of acupoint stimulation,then second resting-state fMRI again.After at least 2 hours of break,the subject had the 3rd session of resting-state scan and then followed by 30 seconds of stimulation at GB20,after that,the 4th session of scan was performed.The interval between the two functional runs(before and after stimulation at GB20)was approximately 45 seconds.The subject in the enroll list with odd number was given acupuncture on GB20 first,and then gave tactile stimulation;those with even numbers were given tactile stimulation on GB 20 first and then acupuncture stimulation.The imaging scans were based on Siemens 3.0 Tesla MRI scanner.After finishing the 2nd and 4th scans,the psychophysical responses of every subject were questioned and scored.Measurements:Statistical parametric mapping was used to preprocess initial data by Data Processing and Analysis of Brain Imaging(DPABI)software,yielding regional homogeneity(ReHo),amplitude of low-frequency fluctuation(ALFF),functional amplitude of low-frequency fluctuation(fALFF),and functional connectivity(FC).In the statistical analysis,Paired t-tests were performed.The intensities and the frequencies of psychophysical response were assessed.The quantitative measurements;Mean ± SE,Mann-Whitney U tests,and Chi-square test were used to compare the components of needle sensation within each group.Results:Compared with sham acupuncture,our results indicated that acupuncture on the left GB20 could induce different effects in the central nervous system on the human brain.These neural responses were in the right and left Parietal Lobe,right Occipital Lobe,and the specific regions including cuneus,precuneus.fALFF value was activated in the right parietal/precuneus(Brodmann area 7)and ReHo after acupuncture at GB20 was higher in the right occipital lobe/cuneus(Brodmann area 19).Centrality results show activation of the right parietal/precuneus,the right occipital/precuneus(Brodmann area 7,19).The Left and right posterior cingulate cortex was selected as a seed-based functional connectivity analysis,showed activation of the left parietal lobe(Brodmann area 7,39,40),and the choice of the ventral medial prefrontal lobe as a seed-based functional connectivity revealed activation of the right parietal lobe/precuneus(Brodmann area 7).We evaluated the needle sensation as reported by the subjects.During acupuncture,more subjects experienced soreness,dull pain,heaviness,fullness and pressure compared with tactile stimulation(P<0.05).However,significant intensity differences(p<0.05)were showed in soreness;dull pain,heaviness,and fullness between acupuncture and tactile stimulation.Actually,significant differences were found in the intensity and frequency of sensations between acupuncture and tactile stimulation control.According to our study,there was a positive relationship between the results of Degree Centrality_Positive Binarized(DCPB)and needle sensation in the acupuncture group.In contrast,the results of needle sensation were positively correlated with the results of right and left Posterior Cingulate Cortex(PCC)in the control group.Conclusion:The present study is the first reported fMRI study for investigation of the sustained effect of acupuncture stimulation at GB20.This preliminary study gives evidence that acupuncture at GB20 can produce the modulation effects on the visual function and Default Mode Network(DMN)involving with self-reference and memory.Our results are in agreement with that GB20 regulates multiple physiological systems and may imply to accomplish a variety of empirically obvious therapeutic effects by the physiological response to acupuncture stimulation.A further question is how these results in healthy subjects can be generalized and applied to patients with disorders responsive to acupuncture.