The Cerebral Functional Areas Activated By Needling At Taixi (KI3)Vs Sham Point In Healthy Volunteers:an FMRI Study

BackgroundTaixi （KI3） acupoint belongs to kidney meridian of foot-shaoyin and is the Shu （steam） point and Yuan（source） point of kidney meridian. KI3can be used to treat headache, dizziness, insomnia, amnesia, spermatorrhea, impotence, sore throats, dentalgia, tinnitus, deafness, cough, asthma, hemoptysis, diabetes, frequent micturition, constipation, menoxenia, painalongspinalcoiumn, and lower limb of cold feeling, etc. In recent years, KI3has been widely used on treating the diseases of nervous system, motor system, respiratory system and gynecology diseases, which achieved significant effect.The acupoint specificity refers to every acupoint is different from non-acupoint and other acupoints in morphology, biophysical properties, pathological characteristics and therapeutic effect. Acupoint specificity has become the research focus of scholars at home and abroad in recent years. Whether acupuncture has specific effects is also controversial. Now, the studies on acupoints specificity include the acupoint versus non-acupoint, different acupoints in same meridian, and acupoints specificity with the relationship of Zangfu meridian, specific acupoints, intervention methods, acupoints combination and functional status, and so on. The Acupoints Specificity-brain theory, proposing acupuncture at acupoint could specifically activate brain functional regions, raised by Professor Lai, better promotes the use of brain imaging technology to carry out acupoint specificity.In1990, Ogawa etc. firstly successfully studied brain functional activity by contrasting the changes of the Blood-Oxygen saturation. Now Blood Oxygenation Level Dependent-fMRI （BOLD-fMRI） has been one of the most commonly used fMRI technology. Its imaging principle is based on the continuous acquisition and statistical analysis of brain images, then finding the difference of brain images. BOLD can reflect the instant brain blood flow by detecting magnetic susceptibility between oxygenated hemoglobin and deoxygenated hemoglobin, as deoxygenated hemoglobin molecules corresponds to the low-intensity signal on the T2images while oxygenated hemoglobin molecules corresponds to the high-intensity signal.In recent years, the study on fMRI has achieved several progresses. Yu GJ etc. applied functional magnetic resonance imaging（fMRI） to observe the reaction of the needle KI3for cerebral activation zones at resting stage and stimulation state alternately, finding that brain activation areas by KI3point by mainly located in the right temporal upper, middle and lower back gyrus and precuneus, which were mainly responsible for auditory language and cognitive function, and traditional Chinese medicine theories were consistent with it. Jiang CG etc. observed the effect of twirling acupuncture in KI3acupoint on functional MRI in MCI patients, which studied the central mechanism of brain function effect with acupuncturing Taixi（KI3） point in MCI pathologic state. What’s more, Jiang CG etc. also observed the effect of needling KI3and sham point on the activation of various encephalic regions in patients with MCI by fMRI technique, finding that needling KI3could activate the target-based encephalic region of MCI patients. All above studies, to some extent, confirmed the acupoints-brain theory.These researches promoted the study on the specificity of meridians and acupoints. Nevertheless, those studies of acupuncture were based on the block design, i.e., stimulation according to the scheme "acupuncture-resting-acupuncture-resting," which can’t be true simulation acupuncture process. Since Biswal etc. published a study on the resting fMRI and Raichle etc. proposed that there was a resting state networks （RSNs） as human brain in the resting state, many researchers have been actively exploring the best experiment design of fMRI in the acupuncture area. At present, many researchers study on the brain network on resting state by the function connection, to measure the relationship between the function of each brain region. Previous studies confirmed that acupuncture had persistent effects, as well as confirmed the specificity of meridians and acupoints in relation to brain function. There is of great significance of the study on the relationship of the acupuncture and brain regions by observing the brain region function changes after acupuncture.This study put forward a hypothesis that acupuncture at KI3could specifically change relative brain regions on the basis of pervious studies. Brain, the most complex information processing organ, not only responds to the acupuncture in different acupoint with different activity of signals but also collects and compares the changes and then delivers the processed signal to some target organs. These data demonstrated the compatibility of combinations of different acupoints based on various clinical effects. Relative to the brain, the effect factors of incoming signal, such as the reason, pathway, pattern, are secondary.In conclusion, this study assessed the resting fMRI cerebral functional imaging and the affected brain regions after acupuncture in different acupoints （KI3and the sham acupoint） and compared their brain functional changes to evaluate possible evidence of the specificity of acupoint and the link of acupoint to brain.ObjectiveIn this study, fMRI was used to analyze different brain regions activated by acupuncture at the KI3or the sham acupoint, so as to find the evidence of the specificity of acupoint and the link of acupoint to brain.MethodThis was a resting fMRI study.The MRI scanning was performed at the MRI Center of the First Affiliated Hospital of Guangzhou University of Chinese Medicine in China from March2013to June2013.All the healthy volunteers came from the Southern Medicinal University and the Guangzhou University of Chinese Medicine. A total of30healthy subjects were randomly distributed into KI3and sham acupoint groups, each group consisting of15persons. A random number table was drawn up by biostatistics professionals using statistical software. All subjects gave full informed consent.The present study contained twelve males and eighteen females, aged from21to23years. Subjects in KI3group included four males and eleven females, average age （21.60±0.83） years old, weighing （55.33±11.19）kg and were （168.6±6.81cm） tall. Subjects in sham acupoint group included eight males and seven females, average age （21.20±0.77） years old, weighing （55.87±8.68）kg and were （167.6±8.58cm） tall. There was no significant difference of age and weight between two groups.Subjects were conscious, placed in a supine position and asked to breathe calmly. The head was fixed with a foam mat, thus greatly reducing active and passive movement. Earplugs （Aero,R5A018） were used to reduce hearing and eyeshades were also used. After subjects rested for15min, the scan began. Volunteers’eyes were covered with eyeshades （Xinhua Tourism supplies Company, Yangzhou, XHYZ₀01） during MRI scanning. The location of Taixi （KI3）:In the depression between the tip of the media malleolus and the tendo calcaneus. Sham point:2cm adjacent to the midpoint of the line connecting the anterior superior iliac spine and lateral border of the patella.The subjects rested for5min at the beginning of the experiment, then underwent an MRI scan and acupuncture. Experiment was performed on a GE3.0T MRI scanner with an8-channel head coil. The MRI data （resting-state BOLD sequence） was collected at15min before needling and15min after withdrawing the needle.1) Transverse T1-weighted image （T1WI） sequence:1min,51s, Fast Spin Echo sequence; OAx T1FLAIR, repetition time1750ms/echo time24ms, inversion time960ms, field of view24cm×24cm/Z, matrix320×224/number of excitations=1, thickness5.0mm/interval1.0mm,30slices total, echo train length8, and bandwidth31.25.2) Resting-state fMRI BOLD data collection:gradient echo-echo-planar imaging sequence scanning was conducted for6min in accordance with the following parameters:repetition time3000ms/minimum, echo time minimum, flip angle90, field of view240mm×240mm, thickness5.0mm/interval1.0mm,30slices each time, matrix96×96/number of excitations=1.The physician’s hands and the volunteers’ skin around the acupoints were sterilized with alcohol before needling. The tubes were purchased from Dongbang AcuPrime Co.（Exeter, England） and the0.3cm×40cm silver needles from Zhongyan Taihe Co.（Beijing, China）.The physician stuck the auxiliary part of the tube on the local skin, put the needle into the matching tube over the acupoint and tapped the end of the needle to make the tip of the needle inserted, removed away the tube and punctured the needle to the depth of15±2mm, and twirled the handle of the needle to get the needling sensation. Then the physician manually stimulated the needle with an even reinforcing and reducing manipulation by twirling the needling with±180°and60times/min. After manipulating the needle for1min, the needle was held in place for30min. During the30min, physician manipulated the needle for1min every10mm.Image processing and analytical methods:Preprocessing was carried out using Data Processing Assistant for Resting-State fMRI （DPARSF; Yan&Zang,2010, http://www.restfMRI.net）, which is based on Statistical Parametric Mapping （SPM8; http://www.fil.ion.ucl.ac.uk/spm） and Resting-State fMRI Data Analysis Toolkit （REST, Song et al.,2011. http://www.restfMRI.net）. This includes DICOM format conversion, removal of10time points before image scanning, time correction, correction of head movement, space standardization and space smoothing. After preprocessing,30cases were included in the statistical analysis.ReHo analysis:using REST1.8software, linear tendency of the data after preprocessing （space standardization was completed, and space smoothing was not finished） was removed by linear regression. Time and curve were convolved using Hamming bandpass filtering. ALFF was extracted （0.01-0.08Hz）. Kendall’s coefficient of concordance of each subject was computed, so each subject had a Kendall coefficient of concordance map, i.e. ReHo map. This map was divided by the mean of the whole brain, and standardized ReHo was obtained and used in statistical analysis.ALFF analysis:using REST1.8software, linear tendency of the data after preprocessing （space smoothing was completed） was removed by linear regression. Time and curve were convolved using Hamming bandpass filtering. ALFF was obtained （0.01-0.08Hz）. ALFF of each subject was computed, so ALFF maps were obtained. ALFF value was divided by the mean of the whole brain, and standardized ALFF was obtained.Statistical analysis:The data were analyzed with REST1.8software. Intragroup standardized ReHo and ALFF values were detected with paired Mest （AlphaSim correction P<0.05, continuous voxel>85）. Finally, the preacupuncture and postacupuncture differences between the alterations of ALFF and ReHo were obtained in subjects of the same group. Restl.8software Viewer was employed to identify the precise anatomical position in the brain with statistical significance on the corresponding MNI coordinate. The results were presented as images.Results1. Brain areas alterations after acupuncture at KI3versus preacupunctureALFF results demonstrated that ALFF apparently increased in the right cerebellum posterior lobe inferior semi-lunar lobule and left cerebrum frontal lobe middle frontal gyrus （BA10）. ReHo results demonstrated that ReHo apparently increased in the left cerebrum temporal lobe fusiform gyrus （BA37） and right cerebrum frontal lobe medial frontal gyrus （BA10） and decreased in the left cerebrum limbic lobe cingulate gyrus （BA31）.2. Brain areas alterations after acupuncture at sham acupoint versus preacupunctureIncreased ALFF was detected in the left cerebrum occipital lobe lingual gyrus （BA18）, right cerebrum occipital lobe middle occipital gyrus （BA19）, right cerebrum parietal lobe postcentral gyrus （BA30）. Decreased ALFF was observed in the right cerebrum frontal lobe superior frontal gyrus （BA10）, left cerebrum occipital lobe middle temporal gyrus （BA21,39）, right cerebrum limbic lobe posterior cingulated （BA30）. Increased ReHo was detected in the right cerebrum occipital lobe lingual gyrus （BA18）. Decreased ReHo （T value was negative） was observed in the left cerebellum posterior lobe pyramis, left cerebrum occipital lobe lingual gyrus （BA18）, right cerebrum frontal lobe medial frontal gyrus （BA10）, left cerebrum temporal lobe middle temporal gyrus （BA39,40）, left cerebrum limbic lobe cingulate gyrus （BA31,7,30,23）.3. Brain areas with changes after acupuncture at KI3versus sham acupointALFF results demonstrated that compared with sham acupoint, some alterations were observed in brain areas after acupuncture at KI3. ALFF increased in the left cerebellum posterior lobe, right cerebrum temporal lobe （BA20）, right cerebellum posterior lobe inferior semi-lunar lobule, left cerebrum sub-lobar extra-nuclear （BA23,29,30）, left cerebrum temporal lobe inferior temporal gyrus （BA20）, right cerebrum parietal lobe Angular gyrus （BA39）, right cerebrum frontal lobe medial frontal gyrus （BA10）, left cerebrum limbic lobe cingulate gyrus （BA24）, left cerebrum frontal lobe middle frontal gyrus （BA6）. ALFF decreased in the left cerebrum parietal lobe precuneus （BA7）, left cerebellum posterior lobe uvula, right cerebrum temporal lobe superior temporal gyrus （BA13）, right cerebrum sub-lobar extra-nuclear （BA30）, right cerebrum precentral gyrus（BA6）, left cerebrum frontal lobe precentral gyrus （BA6）. ReHo results demonstrated that compared with sham acupoint, some alterations were observed in brain areas after acupuncture at KI3. ReHo increased in the right brainstem medulla, left cerebrum temporal lobe （BA20）, right cerebrum temporal lobe fusiform gyrus （BA20）, left cerebellum posterior lobe cerebellar tonsil, right cerebrum frontal lobe superior frontal gyrus （BA10）, left cerebrum frontal lobe superior frontal gyrus （BA8）, right cerebrum frontal lobe superior frontal gyrus （BA6）. ReHo decreased in the left cerebrum limbic lobe parahippocampa gyrus （BA20）, right cerebellum posterior lobe declive, left cerebrum parietal lobe inferior parietal lobule （BA39）, left cerebrum temporal lobe inferior temporal gyrus （BA37）, right cerebrum sub-lobar lentiform nucleus, right cerebrum frontal lobe precentral gyrus （BA4）, left cerebrum parietal lobe sub-gyral （BA40）, left cerebrum limbic lobe cingulate gyrus （BA7）, right cerebrum frontal lobe precentral gyrus （BA3）.ConclusionThe fMRI study on brain areas activity after acupuncture at KI3versus sham acupoint preliminary assured that acupuncture at KI3could change the brain blood flow state. Acupuncture at KI3could specifically activated/deactivated some brain areas related to mind, movement, cognition, sensation and vision, indicating KI3has its meridian specificity and that KI3exert effects on specific brain areas differs from sham acupoint, which was associated with the mechanism of action of KI3.