Fanrong Liang

Characterizing acupuncture stimuli using brain imaging with fMRI: A systematic review and meta-analysis of the literature

Background The mechanisms of action underlying acupuncture, including acupuncture point specificity, are not well understood. In the previous decade, an increasing number of studies have applied fMRI to investigate brain response to acupuncture stimulation. Our aim was to provide a systematic overview of acupuncture fMRI research considering the following aspects: 1) differences between verum and sham acupuncture, 2) differences due to various methods of acupuncture manipulation, 3) differences between patients and healthy volunteers, 4) differences between different acupuncture points. Methodology/Principal Findings We systematically searched English, Chinese, Korean and Japanese databases for literature published from the earliest available up until September 2009, without any language restrictions. We included all studies using fMRI to investigate the effect of acupuncture on the human brain (at least one group that received needle-based acupuncture). 779 papers were identified, 149 met the inclusion criteria for the descriptive analysis, and 34 were eligible for the meta-analyses. From a descriptive perspective, multiple studies reported that acupuncture modulates activity within specific brain areas, including somatosensory cortices, limbic system, basal ganglia, brain stem, and cerebellum. Meta-analyses for verum acupuncture stimuli confirmed brain activity within many of the regions mentioned above. Differences between verum and sham acupuncture were noted in brain response in middle cingulate, while some heterogeneity was noted for other regions depending on how such meta-analyses were performed, such as sensorimotor cortices, limbic regions, and cerebellum. Conclusions Brain response to acupuncture stimuli encompasses a broad network of regions consistent with not just somatosensory, but also affective and cognitive processing. While the results were heterogeneous, from a descriptive perspective most studies suggest that acupuncture can modulate the activity within specific brain areas, and the evidence based on meta-analyses confirmed some of these results. More high quality studies with more transparent methodology are needed to improve the consistency amongst different studies.

Regional homogeneity abnormalities in patients with interictal migraine without aura: a resting-state study.

Previous studies have provided evidence of structural and task‐related functional changes in the brains of patients with migraine without aura. Resting‐state brain activity in patients with migraine provides clues to the pathophysiology of the disease. However, few studies have focused on the resting‐state abnormalities in patients with migraine without aura. In the current study, we employed a data‐driven method, regional homogeneity (ReHo), to analyze the local features of spontaneous brain activity in patients with migraine without aura during the resting state. Twenty‐six patients with migraine without aura and 26 age‐, education‐ and gender‐matched healthy volunteers participated in this study. Compared with healthy controls, patients with migraine without aura showed a significant decrease in ReHo values in the right rostral anterior cingulate cortex (rACC), the prefrontal cortex (PFC), the orbitofrontal cortex (OFC) and the supplementary motor area (SMA). In addition, we found that ReHo values were negatively correlated with the duration of disease in the right rACC and PFC. Our results suggest that the resting‐state abnormalities of these regions may be associated with functional impairments in pain processing in patients with migraine without aura. We hope that our results will improve the understanding of migraine. Copyright

Randomised clinical trial: an assessment of acupuncture on specific meridian or specific acupoint vs. sham acupuncture for treating functional dyspepsia.

Functional dyspepsia (FD) is a common disease without an established optimal treatment.

Reduced fractional anisotropy of corpus callosum modulates inter-hemispheric resting state functional connectivity in migraine patients without aura.

Background Diffusion tensor imaging (DTI) study revealed reduced fractional anisotropy (FA) values in the corpus callosum (CC) in migraine patients without aura. Abnormalities in white matter integrity, particularly in the CC, may affect inter-hemispheric resting state functional connectivity (RSFC). Unfortunately, relatively little is known about the alterations in functional interactions between the cerebral hemispheres during resting state in migraine patients without aura, and even less about how the inter-hemispheric RSFC are affected by the abnormalities of the CC. Methods and findings Twenty-one migraine patients without aura and 21 healthy controls participated in this study, age-, sex-, and education-matched. Tract-based spatial statistics (TBSS) was employed to investigate the white matter alterations of the CC. Meanwhile, voxel-mirrored homotopic connectivity (VMHC) was used to compare the inter-hemispheric RSFC differences between the patients and controls. TBSS analysis revealed reduced FA values in the genu and the splenium of CC in patient group. VMHC analysis showed decreased inter-hemispheric RSFC of anterior cingulate cortex (ACC) in migraine patients without aura relative to that of the controls. Furthermore, in migraine patients without aura, the reduced FA values of the genu of CC correlated with the decreased inter-hemispheric RSFC of the ACC. Conclusions Our findings demonstrated that the migraine patients without aura showed reduced FA values of the genu of CC and decreased inter-hemispheric RSFC of the ACC. The correlation between the above structural and functional changes suggested that the reduced fractional anisotropy (FA) of CC modulates inter-hemispheric VMHC in migraine patients without aura. Our results demonstrated that the VMHC alterations of ACC can reflect the FA changes of the genu of CC in migraine patients without aura.

Abnormal Resting Brain Activity in Patients With Functional Dyspepsia Is Related to Symptom Severity

BACKGROUND & AIMS Abnormal processing of visceral sensation at the level of the central nervous system is believed to be involved in functional dyspepsia. However, compared with studies of stimulation-related changes in brain activity, few studies have focused on resting brain activity, which also is important in pathogenesis. We mapped changes in resting brain glucometabolism of patients with functional dyspepsia, compared with healthy subjects, and attempted to correlate abnormal brain activity with symptom severity. METHODS We performed fluorodeoxyglucose positron emission tomography-computed tomography on 40 patients with functional dyspepsia and 20 healthy subjects who were in resting states. The symptom index of dyspepsia and the Nepean dyspepsia index were used to determine symptom severity. The positron emission tomography-computed tomography data were analyzed using statistical parametric mapping software. RESULTS Compared with healthy subjects, patients with functional dyspepsia had higher levels of glycometabolism in the bilateral insula, anterior cingulate cortex (ACC), middle cingulate cortex (MCC), cerebellum, thalamus, prefrontal cortex, precentral gyrus, postcentral gyrus, middle temporal gyrus, superior temporal gyrus, putamen, right parahippocampal gyrus, claustrum, and left precuneus (P < .001). The signal increase in the ACC, insula, thalamus, MCC, and cerebellum was correlated with symptom index of dyspepsia scores and Nepean dyspepsia index scores (P < .01). The glycometabolism in ACC, insula, thalamus, MCC, and cerebellum of patients with more severe functional dyspepsia was significantly higher than that of patients with less severe functional dyspepsia (P < .005). CONCLUSIONS In patients with functional dyspepsia, resting cerebral glycometabolism differs significantly from that of healthy subjects. The ACC, insula, thalamus, MCC, and cerebellum might be the key regions that determine the severity of symptoms.

Altered Structure and Resting-State Functional Connectivity of the Basal Ganglia in Migraine Patients Without Aura

UNLABELLED The aim of this study was to investigate the relevance of the basal ganglia (BG) in pathogenesis of migraine by assessing the abnormal volume and resting-state networks of the BG in migraine patients without aura (MWoA). The volume of the subsets in the BG was compared between 40 MWoA and 40 age- and gender-matched healthy controls. The resting-state functional connectivity of BG subsets with abnormal volume was also investigated. Reduced volume in the left caudate and the right nucleus accumbens (NAc) was detected in the migraine group compared with healthy controls; meanwhile, increased functional connectivity between the BG and several brain regions within nociceptive and somatosensory processing pathways was observed. Correlation analysis revealed significant correlations between the volume of the bilateral caudate and right NAc and disease duration. In addition, an increased monthly frequency of migraine attack was associated with increased functional connectivity between the bilateral caudate and left insula, and longer disease duration was correlated with increased functional connectivity between the right NAc and bilateral anterior cingulate cortex. Our results revealed abnormal volume of BG and dysfunctional dynamics during interictal resting state within pain pathways of the BG in MWoA, which validated the association between the BG and migraine. PERSPECTIVE Our findings revealed the presence of reduced volume in NAc and caudate of the BG and interictal dysfunctional dynamics within BG networks in MWoA. The abnormal structure and function within the pain-related pathways of the BG were possibly associated with impaired pain processing and modulatory processes in MWoA.

Acupuncture for treating acute attacks of migraine: a randomized controlled trial.

Objective.— To discuss the results of a multicenter randomized controlled trial of the efficacy of verum acupuncture in treating acute migraine attacks.

Influence of Acupuncture Treatment on Cerebral Activity in Functional Dyspepsia Patients and Its Relationship With Efficacy

OBJECTIVES:Acupuncture is a commonly used therapy for treating functional dyspepsia (FD), although the mechanism remains unclear. The objectives of this study were to investigate the differences in cerebral glycometabolism changes evoked by acupuncture and sham acupuncture and to explore the possible correlations between brain responses and clinical efficacy.METHODS:In all, 72 FD patients were randomly assigned to receive either acupuncture or sham acupuncture treatment for 4 weeks. Ten patients in each group were randomly selected for fluorine-18 fluorodeoxyglucose positron emission tomography computed tomography scans to detect cerebral glycometabolism changes. The Nepean Dyspepsia Index (NDI) and Symptom Index of Dyspepsia (SID) were used to evaluate the therapeutic effect.RESULTS:(i) The clinical data showed that after treatment the decrease in SID score in the acupuncture group was significantly greater than that in the sham acupuncture group (P<0.05). The increase in NDI score between the two groups did not differ (P>0.05), and only the improvement in NDI score in the acupuncture group was clinically significant. (ii) The neuroimaging data indicated that after treatment the acupuncture group showed extensive deactivation in cerebral activities compared with the sham acupuncture group. In the acupuncture group, the deactivations of the brainstem, anterior cingulate cortex (ACC), insula, thalamus, and hypothalamus were nearly all related to the decrease in SID score and the increase in NDI score (P<0.05, corrected). In the sham acupuncture group, the deactivations of the brainstem and thalamus tended to be associated with the increase in NDI score (P<0.1, corrected).CONCLUSIONS:Acupuncture and sham acupuncture have relatively different clinical efficacy and brain responses. Acupuncture treatment more significantly improves the symptoms and quality of life of FD patients. The more remarkable modulation on the homeostatic afferent network, including the insula, ACC, and hypothalamus, might be the specific mechanism of acupuncture.

A PET-CT study on the specificity of acupoints through acupuncture treatment in migraine patients

BackgroundIn the field of acupuncture research, the topic of acupoint specificity has received increasing attention, but no unified conclusion has been reached on whether or not acupoint specificity exists. Furthermore, the majority of previous acupuncture neuroimaging studies have been performed using healthy subjects. In this study, patients with migraine were used to investigate acupoint specificity.MethodsThirty patients with migraine were enrolled and randomized into three groups: Traditional Acupuncture Group (TAG), Control Acupuncture Group (CAG), and Migraine Group (MG). The TAG was treated by acupuncture stimulation at Waiguan (TE5), Yang Lingquan (GB34), and Fengchi (GB20). The CAG was treated at Touwei (ST8), Pianli (LI6), and Zusanli (ST36). The MG received no treatment. Positron emission tomography with computed tomography (PET-CT) was used to test for differences in brain activation between the TAG and CAG versus MG, respectively.ResultsTraditional acupuncture treatment was more effective for pain reduction than control acupuncture treatment. The TAG showed higher brain metabolism than the MG in the middle temporal cortex (MTC), orbital frontal cortex (OFC), insula, middle frontal gyrus, angular gyrus, post-cingulate cortex (PCC), the precuneus, and the middle cingulate cortex (MCC). Metabolism decreased in the parahippocampus, hippocampus, fusiform gyrus, postcentral gyrus, and cerebellum in the TAG compared with the MG. In the CAG, metabolism increased compared with the MG in the MTC, supratemporal gyrus, supramarginal gyrus, and MCC, whereas metabolism decreased in the cerebellum.ConclusionsAcupuncture stimulation of different points on similar body regions in migraine patients reduced pain and induced different levels of cerebral glucose metabolism in pain-related brain regions. These findings may support the functional specificity of migraine- treatment-related acupoint.Trial registrationThe number of our clinical trial registration is: ChiCTR-TRC-11001813, and the protocol and inclusion criteria have already been registered as ChiCTR-TRC-11001813.

White-Matter Microstructural Changes in Functional Dyspepsia: A Diffusion Tensor Imaging Study

OBJECTIVES:Recent neuroimaging studies have identified brain microstructural changes in patients with functional gastrointestinal disorders, especially in irritable bowel syndrome. However, whether the microstructure is changed in patients with postprandial distress syndrome (PDS) remains elusive. Therefore, the present study was aimed to examine the white-matter (WM) microstructural changes in patients with PDS.METHODS:Diffusion tensor imaging (DTI) was performed on 36 PDS patients recruited according to the Rome III criteria and 36 healthy controls. Tract-based spatial statistics were adopted to examine the between-group differences in DTI measures including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, and radial diffusivity (RD). The correlations between DTI measures and clinical variables were evaluated using a non-parametric permutation-based test. Multiple comparisons were corrected using the threshold-free cluster enhancement method.RESULTS:The patient group showed increased FA along with reduced MD and RD in multiple WM tracts, including the corona radiata, internal capsule, posterior thalamic radiation, corpus callosum, external capsule, sagittal stratum, and superior longitudinal fasciculus (P<0.05, corrected). The inclusion of anxiety and depression as covariates abolished the between-group difference in these tracts with the exception of the corona radiata. The DTI measures were not found to be correlated with the severity of symptoms or the duration of disease (P>0.05, corrected).CONCLUSIONS:Our findings have provided preliminary evidence of WM microstructural changes in patients with PDS. Part of the changes could be accounted for by a higher level of psychosocial distress in the patient group.