The correlated network of acupuncture effect: a functional connectivity study

Effect of Acupoint Stimulation on Improving Gastrointestinal Motility in Patients After Gastrectomy: A Systematic Review and Meta-Analysis

Introduction: Gastrointestinal immobility is experienced by many patients who undergo gastric surgery. This complication delays enteral nutrition, prolongs hospitalization, and causes discomfort. Acupoint stimulation is a popular alternative nonpharmacological treatment for gastrointestinal immobility. This study aimed to explore the effects of acupoint stimulation on gastrointestinal immobility after gastrectomy. Design: Systematic review and meta-analysis. Methods: Databases (PubMed, Cochrane, Joanna Briggs Institute EBP Database, Medline, CINAHL Complete, and Airiti library) were searched from their inception to April 2022 for relevant articles. Articles in Chinese and English were included, without limitations on year, region, or country. The inclusion criteria were studies with participants >18 years of age, postgastric surgery, and hospitalization. In addition, randomized controlled trials (RCTs) were included. Data were analyzed using random effects models, and data heterogeneity was investigated using subgroup analysis. Meta-analysis was performed using Review Manager 5.4 software. Results: We included 785 participants from six studies. Invasive and noninvasive acupoint stimulation reduced the time of gastrointestinal mobility better than usual care. In the control group, the time of first flatus was 43.56 ± 9.57 h to 108 ± 19.2 h, and the time of first defecation was 77.27 ± 22.67 h to 139.2 ± 24 h. In the experimental group, the time of first flatus and defecation was 36.58 ± 10.75 h to 79.97 ± 37.31 h and 70.56 ± 15.36 h to 108.55 ± 10.75 h, respectively. Subgroup analysis showed that invasive acupoint stimulation with acupuncture reduced the time of first flatus and defecation to 15.03 h (95% confidence interval [CI] = -31.06 to 1.01) and 14.12 h (95% CI = -32.78 to 4.54), respectively. Noninvasive acupoint stimulation, including acupressure and transcutaneous electrical acupoint stimulation (TEAS), reduced the time of first flatus and defecation to 12.33 h and (95% CI = -20.59 to -4.06) and 12.20 h (95% CI = -24.92 to 0.52), respectively. Conclusions: Acupoint stimulation improved the gastrointestinal immobility of postgastrectomy. In the included RCT articles, invasive and noninvasive stimulations were effective. However, noninvasive acupoint stimulation, such as with TEAS and acupressure, was more efficient and convenient than invasive stimulation. Overall, health care professionals with adequate training or under the supervision of an acupuncturist can effectively perform acupoint stimulation to improve the quality of postgastrectomy care. They can select commonly used and effective acupoints to enhance gastrointestinal motility. Clinical relevance: Acupoint stimulation, such as acupressure, electrical acupoint stimulation, or acupuncture, can be included in postgastrectomy routine care to improve gastrointestinal motility and reduce abdominal discomfort.

Influence of the Intensity, Components, and Spreading of the Deqi Sensation on the Analgesic Effect of SP6 Needling in Primary Dysmenorrhea Patients: A Secondary Analysis of a Randomised Controlled Trial

Although deqi, the phenomenon whereby excitation of Qi in the meridians occurs with needling, is critical to the practice of acupuncture and its efficacy, it is poorly understood. So we investigate the influence of the deqi sensation on the analgesic effects of acupuncture in patients who were enrolled in a randomised controlled trial for the treatment of patients with primary dysmenorrhea, a painful and common condition, and cold and dampness stagnation. Two groups were assessed: a deqi group (undergoing deep needling with thick needles and manipulation, n=17) and a non-deqi group (undergoing shallow needling with thin needles and no manipulation, n=51). The Sanyinjiao (SP6) was needled for 30 min in both groups. Pain scores at baseline, upon needle removal, and at 10, 20, and 30 min after needle removal were evaluated by the Visual Analogue Scale for pain. The deqi sensation was evaluated by the Acupuncture Deqi Clinical Assessment Scale. Patients who experienced a genuine deqi sensation (n=39) were selected for further analysis. Compared with patients in the non-deqi group who experienced deqi (n=25), patients who self-reported deqi in the deqi group (n=14) felt a stronger deqi sensation, experienced soreness and fullness more frequently, felt a greater intensity of soreness, fullness, electric sensation, spreading, and radiating, and experienced larger spreading distances. In those who experienced the deqi sensation in the deqi group, the intensity of the sensation, as well as their degree of soreness and fullness, was negatively correlated with pain reduction. In patients who experienced the deqi sensation in the non-deqi group, deqi intensity was positively correlated with pain reduction, while soreness was negatively correlated with pain reduction. The distance of spreading was not correlated with pain reduction in either group. We found, in SP6 needling of patients with primary dysmenorrhea with cold and dampness stagnation, that a moderate deqi response predicted a prolonged analgesic effect better than a strong deqi response.

Influences of De Qi induced by acupuncture on immediate and accumulated analgesic effects in patients with knee osteoarthritis: study protocol for a randomized controlled trial

Background

De Qi is a special sensational response upon acupuncture needling. According to traditional acupuncture theory, the treatment is “effective only after Qi arrival”; that is, De Qi is an important indicator of therapeutic efficacy and good prognosis. However, it is still disputable whether De Qi improves the efficacy of acupuncture therapy. This prospective, randomized controlled trial aims to explore the influence of De Qi induced by acupuncture on immediate and accumulated analgesic effects in patients with knee osteoarthritis (KOA).

Methods/design

Eighty-eight patients with KOA will be recruited and randomly assigned to the De Qi group (enhanced stimulation to evoke De Qi) and the control group (weak stimulation to avoid De Qi) in the Department of Acupuncture and Physical Therapy, Beijing Luhe Hospital Affiliated to Capital Medical University. Each patient will receive three 30-minute sessions per week for 4 consecutive weeks and undergo a 1 month follow-up. The severity of knee pain, as measured on a 100-mm visual analog scale (where 0 indicates no pain and 100 indicates intolerable pain) will be used as the primary outcome, and the Knee injury and Osteoarthritis Outcome Score will be used as the secondary outcome. Both indexes will be measured before and after the 1^st (for evaluating the immediate analgesic effects), 3^rd, 6^th, 9^th, and 12^th (for evaluating the accumulated analgesic effects) treatments and at the end of the follow-up. The intensity of the De Qi sensation will be assessed by the Chinese-Modified Massachusetts General Hospital Acupuncture Sensation Scale at the end of each treatment. Side effects during the treatments will be recorded and analyzed as well. The comparisons between the De Qi group and the control group will be done by using both an intention-to-treat analysis and a per-protocol analysis.

Discussion

This prospective randomized controlled study will be helpful in enhancing our understanding of the analgesic effect of De Qi on patients with KOA and may provide a clinical basis for further investigation of the relationship between De Qi and the therapeutic efficacy of acupuncture, thereby offering some evidence for the role of De Qi in an efficacious acupuncture therapy.

Trial registration

Chinese Clinical Trial Registry, ChiCTR-IIR-16008972. Registered on 4 August 2016 Additional file 2.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1975-7) contains supplementary material, which is available to authorized users.

Sustained Effects of Acupuncture Stimulation Investigated with Centrality Mapping Analysis

Acupuncture can have instant and sustained effects, however, its mechanisms of action are still unclear. Here, we investigated the sustained effect of acupuncture by evaluating centrality changes in resting-state functional magnetic resonance imaging after manually stimulating the acupuncture point ST36 at the lower leg or two control point locations (CP1 same dermatome, CP2 different dermatome). Data from a previously published experiment evaluating instant BOLD effects and S2-seed-based resting state connectivity was re-analyzed using eigenvector centrality mapping and degree centrality mapping. These data-driven methods might add new insights into sustained acupuncture effects on both global and local inter-region connectivity (centrality) by evaluating the summary of connections of every voxel. We found higher centrality in parahippocampal gyrus and middle temporal gyrus after ST36 stimulation in comparison to the two control points. These regions are positively correlated to major hubs of the default mode network, which might be the primary network affected by chronic pain. The stronger integration of both regions within the whole-brain connectome after stimulation of ST36 might be a potential contributor to pain modulation by acupuncture. These findings highlight centrality mapping as a valuable analysis for future imaging studies investigating clinically relevant outcomes associated with physiological response to acupuncture stimulation.

CLINICAL TRIAL REGISTRATION

NCT01079689, ClinicalTrials.gov.

Connectomics: a new direction in research to understand the mechanism of acupuncture

Acupuncture has been used to treat various disorders in China and some other eastern countries for thousands of years. Nowadays, acupuncture is gradually accepted as an alternative and complementary method in western countries for its undeniable therapeutic effects. However, its central mechanism is still unclear. It is especially difficult to reveal how different regions in the brain influence one another and how the relationship is among these regions responding to acupuncture treatment. Recently, by applying neuroimaging techniques and network theory, acupuncture studies can make further efforts to investigate the influence of acupuncture on regional cerebral functional connectivity (FC) and the modulation on “acupuncture-related” networks. Connectomics appears to be a new direction in research to further understand the central mechanism underlying acupuncture. In this paper, an overview of connectomics application in acupuncture research will be discussed, with special emphasis on present findings of acupuncture and its influence on cerebral FC. Firstly, the connectomics concept and its significance on acupuncture will be outlined. Secondly, the commonly used brain imaging techniques will be briefly introduced. Thirdly, the influence of acupuncture on FC will be discussed in greater detail. Finally, the possible direction in forthcoming research will be reviewed by analyzing the limitation of present studies.

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.

Divergent neural processes specific to the acute and sustained phases of verum and SHAM acupuncture

PURPOSE

To discuss which brain region potentially functioned and switched between the immediate and delayed response of acupuncture.

MATERIALS AND METHODS

A nonrepeated event-related functional MRI (fMRI) design was used to investigate the spatial and temporal patterns of acupuncture effects induced by needling an acupoint ST36 (ACU) and a nonmeridian point (SHAM). The standard general linear model was used to detect the immediate neural responses of acupuncture. Graph theory analysis was used to characterize the functional integrated network of the acupuncture delayed effect.

RESULTS

Acupuncture induced significant signal changes in the limbic/paralimbic areas, neocortical regions, brainstem, and cerebellum for immediate effect both in ACU and SHAM. Some of these brain regions showed strong functional connectivity for a delayed effect in ACU. Conjunction analysis showed that the insula played a critical role during the overall process of ACU. No overlapping brain regions were found in SHAM.

CONCLUSION

The findings of this study suggested that the delayed effects may reflect a more significant characteristic underlying acupuncture. Given that the insula as a relay station switched between the immediate and delayed response, it suggested that divergent functional connectivity patterns may mediate the acupuncture-related effects for ACU and SHAM.

Imaging the functional connectivity of the Periaqueductal Gray during genuine and sham electroacupuncture treatment

Background

Electroacupuncture (EA) is currently one of the most popular acupuncture modalities. However, the continuous stimulation characteristic of EA treatment presents challenges to the use of conventional functional Magnetic Resonance Imaging (fMRI) approaches for the investigation of neural mechanisms mediating treatment response because of the requirement for brief and intermittent stimuli in event related or block designed task paradigms. A relatively new analysis method, functional connectivity fMRI (fcMRI), has great potential for studying continuous treatment modalities such as EA. In a previous study, we found that, compared with sham acupuncture, EA can significantly reduce Periaqueductal Gray (PAG) activity when subsequently evoked by experimental pain. Given the PAG's important role in mediating acupuncture analgesia, in this study we investigated functional connectivity with the area of the PAG we previously identified and how that connectivity was affected by genuine and sham EA.

Results

Forty-eight subjects, who were randomly assigned to receive either genuine or sham EA paired with either a high or low expectancy manipulation, completed the study. Direct comparison of each treatment mode's functional connectivity revealed: significantly greater connectivity between the PAG, left posterior cingulate cortex (PCC), and precuneus for the contrast of genuine minus sham; significantly greater connectivity between the PAG and right anterior insula for the contrast of sham minus genuine; no significant differences in connectivity between different contrasts of the two expectancy levels.

Conclusions

Our findings indicate the intrinsic functional connectivity changes among key brain regions in the pain matrix and default mode network during genuine EA compared with sham EA. We speculate that continuous genuine EA stimulation can modify the coupling of spontaneous activity in brain regions that play a role in modulating pain perception.

Time-varied characteristics of acupuncture effects in fMRI studies

When studying the neural responses to acupuncture with a block-designed paradigm, its temporal dynamics predicted by the general linear model (GLM) conforms to typical "on-off" variations during a limited period of the experiment manipulation. Despite a lack of direct evidence associating its psychophysiological response, numerous clinical reports suggest that acupuncture can provide pain relief beyond a needling session. Therefore, a typical GLM analysis may be insensitive or inappropriate for identifying altered neural responses resulting from acupuncture. We developed a new approach to investigate the dynamics underlying sustained effects of acupuncture. Specifically, we designed two separate models to evaluate the baseline activities (prior to stimulation) and neural activities in sequential epochs, using three block-designed functional runs: acupuncture at acupoint ST36, nonmeridian point (NMP) stimulation, and a visual task. We found that the activity patterns during rest were associated with the stimulus types and that the resting activities might be even higher than that of stimulation phases. Such effects of the elevated activity during rest may reduce or eliminate the activity during stimulus conditions or even reverse the sign of brain activation using conventional GLM analysis. Moreover, such sustained responses, followed by acupuncture at ST36 and NMP, exhibited distinct patterns in wide brain structures, particularly in the limbic system and brainstem. These findings may pose great implications for the design and interpretation of a range of acupuncture neuroimaging studies.

Minimal acupuncture is not a valid placebo control in randomised controlled trials of acupuncture: a physiologist's perspective

Placebo-control of acupuncture is used to evaluate and distinguish between the specific effects and the non-specific ones. During 'true' acupuncture treatment in general, the needles are inserted into acupoints and stimulated until deqi is evoked. In contrast, during placebo acupuncture, the needles are inserted into non-acupoints and/or superficially (so-called minimal acupuncture). A sham acupuncture needle with a blunt tip may be used in placebo acupuncture. Both minimal acupuncture and the placebo acupuncture with the sham acupuncture needle touching the skin would evoke activity in cutaneous afferent nerves. This afferent nerve activity has pronounced effects on the functional connectivity in the brain resulting in a 'limbic touch response'. Clinical studies showed that both acupuncture and minimal acupuncture procedures induced significant alleviation of migraine and that both procedures were equally effective. In other conditions such as low back pain and knee osteoarthritis, acupuncture was found to be more potent than minimal acupuncture and conventional non-acupuncture treatment. It is probable that the responses to 'true' acupuncture and minimal acupuncture are dependent on the aetiology of the pain. Furthermore, patients and healthy individuals may have different responses. In this paper, we argue that minimal acupuncture is not valid as an inert placebo-control despite its conceptual brilliance.