Hypothalamus and amygdala response to acupuncture stimuli in Carpal Tunnel Syndrome

Acupuncture for depression: a review of clinical applications

While increasing numbers of patients are seeking acupuncture treatment for depression in recent years, there is limited evidence of the antidepressant (AD) effectiveness of acupuncture. Given the unsatisfactory response rates of many Food and Drug Administration-approved ADs, research on acupuncture remains of potential value. Therefore, we sought to review the efficacy and safety of acupuncture treatment for depression in clinical applications. We conducted a PubMed search for publications through 2011. We assessed the adequacy of each report and abstracted information on reported effectiveness or efficacy of acupuncture as monotherapy for major depressive disorder (MDD) and as augmentation of ADs. We also examined adverse events associated with acupuncture, and evidence for acupuncture as a means of reducing side effects of ADs. Published data suggest that acupuncture, including manual-, electrical-, and laser-based, is a generally beneficial, well-tolerated, and safe monotherapy for depression. However, acupuncture augmentation in AD partial responders and nonresponders is not as well studied as monotherapy; and available studies have only investigated MDD, but not other depressive spectrum disorders. Manual acupuncture reduced side effects of ADs in MDD. We found no data on depressive recurrence rates after recovery with acupuncture treatment. Acupuncture is a potential effective monotherapy for depression, and a safe, well-tolerated augmentation in AD partial responders and nonresponders. However, the body of evidence based on well-designed studies is limited, and further investigation is called for.

Investigation of the delayed neuronal effects of acupuncture manipulations

OBJECTIVES

The aim of this study was to investigate the delayed neuronal effects of acupuncture manipulations by observing blood oxygen level-dependent (BOLD) signal intensities.

SUBJECTS

Fifteen (15) healthy, acupuncture-naive, right-handed subjects (all males; mean age, 23 years; range, 21-24 years) participated in this study.

DESIGN AND INTERVENTIONS

Each subject was scanned in eight sessions that consisted of two repeated baseline scans (Period 1), two repeated scans with acupuncture stimulation at right LR2 (Period 2), two repeated scans with retention (Period 3), and two repeated scans after removal of the needle (Period 4).

OUTCOME MEASURES

Sixteen (16) regions of interest (ROI) were defined. The BOLD signals for each session were obtained for each ROI. A mixed-effects analysis of variance (ANOVA) test was performed in order to investigate the BOLD signal differences of the Periods in the 16 ROIs.

RESULTS

The BOLD signal intensities increased in Periods 2 and 3, and then started to decrease in Period 4 in the right amygdala, supramarginal gyrus, temporal pole, and superior temporal gyrus. However, the BOLD signal intensity in Period 4 was significantly higher than that of Period 1. Especially, BOLD signal intensity was elevated promptly in the insula and the parahippocampal gyrus, whereas it was persistently elevated (delayed effect) in the amygdala.

CONCLUSIONS

BOLD signals were persistently elevated for at least 8 minutes after removal of the acupuncture needle or for at least 19 minutes after rotation of an acupuncture needle in some specific brain areas previously linked with LR2. In those specific brain ROIs, neuronal activation accompanying and following acupuncture showed both prompt and delayed effects.

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.

Neural acupuncture unit: a new concept for interpreting effects and mechanisms of acupuncture

When an acupuncture needle is inserted into a designated point on the body and mechanical or electrical stimulation is delivered, various neural and neuroactive components are activated. The collection of the activated neural and neuroactive components distributed in the skin, muscle, and connective tissues surrounding the inserted needle is defined as a neural acupuncture unit (NAU). The traditionally defined acupoints represent an anatomical landmark system that indicates local sites where NAUs may contain relatively dense and concentrated neural and neuroactive components, upon which acupuncture stimulation would elicit a more efficient therapeutic response. The NAU-based local mechanisms of biochemical and biophysical reactions play an important role in acupuncture-induced analgesia. Different properties of NAUs are associated with different components of needling sensation. There exist several central pathways to convey NAU-induced acupuncture signals, Electroacupuncture (EA) frequency-specific neurochemical effects are related to different peripheral and central pathways transmitting afferent signals from different frequency of NAU stimulation. More widespread and intense neuroimaging responses of brain regions to acupuncture may be a consequence of more efficient NAU stimulation modes. The introduction of the conception of NAU provides a new theoretical approach to interpreting effects and mechanisms of acupuncture in modern biomedical knowledge framework.

The Limbic-Prefrontal Network Modulated by Electroacupuncture at CV4 and CV12

fMRI studies showed that acupuncture could induce hemodynamic changes in brain networks. Many of these studies focused on whether specific acupoints could activate specific brain regions and were often limited to manual acupuncture at acupoints on the limbs. In this fMRI study, we investigated acupuncture's modulation effects on brain functional networks by electroacupuncture (EA) at acupoints on the midline of abdomen. Acupoints Guanyuan (CV4) and Zhongwan (CV12) were stimulated in 21 healthy volunteers. The needling sensations, brain activation, and functional connectivity were studied. We found that the limbic-prefrontal functional network was deactivated by EA at CV4 and CV12. More importantly, the local functional connectivity was significantly changed during EA stimulation, and the change persisted during the period after the stimulation. Although minor differences existed, both acupoints similarly modulated the limbic-prefrontal functional network, which is overlapped with the functional circuits associated with emotional and cognitive regulation.

Fibromyalgia: From treatment to rehabilitation

Fibromyalgia is a clinical syndrome of chronic widespread pain and reduced pain thresholds to palpation. The pathophysiology remains unknown, but there is increasing evidence that peripheral and central sensitization cause an amplification of sensory impulses that may alter pain perception in fibromyalgia patients. Interventions to treat fibromyalgia should aim at different targets simultaneously in order to reduce peripheral and central sensitization. There are both pharmacologic and non-pharmacologic approaches with evidence for effectiveness in the treatment of fibromyalgia and its associated symptoms. Evidence from randomized trials and meta-analyses shows that partial and short-term improvements in fibromyalgia symptoms can be achieved with low doses of antidepressants and with physical activity such as aerobic and strengthening exercises. A multidimensional approach which emphasizes education and integration of exercise and cognitive behavior therapy improves quality of life and reduces pain, fatigue and depressive symptoms when measured on a short term basis. More recently, trials have shown the neuromodulators gabapentin and pregabalin to be effective in reducing pain and improving quality of sleep in fibromyalgia. In addition, small trials of noninvasive brain stimulation have also shown benefits in reducing pain in fibromyalgia. It is essential to keep in mind that some important clinical conditions can mimic and overlap with fibromyalgia and should always be ruled out by a complete history, physical examination and appropriate laboratory testing.

Brief group intervention using emotional freedom techniques for depression in college students: a randomized controlled trial

Two hundred thirty-eight first-year college students were assessed using the Beck Depression Inventory (BDI). Thirty students meeting the BDI criteria for moderate to severe depression were randomly assigned to either a treatment or control group. The treatment group received four 90-minute group sessions of EFT (Emotional Freedom Techniques), a novel treatment that combines exposure, cognitive reprocessing, and somatic stimulation. The control group received no treatment. Posttests were conducted 3 weeks later on those that completed all requirements (N = 18). The EFT group (n = 9) had significantly more depression at baseline than the control group (n = 9) (EFT BDI mean = 23.44, SD = 2.1 versus control BDI mean = 20.33, SD = 2.1). After controlling for baseline BDI score, the EFT group had significantly less depression than the control group at posttest, with a mean score in the "nondepressed" range (P = .001; EFT BDI mean = 6.08, SE = 1.8 versus control BDI mean = 18.04, SE = 1.8). Cohen's d was 2.28, indicating a very strong effect size. These results are consistent with those noted in other studies of EFT that included an assessment for depression and indicate the clinical usefulness of EFT as a brief, cost-effective, and efficacious treatment.

Acupuncture in treatment of carpal tunnel syndrome: A randomized controlled trial study

BACKGROUND

Carpal tunnel syndrome (CTS) is the most preva lent form of peripheral neuropathy. The efficacy of acupuncture in management of mild to moderate CTS has been investigated in limited studies with controversial results. The aim of this study was to assess the short-term effects of acupuncture in treatment of mild to moderate carpal tunnel syndrome.

METHODS

In a randomized controlled trial study, participants were randomly assigned to either control group which night splinting, vitamin B1, B6 and sham acupuncture for four weeks were administered, or intervention group that underwent acupuncture in 8 sessions over 4 weeks and night splinting. The clinical symptoms using global symptom score (GSS) and electrophysiological parameters were assessed at baseline and four weeks after the intervention.

RESULTS

Of 72 patients met the inclusion criteria, 64 patients actually completed the 4 week intervention and were evaluated for the outcome. There was a statistically significant difference in GSS between two arms of treatment after the intervention (p < 0.001) Using repeated measure ANOVA, the GSS in acupuncture group was significantly different after 4 weeks (p <0.001). Among electrophysiological parameters, nerve conduction velocity (NCV) was significantly different between two groups after 4 weeks (p = 0.02). Other parameters showed no statistically significant difference after intervention (p > 0.05).

CONCLUSIONS

Our findings indicated that the acupuncture can improve the overall subjective symptoms of carpal tunnel syndrome and could be adopted in comprehensive care programs of these patients.

Does acupuncture needling induce analgesic effects comparable to diffuse noxious inhibitory controls?

Diffuse noxious inhibitory control (DNIC) is described as one possible mechanism of acupuncture analgesia. This study investigated the analgesic effect of acupuncture without stimulation compared to nonpenetrating sham acupuncture (NPSA) and cold-pressor-induced DNIC. Forty-five subjects received each of the three interventions in a randomized order. The analgesic effect was measured using pressure algometry at the second toe before and after each of the interventions. Pressure pain detection threshold (PPDT) rose from 299 kPa (SD 112 kPa) to 364 kPa (SD 144), 353 kPa (SD 135), and 467 kPa (SD 168) after acupuncture, NPSA, and DNIC test, respectively. There was no statistically significant difference between acupuncture and NPSA at any time, but a significantly higher increase of PPDT in the DNIC test compared to acupuncture and NPSA. PPDT decreased after the DNIC test, whereas it remained stable after acupuncture and NPSA. Acupuncture needling at low pain stimulus intensity showed a small analgesic effect which did not significantly differ from placebo response and was significantly less than a DNIC-like effect of a painful noninvasive stimulus.

Is placebo acupuncture what it is intended to be?

Randomized, placebo-controlled clinical trials are recommended for evaluation of a treatment's efficacy with the goal of separating the specific effects (verum) from the non-specific ones (placebo). In order to be able to carry out placebo-controlled acupuncture trials, minimal/sham acupuncture procedures and a sham acupuncture needle has been used with the intention of being inert. However, clinical and experimental results suggest that sham/minimal acupuncture is not inert since it is reported that both verum acupuncture and sham/minimal acupuncture induce a significant alleviation of pain. This alleviation is as pronounced as the alleviation obtained with standard treatment and more obvious than the one obtained with placebo medication or by the use of waiting list controls. These results also suggest that sham acupuncture needles evoke a physiological response. In healthy individuals sham acupuncture results in activation of limbic structures, whereas a deactivation is seen in patients with pain, i.e. results from healthy individuals do not reflect what is seen in clinical conditions. Also, depending on the etiology of pain (or any under clinical condition under investigation), the response to sham acupuncture is varying. The acupuncture ritual may also be seen as an emotional focused therapy allowing for psychological re-orientation. Sham needling in such context may be as powerful as verum acupuncture. We recommend that the evaluated effects of acupuncture could be compared with those of standard treatment, also taking the individual response into consideration, before its use or non-use is established.

Gene Expression Profile of the Hypothalamus in DNP-KLH Immunized Mice Following Electroacupuncture Stimulation

Clinical evidence indicates that electroacupuncture (EA) is effective for allergic disorder. Recent animal studies have shown that EA treatment reduces levels of IgE and Th2 cytokines in BALB/c mice immunized with 2,4-dinitrophenylated keyhole limpet protein (DNP-KLH). The hypothalamus, a brain center of the neural-immune system, is known to be activated by EA stimulation. This study was performed to identify and characterize the differentially expressed genes in the hypothalamus of DNP-KLH immunized mice that were stimulated with EA or only restrained. To this aim, we conducted a microarray analysis to evaluate the global gene expression profiles, using the hypothalamic RNA samples taken from three groups of mice: (i) normal control group (no treatments); (ii) IMH group (DNP-KLH immunization + restraint); and (iii) IMEA group (immunization + EA stimulation). The microarray analysis revealed that total 39 genes were altered in their expression levels by EA treatment. Ten genes, including T-cell receptor alpha variable region family 13 subfamily 1 (Tcra-V13.1), heat shock protein 1B (Hspa1b) and 2′–5′ oligoadenylate synthetase 1F (Oas1f), were up-regulated in the IMEA group when compared with the IMH group. In contrast, 29 genes, including decay accelerating factor 2 (Daf2), NAD(P)H dehydrogenase, quinone 1 (Nqo1) and programmed cell death 1 ligand 2 (Pdcd1lg2) were down-regulated in the IMEA group as compared with the IMH group. These results suggest that EA treatment can modulate immune response in DNP-KLH immunized mice by regulating expression levels of genes that are associated with innate immune, cellular defense and/or other kinds of immune system in the hypothalamus.

A randomized clinical trial of acupuncture versus oral steroids for carpal tunnel syndrome: a long-term follow-up

We prospectively followed up patients with carpal tunnel syndrome (CTS) in our previous study for 1 year. A total of 77 consecutive patients with electrophysiologically confirmed mild-to-moderate idiopathic CTS were randomized and assigned into 2 treatment arms: 1) 2 weeks of prednisolone 20 mg daily followed by 2 weeks of prednisolone 10 mg daily (n = 39); and 2) acupuncture administered in 8 sessions over 4 weeks (n = 38). In the current study, the patients were further followed up at 7 and 13 months using Global symptom score (GSS) assessments and nerve conduction studies repeated again at 13 months. When comparing with baseline levels, the percentages of patients with treatment failure, moderate improvement, and good improvement were significantly different between the 2 groups at month 7 [10.5, 2.6, and 86.8% for the acupuncture group and 33.3, 7.7, and 59% for the steroid group, respectively (P = .014)] and month 13 [15.8, 2.6, and 81.6% versus 51.3, 0, and 48.7%, respectively (P = .002)]. The acupuncture group had a significantly better improvement in GSS, distal motor latencies and distal sensory latencies when compared to the steroid group throughout the 1-year follow-up period (P < .01). Furthermore, significant correlation was observed between changes of GSS (month 13-baseline) and all parameters of the electrophysiological assessments except for compound muscle action potential amplitude.

PERSPECTIVE

This article demonstrates that short-term acupuncture treatment may result in long-term improvement in mild-to-moderate idiopathic CTS. Acupuncture treatment can be considered as an alternative therapy to other conservative treatments for those who do not opt for early surgical decompression.

Acupuncture modulates temporal neural responses in wide brain networks: evidence from fMRI study

BACKGROUND

Accumulating neuroimaging studies in humans have shown that acupuncture can modulate a widely distributed brain network, large portions of which are overlapped with the pain-related areas. Recently, a striking feature of acupuncture-induced analgesia is found to be associated with its long-last effect, which has a delayed onset and gradually reaches a peak even after acupuncture needling being terminated. Identifying temporal neural responses in these areas that occur at particular time--both acute and sustained effects during acupuncture processes--may therefore shed lights on how such peripheral inputs are conducted and mediated through the CNS. In the present study, we adopted a non-repeated event-related (NRER) fMRI paradigm and control theory based approach namely change-point analysis in order to capture the detailed temporal profile of neural responses induced by acupuncture.

RESULTS

Our findings demonstrated that neural activities at the different stages of acupuncture presented distinct temporal patterns, in which consistently positive neural responses were found during the period of acupuncture needling while much more complex and dynamic activities found during a post-acupuncture period. These brain responses had a significant time-dependent effect which showed different onset time and duration of neural activities. The amygdala and perigenual anterior cingulate cortex (pACC), exhibited increased activities during the needling phase while decreased gradually to reach a peak below the baseline. The periaqueductal gray (PAG) and hypothalamus presented saliently intermittent activations across the whole fMRI session. Apart from the time-dependent responses, relatively persistent activities were also identified in the anterior insula and prefrontal cortices. The overall findings indicate that acupuncture may engage differential temporal neural responses as a function of time in a wide range of brain networks.

CONCLUSIONS

Our study has provided evidence supporting a view that acupuncture intervention involves complex modulations of temporal neural response, and its effect can gradually resolve as a function of time. The functional specificity of acupuncture at ST36 may involve multiple levels of differential activities of a wide range of brain networks, which are gradually enhanced even after acupuncture needle being terminated.

Paradoxes in acupuncture research: strategies for moving forward

In November 2007, the Society for Acupuncture Research (SAR) held an international symposium to mark the 10th anniversary of the 1997 NIH Consensus Development Conference on Acupuncture. The symposium presentations revealed the considerable maturation of the field of acupuncture research, yet two provocative paradoxes emerged. First, a number of well-designed clinical trials have reported that true acupuncture is superior to usual care, but does not significantly outperform sham acupuncture, findings apparently at odds with traditional theories regarding acupuncture point specificity. Second, although many studies using animal and human experimental models have reported physiological effects that vary as a function of needling parameters (e.g., mode of stimulation) the extent to which these parameters influence therapeutic outcomes in clinical trials is unclear. This White Paper, collaboratively written by the SAR Board of Directors, identifies gaps in knowledge underlying the paradoxes and proposes strategies for their resolution through translational research. We recommend that acupuncture treatments should be studied (1) “top down” as multi-component “whole-system” interventions and (2) “bottom up” as mechanistic studies that focus on understanding how individual treatment components interact and translate into clinical and physiological outcomes. Such a strategy, incorporating considerations of efficacy, effectiveness and qualitative measures, will strengthen the evidence base for such complex interventions as acupuncture.

The effects of acupuncture on the brain networks for emotion and cognition: an observation of gender differences

Acupuncture modulates brain activity at the limbic-paralimbic-neocortical network (LPNN) and the default mode network (DMN). Since these brain networks show gender differences when mediating emotional and cognitive tasks, we thus hypothesize that women and men may also respond differently to acupuncture procedure at these brain regions. In order to test this hypothesis, we retrieved the data of 38 subjects, 19 females and 19 males, who had brain fMRI during acupuncture from previous studies and reanalyzed them based on sex status. Deactivation at the LPNN/DMN during needle manipulation of acupuncture was more extensive in females than in males, particularly in the posterior cingulate (BA31), precuneus (BA7m) and angular gyrus (BA39). The functional correlations between the right BA31 and pregenual cingulate (BA32), hippocampus or contralateral BA31 were significantly stronger in females than in males. The angular gyrus (BA39) was functionally correlated with BA31 in females; in contrast, it was anticorrelated with BA31 in males. Soreness, a major component of the psychophysical responses to needle manipulation, deqi, was correlated in intensity with deactivation of the angular gyrus in females; no such relationships were observed in males. In contrast to lesser deactivation at the LPNN/DMN networks, needle manipulation during acupuncture induced greater activation at the secondary somatosensory cortex and stronger functional connectivity with the anterior-middle cingulate (BA32/24) in males than in females. Our study suggests that brains with sex dimorphism may process the acupuncture stimulation differently between women and men.

The brain effects of laser acupuncture in healthy individuals: an FMRI investigation

Background

As laser acupuncture is being increasingly used to treat mental disorders, we sought to determine whether it has a biologically plausible effect by using functional magnetic resonance imaging (fMRI) to investigate the cerebral activation patterns from laser stimulation of relevant acupoints.

Methodology/Principal Findings

Ten healthy subjects were randomly stimulated with a fibreoptic infrared laser on 4 acupoints (LR14, CV14, LR8 and HT7) used for depression following the principles of Traditional Chinese Medicine (TCM), and 1 control non-acupoint (sham point) in a blocked design (alternating verum laser and placebo laser/rest blocks), while the blood oxygenation level-dependent (BOLD) fMRI response was recorded from the whole brain on a 3T scanner. Many of the acupoint laser stimulation conditions resulted in different patterns of neural activity. Regions with significantly increased activation included the limbic cortex (cingulate) and the frontal lobe (middle and superior frontal gyrus). Laser acupuncture tended to be associated with ipsilateral brain activation and contralateral deactivation that therefore cannot be simply attributed to somatosensory stimulation.

Conclusions/Significance

We found that laser stimulation of acupoints lead to activation of frontal-limbic-striatal brain regions, with the pattern of neural activity somewhat different for each acupuncture point. This is the first study to investigate laser acupuncture on a group of acupoints useful in the management of depression. Differing activity patterns depending on the acupoint site were demonstrated, suggesting that neurological effects vary with the site of stimulation. The mechanisms of activation and deactivation and their effects on depression warrant further investigation.

Influence of acupuncture on type I hypersensitivity itch and the wheal and flare response in adults with atopic eczema - a blinded, randomized, placebo-controlled, crossover trial

BACKGROUND

Itch is a major symptom of allergic skin disease. Acupuncture has been shown to exhibit a significant effect on histamine-induced itch in healthy volunteers. We investigated the effect of acupuncture on type I hypersensitivity itch and skin reaction in a double-blind, randomized, placebo-controlled, crossover trial.

METHODS

An allergen stimulus (house dust mite or grass pollen skin prick) was applied to 30 patients with atopic eczema before (direct effect) and after (preventive effect) two experimental approaches or control observation: acupuncture at points Quchi and Xuehai [verum acupuncture (VA), dominant side], 'placebo-point' acupuncture (PA, dominant side), no acupuncture (NA). Itch intensity was recorded on a visual analogue scale. After 10 min, wheal and flare size and skin perfusion (via LASER-Doppler) were measured at the stimulus site, and the validated Eppendorf Itch Questionnaire (EIQ) was answered.

RESULTS

Mean itch intensity was significantly lower in VA (35.7 +/- 6.4) compared to NA (45.9 +/- 7.8) and PA (40.4 +/- 5.8) regarding the direct effect; and significantly lower in VA (34.3 +/- 7.1) and PA (37.8 +/- 5.6) compared to NA (44.6 +/- 6.2) regarding the preventive effect. In the preventive approach, mean wheal and flare size were significantly smaller in VA (0.38 +/- 0.12 cm(2)/8.1 +/- 2.0 cm(2)) compared to PA (0.54 +/- 0.13 cm(2)/13.5 +/- 2.8 cm(2)) and NA (0.73 +/- 0.28 cm(2)/15.1 +/- 4.1 cm(2)), and mean perfusion in VA (72.4 +/- 10.7) compared to NA (84.1 +/- 10.7). Mean EIQ ratings were significantly lower in VA compared to NA and PA in the treatment approach; and significantly lower in VA and PA compared to NA in the preventive approach.

CONCLUSIONS

Acupuncture at the correct points showed a significant reduction in type I hypersensitivity itch in patients with atopic eczema. With time the preventive point-specific effect diminished with regard to subjective itch sensation, whereas it increased in suppressing skin-prick reactions.

Management of shoulder injuries using dry needling in elite volleyball players

These case reports describe the short-term benefits of dry needling in shoulder injuries in four international female volleyball athletes during a month-long intense competitive phase, using both replicable subjective and objective measures. Dry needling of scapulohumeral muscles was carried out. Range of movement, strength and pain were assessed before and after treatment, with a functional assessment of pain immediately after playing and overhead activity, using the short form McGill Pain Questionnaire. All scores were improved post-treatment and athletes were able to continue overhead activities. Previous studies have suggested that myofascial trigger points may cause significant functional weakness and reduced range of motion, with referred pain. Trigger point dry needling has been successful in treating athletes with myofascial pain and impingement symptoms but with only subjective improvement and not during a competitive phase. These cases support the use of dry needling in elite athletes during a competitive phase with short-term pain relief and improved function in shoulder injuries. It may help maintain rotator cuff balance and strength, reducing further pain and injury.

Acupuncture, the limbic system, and the anticorrelated networks of the brain

The study of the mechanism of acupuncture action was revolutionized by the use of functional magnetic resonance imaging (fMRI). Over the past decade, our fMRI studies of healthy subjects have contributed substantially to elucidating the central effect of acupuncture on the human brain. These studies have shown that acupuncture stimulation, when associated with sensations comprising deqi, evokes deactivation of a limbic-paralimbic-neocortical network, which encompasses the limbic system, as well as activation of somatosensory brain regions. These networks closely match the default mode network and the anti-correlated task-positive network described in the literature. We have also shown that the effect of acupuncture on the brain is integrated at multiple levels, down to the brainstem and cerebellum. Our studies support the hypothesis that the effect of acupuncture on the brain goes beyond the effect of attention on the default mode network or the somatosensory stimulation of acupuncture needling. The amygdala and hypothalamus, in particular, show decreased activation during acupuncture stimulation that is not commonly associated with default mode network activity. At the same time, our research shows that acupuncture stimulation needs to be done carefully, limiting stimulation when the resulting sensations are very strong or when sharp pain is elicited. When acupuncture induced sharp pain, our studies show that the deactivation was attenuated or reversed in direction. Our results suggest that acupuncture mobilizes the functionally anti-correlated networks of the brain to mediate its actions, and that the effect is dependent on the psychophysical response. In this work we also discuss multiple avenues of future research, including the role of neurotransmitters, the effect of different acupuncture techniques, and the potential clinical application of our research findings to disease states including chronic pain, major depression, schizophrenia, autism, and Alzheimer's disease.

Electroacupuncture suppresses capsaicin-induced secondary hyperalgesia through an endogenous spinal opioid mechanism

Central sensitization, caused either by tissue inflammation or peripheral nerve injury, plays an important role in persistent pain. An animal model of capsaicin-induced pain has well-defined peripheral and central sensitization components, thus is useful for studying the analgesic effect on two separate components. The focus of this study is to examine the analgesic effects of electroacupuncture (EA) on capsaicin-induced secondary hyperalgesia, which represents central sensitization. Capsaicin (0.1%, 20 microl) was injected into the plantar side of the left hind paw, and foot withdrawal thresholds in response to von Frey stimuli (mechanical sensitivity) were determined for both primary and secondary hyperalgesia in rats. EA (2 Hz, 3 mA) was applied to various pairs of acupoints, GB30-GB34, BL40-BL60, GV2-GV6, LI3-LI6 and SI3-TE8, for 30 min under isoflurane anesthesia and then the effect of EA on mechanical sensitivity of paw was determined. EA applied to the ipsilateral SI3-TE8, but to none of the other acupoints, significantly reduced capsaicin-induced secondary hyperalgesia but not primary hyperalgesia. EA analgesic effect was inhibited by a systemic non-specific opioid receptor (OR) antagonist or an intrathecal mu- or delta-OR antagonist. EA analgesic effect was not affected by an intrathecal kappa-OR antagonist or systemic adrenergic receptor antagonist. This study demonstrates that EA produces a stimulation point-specific analgesic effect on capsaicin-induced secondary hyperalgesia (central sensitization), mediated by activating endogenous spinal mu- and delta-opioid receptors.

Acupuncture in patients with carpal tunnel syndrome: A randomized controlled trial

OBJECTIVES

To investigate the efficacy of acupuncture compared with steroid treatment in patients with mild-to-moderate carpal tunnel syndrome (CTS) as measured by objective changes in nerve conduction studies (NCS) and subjective symptoms assessment in a randomized, controlled study.

METHODS

A total of 77 consecutive and prospective CTS patients confirmed by NCS were enrolled in the study. Those who had fixed sensory complaint over the median nerve and thenar muscle atrophy were excluded. The CTS patients were randomly divided into 2 treatment arms: (1) 2 weeks of prednisolone 20 mg daily followed by 2 weeks of prednisolone 10 mg daily (n = 39), and (2) acupuncture administered in 8 sessions over 4 weeks (n = 38). A validated standard questionnaire as a subjective measurement was used to rate the 5 major symptoms (pain, numbness, paresthesia, weakness/clumsiness, and nocturnal awakening) on a scale from 0 (no symptoms) to 10 (very severe). The total score in each of the 5 categories was termed the global symptom score (GSS). Patients completed standard questionnaires at baseline and 2 and 4 weeks later. The changes in GSS were analyzed to evaluate the statistical significance. NCS were performed at baseline and repeated at the end of the study to assess improvement. All main analyses used intent-to-treat.

RESULTS

A total of 77 patients who fulfilled the criteria for mild-to-moderate CTS were recruited in the study. There were 38 in the acupuncture group and 39 in the steroid group. The evaluation of GSS showed that there was a high percentage of improvement in both groups at weeks 2 and 4 (P < 0.01), though statistical significance was not demonstrated between the 2 groups (P = 0.15). Of the 5 main symptoms scores (pain, numbness, paresthesia, weakness/clumsiness, nocturnal awakening), only 1, nocturnal awakening, showed a significant decrease in acupuncture compared with the steroid group at week 4 (P = 0.03). Patients with acupuncture treatment had a significant decrease in distal motor latency compared with the steroid group at week 4 (P = 0.012). Acupuncture was well tolerated with minimal adverse effects.

CONCLUSIONS

Short-term acupuncture treatment is as effective as short-term low-dose prednisolone for mild-to-moderate CTS. For those who do have an intolerance or contraindication for oral steroid or for those who do not opt for early surgery, acupuncture treatment provides an alternative choice.

Acupuncture mobilizes the brain's default mode and its anti-correlated network in healthy subjects

Previous work has shown that acupuncture stimulation evokes deactivation of a limbic-paralimbic-neocortical network (LPNN) as well as activation of somatosensory brain regions. This study explores the activity and functional connectivity of these regions during acupuncture vs. tactile stimulation and vs. acupuncture associated with inadvertent sharp pain. Acupuncture during 201 scans and tactile stimulation during 74 scans for comparison at acupoints LI4, ST36 and LV3 was monitored with fMRI and psychophysical response in 48 healthy subjects. Clusters of deactivated regions in the medial prefrontal, medial parietal and medial temporal lobes as well as activated regions in the sensorimotor and a few paralimbic structures can be identified during acupuncture by general linear model analysis and seed-based cross correlation analysis. Importantly, these clusters showed virtual identity with the default mode network and the anti-correlated task-positive network in response to stimulation. In addition, the amygdala and hypothalamus, structures not routinely reported in the default mode literature, were frequently involved in acupuncture. When acupuncture induced sharp pain, the deactivation was attenuated or became activated instead. Tactile stimulation induced greater activation of the somatosensory regions but less extensive deactivation of the LPNN. These results indicate that the deactivation of the LPNN during acupuncture cannot be completely explained by the demand of attention that is commonly proposed in the default mode literature. Our results suggest that acupuncture mobilizes the anti-correlated functional networks of the brain to mediate its actions, and that the effect is dependent on the psychophysical response.

Brain encoding of acupuncture sensation--coupling on-line rating with fMRI

Acupuncture-induced sensations have historically been associated with clinical efficacy. These sensations are atypical, arising from sub-dermal receptors, and their neural encoding is not well known. In this fMRI study, subjects were stimulated at acupoint PC-6, while rating sensation with a custom-built, MR-compatible potentiometer. Separate runs included real (ACUP) and sham (SHAM) acupuncture, the latter characterized by non-insertive, cutaneous stimulation. FMRI data analysis was guided by the on-line rating timeseries, thereby localizing brain correlates of acupuncture sensation. Sensation ratings correlated with stimulation more (p<0.001) for SHAM (r=0.63) than for ACUP (r=0.32). ACUP induced stronger and more varied sensations with significant persistence into no-stimulation blocks, leading to more run-time spent rating low and moderate sensations compared to SHAM. ACUP sensation correlated with activation in regions associated with sensorimotor (SII, insula) and cognitive (dorsomedial prefrontal cortex (dmPFC)) processing, and deactivation in default-mode network (DMN) regions (posterior cingulate, precuneus). Compared to SHAM, ACUP yielded greater activity in both anterior and posterior dmPFC and dlPFC. In contrast, SHAM produced greater activation in sensorimotor (SI, SII, insula) and greater deactivation in DMN regions. Thus, brain encoding of ACUP sensation (more persistent and varied, leading to increased cognitive load) demonstrated greater activity in both cognitive/evaluative (posterior dmPFC) and emotional/interoceptive (anterior dmPFC) cortical regions. Increased cognitive load and dmPFC activity may be a salient component of acupuncture analgesia--sensations focus attention and accentuate bodily awareness, contributing to enhanced top-down modulation of any nociceptive afference and central pain networks. Hence, acupuncture may function as a somatosensory-guided mind-body therapy.

Traditional Chinese acupuncture and placebo (sham) acupuncture are differentiated by their effects on mu-opioid receptors (MORs)

Controversy remains regarding the mechanisms of acupuncture analgesia. A prevailing theory, largely unproven in humans, is that it involves the activation of endogenous opioid antinociceptive systems and mu-opioid receptors (MORs). This is also a neurotransmitter system that mediates the effects of placebo-induced analgesia. This overlap in potential mechanisms may explain the lack of differentiation between traditional acupuncture and either non-traditional or sham acupuncture in multiple controlled clinical trials. We compared both short- and long-term effects of traditional Chinese acupuncture (TA) versus sham acupuncture (SA) treatment on in vivo MOR binding availability in chronic pain patients diagnosed with fibromyalgia (FM). Patients were randomized to receive either TA or SA treatment over the course of 4 weeks. Positron emission tomography (PET) with (11)C-carfentanil was performed once during the first treatment session and then repeated a month later following the eighth treatment. Acupuncture therapy evoked short-term increases in MOR binding potential, in multiple pain and sensory processing regions including the cingulate (dorsal and subgenual), insula, caudate, thalamus, and amygdala. Acupuncture therapy also evoked long-term increases in MOR binding potential in some of the same structures including the cingulate (dorsal and perigenual), caudate, and amygdala. These short- and long-term effects were absent in the sham group where small reductions were observed, an effect more consistent with previous placebo PET studies. Long-term increases in MOR BP following TA were also associated with greater reductions in clinical pain. These findings suggest that divergent MOR processes may mediate clinically relevant analgesic effects for acupuncture and sham acupuncture.

Acupuncture for preconditioning of expectancy and/or Pavlovian extinction

Both specific and non-specific factors, as well as the therapist, may play a role in acupuncture therapy. Recent results suggest that verum acupuncture has specific physiological effects and that patients expectations and belief regarding a potentially beneficial treatment modulate activity in the reward and self-appraisal systems in the brain. We suggest that acupuncture treatment may partly be regarded and used as an intervention that preconditions expectancy, which results in both conditional reflexes and conditioning of expected reward and self-appraisal. If so, acupuncture should preferably be applied before the start of the specific treatment (drug or behavioural intervention which is given with the intention of achieving a specific outcome) to enhance the specific and non-specific effects. This hypothesis is further supported by the suggestions that acupuncture may be viewed as a neural stimulus that triggers Pavlovian extinction. If this is the case, acupuncture should preferably be applied repeatedly (ie in a learning process) before the start of the specific treatment to initiate the extinction of previous unpleasant associations like pain or anxiety. Our clinical data suggest that acupuncture may precondition expectancy and conditional reflexes as well as induce Pavlovian extinction. Based on the above we suggest that acupuncture should be tried (as an adjunct) before any specific therapy.

Time-variant fMRI activity in the brainstem and higher structures in response to acupuncture

Acupuncture modulation of activity in the human brainstem is not well known. This structure is plagued by physiological artifact in neuroimaging experiments. In addition, most studies have used short (<15 min) block designs, which miss delayed responses following longer duration stimulation. We used brainstem-focused cardiac-gated fMRI and evaluated time-variant brain response to longer duration (>30 min) stimulation with verum (VA, electro-stimulation at acupoint ST-36) or sham point (SPA, non-acupoint electro-stimulation) acupuncture. Our results provide evidence that acupuncture modulates brainstem nuclei important to endogenous monoaminergic and opioidergic systems. Specifically, VA modulated activity in the substantia nigra (SN), nucleus raphe magnus, locus ceruleus, nucleus cuneiformis, and periaqueductal gray (PAG). Activation in the ventrolateral PAG was greater for VA compared to SPA. Linearly decreasing time-variant activation, suggesting classical habituation, was found in response to both VA and SPA in sensorimotor (SII, posterior insula, premotor cortex) brain regions. However, VA also produced linearly time-variant activity in limbic regions (amygdala, hippocampus, and SN), which was bimodal and not likely habituation--consisting of activation in early blocks, and deactivation by the end of the run. Thus, acupuncture induces different brain response early, compared to 20-30 min after stimulation. We attribute the fMRI differences between VA and SPA to more varied and stronger psychophysical response induced by VA. Our study demonstrates that acupuncture modulation of brainstem structures can be studied non-invasively in humans, allowing for comparison to animal studies. Our protocol also demonstrates a fMRI approach to study habituation and other time-variant phenomena over longer time durations.

The salient characteristics of the central effects of acupuncture needling: limbic-paralimbic-neocortical network modulation

Human and animal studies suggest that acupuncture produces many beneficial effects through the central nervous system. However, the neural substrates of acupuncture actions are not completely clear to date. fMRI studies at Hegu (LI4) and Zusanli (ST36) indicated that the limbic system may play an important role for acupuncture effects. To test if this finding applies to other major classical acupoints, fMRI was performed on 10 healthy adults during manual acupuncture at Taichong (LV3), Xingjian (LV2), Neiting (ST44), and a sham point on the dorsum of the left foot. Although certain differences could be observed between real and sham points, the hemodynamic response (BOLD signal changes) and psychophysical response (sensory experience) to acupuncture were generally similar for all four points. Acupuncture produced extensive deactivation of the limbic-paralimbic-neocortical system. Clusters of deactivated regions were seen in the medial prefrontal cortex (frontal pole, pregenual cingulate), the temporal lobe (amygdala, hippocampus, and parahippocampus) and the posterior medial cortex (precuneus, posterior cingulate). The sensorimotor cortices (somatosensory cortices, supplementary motor cortex), thalamus and occasional paralimbic structures such as the insula and anterior middle cingulate cortex showed activation. Our results provide additional evidence in support of previous reports that acupuncture modulates the limbic-paralimbic-neocortical network. We hypothesize that acupuncture may mediate its antipain, antianxiety, and other therapeutic effects via this intrinsic neural circuit that plays a central role in the affective and cognitive dimensions of pain as well as in the regulation and integration of emotion, memory processing, autonomic, endocrine, immunological, and sensorimotor functions.

Brain areas involved in acupuncture treatment on functional dyspepsia patients: a PET-CT study

Neuroimaging studies on brain responses to acupuncture stimulations have received considerable attention recently. The majority of these studies are centered on healthy controls (HC) and neuropathy, while little work has addressed other disorders. This study aimed to investigate the influence of acupuncture stimulations on brain activities in functional dyspepsia (FD) patients. Eight FD patients and eight healthy controls (HC) were involved in this study. Each HC received an 18F-FDG PET-CT scan at baseline, while each patient received scans at baseline and after acupuncture stimulations. Manual acupuncture stimulations were performed at ST34 (Liangqiu), ST36 (Zusanli), ST40 (Fenglong) and ST42 (Chongyang) in FD patients. The images were analyzed with the Statistical Parametric Mapping software 2.0. Compared to HC, the FD patients showed a lower glycometabolism in the right orbital gyrus, the left caudate tail and the cingulate gyrus, and a higher glycometabolism in the left inferior temporal gyrus (p<0.005). After acupuncture stimulations, the FD patients showed a glycometabolism decrease in the postcentral gyrus and the cerebella, and an increase in the visual-related cortices(p<0.005). The results suggest that the anterior cingulate cortex, the prefrontal cortices and the caudate tail involve in processing gastric perceptions in FD patients and that the deactivation of the primary somatosensory area and the cerebella is contributable to acupuncture stimulation, while activation of the visual-related cortex is a response to pain or acupoint actions.

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.

The status and future of acupuncture mechanism research

On November 8-9, 2007, the Society for Acupuncture Research (SAR) hosted an international conference to mark the tenth anniversary of the landmark NIH [National Institutes of Health] Consensus Development Conference on Acupuncture. More than 300 acupuncture researchers, practitioners, students, funding agency personnel, and health policy analysts from 20 countries attended the SAR meeting held at the University of Maryland School of Medicine, Baltimore, MD. This paper summarizes important invited lectures in the area of basic and translational acupuncture research. Specific areas include the scientific assessment of acupuncture points and meridians, the neural mechanisms of cardiovascular regulation by acupuncture, mechanisms for electroacupuncture applied to persistent inflammation and pain, basic and translational research on acupuncture in gynecologic applications, the application of functional neuroimaging to acupuncture research with specific application to carpal-tunnel syndrome and fibromyalgia, and the association of the connective tissue system to acupuncture research. In summary, mechanistic models for acupuncture effects that have been investigated experimentally have focused on the effects of acupuncture needle stimulation on the nervous system, muscles, and connective tissue. These mechanistic models are not mutually exclusive. Iterative testing, expanding, and perhaps merging of such models will potentially lead to an incremental understanding of the effects of manual and electrical stimulation of acupuncture needles that is solidly rooted in physiology.

Expectancy and treatment interactions: a dissociation between acupuncture analgesia and expectancy evoked placebo analgesia

Recent advances in placebo research have demonstrated the mind's power to alter physiology. In this study, we combined an expectancy manipulation model with both verum and sham acupuncture treatments to address: 1) how and to what extent treatment and expectancy effects - including both subjective pain intensity levels (pain sensory ratings) and objective physiological activations (fMRI) - interact; and 2) if the underlying mechanism of expectancy remains the same whether placebo treatment is given alone or in conjunction with active treatment. The results indicate that although verum acupuncture+high expectation and sham acupuncture+high expectation induced subjective reports of analgesia of equal magnitude, fMRI analysis showed that verum acupuncture produced greater fMRI signal decrease in pain related brain regions during application of calibrated heat pain stimuli on the right arm. We believe our study provides brain imaging evidence for the existence of different mechanisms underlying acupuncture analgesia and expectancy evoked placebo analgesia. Our results also suggest that the brain network involved in expectancy may vary under different treatment situations (verum and sham acupuncture treatment).

Adenoviral gene transfer of acetylcholinesterase T subunit in the hypothalamus potentiates electroacupuncture analgesia in rats

Our previous studies, using cDNA microarray and real-time reverse transcription-polymerase chain reaction, showed that acetylcholinesterase T subunit (AChET) gene was more abundantly expressed in the hypothalamus of the responder rats that were sensitive to electroacupuncture (EA) in the tail flick latency (TFL) test than in that of the non-responder rats that were insensitive to EA. In this study, we hypothesized that the expression of the AChET gene in the hypothalamus modulates EA analgesia in rats. To explore the hypothesis, we constructed an AChET-encoding adenovirus and a control virus expressing only green fluorescence protein, either of which was then injected into the hypothalamus of Sprague-Dawley rats. The hypothalamic activity of acetylcholinesterase was significantly higher in rats that were injected with the AChET virus than in rats that were injected with the control virus. The basal pain threshold measured by a TFL test was not changed by microinjection of AChET or control virus into the hypothalamus when EA treatment was not conducted. However, the analgesic effect of EA was significantly enhanced from 7 days after microinjection of the AChET virus into the hypothalamus but not after injection of the control virus. Furthermore, expression of the AChET in the hypothalamus did not affect body core temperature, body weight, motor function or learning and memory ability. Taken together, these results suggest that adenoviral expression of the AChET gene in the hypothalamus potentiates EA analgesia in rats without apparent side-effects.

FMRI connectivity analysis of acupuncture effects on an amygdala-associated brain network

Background

Recently, increasing evidence has indicated that the primary acupuncture effects are mediated by the central nervous system. However, specific brain networks underpinning these effects remain unclear.

Results

In the present study using fMRI, we employed a within-condition interregional covariance analysis method to investigate functional connectivity of brain networks involved in acupuncture. The fMRI experiment was performed before, during and after acupuncture manipulations on healthy volunteers at an acupuncture point, which was previously implicated in a neural pathway for pain modulation. We first identified significant fMRI signal changes during acupuncture stimulation in the left amygdala, which was subsequently selected as a functional reference for connectivity analyses. Our results have demonstrated that there is a brain network associated with the amygdala during a resting condition. This network encompasses the brain structures that are implicated in both pain sensation and pain modulation. We also found that such a pain-related network could be modulated by both verum acupuncture and sham acupuncture. Furthermore, compared with a sham acupuncture, the verum acupuncture induced a higher level of correlations among the amygdala-associated network.

Conclusion

Our findings indicate that acupuncture may change this amygdala-specific brain network into a functional state that underlies pain perception and pain modulation.

Acupuncture modulates resting state connectivity in default and sensorimotor brain networks

Previous studies have defined low-frequency, spatially consistent networks in resting fMRI data which may reflect functional connectivity. We sought to explore how a complex somatosensory stimulation, acupuncture, influences intrinsic connectivity in two of these networks: the default mode network (DMN) and sensorimotor network (SMN). We analyzed resting fMRI data taken before and after verum and sham acupuncture. Electrocardiography data were used to infer autonomic modulation through measures of heart rate variability (HRV). Probabilistic independent component analysis was used to separate resting fMRI data into DMN and SMN components. Following verum, but not sham, acupuncture there was increased DMN connectivity with pain (anterior cingulate cortex (ACC), periaqueductal gray), affective (amygdala, ACC), and memory (hippocampal formation, middle temporal gyrus) related brain regions. Furthermore, increased DMN connectivity with the hippocampal formation, a region known to support memory and interconnected with autonomic brain regions, was negatively correlated with acupuncture-induced increase in a sympathetic related HRV metric (LFu), and positively correlated with a parasympathetic related metric (HFu). Following verum, but not sham, acupuncture there was also increased SMN connectivity with pain-related brain regions (ACC, cerebellum). We attribute differences between verum and sham acupuncture to more varied and stronger sensations evoked by verum acupuncture. Our results demonstrate for the first time that acupuncture can enhance the post-stimulation spatial extent of resting brain networks to include anti-nociceptive, memory, and affective brain regions. This modulation and sympathovagal response may relate to acupuncture analgesia and other potential therapeutic effects.

Neuroimaging acupuncture effects in the human brain

Acupuncture is an ancient East Asian healing modality that has been in use for more than 2000 years. Unfortunately, its mechanisms of action are not well understood, and controversy regarding its clinical efficacy remains. Importantly, acupuncture needling often evokes complex somatosensory sensations and may modulate the cognitive/affective perception of pain, suggesting that many effects are supported by the brain and extending central nervous system (CNS) networks. Modern neuroimaging techniques such as functional magnetic resonance imaging, positron emission tomography, electroencephalography, and magnetoencephalography provide a means to safely monitor brain activity in humans and may be used to help map the neurophysiological correlates of acupuncture. In this review, we will summarize data from acupuncture neuroimaging research and discuss how these findings contribute to current hypotheses of acupuncture action.

Did ‘the Princess on the Pea— Suffer from Fibromyalgia Syndrome?

Fibromyalgia syndrome (FMS) is a chronic pain syndrome characterised by central sensitisation resulting in hypersentivity of the skin and deeper tissues as well as fatigue. Possibly the princess in Hans Christian Andersen's ‘The Princess and the Pea’ suffered from FMS since chronic sleep disturbances are typical in FMS. These sleep disturbances have been attributed to a dysfunction in the systems regulating sleep and wakefulness resulting in loss of deep sleep. In addition, many patients with FMS experience cognitive dysfunction, characterised by impaired concentration and short term memory consolidation, a complaint also commonly reported in other sleep disorders.

In recent reviews evaluating the efficacy of acupuncture in FMS it has been concluded that acupuncture has no specific effect. A prerequisite for this conclusion is that all the major symptoms in the syndrome have been assessed. However, previous studies have generally focused on the pain alleviating effect of acupuncture in FMS. We have observed that not only pain but also sleep and cognitive dysfunction may be ameliorated in response to acupuncture, suggesting that these variables should be taken into account when evaluating the effects of acupuncture in FMS. Furthermore, the results demonstrated great individual variability apart from the systematic effects related to the group, indicating that individually performed treatment strategies are required. Our suggestion is supported by experimental and clinical studies showing that acupuncture may affect in somnia and alertness, and that there may be neurophysiologic bases for these specific effects.

The cerebral signature for pain perception and its modulation

Our understanding of the neural correlates of pain perception in humans has increased significantly since the advent of neuroimaging. Relating neural activity changes to the varied pain experiences has led to an increased awareness of how factors (e.g., cognition, emotion, context, injury) can separately influence pain perception. Tying this body of knowledge in humans to work in animal models of pain provides an opportunity to determine common features that reliably contribute to pain perception and its modulation. One key system that underpins the ability to change pain intensity is the brainstem's descending modulatory network with its pro- and antinociceptive components. We discuss not only the latest data describing the cerebral signature of pain and its modulation in humans, but also suggest that the brainstem plays a pivotal role in gating the degree of nociceptive transmission so that the resultant pain experienced is appropriate for the particular situation of the individual.