Somatosensory cortical plasticity in carpal tunnel syndrome treated by acupuncture

Enhancement of Motor Learning and Corticospinal Excitability: The Role of Electroacupuncture and Motor Training in Healthy Volunteers

BACKGROUND This study embarked on an innovative exploration to elucidate the effects of integrating electroacupuncture (EA) with motor training (MT) on enhancing corticospinal excitability and motor learning. Central to this investigation is the interplay between homeostatic and non-homeostatic metaplasticity processes, providing insights into how these combined interventions may influence neural plasticity and motor skill acquisition. MATERIAL AND METHODS The investigation enrolled 20 healthy volunteers, subjecting them to 4 distinct interventions to parse out the individual and combined effects of EA and MT. These interventions were EA alone, MT alone, EA-priming followed by MT, and MT-priming followed by EA. The assessment of changes in primary motor cortex (M1) excitability was conducted through motor-evoked potentials (MEPs), while the grooved pegboard test (GPT) was used to evaluate alterations in motor performance. RESULTS The findings revealed that EA and MT independently contributed to enhanced M1 excitability and motor performance. However, the additional priming with EA or MT did not yield further modulation in MEPs amplitudes. Notably, EA-priming was associated with improved GPT completion times, underscoring its potential in facilitating motor learning. CONCLUSIONS The study underscores that while EA and MT individually augment motor cortex excitability and performance, their synergistic application does not further enhance or inhibit cortical excitability. This points to the involvement of non-homeostatic metaplasticity mechanisms. Nonetheless, EA emerges as a critical tool in preventing M1 overstimulation, thereby continuously fostering motor learning. The findings call for further research into the strategic application of EA, whether in isolation or with MT, within clinical settings to optimize rehabilitation outcomes.

Altered brain function and structure in carpal tunnel syndrome: a systematic review and meta-analysis of structural and functional brain imaging

This systematic review with a meta-analysis aimed to identify the altered brain structure and function in carpal tunnel syndrome (CTS) by summarizing the literature about magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), and magnetoencephalography (MEG) outcomes compared to healthy controls (HC). CTS is the most common nerve entrapment in the arm associated with altered peripheral and central nociceptive system. PRISMA guidelines were used to report the outcomes. Six databases were searched for relevant literature (Web of Science, Scopus, PubMed, Sage, EBSCO host, and Cochrane). Eligible studies comparing MRI, fMRI, and MEG findings in people with CTS (present for at least 2 months) and HC through the following parameters: (1) interdigit cortical separation distance, (2) white and grey matter changes, (3) peak latency of M20 wave and recovery function of N20 from the somatosensory cortex (SI), and (4) surface area of activated digit cortical representation. The results from different studies were pooled and a meta-analysis was done. From 17 included, there was a significant reduction of interdigit cortical separation distance of index-middle and index-little fingers in the CTS (SMD = - 0.869, 95% CI (- 1.325, - 0.413), p-value = 0.000) and (SMD = - 0.79, 95% CI (- 1.217, - 0.364), p-value = 0.000), respectively. Middle-little fingers interdigit separation showed no difference (SMD = - 0.2, 95% CI (- 0.903, 1.309), p-value = 0.718). There is evidence supporting the altered brain structure and function in CTS as evidenced by reduction of interdigit cortical separation distance, and excessive blurring and disinhibition of SI, with low resting state functional connectivity. Thus, centrally directed therapeutic approaches might complement peripheral treatments.

Motor Imagery and Pain Processing in Patients With Entrapment Neuropathies: A Cross-sectional Study

OBJECTIVES

(1) To assess the ability to generate both kinesthetic and visual motor imagery in participants with carpal tunnel syndrome (CTS), compared with asymptomatic participants. (2) To assess the influence of psychophysiological and functional variables in the motor imagery process.

METHODS

Twenty patients with unilateral CTS and 18 pain-free individuals were recruited. An observational case-control study with a nonprobability sample was conducted to assess visual and kinesthetic movement imagery ability and psychophysiological variables in patients with CTS compared with asymptomatic participants in a control group. The trial was conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology statement.

RESULTS

CTS patients have more difficulties in generating visual motor images compared with asymptomatic individuals ( t =-2.099; P <0.05; d=0.70). They need more time to complete the mental tasks (visual t =-2.424; P <0.05 and kinesthetic t =-2.200; P <0.05). A negative correlation was found between the ability to imagine and functional deficits ( r =-0.569; P =0.021) for the kinesthetic subscale and temporal summation ( r =-0.515; P <0.5). A positive correlation was found between pain pressure threshold homolateral (homolateral) and time to generate the visual mental images ( r =0.537; P <0.05).

DISCUSSION

CTS patients have greater difficulty generating motor images than asymptomatic individuals. Patients also spend more time during mental tasks. CTS patients present a relationship between temporal summation and the capacity to generate kinesthetic images. In addition, the CST patients presented a correlation between chronometry mental tasking and mechanical hyperalgesia.

Application and underlying mechanism of acupuncture for the nerve repair after peripheral nerve injury: remodeling of nerve system

Peripheral nerve injury (PNI) is a structural event with harmful consequences worldwide. Due to the limited intrinsic regenerative capacity of the peripheral nerve in adults, neural restoration after PNI is difficult. Neurological remodeling has a crucial effect on the repair of the form and function during the regeneration of the peripheral nerve after the peripheral nerve is injured. Several studies have demonstrated that acupuncture is effective for PNI-induced neurologic deficits, and the potential mechanisms responsible for its effects involve the nervous system remodeling in the process of nerve repair. Moreover, acupuncture promotes neural regeneration and axon sprouting by activating related neurotrophins retrograde transport, such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), N-cadherin, and MicroRNAs. Peripheral nerve injury enhances the perceptual response of the central nervous system to pain, causing central sensitization and accelerating neuronal cell apoptosis. Together with this, the remodeling of synaptic transmission function would worsen pain discomfort. Neuroimaging studies have shown remodeling changes in both gray and white matter after peripheral nerve injury. Acupuncture not only reverses the poor remodeling of the nervous system but also stimulates the release of neurotrophic substances such as nerve growth factors in the nervous system to ameliorate pain and promote the regeneration and repair of nerve fibers. In conclusion, the neurological remodeling at the peripheral and central levels in the process of acupuncture treatment accelerates nerve regeneration and repair. These findings provide novel insights enabling the clinical application of acupuncture in the treatment of PNI.

Use of diffusion tensor imaging as a prognostic biomarker after decompression surgery for carpal tunnel syndrome

BACKGROUND

Magnetic resonance diffusion tensor imaging (MR-DTI) has been increasingly applied for carpal tunnel syndrome (CTS) diagnosis, but relatively little is known about the effect of CTS treatment on median nerve (MN) integrity and functional outcome prediction.

PURPOSE

To assess how structural changes in MR-DTI of the MN correlates with symptom severity, functional status, and electrophysiological parameters in patients suffering from CTS before and after decompression surgery.

MATERIAL AND METHODS

Nine wrists were prospectively enrolled to perform MR-DTI pre- and postoperatively. The apparent diffusion coefficients (ADC) and fractional anisotropy (FA) of the MN were examined in three different regions-distal radioulnar joint, pisiform bone, and hamate bone-and correlated with clinical and electrophysiological parameters.

RESULTS

Postoperatively, mean Boston Carpal Tunnel Questionnaire scores decreased 1.55 points (range = 0.08-3; P = 0.0172) and 1.01 points (-0.13 to 1.88; P = 0.0381) in the symptomatic and functional domains, respectively. Postoperative clinical improvement was reflected in proximal FA elevation (P = 0.0078), but not in diffusivity in comparison to baseline examination. Preoperative electrophysiological parameters were correlated with a reduction in the pre- (sensory latencies [rho = -0.6826; P = 0.0312]) and postoperative (motor latencies [rho = -0.7488; P = 0.0325]) distal FA values. Higher sensory amplitudes indicated higher postoperative proximal FA values (rho = 0.7618; P = 0.0280) ​​and lower postoperative proximal ADC values (rho = -0.9047; P = 0.0020).

CONCLUSION

Our study demonstrated that pre- and postoperative proximal FA values are useful biomarkers for the structural evaluation of the MN in patients with CTS. Symptomatic improvement can be better predicted by analyzing FA changes.

Is the left/right judgment task performance altered in unilateral carpal tunnel syndrome: And associated with symptom severity?

BACKGROUND

Left/right judgment task performance (LRJT) is impaired in severe neuropathic pain conditions. However, comparison of LRJT performance in patients with carpal tunnel syndrome (CTS) with a control group with similar cognitive functions has not been investigated.

OBJECTIVE

The aim of the study was to compare the LRJT performance of CTS patients with healthy controls and the unaffected side.

METHODS

Seventy-five CTS patients with dominant, right-hand involvement and 75 control subjects were included in the study. The Recognize® tablet application was used for LRJT performance. Tactile acuity (Two-point discrimination) and handgrip strength; pain severity (Visual Analog Scale) and neuropathic component of pain (Pain Detect Questionnaire); symptom severity and functional impact of CTS (Boston CTS Assessment Test) were evaluated. Mixed-design ANOVAs and correlation analyses were used for data analysis.

DESIGN

Cross-sectional study.

RESULTS

Analysis of variance showed that there was no significant effect of side (affected versus unaffected) or group (CTS versus control group) on recognition accuracy or time. Significant group*site interactions were found for the two-point discrimination F (1,148) = 6.388, p = 0.013; and for handgrip strength F (1,148) = 17.552, p < 0.01. A statistically significant negative correlation was found between recognition accuracy and symptom duration and a significant positive correlation was found between recognition accuracy and handgrip strength in CTS patients (r = -0.267, p = 0.020; r = 0.290, p = 0.012).

CONCLUSION

CTS patients recognize the affected side as accurately and quickly as the unaffected side and control group. Further research is needed to clarify the relationship between LRJT performance in the severely affected CTS group.

GOV REGISTRATION NUMBER

NCT04967144 CLINICALTRIALS.

GOV REGISTRATION DATE

19 July 2021.

Acupuncture therapy as an Evidence-Based Nonpharmacologic Strategy for Comprehensive Acute Pain Care: the Academic Consortium Pain Task Force White Paper Update

Background

A crisis in pain management persists, as does the epidemic of opioid overdose deaths, addiction, and diversion. Pain medicine is meeting these challenges by returning to its origins: the Bonica model of multidisciplinary pain care. The 2018 Academic Consortium White Paper detailed the historical context and magnitude of the pain crisis and the evidence base for nonpharmacologic strategies. More than 50% of chronic opioid use begins in the acute pain care setting. Acupuncture may be able to reduce this risk.

Objective

This article updates the evidence base for acupuncture therapy for acute pain with a review of systematic reviews and meta-analyses on postsurgical/perioperative pain with opioid sparing and acute nonsurgical/trauma pain, including acute pain in the emergency department.

Methods

To update reviews cited in the 2018 White Paper, electronic searches were conducted in PubMed, MEDLINE, CINAHL, and the Cochrane Central Register of Controlled Trials for “acupuncture” and “acupuncture therapy” and “acute pain,” “surgery,” “peri-operative,” “trauma,” “emergency department,” “urgent care,” “review(s) ,” “systematic review,” “meta-analysis,” with additional manual review of titles, links, and reference lists.

Results

There are 22 systematic reviews, 17 with meta-analyses of acupuncture in acute pain settings, and a review for acute pain in the intensive care unit. There are additional studies of acupuncture in acute pain settings.

Conclusion

The majority of reviews found acupuncture therapy to be an efficacious strategy for acute pain, with potential to avoid or reduce opioid reliance. Future multicenter trials are needed to clarify the dosage and generalizability of acupuncture for acute pain in the emergency department. With an extremely low risk profile, acupuncture therapy is an important strategy in comprehensive acute pain care.

The Correlation between Functional Connectivity of the Primary Somatosensory Cortex and Cervical Spinal Cord Microstructural Injury in Patients with Cervical Spondylotic Myelopathy

Objectives

To explore functional connectivity reorganization of the primary somatosensory cortex, the chronic microstructure damage of the cervical spinal cord, and their relationship in cervical spondylotic myelopathy (CSM) patients.

Methods

Thirty-three patients with CSM and 23 healthy controls (HCs) were recruited for rs-fMRI and cervical spinal cord diffusion tensor imaging (DTI) scans. Six subregions (including leg, back, chest, hand, finger and face) of bilateral primary somatosensory cortex (S1) were selected for seed-based whole-brain functional connectivity (FC). Then, we calculated the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of the cervical spinal cord. Correlation analysis was conducted between FC values of brain regions and DTI parameters of cervical spinal cord (ADC, FA), and their relationship with each other and clinical parameters.

Results

Compared with the HC group, the CSM group showed decreased FC between areas of the left S1_hand, the left S1_leg, the right S1_chest, and the right S1_leg with brain regions. The mean FA values of the cervical spinal cord in CSM patients were positively correlated with JOA scores. Especially, the FA_pos values of bilateral posterior funiculus were positively correlated with JOA scores. The ADC and FA values of bilateral posterior funiculus in the cervical spinal cord were also positively correlated with the FC values.

Conclusions

There was synchronization between chronic cervical spinal cord microstructural injury and cerebral cortex sensory function compensatory recombination. DTI parameters of the posterior cervical spinal cord could objectively reflect the degree of cerebral cortex sensory function impairment to a certain extent.

Brain Structural Changes in Carpal Tunnel Syndrome Patients: From the Perspectives of Structural Connectivity and Structural Covariance Network

BACKGROUND

Carpal tunnel syndrome (CTS) is a common peripheral entrapment neuropathy. However, CTS-related changes of brain structural covariance and structural covariance networks (SCNs) patterns have not been clearly studied.

OBJECTIVE

To explore CTS-related brain changes from perspectives of structural connectivity and SCNs.

METHODS

Brain structural magnetic resonance images were acquired from 27 CTS patients and 19 healthy controls (HCs). Structural covariance and SCNs were constructed based on gray matter volume. The global network properties including clustering coefficient (Cp), characteristic path length (Lp), small-worldness index, global efficiency (Eglob), and local efficiency (Eloc) and regional network properties including degree, betweenness centrality (BC), and Eloc of a given node were calculated with graph theoretical analysis.

RESULTS

Compared with HCs, the strength of structural connectivity between the dorsal anterior insula and medial prefrontal thalamus decreased (P < .001) in CTS patients. There was no intergroup difference of area under the curve for Cp, Lp¸ Eglob, and Eloc (all P > .05). The real-world SCN of CTS patients showed a small-world topology ranging from 2% to 32%. CTS patients showed lower nodal degrees of the dorsal anterior insula and medial prefrontal thalamus, and higher Eloc of a given node and BC in the lateral occipital cortex (P < .001) and the dorsolateral middle temporal gyrus (P < .001) than HCs, respectively.

CONCLUSION

CTS had a profound impact on brain structures from perspectives of structural connectivity and SCNs.

S1 Brain Connectivity in Carpal Tunnel Syndrome Underlies Median Nerve and Functional Improvement Following Electro-Acupuncture

Carpal Tunnel Syndrome (CTS) is a median nerve entrapment neuropathy that alters primary somatosensory cortex (S1) organization. While electro-acupuncture (EA), a form of peripheral neuromodulation, has been shown to improve clinical and neurophysiological CTS outcomes, the role of EA-evoked brain response during therapy (within and beyond S1) for improved outcomes is unknown. We investigated S1-associated whole brain fMRI connectivity during both a resting and sustained EA stimulation state in age-matched healthy controls (N = 28) and CTS patients (N = 64), at baseline and after 8 weeks of acupuncture therapy (local, distal, or sham EA). Compared to healthy controls, CTS patients at baseline showed decreased resting state functional connectivity between S1 and thalamic pulvinar nucleus. Increases in S1/pulvinar connectivity strength following verum EA therapy (combined local and distal) were correlated with improvements in median nerve velocity (r = 0.38, p = 0.035). During sustained local EA, compared to healthy controls, CTS patients demonstrated increased functional connectivity between S1 and anterior hippocampus (aHipp). Following 8 weeks of local EA therapy, S1/aHipp connectivity significantly decreased and greater decrease was associated with improvement in patients' functional status (r = 0.64, p = 0.01) and increased median nerve velocity (r = -0.62, p = 0.013). Thus, connectivity between S1 and other brain areas is also disrupted in CTS patients and may be improved following EA therapy. Furthermore, stimulus-evoked fMRI connectivity adds therapy-specific, mechanistic insight to more common resting state connectivity approaches. Specifically, local EA modulates S1 connectivity to sensory and affective processing regions, linked to patient function and median nerve health.

Greater Somatosensory Afference With Acupuncture Increases Primary Somatosensory Connectivity and Alleviates Fibromyalgia Pain via Insular γ-Aminobutyric Acid: A Randomized Neuroimaging Trial

OBJECTIVE

Acupuncture is a complex multicomponent treatment that has shown promise in the treatment of fibromyalgia (FM). However, clinical trials have shown mixed results, possibly due to heterogeneous methodology and lack of understanding of the underlying mechanism of action. The present study was undertaken to understand the specific contribution of somatosensory afference to improvements in clinical pain, and the specific brain circuits involved.

METHODS

Seventy-six patients with FM were randomized to receive either electroacupuncture (EA), with somatosensory afference, or mock laser acupuncture (ML), with no somatosensory afference, twice a week over 8 treatments. Patients with FM in each treatment group were assessed for pain severity levels, measured using Brief Pain Inventory (BPI) scores, and for levels of functional brain network connectivity, assessed using resting state functional magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy in the right anterior insula, before and after treatment.

RESULTS

Fibromyalgia patients who received EA therapy experienced a greater reduction in pain severity, as measured by the BPI, compared to patients who received ML therapy (mean difference in BPI from pre- to posttreatment was -1.14 in the EA group versus -0.46 in the ML group; P for group × time interaction = 0.036). Participants receiving EA treatment, as compared to ML treatment, also exhibited resting functional connectivity between the primary somatosensory cortical representation of the leg (S1_leg ; i.e. primary somatosensory subregion activated by EA) and the anterior insula. Increased S1_leg -anterior insula connectivity was associated with both reduced levels of pain severity as measured by the BPI (r = -0.44, P = 0.01) and increased levels of γ-aminobutyric acid (GABA+) in the anterior insula (r = 0.48, P = 0.046) following EA therapy. Moreover, increased levels of GABA+ in the anterior insula were associated with reduced levels of pain severity as measured by the BPI (r = -0.59, P = 0.01). Finally, post-EA treatment changes in levels of GABA+ in the anterior insula mediated the relationship between changes in S1_leg -anterior insula connectivity and pain severity on the BPI (bootstrap confidence interval -0.533, -0.037).

CONCLUSION

The somatosensory component of acupuncture modulates primary somatosensory functional connectivity associated with insular neurochemistry to reduce pain severity in FM.

Reduced tactile acuity in chronic low back pain is linked with structural neuroplasticity in primary somatosensory cortex and is modulated by acupuncture therapy

Prior studies have shown that patients suffering from chronic Low Back Pain (cLBP) have impaired somatosensory processing including reduced tactile acuity, i.e. reduced ability to resolve fine spatial details with the perception of touch. The central mechanism(s) underlying reduced tactile acuity are unknown but may include changes in specific brain circuitries (e.g. neuroplasticity in the primary somatosensory cortex, S1). Furthermore, little is known about the linkage between changes in tactile acuity and the amelioration of cLBP by somatically-directed therapeutic interventions, such as acupuncture. In this longitudinal neuroimaging study, we evaluated healthy control adults (HC, N ​= ​50) and a large sample of cLBP patients (N ​= ​102) with structural brain imaging (T1-weighted MRI for Voxel-Based Morphometry, VBM; Diffusion Tensor Imaging, DTI) and tactile acuity testing using two-point discrimination threshold (2PDT) over the lower back (site of pain) and finger (control) locations. Patients were evaluated at baseline and following a 4-week course of acupuncture, with patients randomized to either verum acupuncture, two different forms of sham acupuncture (designed with or without somatosensory afference), or no-intervention usual care control. At baseline, cLBP patients demonstrated reduced acuity (greater 2PDT, P ​= ​0.01) over the low back, but not finger (P ​= ​0.29) locations compared to HC, suggesting that chronic pain affects tactile acuity specifically at body regions encoding the experience of clinical pain. At baseline, Gray Matter Volume (GMV) was elevated and Fractional Anisotropy (FA) was reduced, respectively, in the S1-back region of cLBP patients compared to controls (P ​< ​0.05). GMV in cLBP correlated with greater 2PDT-back scores (ρ ​= ​0.27, P ​= ​0.02). Following verum acupuncture, tactile acuity over the back was improved (reduced 2PDT) and greater improvements were associated with reduced S1-back GMV (ρ ​= ​0.52, P ​= ​0.03) and increased S1-back adjacent white matter FA (ρ ​= ​-0.56, P ​= ​0.01). These associations were not seen for non-verum control interventions. Thus, S1 neuroplasticity in cLBP is linked with deficits in tactile acuity and, following acupuncture therapy, may represent early mechanistic changes in somatosensory processing that track with improved tactile acuity.

Functional MRI Investigation of Ultrasound Stimulation at ST 36

Background

Clinical and experimental data suggest that ultrasound stimulation (US) at acupoints can produce similar effective treatment compared to manual acupuncture (MA). Although the brain activation to MA at acupoints is investigated by numerous studies, the brain activation to US at acupoints remains unclear.

Methods

In the present work, we employed task state functional magnetic resonance imaging (fMRI) to explore the human brain's activation to US and MA at ST 36 (Zusanli) which is one of the most commonly used acupoints in acupuncture-related studies. 16 healthy subjects underwent US and MA procedures in an interval of more than one week. On-off block design stimulation was used for the recording of fMRI-related brain patterns.

Results

Both US and MA at ST 36 produced activations in somatosensory and limbic/paralimbic regions (postcentral gyrus, insula, middle prefrontal cortex, and anterior cingulate cortex). Only US at ST 36 produced a significant signal increase in the inferior parietal lobule and decrease in the posterior cingulate cortex, whereas MA at ST 36 produced a significant signal increase in the lentiform nucleus and cerebellum.

Conclusions

Our results indicate that US may be a possible noninvasive alternative method to MA due to its similar activation patterns.

A magnetoencephalographic study of longitudinal brain function alterations following carpal tunnel release

We investigate changes in brain function before and after carpal tunnel release. Magnetoencephalography (MEG), during which we recorded somatosensory evoked cortical magnetic fields (SEFs), and a clinical evaluation were performed before surgery and 6 months after. The distance on the vertical axis between the equivalent current dipoles (ECDs) for the first and third digits before surgery was significantly less than after surgery. There were no significant differences in values between the control participant and patients after surgery. In terms of distal motor latency, there was a negative correlation with the distance. The recovery function of the root mean square (RMS) before surgery for the N20m was less suppressed at 10 ms of ISI in patients, compared to controls. There were no significant differences in the RMS values for patients before and after surgery. Our results indicate that treating peripheral nerve lesions, such as in carpal tunnel release, positively modifies brain function.

Peripheral nerve injuries, pain, and neuroplasticity

INTRODUCTION

Peripheral nerve injuries (PNIs) cause both structural and functional brain changes that may be associated with significant sensorimotor abnormalities and pain.

PURPOSE OF THE STUDY

The aim of this narrative review is to provide hand therapists an overview of PNI-induced neuroplasticity and to explain how the brain changes following PNI, repair, and during rehabilitation.

METHODS

Toward this goal, we review key aspects of neuroplasticity and neuroimaging and discuss sensory testing techniques used to study neuroplasticity in PNI patients.

RESULTS

We describe the specific brain changes that occur during the repair and recovery process of both traumatic (eg, transection) and nontraumatic (eg, compression) nerve injuries. We also explain how these changes contribute to common symptoms including hypoesthesia, hyperalgesia, cold sensitivity, and chronic neurogenic pain. In addition, we describe how maladaptive neuroplasticity as well as psychological and personality characteristics impacts treatment outcome.

DISCUSSION AND CONCLUSION

Greater understanding of the brain's contribution to symptoms in recovering PNI patients could help guide rehabilitation strategies and inform the development of novel techniques to counteract these maladaptive brain changes and ultimately improve outcomes.

Insights About the Neuroplasticity State on the Effect of Intramuscular Electrical Stimulation in Pain and Disability Associated With Chronic Myofascial Pain Syndrome (MPS): A Double-Blind, Randomized, Sham-Controlled Trial

Background: There is limited evidence concerning the effect of intramuscular electrical stimulation (EIMS) on the neural mechanisms of pain and disability associated with chronic Myofascial Pain Syndrome (MPS). Objectives: To provide new insights into the EIMS long-term effect on pain and disability related to chronic MPS (primary outcomes). To assess if the neuroplasticity state at baseline could predict the long-term impact of EIMS on disability due to MPS we examined the relationship between the serum brain-derived-neurotrophic-factor (BDNF) and by motor evoked potential (MEP). Also, we evaluated if the EIMS could improve the descending pain modulatory system (DPMS) and the cortical excitability measured by transcranial magnetic stimulation (TMS) parameters. Methods: We included 24 right-handed female with chronic MPS, 19-65 years old. They were randomically allocated to receive ten sessions of EIMS, 2 Hz at the cervical paraspinal region or a sham intervention (n = 12). Results: A mixed model analysis of variance revealed that EIMS decreased daily pain scores by -73.02% [95% confidence interval (CI) = -95.28 to -52.30] and disability due to pain -43.19 (95%CI, -57.23 to -29.39) at 3 months of follow up. The relative risk for using analgesics was 2.95 (95% CI, 1.36 to 6.30) in the sham group. In the EIMS and sham, the change on the Numerical Pain Scale (NPS0-10) throughout CPM-task was -2.04 (0.79) vs. -0.94 (1.18), respectively, (P = 0.01). EIMS reduced the MEP -28.79 (-53.44 to -4.15), while improved DPMS and intracortical inhibition. The MEP amplitude before treatment [(Beta = -0.61, (-0.58 to -0.26)] and a more significant change from pre- to post-treatment on serum BDNF) (Beta = 0.67; CI95% = 0.07 to 1.26) were predictors to EIMS effect on pain and disability due to pain. Conclusion: These findings suggest that a bottom-up effect induced by the EIMS reduced the analgesic use, improved pain, and disability due to chronic MPS. This effect might be mediated by an enhancing of corticospinal inhibition as seen by an increase in IC and a decrease in MEP amplitude. Likewise, the MEP amplitude before treatment and the changes induced by the EIMS in the serum BDNF predicted it's long-term clinical impact on pain and disability due MPS. The trial is recorded in ClinicalTrials.gov: NCT02381171.

Acupuncture's Role in Solving the Opioid Epidemic: Evidence, Cost-Effectiveness, and Care Availability for Acupuncture as a Primary, Non-Pharmacologic Method for Pain Relief and Management-White Paper 2017

The United States (U.S.) is facing a national opioid epidemic, and medical systems are in need of non-pharmacologic strategies that can be employed to decrease the public's opioid dependence. Acupuncture has emerged as a powerful, evidence-based, safe, cost-effective, and available treatment modality suitable to meeting this need. Acupuncture has been shown to be effective for the management of numerous types of pain conditions, and mechanisms of action for acupuncture have been described and are understandable from biomedical, physiologic perspectives. Further, acupuncture's cost-effectiveness can dramatically decrease health care expenditures, both from the standpoint of treating acute pain and through avoiding addiction to opioids that requires costly care, destroys quality of life, and can lead to fatal overdose. Numerous federal regulatory agencies have advised or mandated that healthcare systems and providers offer non-pharmacologic treatment options for pain. Acupuncture stands out as the most evidence-based, immediately available choice to fulfil these calls. Acupuncture can safely, easily, and cost-effectively be incorporated into hospital settings as diverse as the emergency department, labor and delivery suites, and neonatal intensive care units to treat a variety of commonly seen pain conditions. Acupuncture is already being successfully and meaningfully utilized by the Veterans Administration and various branches of the U.S. Military, in some studies demonstrably decreasing the volume of opioids prescribed when included in care.

The National Cancer Institute's Conference on Acupuncture for Symptom Management in Oncology: State of the Science, Evidence, and Research Gaps

The Division of Cancer Treatment and Diagnosis, Office of Cancer Complementary and Alternative Medicine, at the National Cancer Institute (NCI) held a symposium on "Acupuncture for Cancer Symptom Management" on June 16 and 17, 2016. Invited speakers included 19 scientists and scholars with expertise in acupuncture and cancer research from the United States, Europe, and China. The conference reviewed the NCI's grant funding on acupuncture, analyzed the needs of cancer patients, reviewed safety issues, and assessed both the current scientific evidence and research gaps of acupuncture in oncology care. Researchers and stakeholders presented and discussed basic mechanisms of acupuncture; clinical evidence for specific symptoms; and methodological challenges such as placebo effects, novel biostatistical methods, patient-reported outcomes, and comparative effectiveness research. This paper, resulting from the conference, summarizes both the current state of the science and clinical evidence of oncology acupuncture, identifies key scientific gaps, and makes recommendations for future research to increase understanding of both the mechanisms and effects of acupuncture for cancer symptom management.

Cortical remodeling after electroacupuncture therapy in peripheral nerve repairing model

Electroacupuncture (EA) is an alternative therapy for peripheral nerve injury (PNI). The treatment relies on post-therapeutic effect rather than real-time effect. We utilized fMRI to clarify the resting-state alteration caused by sustained effect of EA on peripheral nerve repairing model. Twenty-four rats were divided equally into three groups: normal group, model group and intervention group. Rats of the model and intervention group underwent sciatic nerve transection and direct anastomosis. EA intervention at ST-36 and GB-30 was conducted continuously for 4 months on the intervention group. Behavioral assessments and fMRI were performed 1 month and 4 months after surgery. Intervention group showed significant improvement on the gait parameters max contact mean intensity (MCMI) and thermal withdrawal latency (TWL) than model group. EA-related sustained effects of amplitude of low frequency fluctuations (ALFF) could be described as a remolding pattern of somatosensory area and sensorimotor integration regions which presented higher ALFF in the contralateral hemisphere and lower in the ipsilateral hemisphere than model group. Interhemispheric functional connectivity (FC) analysis showed a significantly lower FC after EA therapy between the largest significantly different clusters in bilateral somatosensory cortices than the model group 4 months after surgery(p < 0.05). And the model group presented significantly higher FC than the normal group at both two time-points (p < 0.01). The sustained effect of EA on peripheral nerve repairing rats appeared to induce both regional and extensive neuroplasticity in bilateral hemispheres. We proposed that such EA-related effect was a reverse of maladaptive plasticity caused by PNI.

A Longitudinal Mapping Study on Cortical Plasticity of Peripheral Nerve Injury Treated by Direct Anastomosis and Electroacupuncture in Rats

OBJECTIVE

We used functional magnetic resonance imaging to provide a longitudinal description of cortical plasticity caused by electroacupuncture (EA) of sciatic nerve transection and direct anastomosis in rats.

METHODS

Sixteen rats in a sciatic nerve transection and direct anastomosis model were randomly divided into intervention and control groups. EA intervention in the position of ST-36, GB-30 was conducted continuously for 4 months in the intervention group. Functional magnetic resonance imaging and gait assessment were performed every month after intervention.

RESULTS

The somatosensory area was more activated in the first 2 months and then deactivated in the rest 2 months when EA was applied. The pain-related areas had the same activation pattern as the somatosensory area. The limbic/paralimbic areas fluctuated more during the EA intervention, which was not constantly activated or deactivated as previous studies reported. We attributed such changes in somatosensory and pain-related areas to the gradual reduction of sensory afferentation. The alterations in limbic/paralimbic system might be associated with the confrontation between the upregulating effect of paresthesia or pain and the downregulating effect of EA intervention through the autonomic nerve system. The gait analysis showed significantly higher maximum contact mean intensity in the intervention group.

CONCLUSIONS

The alterations in the brain brought about by the long-term therapeutic effect of EA could be described as a synchronized activation pattern in the somatosensory and pain-related areas and a fluctuating pattern in the limbic/paralimbic system.

A Longitudinal fMRI Research on Neural Plasticity and Sensory Outcome of Carpal Tunnel Syndrome

Peripheral nerve compression is reported to induce cortical plasticity, which was well pictured by former researches. However, the longitudinal changes brought by surgical treatment are not clear. In this research, 18 subjects who suffered from bilateral carpal tunnel syndrome were evaluated using task-dependent fMRI and electromyography assessment before and after surgery. The third digit was tactually simulated by von Frey filaments. The results demonstrated that the pattern of activation was similar but a decreased extent of activation in the postcentral gyrus, inferior frontal lobe, superior frontal lobe, and parahippocampal gyrus after surgery was found. The correlation analysis showed a significant correlation between the decreased number of activated voxels and the improvement of EMG performance. This result implied a potential connection between fMRI measurement and clinical improvement.

Essential literature for the chiropractic profession: Results and implementation challenges from a survey of international chiropractic faculty

OBJECTIVE

Scientific literature applicable to chiropractic practice proliferates in quantity, quality, and source. Chiropractic is a worldwide profession and varies in scope between states or provinces and from country to country. It is logical to consider that the focus and emphasis of chiropractic education varies between programs as well. This original research study endeavored to determine "essential literature" recommended by chiropractic faculty. The purpose of this article is (1) to share our results and (2) to promote discussion and explore means for future collaboration of chiropractic faculty through a worldwide platform.

METHODS

A 2-phase recruitment occurred initially at the institutional level and subsequently at the faculty level. A Web-based survey used qualitative data collection methods to gather bibliographic citations. Descriptive statistics were calculated for demographics, and citation responses were ranked per number of recommendations, grouped into categories, and tabulated per journal source and publication date.

RESULTS

Forty-one chiropractic programs were contacted, resulting in 30 participating chiropractic programs (16 US and 14 international). Forty-five faculty members completed the entire survey, submitting 126 peer-reviewed publications and 25 additional citations. Readings emphasized clinical management of spine pain, the science of spinal manipulation, effectiveness of manual therapies, teaching of chiropractic techniques, outcomes assessments, and professional issues.

CONCLUSION

A systematic approach to surveying educators in international chiropractic institutions was accomplished. The results of the survey provide a list of essential literature for the chiropractic profession. We recommend establishing a chiropractic faculty registry for improved communication and collaboration.

Local and Extensive Neuroplasticity in Carpal Tunnel Syndrome: A Resting-State fMRI Study

Carpal tunnel syndrome (CTS) is a most common peripheral nerve entrapment neuropathy characterized by sensorimotor deficits in median nerve innervated digits. Block-design task-related functional magnetic resonance imaging (fMRI) studies have been used to investigate CTS-related neuroplasticity in the primary somatosensory cortices. However, considering the persistence of digital paresthesia syndrome caused by median nerve entrapment, spontaneous neuronal activity might provide a better understanding of CTS-related neuroplasticity, which remains unexplored. The present study aimed to investigate both local and extensive spontaneous neuronal activities with resting-state fMRI. A total of 28 bilateral CTS patients and 24 normal controls were recruited, and metrics, including amplitude of low-frequency fluctuation (ALFF) and voxel-wise functional connectivity (FC), were used to explore synaptic activity at different spatial scales. Correlations with clinical measures were further investigated by linear regression. Decreased amplitudes of low-frequency fluctuation were observed in the bilateral primary sensory cortex (SI) and secondary sensory cortex (SII) in CTS patients (AlphaSim corrected P < .05). This was found to be negatively related to the sensory thresholds of corresponding median nerve innervated fingers. In the voxel-wise FC analysis, with predefined seed regions of interest in the bilateral SI and primary motor cortex, we observed decreased interhemispheric and increased intrahemispheric FC. Additionally, both interhemispheric and intrahemispheric FC were found to be significantly correlated with the mean ALFF.

The Acupuncture Effect on Median Nerve Morphology in Patients with Carpal Tunnel Syndrome: An Ultrasonographic Study

Introduction

The aim of this study was to explore the acupuncture effect on the cross-sectional area (CSA) of the median nerve at the wrist in patients with carpal tunnel syndrome (CTS) and, additionally, to identify whether clinical, electrophysiological, and ultrasonographic changes show any association.

Methods

Forty-five limbs of 27 female patients were randomly divided into two groups (acupuncture and control). All patients used night wrist splint. The patients in the acupuncture group received additional acupuncture therapy. Visual analog scale (VAS), Duruöz Hand Index (DHI), Quick Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire scores, electrophysiologic measurements, and median nerve CSAs were noted before and after the treatment in both groups.

Results

VAS, DHI, Quick DASH scores, and electrophysiological measurements were improved in both groups. The median nerve CSA significantly decreased in the acupuncture group, whereas there was no change in the control group.

Conclusion

After acupuncture therapy, the patients with CTS might have both clinical and morphological improvement.

Rewiring the primary somatosensory cortex in carpal tunnel syndrome with acupuncture

Carpal tunnel syndrome is the most common entrapment neuropathy, affecting the median nerve at the wrist. Acupuncture is a minimally-invasive and conservative therapeutic option, and while rooted in a complex practice ritual, acupuncture overlaps significantly with many conventional peripherally-focused neuromodulatory therapies. However, the neurophysiological mechanisms by which acupuncture impacts accepted subjective/psychological and objective/physiological outcomes are not well understood. Eligible patients (n = 80, 65 female, age: 49.3 ± 8.6 years) were enrolled and randomized into three intervention arms: (i) verum electro-acupuncture 'local' to the more affected hand; (ii) verum electro-acupuncture at 'distal' body sites, near the ankle contralesional to the more affected hand; and (iii) local sham electro-acupuncture using non-penetrating placebo needles. Acupuncture therapy was provided for 16 sessions over 8 weeks. Boston Carpal Tunnel Syndrome Questionnaire assessed pain and paraesthesia symptoms at baseline, following therapy and at 3-month follow-up. Nerve conduction studies assessing median nerve sensory latency and brain imaging data were acquired at baseline and following therapy. Functional magnetic resonance imaging assessed somatotopy in the primary somatosensory cortex using vibrotactile stimulation over three digits (2, 3 and 5). While all three acupuncture interventions reduced symptom severity, verum (local and distal) acupuncture was superior to sham in producing improvements in neurophysiological outcomes, both local to the wrist (i.e. median sensory nerve conduction latency) and in the brain (i.e. digit 2/3 cortical separation distance). Moreover, greater improvement in second/third interdigit cortical separation distance following verum acupuncture predicted sustained improvements in symptom severity at 3-month follow-up. We further explored potential differential mechanisms of local versus distal acupuncture using diffusion tensor imaging of white matter microstructure adjacent to the primary somatosensory cortex. Compared to healthy adults (n = 34, 28 female, 49.7 ± 9.9 years old), patients with carpal tunnel syndrome demonstrated increased fractional anisotropy in several regions and, for these regions we found that improvement in median nerve latency was associated with reduction of fractional anisotropy near (i) contralesional hand area following verum, but not sham, acupuncture; (ii) ipsilesional hand area following local, but not distal or sham, acupuncture; and (iii) ipsilesional leg area following distal, but not local or sham, acupuncture. As these primary somatosensory cortex subregions are distinctly targeted by local versus distal acupuncture electrostimulation, acupuncture at local versus distal sites may improve median nerve function at the wrist by somatotopically distinct neuroplasticity in the primary somatosensory cortex following therapy. Our study further suggests that improvements in primary somatosensory cortex somatotopy can predict long-term clinical outcomes for carpal tunnel syndrome.

Acupuncture for the Treatment of Peripheral Neuropathy: A Systematic Review and Meta-Analysis

OBJECTIVES

Neuropathy and its associated pain pose great therapeutic challenges. While there has been a recent surge in acupuncture use and research, little remains known about its effects on nerve function. This review aims to assess the efficacy of acupuncture in the treatment of neuropathy of various etiologies.

METHODS

The Medline, AMED, Cochrane, Scopus, CINAHL, and clintrials.gov databases were systematically searched from inception to July 2015. Randomized controlled trials (RCTs) assessing acupuncture's efficacy for poly- and mononeuropathy were reviewed. Parallel and crossover RCTs focused on acupuncture's efficacy were reviewed and screened for eligibility. The Scale for Assessing Scientific Quality of Investigations in Complementary and Alternative Medicine was used to assess RCT quality. RCTs with score of >9 and active control treatments such as sham acupuncture or medical therapy were included.

RESULTS

Fifteen studies were included: 13 original RCTs, a long-term follow-up, and a re-analysis of a prior RCT. The selected RCTs studied acupuncture for neuropathy caused by diabetes, Bell's palsy, carpal tunnel syndrome, human immunodeficiency virus (HIV), and idiopathic conditions. Acupuncture regimens, control conditions, and outcome measures differed among studies, and various methodological issues were identified. Still, the majority of RCTs showed benefit for acupuncture over control in the treatment of diabetic neuropathy, Bell's palsy, and carpal tunnel syndrome. Acupuncture is probably effective in the treatment of HIV-related neuropathy, and there is insufficient evidence for its benefits in idiopathic neuropathy. Acupuncture appears to improve nerve conduction study parameters in both sensory and motor nerves. Meta-analyses were conducted on all diabetic neuropathy and Bell's palsy individual subject data (six RCTs; a total of 680 subjects) using a summary estimate random effects model, which showed combined odds ratio of 4.23 (95% confidence interval 2.3-7.8; p < 0.001) favoring acupuncture over control for neuropathic symptoms.

CONCLUSIONS

Acupuncture is beneficial in some peripheral neuropathies, but more rigorously designed studies using sham-acupuncture control are needed to characterize its effect and optimal use better.

Acupuncture for chronic pain and depression in primary care: a programme of research

Background

There has been an increase in the utilisation of acupuncture in recent years, yet the evidence base is insufficiently well established to be certain about its clinical effectiveness and cost-effectiveness. Addressing the questions related to the evidence base will reduce uncertainty and help policy- and decision-makers with regard to whether or not wider access is appropriate and provides value for money.

Aim

Our aim was to establish the most reliable evidence on the clinical effectiveness and cost-effectiveness of acupuncture for chronic pain by drawing on relevant evidence, including recent high-quality trials, and to develop fresh evidence on acupuncture for depression. To extend the evidence base we synthesised the results of published trials using robust systematic review methodology and conducted a randomised controlled trial (RCT) of acupuncture for depression.

Methods and results

We synthesised the evidence from high-quality trials of acupuncture for chronic pain, consisting of musculoskeletal pain related to the neck and low back, osteoarthritis of the knee, and headache and migraine, involving nearly 18,000 patients. In an individual patient data (IPD) pairwise meta-analysis, acupuncture was significantly better than both sham acupuncture (p < 0.001) and usual care (p < 0.001) for all conditions. Using network meta-analyses, we compared acupuncture with other physical therapies for osteoarthritis of the knee. In both an analysis of all available evidence and an analysis of a subset of better-quality trials, using aggregate-level data, we found acupuncture to be one of the more effective therapies. We developed new Bayesian methods for analysing multiple individual patient-level data sets to evaluate heterogeneous continuous outcomes. An accompanying cost-effectiveness analysis found transcutaneous electrical nerve stimulation (TENS) to be cost-effective for osteoarthritis at a threshold of £20,000 per quality-adjusted life-year when all trials were synthesised. When the analysis was restricted to trials of higher quality with adequate allocation concealment, acupuncture was cost-effective. In a RCT of acupuncture or counselling compared with usual care for depression, in which half the patients were also experiencing comorbid pain, we found acupuncture and counselling to be clinically effective and acupuncture to be cost-effective. For patients in whom acupuncture is inappropriate or unavailable, counselling is cost-effective.

Conclusion

We have provided the most robust evidence from high-quality trials on acupuncture for chronic pain. The synthesis of high-quality IPD found that acupuncture was more effective than both usual care and sham acupuncture. Acupuncture is one of the more clinically effective physical therapies for osteoarthritis and is also cost-effective if only high-quality trials are analysed. When all trials are analysed, TENS is cost-effective. Promising clinical and economic evidence on acupuncture for depression needs to be extended to other contexts and settings. For the conditions we have investigated, the drawing together of evidence on acupuncture from this programme of research has substantially reduced levels of uncertainty. We have identified directions for further research. Our research also provides a valuable basis for considering the potential role of acupuncture as a referral option in health care and enabling providers and policy-makers to make decisions based on robust sources of evidence.

Trial registration

Current Controlled Trials ISRCTN63787732.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Recovery function of somatosensory evoked brain response in patients with carpal tunnel syndrome: A magnetoencephalographic study

OBJECTIVE

The recovery function of somatosensory evoked magnetic fields (SEFs) was recorded to investigate excitatory and inhibitory balance in the somatosensory cortex of patients with carpal tunnel syndrome.

METHODS

SEFs were recorded in patients and controls. Recordings were taken following median nerve stimulation with single and double pulses with interstimulus intervals of 10-200ms. The root mean square for the N20m component following the second stimulation was analyzed. SEFs following stimulation of the first and middle digits were also recorded and the location for the equivalent current dipoles was estimated in three-dimensional planes.

RESULTS

Distances on the vertical axis between the equivalent current dipoles for the first and third digits were shorter in patients than in control participants. The root mean square for the N20m recovered earlier in patients compared to controls; this was statistically significant at an interstimulus interval of 10ms. There was no relationship between N20m recovery and the equivalent current dipole location in the primary somatosensory cortex.

CONCLUSIONS

Carpal tunnel syndrome was associated with functional disinhibition and destruction of the somatotopic organization in the primary somatosensory cortex.

SIGNIFICANCE

Disinhibitory changes might induce a maladaptation of the central nervous system relating to pain.

The Status of the Quality Control in Acupuncture-Neuroimaging Studies

Using neuroimaging techniques to explore the central mechanism of acupuncture gains increasing attention, but the quality control of acupuncture-neuroimaging study remains to be improved. We searched the PubMed Database during 1995 to 2014. The original English articles with neuroimaging scan performed on human beings were included. The data involved quality control including the author, sample size, characteristics of the participant, neuroimaging technology, and acupuncture intervention were extracted and analyzed. The rigorous inclusion and exclusion criteria are important guaranty for the participants' homogeneity. The standard operation process of acupuncture and the stricter requirement for acupuncturist play significant role in quality control. More attention should be paid to the quality control in future studies to improve the reproducibility and reliability of the acupuncture-neuroimaging studies.

Unanticipated Insights into Biomedicine from the Study of Acupuncture

Research into acupuncture has had ripple effects beyond the field of acupuncture. This paper identifies five exemplars to illustrate that there is tangible evidence of the way insights gleaned from acupuncture research have informed biomedical research, practice, or policy. The first exemplar documents how early research into acupuncture analgesia has expanded into neuroimaging research, broadening physiologic understanding and treatment of chronic pain. The second describes how the acupuncture needle has become a tool to enhance biomedical knowledge of connective tissue. The third exemplar, which illustrates use of a modified acupuncture needle as a sham device, focuses on emergent understanding of placebo effects and, in turn, on insights into therapeutic encounters in treatments unrelated to acupuncture. The fourth exemplar documents that two medical devices now in widespread use were inspired by acupuncture: transcutaneous electrical nerve stimulators for pain control and antinausea wrist bands. The final exemplar describes how pragmatic clinical trial designs applied in acupuncture research have informed current general interest in comparative effectiveness research. In conclusion, these exemplars of unanticipated outcomes of acupuncture research comprise an additional rationale for continued support of basic and clinical research evaluating acupuncture and other under-researched therapies.

Does Acupuncture Alter Pain-related Functional Connectivity of the Central Nervous System? A Systematic Review

Acupuncture has been studied for several decades to establish evidence-based clinical practice. This systematic review aims to evaluate evidence for the effectiveness of acupuncture in influencing the functional connectivity of the central nervous system in patients with musculoskeletal pain. A systematic search of the literature was conducted to identify studies in which the central response of acupuncture in patients with musculoskeletal pain was evaluated by neuroimaging techniques. Databases searched were AMED, CINAHL, Cochrane Library, EMBASE, MEDLINE, PEDro, Pubmed, SCOPUS, SPORTDiscuss, and Web of Science. Included studies were assessed by two independent reviewers for their methodological quality by using the Downs and Black questionnaire and for their levels of completeness and transparency in reporting acupuncture interventions by using Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA) criteria. Seven studies met the inclusion criteria. Three studies were randomized controlled trials (RCTs) and four studies were nonrandomized controlled trials (NRCTs). The neuroimaging techniques used were functional magnetic resonance imaging (fMRI) and positron emission tomography (PET). Positive effects on the functional connectivity of the central nervous system more consistently occurred during long-term acupuncture treatment. The results were heterogeneous from a descriptive perspective; however, the key findings support acupuncture's ability to alter pain-related functional connectivity in the central nervous system in patients with musculoskeletal pain.

The somatosensory link in fibromyalgia: functional connectivity of the primary somatosensory cortex is altered by sustained pain and is associated with clinical/autonomic dysfunction

OBJECTIVE

Fibromyalgia (FM) is a chronic functional pain syndrome characterized by widespread pain, significant pain catastrophizing, sympathovagal dysfunction, and amplified temporal summation for evoked pain. While several studies have demonstrated altered resting brain connectivity in FM, studies have not specifically probed the somatosensory system and its role in both somatic and nonsomatic FM symptoms. Our objective was to evaluate resting primary somatosensory cortex (S1) connectivity and to explore how sustained, evoked deep tissue pain modulates this connectivity.

METHODS

We acquired functional magnetic resonance imaging and electrocardiography data on FM patients and healthy controls during rest (the rest phase) and during sustained mechanical pressure-induced pain over the lower leg (the pain phase). Functional connectivity associated with different S1 subregions was calculated, while S1(leg) connectivity (representation of the leg in the primary somatosensory cortex) was contrasted between the rest phase and the pain phase and was correlated with clinically relevant measures in FM.

RESULTS

During the rest phase, FM patients showed decreased connectivity between multiple ipsilateral and cross-hemispheric S1 subregions, which was correlated with clinical pain severity. Compared to the rest phase, the pain phase produced increased S1(leg) connectivity to the bilateral anterior insula in FM patients, but not in healthy controls. Moreover, in FM patients, sustained pain-altered S1(leg) connectivity to the anterior insula was correlated with clinical/behavioral pain measures and autonomic responses.

CONCLUSION

Our study demonstrates that both somatic and nonsomatic dysfunction in FM, including clinical pain, pain catastrophizing, autonomic dysfunction, and amplified temporal summation, are closely linked with the degree to which evoked deep tissue pain alters S1 connectivity to salience/affective pain-processing regions. Additionally, diminished connectivity between S1 subregions during the rest phase in FM may result from ongoing widespread clinical pain.

Electroacupuncture analgesia is associated with increased serum brain-derived neurotrophic factor in chronic tension-type headache: a randomized, sham controlled, crossover trial

Background

Chronic tension-type headache (CTTH) is characterized by almost daily headaches and central sensitization, for which electroacupuncture (EA) might be effective. The central nervous system (CNS) plasticity can be tracked in serum using the brain-derived neurotrophic factor (BDNF), a neuroplasticity mediator. Thus, we tested the hypothesis that EA analgesia in CTTH is related to neuroplasticity indexed by serum BDNF.

Methods

We enrolled females aged 18–60 years with CTTH in a randomized, blinded, placebo-controlled crossover trial, comparing ten EA sessions applied for 30 minutes (2–10 Hz, intensity by tolerance) in cervical areas twice per week vs. a sham intervention. Treatment periods were separated by two washout weeks. Pain on the 10-cm visual analog scale (VAS) and serum BDNF were assessed as primary outcomes.

Results

Thirty-four subjects underwent randomization, and twenty-nine completed the protocol. EA was superior to sham to alleviate pain (VAS scores 2.38 ± 1.77 and 3.02 ± 2.49, respectively, P = 0.005). The VAS scores differed according to the intervention sequence, demonstrating a carryover effect (P < 0.05). Using multiple regression, serum BDNF was adjusted for the Hamilton depression rating scale (HDRS) and the VAS scores (r-squared = 0.07, standard β coefficients = −0.2 and −0.14, respectively, P < 0.001). At the end of the first intervention period, the adjusted BDNF was higher in the EA phase (29.31 ± 3.24, 27.53 ± 2.94 ng/mL, Cohen’s d = 0.55).

Conclusion

EA analgesia is related to neuroplasticity indexed by the adjusted BDNF. EA modulation of pain and BDNF occurs according to the CNS situation at the moment of its administration, as it was related to depression and the timing of its administration.

Neural mechanisms of acupuncture as revealed by fMRI studies

As an ancient therapeutic method, acupuncture has been used to treat many diseases as an adjunctive therapy. However, its clinical efficacy remains controversial and the neural mechanisms have not been well understood. Accumulating studies have revealed that fMRI has made it possible to study brain responses to acupuncture. This review aims to provide scientific evidence to support the notion and discuss how these findings contribute to the neural mechanisms of acupuncture.

Is neuroplasticity in the central nervous system the missing link to our understanding of chronic musculoskeletal disorders?

Background

Musculoskeletal rehabilitative care and research have traditionally been guided by a structural pathology paradigm and directed their resources towards the structural, functional, and biological abnormalities located locally within the musculoskeletal system to understand and treat Musculoskeletal Disorders (MSD). However the structural pathology model does not adequately explain many of the clinical and experimental findings in subjects with chronic MSD and, more importantly, treatment guided by this paradigm fails to effectively treat many of these conditions.

Discussion

Increasing evidence reveals structural and functional changes within the Central Nervous System (CNS) of people with chronic MSD that appear to play a prominent role in the pathophysiology of these disorders. These neuroplastic changes are reflective of adaptive neurophysiological processes occurring as the result of altered afferent stimuli including nociceptive and neuropathic transmission to spinal, subcortical and cortical areas with MSD that are initially beneficial but may persist in a chronic state, may be part and parcel in the pathophysiology of the condition and the development and maintenance of chronic signs and symptoms. Neuroplastic changes within different areas of the CNS may help to explain the transition from acute to chronic conditions, sensory-motor findings, perceptual disturbances, why some individuals continue to experience pain when no structural cause can be discerned, and why some fail to respond to conservative interventions in subjects with chronic MSD. We argue that a change in paradigm is necessary that integrates CNS changes associated with chronic MSD and that these findings are highly relevant for the design and implementation of rehabilitative interventions for this population.

Summary

Recent findings suggest that a change in model and approach is required in the rehabilitation of chronic MSD that integrate the findings of neuroplastic changes across the CNS and are targeted by rehabilitative interventions. Effects of current interventions may be mediated through peripheral and central changes but may not specifically address all underlying neuroplastic changes in the CNS potentially associated with chronic MSD. Novel approaches to address these neuroplastic changes show promise and require further investigation to improve efficacy of currents approaches.

Different effects of transcutaneous electric nerve stimulation and electroacupuncture at ST36-ST37 on the cerebral cortex

BACKGROUND

The effects of transcutaneous electric nerve stimulation (TENS) and electroacupuncture (EA) on the cerebral cortex are largely unclear. The purpose of the present study was to investigate the effect of TENS and EA on the cerebral cortex by examining their effect on the median nerve-somatosensory evoked potentials (MN-SEPs).

METHODS

Twenty volunteers were studied. The cortical and cervical spinal potentials were recorded by median nerve stimulation at the left wrist. Sham TENS, 2 Hz TENS and 2 Hz EA were applied to both ST36 and ST37. MN-SEPs were recorded during sham TENS, 2 Hz TENS and 2 Hz EA, with at least 1 week interval for each subject. One-way analysis of variance was used to determine the differences in latency and amplitude of the MN-SEPs observed in the stimulation and post-stimulation periods compared with baseline. Scheffe's post hoc correction was employed to identify pairwise differences.

RESULTS

No differences in mean latency were found between the stimulation procedures during the stimulation and post-stimulation periods. 2 Hz EA but not sham TENS or 2 Hz TENS caused higher mean amplitudes in N20 and N30 during the stimulation and post-stimulation periods.

CONCLUSIONS

EA, but not TENS, induces changes in certain components of the signal.

Efficacies of Acupuncture and Anti-inflammatory Treatment for Carpal Tunnel Syndrome

This study compared the efficacies of acupuncture and anti-inflammatory treatment in patients with carpal tunnel syndrome (CTS). Fifty patients with mild to moderate CTS were randomly divided into two groups. Both groups received night wrist splints as the standard conservative treatment for 1 month. The acupuncture group also received eight sessions of acupuncture therapy (twice a week for 4 weeks). The control group received 400 mg of ibuprofen three times a day for 10 days. The visual analog scale (VAS) score, the score on the Boston Carpal Tunnel Questionnaire for Functional Status and Symptom Severity (BCTQ FUNCT and SYMPT), and the electrodiagnostic findings were evaluated at baseline and 1 month after treatment. At the final follow up, significant improvements were found in both groups (p < 0.05). Statistically significant improvements were observed in the VAS score, the score on the global BCTQ FUNCT and SYMPT, and the electrodiagnostic findings, but not in the distal motor latency (DML), in the acupuncture group (p < 0.05). Our findings indicate that acupuncture affected the score on the global BCTQ FUNCT and SYMPT, the VAS score, and the electrodiagnostic findings, except the DML, more than ibuprofen did and that acupuncture might be an effective treatment for CTS.

Acupuncture applied as a sensory discrimination training tool decreases movement-related pain in patients with chronic low back pain more than acupuncture alone: a randomised cross-over experiment

BACKGROUND

High-quality clinical evidence suggests that although acupuncture appears superior to usual care in the management of chronic low back pain, there is little meaningful difference between true and sham acupuncture. This suggests that the benefits of acupuncture are mediated by the placebo response. An alternative explanation is that sham acupuncture is an active treatment and shares a mechanism of action with traditionally applied acupuncture. One plausible candidate for this mechanism is improvement in self-perception mediated through the sensory discrimination-like qualities of acupuncture. We aimed to compare the effects of acupuncture with a sensory discrimination training component to acupuncture without.

METHODS

25 people with chronic low back pain were enroled in a randomised cross-over experiment. We compared the effect of acupuncture delivered when sensory discrimination is optimised to acupuncture delivered when it is not, on movement-related back pain immediately after each intervention.

RESULTS

We found that the average pain intensity after participants had received acupuncture with sensory discrimination training (2.8±2.5) was less than when they received acupuncture without sensory discrimination training (3.6±2.0). This difference was statistically significant (after adjustment; mean difference=-0.8, 95% CI -1.4 to -0.3; p=0.011).

CONCLUSIONS

Our findings are consistent with the idea that acupuncture may offer specific benefit that is not dependent on precisely where the needles are inserted so much as that the patient attends to where they are inserted. If so, the location of the needles might be better focused on the painful area and the need for penetration of the skin may be mitigated.

Reappraising entrapment neuropathies--mechanisms, diagnosis and management

The diagnosis of entrapment neuropathies can be difficult because symptoms and signs often do not follow textbook descriptions and vary significantly between patients with the same diagnosis. Signs and symptoms which spread outside of the innervation territory of the affected nerve or nerve root are common. This Masterclass provides insight into relevant mechanisms that may account for this extraterritorial spread in patients with entrapment neuropathies, with an emphasis on neuroinflammation at the level of the dorsal root ganglia and spinal cord, as well as changes in subcortical and cortical regions. Furthermore, we describe how clinical tests and technical investigations may identify these mechanisms if interpreted in the context of gain or loss of function. The management of neuropathies also remains challenging. Common treatment strategies such as joint mobilisation, neurodynamic exercises, education, and medications are discussed in terms of their potential to influence certain mechanisms at the site of nerve injury or in the central nervous system. The mechanism-oriented approach for this Masterclass seems warranted given the limitations in the current evidence for the diagnosis and management of entrapment neuropathies.

Acupuncture Evoked Response in Contralateral Somatosensory Cortex Reflects Peripheral Nerve Pathology of Carpal Tunnel Syndrome

BACKGROUND

Most neuroimaging studies exploring brain response to different acupoints have been performed in healthy adults.

OBJECTIVE

The aim of this study was to compare brain responses to acupuncture at local versus distal acupoints in patients with carpal tunnel syndrome (CTS), who have chronic pain, versus healthy controls (HC) and correlate these responses with median nerve function.

MATERIALS AND METHODS

Brain response to electroacupuncture (EA; 2Hz) was evaluated with event-related functional MRI (fMRI) in patients with CTS (n=37) and age-matched HC (n=30). EA was applied at acupoints local (PC 7 to TW 5) and distal (SP 6 to LV 4) to the CTS lesions.

RESULTS

Brain response in both groups and acupoints included activation of the bilateral secondary somatosensory cortex (S2) and insula, and the contralesional primary somatosensory cortex (cS1). Deactivation was noted in ipsilesional primary somatosensory cortex (S1). A significant difference between local and distal acupoints was found in cS1 for HC, but not CTS. Furthermore, cS1 activation by EA at local acupoints was negatively correlated with median nerve peak sensory latency in HC, but was positively correlated in CTS. No correlation was found for EA at distal acupoints for either group.

CONCLUSIONS

Brain response to EA differs between CTS and HC and, for local acupoint stimulation, is associated with median nerve function, reflecting the peripheral nerve pathophysiology of CTS.

Acupuncture-evoked response in somatosensory and prefrontal cortices predicts immediate pain reduction in carpal tunnel syndrome

The linkage between brain response to acupuncture and subsequent analgesia remains poorly understood. Our aim was to evaluate this linkage in chronic pain patients with carpal tunnel syndrome (CTS). Brain response to electroacupuncture (EA) was evaluated with functional MRI. Subjects were randomized to 3 groups: (1) EA applied at local acupoints on the affected wrist (PC-7 to TW-5), (2) EA at distal acupoints (contralateral ankle, SP-6 to LV-4), and (3) sham EA at nonacupoint locations on the affected wrist. Symptom ratings were evaluated prior to and following the scan. Subjects in the local and distal groups reported reduced pain. Verum EA produced greater reduction of paresthesia compared to sham. Compared to sham EA, local EA produced greater activation in insula and S2 and greater deactivation in ipsilateral S1, while distal EA produced greater activation in S2 and deactivation in posterior cingulate cortex. Brain response to distal EA in prefrontal cortex (PFC) and brain response to verum EA in S1, SMA, and PFC were correlated with pain reduction following stimulation. Thus, while greater activation to verum acupuncture in these regions may predict subsequent analgesia, PFC activation may specifically mediate reduced pain when stimulating distal acupoints.