Functional Magnetic Resonance Imaging of Cerebral Hemodynamic Responses to Pain Following Thoracic Thrust Manipulation in Individuals With Neck Pain: A Randomized Trial

The effect of a spinal thrust manipulation's audible pop on brain wave activity: a quasi-experimental repeated measure design

Introduction

High velocity thrust manipulation is commonly used when managing joint dysfunctions. Often, these thrust maneuvers will elicit an audible pop. It has been unclear what conclusively causes this audible sound and its clinical meaningfulness. This study sought to identify the effect of the audible pop on brainwave activity directly following a prone T7 thrust manipulation in asymptomatic/healthy subjects.

Methods

This was a quasi-experimental repeated measure study design in which 57 subjects completed the study protocol. Brain wave activity was measured with the Emotiv EPOC+, which collects data with a frequency of 128 HZ and has 14 electrodes. Testing was performed in a controlled environment with minimal electrical interference (as measured with a Gauss meter), temperature variance, lighting variance, sound pollution, and other variable changes that could have influenced or interfered with pure EEG data acquisition. After accommodation each subject underwent a prone T7 posterior-anterior thrust manipulation. Immediately after the thrust manipulation the brainwave activity was measured for 10 seconds.

Results

The non-audible group (N = 20) consisted of 55% males, and the audible group (N = 37) consisted of 43% males. The non-audible group EEG data revealed a significant change in brain wave activity under some of the electrodes in the frontal, parietal, and the occipital lobes. In the audible group, there was a significant change in brain wave activity under all electrodes in the frontal lobes, the parietal lobe, and the occipital lobes but not the temporal lobes.

Conclusion

The audible sounds caused by a thoracic high velocity thrust manipulation did not affect the activity in the audible centers in the temporal brain region. The results support the hypothesis that thrust manipulation with or without audible sound results in a generalized relaxation immediately following the manipulation. The absence of a significant difference in brainwave activity in the frontal lobe in this study might indicate that the audible pop does not produce a "placebo" mechanism.

Waste not, want not: call to action for spinal manipulative therapy researchers

BACKGROUND

Research waste is defined as research outcomes with no or minimal societal benefits. It is a widespread problem in the healthcare field. Four primary sources of research waste have been defined: (1) irrelevant or low priority research questions, (2) poor design or methodology, (3) lack of publication, and (4) biased or inadequate reporting. This commentary, which was developed by a multidisciplinary group of researchers with spinal manipulative therapy (SMT) research expertise, discusses waste in SMT research and provides suggestions to improve future research.

MAIN TEXT

This commentary examines common sources of waste in SMT research, focusing on design and methodological issues, by drawing on prior research and examples from clinical and mechanistic SMT studies. Clinical research is dominated by small studies and studies with a high risk of bias. This problem is compounded by systematic reviews that pool heterogenous data from varying populations, settings, and application of SMT. Research focusing on the mechanisms of SMT often fails to address the clinical relevance of mechanisms, relies on very short follow-up periods, and has inadequate control for contextual factors.

CONCLUSIONS

This call to action is directed to researchers in the field of SMT. It is critical that the SMT research community act to improve the way research is designed, conducted, and disseminated. We present specific key action points and resources, which should enhance the quality and usefulness of future SMT research.

Effectiveness and safety of thoracic manipulation in the treatment of neck pain: An updated systematic review and meta-analysis

BACKGROUND

The purpose of this meta-analysis was to evaluate the effectiveness and safety of thoracic manipulation (TM) in patients with neck pain (NP).

OBJECTIVE

The purpose of this meta-analysis was to evaluate the effectiveness and safety of thoracic manipulation (TM) in patients with neck pain (NP).

METHODS

Seven electronic databases were searched from their inception through October 2023 by two authors. The methodological quality assessments were performed with the Physiotherapy Evidence Database (PEDro) scale. Pain, cervical range of motion (ROM), disability, and quality of life (QOL) were estimated for TM treatment in patients with NP.

RESULTS

Eighteen randomized controlled trials (RCTs) with 914 patients were included with a PEDro score of 6.923 ± 3.120. Pooled effect sizes of pain (SMD =-0.481, 95% CI -0.653 to -0.309, P= 0.000), disability (SMD =-1.435, 95% CI -2.480 to -0.390, P= 0.007), QOL-physical component score (PCS) (SMD = 0.658, 95% CI 0.290 to 1.025, P= 0.000), ROM of flexion (SMD = 0.921, 95% CI 0.287 to 1.555, P= 0.000), ROM of extension (SMD = 0.572, 95% CI 0.321 to 0.822, P= 0.000), ROM of left lateral flexion (SMD = 0.593, 95% CI 0.075 to 1.112, P= 0.025) and ROM of left rotation (SMD = 0.230, 95% CI 0.010 to 0.450, P= 0.04) were favored by the TM group.

CONCLUSIONS

TM provides short-term effect on relieving neck pain, increasing cervical ROM, and disability in patients with NP without serious side effects. Continuous therapy and distraction therapy are recommended as optimal choice on reducing pain and improving cervical ROM, especially in patients with chronic NP (> 3 months). The TM-induced improvements in the QOL of patients with NP should be verified by more further high-quality RCTs.

Review of effects of spinal manipulative therapy on neurological symptoms

BACKGROUND

Neurological disorders are the leading cause of disability in the world. Neurological symptoms significantly affect the well-being of the individual. Spinal manipulative therapy (SMT) is a complementary method often used for people with neurological disorders.

OBJECTIVE

This study aimed to review the existing literature on the effects of SMT on common clinical symptoms of neurologic disorders and the quality of life.

METHODS

Narrative review was conducted through the literature published between January 2000 and April 2020 in English. The search was performed across four databases: PubMed, Google Scholar, PEDro, and Index to Chiropractic Literature. We used combinations of keywords related to SMT, neurological symptoms, and quality of life. Studies on both symptomatic and asymptomatic populations of different ages were included.

RESULTS

35 articles were selected. Evidence for the administration of SMT for neurological symptoms is insufficient and sparse. Most studies focused on the effects of SMT on pain, revealing its benefits for spinal pain. SMT may increase strength in asymptomatic people and populations with spinal pain and stroke. SMT was reported to affect spasticity, muscle stiffness, motor function, autonomic function, and balance problems, but these studies were limited in number to make conclusions. An important finding was the positive influence of SMT on the quality of life in people with spinal pain, balance impairments, and cerebral palsy.

CONCLUSION

SMT may be beneficial for the symptomatic treatment of neurological disorders. SMT can positively affect the quality of life. However, limited evidence is available, and further high-quality research is required.

Segmental Chiropractic Spinal Manipulation Does not Reduce Pain Amplification and the Associated Pain-Related Brain Activity in a Capsaicin-Heat Pain Model

Musculoskeletal injuries lead to sensitization of nociceptors and primary hyperalgesia (hypersensitivity to painful stimuli). This occurs with back injuries, which are associated with acute pain and increased pain sensitivity at the site of injury. In some cases, back pain persists and leads to central sensitization and chronic pain. Thus, reducing primary hyperalgesia to prevent central sensitization may limit the transition from acute to chronic back pain. It has been shown that spinal manipulation (SM) reduces experimental and clinical pain, but the effect of SM on primary hyperalgesia and hypersensitivity to painful stimuli remains unclear. The goal of the present study was to investigate the effect of SM on pain hypersensitivity using a capsaicin-heat pain model. Laser stimulation was used to evoke heat pain and the associated brain activity, which were measured to assess their modulation by SM. Eighty healthy participants were recruited and randomly assigned to one of the four experimental groups: inert cream and no intervention; capsaicin cream and no intervention; capsaicin cream and SM at T7; capsaicin cream and placebo. Inert or capsaicin cream (1%) was applied to the T9 area. SM or placebo were performed 25 min after cream application. A series of laser stimuli were delivered on the area of cream application (1) before cream application, (2) after cream application but before SM or placebo, and (3) after SM or placebo. Capsaicin cream induced a significant increase in laser pain (p < 0.001) and laser-evoked potential amplitude (p < 0.001). However, SM did not decrease the amplification of laser pain or laser-evoked potentials by capsaicin. These results indicate that segmental SM does not reduce pain hypersensitivity and the associated pain-related brain activity in a capsaicin-heat pain model.

The Challenges and Perspectives of the Integration Between Virtual and Augmented Reality and Manual Therapies

Virtual reality (VR) and augmented reality (AR) have been combined with physical rehabilitation and psychological treatments to improve patients' emotional reactions, body image, and physical function. Nonetheless, no detailed investigation assessed the relationship between VR or AR manual therapies (MTs), which are touch-based approaches that involve the manipulation of tissues for relieving pain and improving balance, postural stability and well-being in several pathological conditions. The present review attempts to explore whether and how VR and AR might be integrated with MTs to improve patient care, with particular attention to balance and to fields like chronic pain that need an approach that engages both mind and body. MTs rely essentially on touch to induce tactile, proprioceptive, and interoceptive stimulations, whereas VR and AR rely mainly on visual, auditory, and proprioceptive stimulations. MTs might increase patients' overall immersion in the virtual experience by inducing parasympathetic tone and relaxing the mind, thus enhancing VR and AR effects. VR and AR could help manual therapists overcome patients' negative beliefs about pain, address pain-related emotional issues, and educate them about functional posture and movements. VR and AR could also engage and change the sensorimotor neural maps that the brain uses to cope with environmental stressors. Hence, combining MTs with VR and AR could define a whole mind-body intervention that uses psychological, interoceptive, and exteroceptive stimulations for rebalancing sensorimotor integration, distorted perceptions, including visual, and body images. Regarding the technology needed to integrate VR and AR with MTs, head-mounted displays could be the most suitable devices due to being low-cost, also allowing patients to follow VR therapy at home. There is enough evidence to argue that integrating MTs with VR and AR could help manual therapists offer patients better and comprehensive treatments. However, therapists need valid tools to identify which patients would benefit from VR and AR to avoid potential adverse effects, and both therapists and patients have to be involved in the development of VR and AR applications to define truly patient-centered therapies. Furthermore, future studies should assess whether the integration between MTs and VR or AR is practically feasible, safe, and clinically useful.

The Effects of 4 Weeks of Chiropractic Spinal Adjustments on Motor Function in People with Stroke: A Randomized Controlled Trial

Chiropractic spinal adjustments have been shown to result in short-term increases in muscle strength in chronic stroke patients, however, the effect of longer-term chiropractic spinal adjustments on people with chronic stroke is unknown. This exploratory study assessed whether 4 weeks of chiropractic spinal adjustments, combined with physical therapy (chiro + PT), had a greater impact than sham chiropractic with physical therapy (sham + PT) did on motor function (Fugl Meyer Assessment, FMA) in 63 subacute or chronic stroke patients. Secondary outcomes included health-related quality of life and other measures of functional mobility and disability. Outcomes were assessed at baseline, 4 weeks (post-intervention), and 8 weeks (follow-up). Data were analyzed using linear mixed-effects models or generalized linear mixed models. A post-hoc responder analysis was performed to investigate the clinical significance of findings. At 4 weeks, there was a larger effect of chiro + PT, compared with sham + PT, on the FMA (difference = 6.1, p = 0.04). The responder analysis suggested the improvements in motor function seen following chiropractic spinal adjustments may have been clinically significant. There was also a robust improvement in both groups in most measures from baseline to the 4- and 8-week assessments, but between-group differences were no longer significant at the 8-week assessment. Four weeks of chiro + PT resulted in statistically significant improvements in motor function, compared with sham + PT, in people with subacute or chronic stroke. These improvements appear to be clinically important. Further trials, involving larger group sizes and longer follow-up and intervention periods, are required to corroborate these findings and further investigate the impacts of chiropractic spinal adjustments on motor function in post-stroke survivors. ClinicalTrials.gov Identifier NCT03849794.

Neurophysiological mechanisms of chiropractic spinal manipulation for spine pain

Together, neck pain and back pain are the first cause of disability worldwide, accounting for more than 10% of the total years lived with disability. In this context, chiropractic care provides a safe and effective option for the management of a large proportion of these patients. Chiropractic is a healthcare profession mainly focused on the spine and the treatment of spinal disorders, including spine pain. Basic studies have examined the influence of chiropractic spinal manipulation (SM) on a variety of peripheral, spinal and supraspinal mechanisms involved in spine pain. While spinal cord mechanisms of pain inhibition contribute at least partly to the pain-relieving effects of chiropractic treatments, the evidence is weaker regarding peripheral and supraspinal mechanisms, which are important components of acute and chronic pain. This narrative review highlights the most relevant mechanisms of pain relief by SM and provides a perspective for future research on SM and spine pain, including the validation of placebo interventions that control for placebo effects and other non-specific effects that may be induced by SM. SIGNIFICANCE: Spinal manipulation inhibits back and neck pain partly through spinal segmental mechanisms and potentially through peripheral mechanisms regulating inflammatory responses. Other mechanisms remain to be clarified. Controls and placebo interventions need to be improved in order to clarify the contribution of specific and non-specific effects to pain relief by spinal manipulative therapy.

Functional MRI Signature of Chronic Pain Relief From Deep Brain Stimulation in Parkinson Disease Patients

BACKGROUND

Chronic pain occurs in 83% of Parkinson disease (PD) patients and deep brain stimulation (DBS) has shown to result in pain relief in a subset of patients, though the mechanism is unclear.

OBJECTIVE

To compare functional magnetic resonance imaging (MRI) data in PD patients with chronic pain without DBS, those whose pain was relieved (PR) with DBS and those whose pain was not relieved (PNR) with DBS.

METHODS

Functional MRI (fMRI) with blood oxygen level-dependent activation data was obtained in 15 patients in control, PR, and PNR patients. fMRI was obtained in the presence and absence of a mechanical stimuli with DBS ON and DBS OFF. Voxel-wise analysis using pain OFF data was used to determine which regions were altered during pain ON periods.

RESULTS

At the time of MRI, pain was scored a 5.4 ± 1.2 out of 10 in the control, 4.25 ± 1.18 in PNR, and 0.8 ± 0.67 in PR cohorts. Group analysis of control and PNR groups showed primary somatosensory (SI) deactivation, whereas PR patients showed thalamic deactivation and SI activation. DBS resulted in more decreased activity in PR than PNR (P < .05) and more activity in anterior cingulate cortex (ACC) in PNR patients (P < .05).

CONCLUSION

Patients in the control and PNR groups showed SI deactivation at baseline in contrast to the PR patients who showed SI activation. With DBS ON, the PR cohort had less activity in SI, whereas the PNR had more anterior cingulate cortex activity. We provide pilot data that patients whose pain responds to DBS may have a different fMRI signature than those who do not, and PR and PNR cohorts produced different brain responses when DBS is employed.

Tuina for cervical vertigo: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND PURPOSE

Cervical vertigo (CV), one of the most common causes of vertigo, makes patients feel dizzy, which seriously affects patients' lives. As a traditional Chinese bone-setting manipulation, Tuina is widely used to treat CV. This article aims to evaluate the effectiveness and safety of Tuina for CV.

METHODS

Nine databases were searched. Methodological quality was evaluated with the Cochrane Collaboration's tool. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was applied to determine confidence in the effect estimates. Stata 12.0 software was used to carry out the meta-analysis, and a trial sequential analysis (TSA) was performed with TSA 0.9.

RESULTS

Nine randomized controlled trials (RCTs) were included. Low-quality evidence suggested that Tuina showed a significantly higher effectiveness rate compared to massage therapy (risk ratio (RR) = 1.11, 95% confidence intervals (CI): 1.05 to 1.17, p < 0.0001) and cervical traction (RR = 1.37, 95% CI: 1.09 to 1.72, p = 0.007; I² = 0%, p = 0.826). Two trials reported that Tuina was better than acupuncture (RR = 1.40, 95% CI: 1.07 to 1.83) or betahistine mesilate (RR = 1.17, 95% CI: 0.99 to 1.37) based on an improved effectiveness rate. Low-quality evidence showed that Tuina was superior to massage therapy in improving scores on the evaluation scale for cervical vertigo (ESCV) (weighted mean differences (WMD) = 2.52, 95% CI: 1.11 to 3.94, p < 0.0001). Adverse events were tolerable. TSA revealed that an improved effectiveness rate was indicated.

CONCLUSION

Tuina might improve the effectiveness rate and ESCV scores in patients with CV. However, the level of all the available evidence was low, and larger-scale and well-designed RCTs should be encouraged.

Evidence for decreased Neurologic Pain Signature activation following thoracic spinal manipulation in healthy volunteers and participants with neck pain

•

The use of brain-based models of pain were explored in two clinical studies.

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Neurologic pain signature activation decreased following spinal manipulation.

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Spinal manipulation altered the processing of pain-related brain activity.

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We provide evidence for a centrally mediated therapeutic action of spinal manipulation.

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Brain-based models have potential as objective clinical biomarkers of pain.

Background Context

Spinal manipulation (SM) is a common treatment for neck and back pain, theorized to mechanically affect the spine leading to therapeutic mechanical changes. The link between specific mechanical effects and clinical improvement is not well supported. SM's therapeutic action may instead be partially mediated within the central nervous system.

Purpose

To introduce brain-based models of pain for spinal pain and manual therapy research, characterize the distributed central mechanisms of SM, and advance the preliminary validation of brain-based models as potential clinical biomarkers of pain.

Study Design

Secondary analysis of two functional magnetic resonance imaging studies investigating the effect of thoracic SM on pain-related brain activity: A non-controlled, non-blinded study in healthy volunteers (Study 1, n = 10, 5 females, and mean age = 31.2 ± 10.0 years) and a randomized controlled study in participants with acute to subacute neck pain (Study 2, n = 24, 16 females, mean age = 38.0 ± 15.1 years).

Methods

Functional magnetic resonance imaging was performed during noxious mechanical stimulation of the right index finger cuticle pre- and post-intervention. The effect of SM on pain-related activity was studied within brain regions defined by the Neurologic Pain Signature (NPS) that are predictive of physical pain.

Results

In Study 1, evoked mechanical pain (p < 0.001) and NPS activation (p = 0.010) decreased following SM, and the changes in evoked pain and NPS activation were correlated (r_RM² = 0.418, p = 0.016). Activation within the NPS subregions of the dorsal anterior cingulate cortex (dACC, p = 0.012) and right secondary somatosensory cortex/operculum (rS2_Op, p = 0.045) also decreased following SM, and evoked pain was correlated with dACC activity (r_RM² = 0.477, p = 0.019). In Study 2, neck pain (p = 0.046) and NPS (p = 0.033) activation decreased following verum but not sham SM. Associations between evoked pain, neck pain, and NPS activation, were not significant and less clear, possibly due to inadequate power, methodological limitations, or other confounding factors.

Conclusions

The findings provide preliminary evidence that SM may alter the processing of pain-related brain activity within specific pain-related brain regions and support the use of brain-based models as clinical biomarkers of pain.

Unravelling functional neurology: does spinal manipulation have an effect on the brain? - a systematic literature review

Background

A recent hypothesis purports that spinal manipulation may cause changes at a brain level. Functional Neurology, a mainly chiropractic approach, promotes the use of spinal manipulation to improve ‘brain function’ as if it were a proven construct. No systematic review has been performed to investigate how well founded this hypothesis is.

Objective

To investigate whether spinal manipulation has an effect on ‘brain function’ that is associated with any clinical benefits.

Method

In this systematic review, the literature was searched in PubMed, Embase, and PEDro (final search February 2018). We included randomized or non-randomized controlled studies, in which spinal manipulation was performed to any region of the spine, applied on either symptomatic or asymptomatic humans, and compared to a sham or to another type of control. The outcome measures had to be stated as direct or proxy markers of ‘brain function’. Articles were reviewed blindly by at least two reviewers, using a quality checklist designed for the specific needs of the review. Studies were classified as of ‘acceptable’, ‘medium’, or ‘low’ methodological quality. Results were reported in relation to (i) control intervention (sham, ‘inactive control’, or ‘another physical stimulus’) and (ii) study subjects (healthy, symptomatic, or with spinal pain” subjects/spinal pain”), taking into account the quality. Only results obtained from between-group or between-intervention comparisons were considered in the final analysis.

Results

Eighteen of 1514 articles were included. Studies were generally of ‘low’ or ‘medium’ methodological quality, most comparing spinal manipulation to a control other than a sham. Thirteen out of the 18 studies could be included in the final analysis. Transitory effects of different types of ‘brain function’ were reported in the three studies comparing spinal manipulation to sham (but of uncertain credibility), in “subclinical neck/spinal pain” subjects or in symptomatic subjects. None of these three studies, of ‘medium’ or ‘acceptable’ quality, investigated whether the neurophysiological effects reported were associated with clinical benefits. The remaining 10 studies, generally of ‘low’ or ‘medium’ quality, compared spinal manipulation to ‘inactive control’ or ‘another physical stimulus’ and similarly reported significant between-group differences but inconsistently.

Conclusion

The available evidence suggests that changes occur in ‘brain function’ in response to spinal manipulation but are inconsistent across and - sometimes - within studies. The clinical relevance of these changes is unknown. It is therefore premature to promote the use of spinal manipulation as a treatment to improve ‘brain function’.

Electronic supplementary material

The online version of this article (10.1186/s12998-019-0265-8) contains supplementary material, which is available to authorized users.