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Objective The purpose of this systematic review is to systematically review the evidence relating to findings generated by multivariate pattern analysis (MVPA) following structural or functional magnetic resonance imaging (fMRI) to determine if this analysis is able to: a) Discriminate between individuals with musculoskeletal pain and healthy controls, b) Predict pain perception in healthy individuals stimulated with a noxious stimulus compared to those stimulated with a non-noxious stimulus. Methods MEDLINE, CINAHL, Embase, PEDro, Google Scholar, Cochrane library and Web of Science were systematically screened for relevant literature using different combinations of keywords regarding structural and functional MRI analysed with MVPA, both in individuals with musculoskeletal pain and healthy controls. Reference lists of included articles were hand-searched for additional literature. Eligible articles were assessed on risk of bias and reviewed by two independent researchers. Results The search query returned 18 articles meeting the inclusion criteria. Methodological quality varied from poor to good. Seven studies investigated the ability of machine-learning algorithms to differentiate patient groups from healthy control participants. Overall, the review demonstrated that MVPA can discriminate between individuals with MSK pain and healthy controls with an overall accuracy ranging from 53% to 94%. Twelve studies utilized healthy control participants (using them as their own controls), during experimental pain paradigms aimed to investigate the ability of machine-learning to differentiate individuals stimulated with noxious stimuli from those stimulated with non-noxious stimuli, with ‘pain’ detection rates ranging from 60% to 94%. However, significant heterogeneity in patient conditions, study methodology and brain imaging techniques resulted in various findings that make study comparisons and formal conclusions challenging. Conclusion There is preliminary and emerging evidence that MVPA analyses of structural or functional MRI are able to discriminate between patients and healthy controls, and also discriminate between noxious and non-noxious stimulation. No prospective studies were found in this review to allow determination of the prognostic or diagnostic capabilities or treatment responsiveness of these analyses. Future studies would also benefit from combining various behavioural, genotype and phenotype data into analyses to assist with development of sensitive and specific signatures that could guide future individualized patient treatment options and evaluate how treatments exert their effects. [ABSTRACT FROM AUTHOR]

Joint Position Sense Error (JPSE) is a measure of cervical spine proprioception, and a simple method for measuring the JPSE could help in monitoring and evaluating the outcomes of rehabilitation of people with neck pain. In this study we demonstrate preliminary results of a method for measuring JPSE that does not require the participant to wear any equipment. Based on free publicly available head tracking software, compatible with any webcam, we developed a webpage which instructs the participant in performing a self-administered version of the test. The aim of this proof-of-concept study was to demonstrate the viability of this system. We compared our absolute error values (3.68 ± 1.2° after extension, 3.46 ± 1.66° after flexion, 3.89 ± 2.34° after rotation to the left and 4.02 ± 1.82°after rotation to the right) to values from literature, finding that our results do not differ from those of 6 out of 11 studies (which used more complex and expensive setups). The results indicate that our system allows assessment of the JPSE with a standard computer. Being based on a website, the system has potential for telemedicine use. Further research is required to validate the system before it can be recommended for use in clinical practice. [ABSTRACT FROM AUTHOR]

Abstract: Impaired integration of the body schema with motor processes may contribute to painful and/or restricted movement in chronic pain. Laterality judgment tasks assess this integration of the body schema with motor processes. The purpose of this study was to assess if patients with chronic whiplash associated disorders (WAD) are impaired on laterality judgment tasks. Accuracy (ACC) and reaction time (RT) for foot and neck laterality tasks were assessed in 64 (35 female) patients with chronic (>6months) WAD and 24 (14 female) asymptomatic subjects. Pain characteristics, post-traumatic stress symptoms, cold pain thresholds (CPT) and pressure pain thresholds (PPT) were collected for patients with WAD. The effect of WAD and body part on laterality task performance was assessed. For patients with WAD, the correlations between neck task performance and pain characteristics, post-traumatic stress symptoms and pain thresholds were assessed. There was no effect of group on laterality performance. Subjects showed better RT (p < 0.001) and ACC (p = 0.001) on the neck task in comparison to the foot task. There was a significant correlation between CPT and ACC (r = 0.33) and RT (r = −0.33) on the neck laterality task in patients with WAD. Cervical spine PPT were significantly correlated with accuracy (r = 0.36) and RT (r = 0.29) in patients with WAD. These findings suggest that patients with chronic WAD are not impaired on neck or foot laterality judgment tasks. Laterality training is not indicated in the management of chronic WAD. [Copyright &y& Elsevier]

Abstract: There is emerging evidence of altered pain signal processing as a likely underlying mechanism in chronic lateral epicondylalgia (LE), yet this remains to be assessed. Furthermore, it has been proposed that neurodynamic tests reflect nociceptive withdrawal responses. Therefore, the objective was to improve our understanding of spinal cord excitability as measured by nociceptive flexion reflex (NFR) threshold in chronic LE with and without a positive neurodynamic test. NFR threshold, pain-free grip, and pressure pain threshold were measured in 30 LE participants and 31 healthy controls. Test of neural tissue involvement (using upper limb neural tension, radial bias) was used to differentiate LE participants with or without a positive neurodynamic test. There were significant differences in NFR threshold between the control and LE with or without a positive neurodynamic test (F[2,54] = 5.68, P = .006), after adjusting for age, sex, pain rating at NFR threshold, and reflex size (NFR interval peak z score). The mean differences (95% confidence interval) in NFR threshold between the control and LE with or without a positive neurodynamic test were 3.74 mA (.637, 6.84) and 3.38 mA (.0245, 6.74) respectively. Perspective: The results suggest evidence of spinal cord hyperexcitability, particularly sensory hypersensitivity, in LE with or without a positive neurodynamic test. Our data appear to support the hypothesis that continued peripheral afferent stimulation results in facilitation of nociceptive pathways in this patient population. [Copyright &y& Elsevier]

Abstract: Sensory hypersensitivity indicative of augmented central pain processing is a feature of chronic whiplash associated disorders (WAD). This study investigated the immediate effects of a cervical spine manual therapy (SMT) technique on measures of central hyperexcitability. In a randomised, single blind, clinical trial, 39 participants with chronic WAD were randomly assigned to a cervical SMT (lateral glide) or manual contact intervention. The Neck Disability Index (NDI) and GHQ-28 were administered at baseline. Pressure pain thresholds (PPTs), thermal pain thresholds (TPTs) and Nociceptive Flexion Reflex (NFR) responses (threshold and VAS of pain) were measured pre and post intervention. There was a significantly greater increase in NFR threshold following SMT compared to the manual contact intervention (p = 0.04). PPTs at the cervical spine increased following both SMT (mean ± SE: 24.1 ± 7.3%) and manual contact (21 ± 8.4%) with no difference between interventions. There was no difference between interventions for pain ratings with the NFR test, PPTs at the Median Nerve or Tibialis Anterior, heat or cold TPT. SMT may be effective in reducing spinal hyperexcitability in chronic WAD. [Copyright &y& Elsevier]

Abstract: Whiplash is a heterogeneous condition with some individuals showing features suggestive of neuropathic pain. This study investigated the presence of a neuropathic pain component in acute whiplash using the Self-reported Leeds Assessment of Neuropathic Signs and Symptoms'' scale (S-LANSS) and evaluated relationships among S-LANSS responses, pain/disability, sensory characteristics (mechanical, thermal pain thresholds, and Brachial plexus provocation test (BPPT) responses) and psychological distress (General Health Questionnaire-28 (GHQ-28)). Participants were 85 people with acute whiplash (<4 weeks) (54 females, age 36.27±12.69 years). Thirty-four percent demonstrated a predominantly neuropathic pain component (S-LANSS≥12). This group showed higher pain/disability, cold hyperalgesia, cervical mechanical hyperalgesia, and less elbow extension with the BPPT (p <0.03) when compared to the group with non-neuropathic pain (S-LANSS≤12). Pressure pain thresholds (PPTs) at distant sites and psychological distress (GHQ-28) were not different between the groups (p >0.09). None of the S-LANSS items could discriminate those with cold hyperalgesia (p =0.06). A predominantly neuropathic pain component is related to a complex presentation of higher pain/disability and sensory hypersensitivity. The S-LANSS may be a useful tool and the BPPT a useful clinical test in the early assessment of whiplash. [Copyright &y& Elsevier]