The fear-avoidance model as an embodied prediction of threat.

The fear-avoidance model is a well-established framework in the understanding of persistent pain. It proposes a dichotomous path: either the context is interpreted as safe; there is no fear reaction and, therefore, the individual engages in active (positive) coping; or the context is interpreted as threatening, leading to a self-reinforcing vicious circle of fear and (negative) avoidance. We propose an embodied interpretation of this phenomenon employing the joint framework of predictive coding and active inference. The key idea is that multisensory integration of exteroceptive, proprioceptive, and interoceptive sensory inputs can lead to dysfunctional experiences of threat in nonthreatening situations. Threat inference can promote fear responses, maladaptive strategies (i.e., avoidance) and self-provides evidence for threat in associated or future contexts, or both. Under this treatment, the prediction of nonrealized threat becomes self-evidencing and context-invariant, and hence self-perpetuating. Safety cues are unable to attenuate the interpretation of the negative context as the dominant inference of the context is threatful and gains more precision and becomes resistant over time. Our model provides an explanation for the emergence of a dysfunctional fear response in the clinical setting despite apparent safety based on modern concepts from theoretical (computational) neuroscience.

Integrating jigsaw puzzle thinking into practice: the assessment of cervical spine radiculopathy.

PURPOSE OF REVIEW: Cervical spine radiculopathy (CSR) presents a complex socioeconomic problem for patients, clinicians, families, employers and healthcare systems. Due to the heterogeneity of clinical presentation and underlying mechanisms, clinical assessment can be challenging. This review will examine the literature on the underlying pathophysiology and studies investigating the holistic assessment strategies for this disabling condition. The authors will focus particular attention on the psychological factors associated with CSR and the physical and imaging strategies to establish a diagnosis. RECENT FINDINGS: Contemporary CSR assessment should identify the underlying pathomechanisms and how this may impact the somatosensory nervous system integrity and function. No physical assessment test in isolation will establish CSR diagnosis; therefore, clinicians should utilise a cluster of tests and recognise the potential limitations as part of a clinical reasoning framework. The assessment of the somatosensory nervous system can provide insights into particular subgroups of CSR presentation, which may provide interesting opportunities to continue to enhance individualised assessment and management strategies for CSR. The interplay between psychological factors can influence the diagnosis and recovery times for a person with CSR, and clinicians should continue to explore how these factors may influence a person's prognosis. The authors will discuss the opportunities for future research and limitations of contemporary approaches to assessment, underpinned by evidence, and how this supports a clinical assessment to establish CSR diagnosis. SUMMARY: Research should continue to investigate how clinicians assess the interplay between physical and psychological factors to inform the establishment of CSR. Specifically, there is a need to investigate the validity and reliability of combining somatosensory, motor and imaging assessment findings to reach a diagnosis and inform onward management plans.

The association between psychosocial factors and mental health symptoms in cervical spine pain with or without radiculopathy on health outcomes: a systematic review.

BACKGROUND: Neck pain, with or without radiculopathy, can have significant negative effects on physical and mental wellbeing. Mental health symptoms are known to worsen prognosis across a range of musculoskeletal conditions. Understanding the association between mental health symptoms and health outcomes in this population has not been established. Our aim was to systematically review the association between psychosocial factors and/or mental health symptoms on health outcomes in adults with neck pain, with or without radiculopathy. METHODS: A systematic review of published and unpublished literature databases was completed. Studies reporting mental health symptoms and health outcomes in adults with neck pain with or without radiculopathy were included. Due to significant clinical heterogeneity, a narrative synthesis was completed. Each outcome was assessed using GRADE. RESULTS: Twenty-three studies were included (N = 21,968 participants). Sixteen studies assessed neck pain only (N = 17,604 participants); seven studies assessed neck pain with radiculopathy (N = 4,364 participants). Depressive symptoms were associated with poorer health outcomes in people with neck pain and neck pain with radiculopathy. These findings were from seven low-quality studies, and an additional six studies reported no association. Low-quality evidence reported that distress and anxiety symptoms were associated with poorer health outcomes in people with neck pain and radiculopathy and very low-quality evidence showed this in people with neck pain only. Stress and higher job strain were negatively associated with poorer health outcomes measured by the presence of pain in two studies of very low quality. CONCLUSIONS: Across a small number of highly heterogenous, low quality studies mental health symptoms are negatively associated with health outcomes in people with neck pain with radiculopathy and neck pain without radiculopathy. Clinicians should continue to utilise robust clinical reasoning when assessing the complex factors impacting a person's presentation with neck pain with or without radiculopathy. PROSPERO REGISTRATION NUMBER: CRD42020169497.

Association between psychosocial factors and mental health symptoms to cervical spine pain with or without radiculopathy on health outcomes: systematic review protocol.

INTRODUCTION: Cervical spine pain with or without radiculopathy (CSp ± R) has significant negative impacts to a person's quality of life. Psychosocial factors and/or mental health symptoms are associated with spinal pain with or without radiculopathy and negatively impact health outcomes. This area of research is not yet established for CSp ± R. Our objective is to conduct a systematic review assessing the association between psychosocial factors and/or mental health symptoms and health outcomes in adults with CSp ± R. METHODS: A systematic electronic search of 3 online databases will retrieve studies in which adults (older than 18 years) with CSp ± R, assessing how psychosocial factors or mental health symptoms impact outcomes related to disability, pain, and/or healthcare utilisation. Data extracted will include study design, CSp ± R definition, psychosocial and/or mental health symptoms, and health outcomes. Reporting study quality through the Newcastle-Ottawa Quality Scale Assessment and certainty through Grading of Recommendations, Assessment, Development and Evaluations will be completed. Studies will be assessed from a clinical perspective, methodology design, and statistical testing to determine whether studies can be pooled for meta-analysis. If there is significant clinical heterogeneity, narrative description will be undertaken. PERSPECTIVE: This will be a comprehensive synthesis review to enhance understanding of the association of psychosocial factors and/or mental health symptoms and CSp ± R on health outcomes. The findings will support the formulation of prognosis, collaborative management decisions, and guide healthcare resources to improve outcomes for this patient group. The review will identify gaps in research, thereby informing future experimental and observational study design.

Cervical spine radiculopathy epidemiology: A systematic review.

BACKGROUND AND OBJECTIVE: Cervical spine radiculopathy (CSR) is a disabling condition that has significant negative impacts on a person's mental health, physical functioning and social participation. Research has reported variable CSR incidence and prevalence among different populations. To date, no systematic review has been completed investigating the prevalence or incidence of CSR; therefore, our objective was to determine the incidence and/or prevalence of CSR in adults. DESIGN AND METHOD: A systematic review was conducted including searches of PubMed (MEDLINE), EMBASE and CINAHL from inception to February 25, 2020. Studies including data on incidence and/or prevalence of CSR were included. Methodological quality was assessed using a modified Hayden, Cote and Bombardier appraisal checklist. Data were analysed narratively. RESULTS: Nine low- to high-quality studies were included in the final review. Incidence ranged between 0.832 and 1.79 per 1,000 person-years from two high-quality and one low-quality study. Prevalence values ranged from 1.21 to 5.8 per 1,000 from four medium- to high-quality studies. Prevalence values of 1.14% [95% confidence interval (CI): 0.45-1.82] and 1.31% (95% CI: 0.66-1.96) for males and females, respectively, were reported from one medium-quality study. One medium-quality study reported an unadjusted prevalence value of 6.3% for males and females. CONCLUSIONS: This is the first systematic review investigating the epidemiology of CSR in an adult population. This review reports a variable incidence rate and prevalence of CSR among specific populations; however, this was based on nine studies. There is a priority to investigate CSR epidemiology across other populations globally and standardising CSR diagnostic criteria.

Mechanisms-based classifications of musculoskeletal pain: part 1 of 3: symptoms and signs of central sensitisation in patients with low back (± leg) pain.

As a mechanisms-based classification of pain 'central sensitisation pain' (CSP) refers to pain arising from a dominance of neurophysiological dysfunction within the central nervous system. Symptoms and signs associated with an assumed dominance of CSP in patients attending for physiotherapy have not been extensively studied. The purpose of this study was to identify symptoms and signs associated with a clinical classification of CSP in patients with low back (± leg) pain. Using a cross-sectional, between-subjects design; four hundred and sixty-four patients with low back (± leg) pain were assessed using a standardised assessment protocol. Patients' pain was assigned a mechanisms-based classification based on experienced clinical judgement. Clinicians then completed a clinical criteria checklist specifying the presence or absence of various clinical criteria. A binary logistic regression analysis with Bayesian model averaging identified a cluster of three symptoms and one sign predictive of CSP, including: 'Disproportionate, non-mechanical, unpredictable pattern of pain provocation in response to multiple/non-specific aggravating/easing factors', 'Pain disproportionate to the nature and extent of injury or pathology', 'Strong association with maladaptive psychosocial factors (e.g. negative emotions, poor self-efficacy, maladaptive beliefs and pain behaviours)' and 'Diffuse/non-anatomic areas of pain/tenderness on palpation'. This cluster was found to have high levels of classification accuracy (sensitivity 91.8%, 95% confidence interval (CI): 84.5-96.4; specificity 97.7%, 95% CI: 95.6-99.0). Pattern recognition of this empirically-derived cluster of symptoms and signs may help clinicians identify an assumed dominance of CSP in patients with low back pain disorders in a way that might usefully inform their management.

Mechanisms-based classifications of musculoskeletal pain: part 3 of 3: symptoms and signs of nociceptive pain in patients with low back (± leg) pain.

As a mechanisms-based classification of pain 'nociceptive pain' (NP) refers to pain attributable to the activation of the peripheral receptive terminals of primary afferent neurones in response to noxious chemical, mechanical or thermal stimuli. The symptoms and signs associated with clinical classifications of NP have not been extensively studied. The purpose of this study was to identify symptoms and signs associated with a clinical classification of NP in patients with low back (± leg) pain. Using a cross-sectional, between-subjects design; four hundred and sixty-four patients with low back (± leg) pain were assessed using a standardised assessment protocol after which their pain was assigned a mechanisms-based classification based on experienced clinical judgement. Clinicians then completed a clinical criteria checklist indicating the presence/absence of various symptoms and signs. A regression analysis identified a cluster of seven clinical criteria predictive of NP, including: 'Pain localised to the area of injury/dysfunction', 'Clear, proportionate mechanical/anatomical nature to aggravating and easing factors', 'Usually intermittent and sharp with movement/mechanical provocation; may be a more constant dull ache or throb at rest', and the absence of 'Pain in association with other dysesthesias', 'Night pain/disturbed sleep', 'Antalgic postures/movement patterns' and 'Pain variously described as burning, shooting, sharp or electric-shock-like'. This cluster was found to have high levels of classification accuracy (sensitivity 90.9%, 95% CI: 86.6-94.1; specificity 91.0%, 95% CI: 86.1-94.6). Pattern recognition of this empirically-derived cluster of symptoms and signs may help clinicians identify an assumed dominance of NP mechanisms in patients with low back pain disorders.

Mechanisms-based classifications of musculoskeletal pain: part 2 of 3: symptoms and signs of peripheral neuropathic pain in patients with low back (± leg) pain.

As a mechanisms-based classification of pain 'peripheral neuropathic pain' (PNP) refers to pain arising from a primary lesion or dysfunction in the peripheral nervous system. Symptoms and signs associated with an assumed dominance of PNP in patients attending for physiotherapy have not been extensively studied. The purpose of this study was to identify symptoms and signs associated with a clinical classification of PNP in patients with low back (± leg) pain. Using a cross-sectional, between-subjects design; four hundred and sixty-four patients with low back (± leg) pain were assessed using a standardised assessment protocol. Patients' pain was assigned a mechanisms-based classification based on experienced clinical judgement. Clinicians then completed a clinical criteria checklist specifying the presence or absence of various clinical criteria. A binary logistic regression analysis with Bayesian model averaging identified a cluster of two symptoms and one sign predictive of PNP, including: 'Pain referred in a dermatomal or cutaneous distribution', 'History of nerve injury, pathology or mechanical compromise' and 'Pain/symptom provocation with mechanical/movement tests (e.g. Active/Passive, Neurodynamic) that move/load/compress neural tissue'. This cluster was found to have high levels of classification accuracy (sensitivity 86.3%, 95% CI: 78.0-92.3; specificity 96.0%, 95% CI: 93.4-97.8; diagnostic odds ratio 150.9, 95% CI: 69.4-328.1). Pattern recognition of this empirically-derived cluster of symptoms and signs may help clinicians identify an assumed dominance of PNP mechanisms in patients with low back pain disorders in a way that might usefully inform subsequent patient management.