Cervical spine findings on MRI in people with neck pain compared with pain‐free controls: A systematic review and meta‐analysis

11. Cervicogenic headache and occipital neuralgia

INTRODUCTION

Cervicogenic headache (CEH) and occipital neuralgia (ON) are headaches originating in the occiput and that radiate to the vertex. Because of the intimate relationship between structures based in the occiput and those in the upper cervical region, there is significant overlap between the presentation of CEH and ON. Diagnosis starts with a headache history to assess for diagnostic criteria formulated by the International Headache Society. Physical examination evaluates range of motion of the neck and the presence of tender areas or pressure points.

METHODS

The literature for the diagnosis and treatment of CEH and ON was searched from 2015 through August 2022, retrieved, and summarized.

RESULTS

Conservative treatment includes pain education and self-care, analgesic medication, physical therapy (such as reducing secondary muscle tension and improving posture), the use of TENS (transcutaneous electrical nerve stimulation), or a combination of the aforementioned treatments. Injection at various anatomical locations with local anesthetic with or without corticosteroids can provide pain relief for a short period. Deep cervical plexus block can result in improved pain for less than 6 months. In both CEH and ON, an occipital nerve block can provide important diagnostic information and improve pain in some patients, with PRF providing greater long-term pain control. Radiofrequency ablation of the cervical facet joints can result in improvement for over 1 year. Occipital nerve stimulation (ONS) should be considered for the treatment of refractory ON.

CONCLUSION

The treatment of CEH preferentially consists of radiofrequency treatment of the facet joints, while for ON, pulsed radiofrequency of the occipital nerves is indicated. For refractory cases, ONS may be considered.

Needle-scalpel therapy inhibits the apoptosis of nucleus pulposus cells via the SDF-1/CXCR4 axis in a rat degenerative cervical intervertebral disc model

As a common disease, cervical spondylosis (CS) results from the degeneration of the cervical intervertebral disc. However, there are still no effective clinical strategies for the treatment of this disease. Needle-scalpel (Ns), a therapy guided by traditional Chinese medicine theory, alleviates intervertebral disc degradation and is widely used in the clinic to treat CS. Stromal cell-derived factor-1 (SDF-1) and its receptor CXC receptor 4 (CXCR4) in nucleus pulposus cells play an important role in CS onset and development. This study aimed to explore whether Ns can relieve pain and regulate the SDF-1/CXCR4 axis in nucleus pulposus cells to inhibit apoptosis, thereby delaying cervical intervertebral disc degradation in a rat model of CS. It was found that the Ns-treated groups exhibited higher mechanical allodynia scores than the model group, and H&E staining, MRI, and scanning electron microscopy revealed that Ns therapy inhibited intervertebral disc degeneration. Additionally, Ns therapy significantly inhibited increases in the RNA and protein expression levels of SDF-1 and CXCR4. Furthermore, these treatments alleviated the apoptosis of nucleus pulposus cells, which manifested as a decline in the proportion of apoptotic nucleus pulposus cells and inhibition of the decrease in the levels of Bcl-2/Bax. These findings indicated that Ns mitigated CS-induced pain, inhibited the apoptosis of nucleus pulposus cells, and alleviated intervertebral disc degeneration in CS rats. These effects may be mediated by specifically regulating the SDF-1/CXCR4 signaling axis. Based on these findings, we conclude that Ns might serve as a promising therapy for the treatment of CS.

A clinical audit of the Emergency Department: Doctors' opinions on the diagnosis and management of cervical spine radiculopathy

OBJECTIVE

A clinical audit was carried out on the opinions of doctors working in the Emergency Department (ED) of a large urban hospital regarding the diagnosis and management of cervical spine radiculopathy (CSR). Using international guidelines and current research, it aimed to determine if patients attending this ED were diagnosed and managed in line with best practice, and to identify any discrepancies or areas for improvement in relation to this.

METHOD

Doctors working in this ED were sent an online questionnaire and descriptive analysis was performed on the results to ascertain how they diagnose and manage patients who present with symptoms of CSR. It covered; presentation and definitions of CSR, identification of red flags, clinical tests used, diagnostic test criteria, appropriate management, education and advice given, and the criteria for further management. Additionally, it looked at their opinion on the services' needs.

RESULTS

Most agreed that CSR will improve within 4 weeks with non-operative management; however, there was a lack of consensus regarding the most affected nerve root, differential diagnosis and appropriate diagnostic tests. Opinions aligned regarding the identification of red flags and early management, especially with widespread neurological deficits. However, the management of ongoing pain or new neurological signs, differed between clinicians. Most participants strongly agreed that access to MRIs affected referrals within an ED episode.

CONCLUSION

Overall, the opinions matched recommended guidelines; however, some gaps in knowledge and differing management approaches were identified, indicating the need for ongoing education and standardisation of management.

Conditioned pain modulation and psychological factors in young adults with recurrent or chronic neck pain

BACKGROUND

Controversy exists with the presence of alterations in descending pain inhibition mechanisms in patients with non-specific neck pain (NSNP). The aim of the present study was to evaluate the status of conditioned pain modulation CPM, remote pressure pain thresholds (PPT), and psychological factors in a specific subgroup of patients with NSNP such as young adult students. In addition, possible associations between CPM, psychological factors, and pain characteristics were analyzed.

METHODS

Thirty students with recurrent or chronic NSNP and 30 pain-free students were included in this cross-sectional study. The following measures were assessed: CPM, remote PPT, psychological factors (depression, anxiety, pain catastrophizing, and kinesiophobia), pain characteristics (duration, intensity, severity of chronic pain, interference with daily life), and central sensitization inventory (CSI).

RESULTS

No significant differences were found in the efficacy of CPM between students with chronic or recurrent NSNP and pain-free students (β coefficient = -0.67; 95% CI = -1.54, 0.20). However, students with pain showed a significantly higher remote PPT (mean difference = -1.94; 95% CI = -2.71, -1.18). and a greater presence of anxious (mean difference = 6; 95% CI = 2, 9) and depressive symptoms (mean difference = 8.57; 95% CI = 3.97, 13.16). In addition, significant moderate or strong correlations were found between CPM and pain intensity (partial r = 0.41), pain catastrophizing and mean pain intensity (r = 0.37), grade (r = 0.50), and interference of pain (r = 0.57), kinesiophobia and disability (r = 0.38), and depression and CSI (r = 0.39).

CONCLUSIONS

Young adult students with chronic or recurrent NSNP present remote hyperalgesia and symptoms of depression and anxiety but not dysfunctional CPM.

C-Reactive Protein (CRP) is Associated With Chronic Pain Independently of Biopsychosocial Factors

Inflammation is linked with chronic pain but the extent to which this relationship is associated with biopsychosocial factors is not known. We investigated relationships between blood C-reactive protein (CRP) and regional chronic pain conditions adjusting for a large range and number of potential confounders. We performed cross-sectional analyses using the UK Biobank (N = 415,567) comparing CRP in people reporting any of 9 types of regional chronic pain with pain-free controls. Using logistic regression modelling, we explored relationships between CRP and the presence of chronic pain, with demographic, socioeconomic, psychological/lifestyle factors, and medical comorbidities as covariates. CRP was higher in chronic pain at any site compared with controls (Females: median [interquartile range] 1.60 mg/L [2.74] vs 1.17 mg/L [1.87], P < .001; Males: 1.44 mg/L [2.12] vs 1.15 mg/L [1.65], P < .001). In males, associations between CRP and all types of chronic pain were attenuated but remained significant after adjustment for biopsychosocial covariates (OR range 1.08-1.49, P ≤ .001). For females, adjusted associations between CRP and pain remained significant for most chronic pain types (OR range 1.07-1.34, P < .001) except for facial pain (OR 1.04, P = .17) and headache (OR 1.02, P = .07)-although these non-significant findings may reflect reduced sample size. The significant association between CRP and chronic pain after adjustment for key biopsychosocial confounders implicates an independent underlying biological mechanism of inflammation in chronic pain. The presence of yet unknown or unmeasured confounding factors cannot be ruled out. Our findings may inform better-targeted treatments for chronic pain. PERSPECTIVE: Using a large-scale dataset, this article investigates associations between chronic pain conditions and blood C-reactive protein (CRP), to evaluate the confounding effects of a range of biopsychosocial factors. CRP levels were higher in those with chronic pain versus controls after adjusting for confounders-suggesting a possible independent biological mechanism.

The association between cervical degenerative MRI findings and self-reported neck pain, disability and headache: a cross-sectional exploratory study

BACKGROUND

Neck pain and headache are highly prevalent conditions and leading causes of disability worldwide. Although MRI is widely used in the management of these conditions, there is uncertainty about the clinical significance of cervical MRI findings in patients with neck pain or headache. Therefore, this study aims to investigate the association between cervical degenerative MRI findings and self-reported neck pain, neck disability, and headache.

METHODS

This study was a secondary analysis of a cohort of patients with low back pain aged 18-40 years recruited from a non-surgical outpatient spine clinic. The cervical MRI and outcome measures used in this analysis were collected at a four-year follow-up (2014-2017). Self-reported outcome measures included neck pain intensity, neck disability as measured by the Neck Disability Index, and headache as measured by a single NDI item. Cervical MRI findings included disc degeneration, disc contour changes, and vertebral endplate signal changes (VESC). Multivariable logistic regression analyses, adjusted for age and sex, were used to analyse the associations between MRI findings and neck pain, neck disability, and headache.

RESULTS

A total of 600 participants who underwent MRI and completed the relevant questionnaires at follow-up were included. The median age was 37 years (interquartile range 31-41) and 325 (54%) were female. Of the included participants, 181 (31%) had moderate or severe neck pain, 274 (59%) had moderate or severe neck disability, 193 (42%) reported headaches, and 211 (35%) had one or more cervical degenerative MRI findings. Cervical disc degeneration and disc contour changes were positively associated with moderate or severe neck pain with odds ratio 1.6 (95% CI 1.1-2.4) and 1.6 (1.1-2.3), respectively. VESC was associated with moderate or severe neck disability with odds ratio 3.3 (1.3-8.4). No statistically significant associations were found between the MRI findings assessed and headache.

CONCLUSIONS

In this cross-sectional exploratory study, we found that cervical disc degeneration and disc contour changes were associated with neck pain, and VESC was associated with neck disability. None of the MRI findings were associated with headache. The results suggest that cervical degenerative changes may contribute to the aetiology of neck symptoms, but the associations are modest and cannot guide clinical decisions.

Defining text neck: a scoping review

BACKGROUND

Text neck is regarded as a global epidemic. Yet, there is a lack of consensus concerning the definitions of text neck which challenges researchers and clinicians alike.

PURPOSE

To investigate how text neck is defined in peer-reviewed articles.

METHODS

We conducted a scoping review to identify all articles using the terms "text neck" or "tech neck." Embase, Medline, CINAHL, PubMed and Web of Science were searched from inception to 30 April 2022. We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMAScR) guidelines. No limitation was applied for language or study design. Data extraction included study characteristics and the primary outcome relating to text neck definitions.

RESULTS

Forty-one articles were included. Text neck definitions varied across studies. The most frequent components of definitions were grouped into five basis for definition: Posture (n = 38; 92.7%), with qualifying adjectives meaning incorrect posture (n = 23; 56.1%) and posture without a qualifying adjective (n = 15; 36.6%); Overuse (n = 26; 63.4%); Mechanical stress or tensions (n = 17; 41.4%); Musculoskeletal symptoms (n = 15; 36.6%) and; Tissue damage (n = 7; 17.1%).

CONCLUSION

This study showed that posture is the defining characteristic of text neck in the academic literature. For research purposes, it seems that text neck is a habit of texting on the smartphone in a flexed neck position. Since there is no scientific evidence linking text neck with neck pain regardless of the definition used, adjectives like inappropriate or incorrect should be avoided when intended to qualify posture.

Manual Therapy Effects on Nonspecific Neck Pain Are Not Mediated by Mechanisms Related to Conditioned Pain Modulation: A Randomized Clinical Trial

BACKGROUND

Manual therapy (MT) is a treatment recommended by clinical practice guidelines in the management of patients with neck pain. However, the mechanisms through which MT works remain unknown. The aim of the present study is to investigate if MT is mediated by mechanisms related to conditioned pain modulation (CPM), comparing the effects of painful with a pain-free MT treatment.

METHODS

A two-arm, parallel, randomized controlled clinical trial with concealed allocation and blinding of the outcome assessor was conducted in university students with chronic or recurrent nonspecific neck pain (NSNP). Participants received either a painful or pain-free MT session. Psychophysical variables including pressure pain thresholds, CPM, temporal summation of pain and cold pain intensity were assessed before and immediately after treatment. In addition, changes in neck pain intensity over the following 7 days and self-perceived improvement immediately and 7 days after treatment were assessed.

RESULTS

No significant differences were found between groups in any of the psychophysical variables or in patients' self-perceived improvement. Only a significantly greater decrease in neck pain intensity immediately after treatment was found in the pain-free MT group compared to the painful MT group.

CONCLUSION

The results suggest that the immediate and short-term effects of MT on NSNP are not mediated by CPM-related mechanisms.

Imaging of muscle and adipose tissue in the spine: A narrative review

Interpretation of the morphology and characteristics of soft tissues, such as paravertebral muscles and fat, has always been a "relative blind spot" in the spine. The imaging features of the non-bony structures of the spine have been studied and reinterpreted, and changes in the non-bony structure are associated with spinal disease. Soft tissue parameters such as, the "paraspinal muscle cross-sectional area," "subcutaneous fat thickness," and the "paraspinal muscle fat infiltration rate" on computed tomography, magnetic resonance imaging and other imaging techniques are reproducible in the diagnosis, treatment and prognosis of spinal disorders and have the potential for clinical application. In addition, focus on the association between sarcopenia and spinal epidural lipomatosis with spinal disorders is increasing. Currently, there is no summary of studies on fat and muscle in the spinal region. Given this, within the context of recent research trends, this article provides a synthesis of research on adipose and muscle tissue in the spine, discusses advances in the study of the imaging manifestations of these structures in spinal disorders, and expands the perspectives.

Gender Differences in Cervical Spine Motions and Loads With Head Supported Mass Using Finite Element Models

While many studies have been conducted to delineate the role of gender in rear impact via experiments, clinical investigations, modeling, and epidemiological research, the effect of the added head mass on segmental motions has received less attention. The objective of the study is to determine the role of the head supported mass on the segmental motions and loads on the cervical spinal column from rear impact loading. The study used finite element modeling. The model was subjected to mesh convergence studies. It was validated with human cadaver experimental data by applying the rear impact acceleration pulse to the base of the spine. At all levels of the subaxial spinal column, a comparison was made between male and female spines and with and without the use of an army combat helmet. For this purpose, segmental motions, forces, and bending moments were used as biomechanical parameters. Results showed that female spines responded with increased motions than males, and the presence of a helmet increased motions and loads in males and female spines at all levels. Numerical data are given. Head supported mass affects spine responses at all levels. The present computational modeling study, from one geometry for the male spine and one geometry for the female spine (limitations are addressed in the paper), provided insights into the mechanisms of the internal load transfer with the presence of head supported mass, prevalent in certain civilian occupations and active-duty Service members in the military.

Morphology and composition of the ventral neck muscles in individuals with chronic whiplash related disorders compared to matched healthy controls: a cross-sectional case-control study

BACKGROUND

OBJECTIVE: Studies of cross-sectional area (CSA) (morphology) and muscle fat infiltration (MFI) (composition) in ventral neck muscles is scarce in patients with chronic whiplash associated disorders (WAD), especially for men and those with severe WAD compared with matched healthy controls. The aim was to compare CSA and MFI of sternocleidomastoid (SCM), longus capitis (LCA) and longus colli (LCO) in patients with chronic right-sided dominant moderate (Neck Disability Index: NDI < 40) or severe WAD (NDI ≥ 40), compared to age- and sex-matched healthy controls.

METHODS

Cross-sectional case-control study with blinded investigators. Thirty-one patients with chronic WAD (17 women and 14 men, mean age 40 years) (SD 12.6, range 20-62)) and 31 age- and sex-matched healthy controls underwent magnetic resonance imaging of ventral neck muscles segmental level C4.

RESULTS

Unique to the severe group was a larger magnitude of MFI in right SCM (p = 0.02) compared with healthy controls. There was no significant difference between the groups with regards to the other muscles and measures.

CONCLUSIONS

Individuals with severe right-sided dominant WAD have a higher MFI in the right SCM compared to healthy controls. No other differences were found between the groups. The present study indicates that there are changes in the composition of muscles on the side of greatest pain.

Microscopic changes in the spinal extensor musculature in people with chronic spinal pain: a systematic review

BACKGROUND CONTEXT

Chronic spinal pain is one the most common musculoskeletal disorders. Previous studies have observed microscopic structural changes in the spinal extensor muscles in people with chronic spinal pain. This systematic review synthesizes and analyzes all the existing evidence of muscle microscopic changes in people with chronic spinal pain.

PURPOSE

To assess the microscopy of spinal extensor muscles including the fiber type composition, the area occupied by fiber types, fiber size/cross sectional area (CSA), and narrow diameter (ND) in people with and without chronic spinal pain. Further, to compare these outcome measures across different regions of the spine in people with chronic neck, thoracic and low back pain.

STUDY DESIGN

Systematic review with meta-analysis.

METHODS

MEDLINE (Ovid Interface), Embase, PubMed, CINAHL Plus, and Web of Science were searched from inception to October 2020. Key journals, conference proceedings, grey literature and hand searching of reference lists from eligible studies were also searched. Two independent reviewers were involved in the selection process. Only studies examining the muscle microscopy of the spinal extensor muscles (erector spinae [ES] and/or multifidus [MF]) between people with and without chronic spinal pain were selected. The risk of bias from the studies was assessed using modified Newcastle Ottawa Scale and the level of evidence was established using the GRADE approach. Data were synthesized based on homogeneity on the methodology and outcome measures of the studies for ES and MF muscles and only four studies were eligible for analysis.

RESULTS

All the five studies included were related to chronic low back pain (CLBP). Meta-analysis (inverse variance method for random effect to calculate mean difference and 95% CI) was performed for the ES fiber type composition by numbers for both type I and type II fibers (I²=43% and 0% respectively indicating homogeneity of studies) and showed no difference between the people with and without CLBP with an overall effect estimate Z= 1.49 (p=.14) and Z=1.06 (p=.29) respectively. Meta-analysis was performed for ES fiber CSA for both type I and type II fibers (I²=0 for both) and showed no difference between people with and without CLBP with an overall effect estimate Z=0.08 (p=.43) and Z=0.75 (p=.45) respectively. Analysis was not performed for ES area occupied by fiber types and ND due to heterogeneity of studies and lack of evidence respectively. Similarly, meta-analysis was not performed for MF fiber type composition by numbers due to heterogeneity of studies. MF analysis for area occupied by fiber type, fiber CSA and ND did not yield sufficient evidence.

CONCLUSIONS

For the ES muscle, there was no difference in fiber type composition and fiber CSA between people with and without CLBP and no conclusions could be drawn for ND for the ES. For the MF, no conclusions could be drawn for any of the muscle microscopy outcome measures. Overall, the quality of evidence is very low and there is very low evidence that there are no differences in microscopic muscle features between people with and without CLBP.

Associations between resting heart rate, resting blood pressure, psychological variables and pain processing in chronic whiplash-associated disorder: a cross-sectional study

Objective

Autonomic nervous system dysfunction has been implicated in chronic whiplash-associated disorder (WAD). However, the relationship between autonomic variables (e.g., resting heart rate and blood pressure) and clinical factors in chronic WAD is not well understood. This study sought to examine the associations between resting heart rate, resting blood pressure, pain processing and psychological variables in chronic WAD and in pain-free controls.

Design

Secondary analysis of a cross-sectional study.

Setting

University clinical research laboratory.

Subjects

Thirty-six people with chronic WAD Grade II (mean [SD] age 40.1 [14.6] years, 28 females) and 25 pain-free controls (35.6 [13.0] years, 17 females).

Methods

Participants had resting heart rate, systolic and diastolic blood pressure measured. Pain processing measures comprised: (i) pain pressure threshold at the cervical spine, hand and leg, (ii) temporal summation at the cervical spine and hand, and (iii) conditioned pain modulation. Psychological outcomes included measures of kinesiophobia, pain catastrophizing and post-traumatic stress symptoms. Correlations between autonomic variables, pain processing and psychological variables were determined (P < .05, 5% FDR).

Results

No significant correlations between autonomic and pain processing variables, or autonomic and psychological variables were found in the chronic WAD group. In the control group, diastolic blood pressure was positively correlated with cervical spine pressure pain threshold (r = 0.53, P = .007).

Conclusions

An association between blood pressure and pain sensitivity was observed in the control group but not the chronic WAD group. Such an association appears to be disrupted in chronic WAD, which may infer involvement of autonomic pathways in the pathophysiology of this condition.

Effectiveness of Specific Neck Exercise for Nonspecific Neck Pain; Usefulness of Strategies for Patient Selection and Tailored Exercise-A Systematic Review With Meta-Analysis

OBJECTIVE

Specific neck exercises (SNE) targeting deep cervical flexors and extensors are commonly used for the treatment of nonspecific neck pain (NSNP). However, whether SNE are more effective than alternative exercise interventions (AEI) remains unclear. Furthermore, it has been postulated that SNE may be most effective when they are tailored and targeted to patients with evidence of motor control dysfunction, yet this notion also remains unproven. The objectives of this study were to compare the effectiveness of SNE with that of AEI for reducing pain and disability in people with NSNP and to assess whether the effectiveness of SNE is increased when the exercises are tailored and provided to patients with evidence of motor control dysfunction.

METHODS

For this systematic review with meta-analysis, Medline, Web of Science, Scopus, and Physiotherapy Evidence Database were searched. Eligibility criteria included randomized controlled trials evaluating the effectiveness of SNE against that of AEI in people with NSNP. Meta-analysis included subgroup analyses to determine the effect of exercise tailoring and participant selection criteria on the effectiveness of SNE.

RESULTS

Twelve studies were included. Meta-analysis revealed greater effectiveness of SNE in the short to medium term for reducing pain (pooled standardized mean difference [SMD] = -0.41; 95% CI = -0.76 to -0.06; P = .02) and disability (pooled SMD = -0.41; 95% CI = -0.78 to -0.04; P = .03) but no differences in the long term for pain (pooled SMD = -1.30; 95% CI = -3.35 to 0.75; P = .21) and disability (pooled SMD = -1.81; 95% CI = -4.29 to 0.67; P = .15), although evidence was limited for the latter. The effectiveness of SNE was not superior in studies that included only participants with motor control dysfunction or when exercises were tailored to each participant. Overall, the studies were of low quality. Grading of Recommendations Assessment, Development and Evaluation revealed low certainty, serious risk of bias, and inconsistency of findings for short- to medium-term effects and very low certainty, serious risk of bias, and very serious inconsistency for long-term effects.

CONCLUSION

The preferential use of SNE may be recommended to achieve better short- to medium-term outcomes, although the low quality of evidence affects the certainty of these findings. Currently used strategies for selecting patients and tailoring SNE are not supported by the evidence and therefore cannot be recommended for clinical practice.

IMPACT

SNE are more effective than AEI for reducing pain and disability in patients with NSNP in the short to medium term, but overall evidence is of low quality, affecting the certainty of the findings. Tests of muscle dysfunction (mostly the craniocervical flexion test) currently used in studies to select patients and tailor SNE do not result in greater effectiveness of these exercises.

LAY SUMMARY

Evidence suggests SNE are more effective than other forms of exercise, although evidence is overall of low quality. Use of the craniocervical flexion test in isolation to select participants and/or tailor SNE cannot be recommended.

Advanced magnetic resonance imaging of chronic whiplash patients: a clinical practice-based feasibility study

BACKGROUND

Whiplash injury is common following road traffic crashes affecting millions worldwide, with up to 50% of the injured developing chronic symptoms and 15% having a reduced working capability due to ongoing disability. Many of these patients receive treatment in primary care settings based upon clinical and diagnostic imaging findings. Despite the identification of different types of injuries in the whiplash patients, clinically significant relationships between injuries and chronic symptoms remains to be fully established. This study investigated the feasibility of magnetic resonance imaging (MRI) techniques including quantitative diffusion weighted imaging and measurements of cerebrospinal fluid (CSF) flow as novel non-invasive biomarkers in a population of healthy volunteers and chronic whiplash patients recruited from a chiropractic clinic for the purpose of improving our understanding of whiplash injury.

METHODS

Twenty chronic whiplash patients and 18 healthy age- and gender matched control subjects were included [mean age ± SD (sex ratio; females/males), case group: 37.8 years ± 9.1 (1.22), control group: 35.1 years ± 9.2 (1.25)]. Data was collected from May 2019 to July 2020. Data from questionnaires pertaining to the car crash, acute and current symptoms were retrieved and findings from clinical examination and MRI including morphologic, diffusion weighted and phase-contrast images were recorded. The apparent diffusion coefficient and fractional anisotropy were calculated, and measurement and analysis of CSF flow was conducted. Statistical analyses included Fisher's exact test, Mann Whitney U test and analysis of variance between groups.

RESULTS

The studied population was described in detail using readily available clinical tools. No statistically significant differences were found between the groups on MRI.

CONCLUSIONS

This study did not show that MRI-based measures of morphology, spinal cord and nerve root diffusion or cerebrospinal fluid flow are sensitive biomarkers to distinguish between chronic whiplash patients and healthy controls. The detailed description of the chronic whiplash patients using readily available clinical tools may be of great relevance to the clinician. In the context of feasibility, clinical practice-based advanced imaging studies with a technical setup similar to the presented can be expected to have a high likelihood of successful completion.

Genetic basis to structural grey matter associations with chronic pain

Structural neuroimaging studies of individuals with chronic pain conditions have often observed decreased regional grey matter at a phenotypic level. However, it is not known if this association can be attributed to genetic factors. Here we employed a novel integrative data-driven and hypothesis-testing approach to determine whether there is a genetic basis to grey matter morphology differences in chronic pain. Using publicly available genome-wide association study summary statistics for regional chronic pain conditions (n = 196 963) and structural neuroimaging measures (n = 19 629-34 000), we applied bivariate linkage disequilibrium-score regression and latent causal variable analyses to determine the genetic correlations (rG) and genetic causal proportion (GCP) between these complex traits, respectively. Five a priori brain regions (i.e. prefrontal cortex, cingulate cortex, insula, thalamus and superior temporal gyrus) were selected based on systematic reviews of grey matter morphology studies in chronic pain. Across this evidence-based selection of five brain regions, 10 significant negative genetic correlations (out of 369) were found (false discovery rate < 5%), suggesting a shared genetic basis to both reduced regional grey matter morphology and the presence of chronic pain. Specifically, negative genetic correlations were observed between reduced insula grey matter morphology and chronic pain in the abdomen (mean insula cortical thickness), hips (left insula volume) and neck/shoulders (left and right insula volume). Similarly, a shared genetic basis was found for reduced posterior cingulate cortex volume in chronic pain of the hip (left and right posterior cingulate), neck/shoulder (left posterior cingulate) and chronic pain at any site (left posterior cingulate); and for reduced pars triangularis volume in chronic neck/shoulder (left pars triangularis) and widespread pain (right pars triangularis). Across these negative genetic correlations, a significant genetic causal proportion was only found between mean insula thickness and chronic abdominal pain [rG (standard error, SE) = -0.25 (0.08), P = 1.06 × 10-3; GCP (SE) = -0.69 (0.20), P = 4.96 × 10-4]. This finding suggests that the genes underlying reduced cortical thickness of the insula causally contribute to an increased risk of chronic abdominal pain. Altogether, these results provide independent corroborating evidence for observational reports of decreased grey matter of particular brain regions in chronic pain. Further, we show for the first time that this association is mediated (in part) by genetic factors. These novel findings warrant further investigation into the neurogenetic pathways that underlie the development and prolongation of chronic pain conditions.

Association between muscle morphology changes, cervical spine degeneration and clinical features in patients with chronic nonspecific neck pain: a magnetic resonance imaging analysis

PURPOSE

The primary objective of the present study was to investigate the correlations among cervical paraspinal muscle morphology changes (fatty infiltration (FI) and muscle atrophy), cervical degeneration and clinical features in patients with chronic nonspecific neck pain (CNSNP).

METHODS

The magnetic resonance imaging (MRI) data of 55 consecutive patients (average age 35.80) with CNSNP were analyzed in this cross-sectional study. Muscle morphology changes in seven groups of paraspinal muscles, indicated by the adjusted cross-sectional area (aCSA) and FI ratio (FI%), were measured from C3/4 to C6/7. The correlations of these changes with disc degeneration, cervical balance (C2-7 angle and cervical alignment) and clinical features (severity of neck pain and related disability and the frequency of acute neck pain (ANP) recurrence) were evaluated.

RESULTS

Significant correlations between FI% and aCSA and the grade of disc degeneration were observed in specific muscle groups at each level (p<0.05). Morphological changes in the deep extensors and superficial paraspinal muscles were significantly associated with cervical balance parameters (p<0.05). The FI% showed a significant positive correlation, while aCSA showed a significant negative correlation with the severity of neck pain and related disability (p<0.05). Correlations between morphological changes and the frequency of ANP recurrence were also present for some muscles (p<0.05).

CONCLUSION

Correlations among muscle morphology changes, cervical degeneration and clinical features were established for patients with CNSNP, and muscle volume changes and FI might affect CNSNP in diverse manners through different paraspinal muscle groups. These results implicated the complex contribution of muscle morphological changes to cervical degeneration and the clinical course of CNSNP.

Exercise Effects on Neck Function Among F-15E Aircrew

BACKGROUND: Neck pain (NP) is common among high performance aircrew, yet evidence remains insufficient to guide examination, treatment, and prevention. The purpose of this randomized pilot study was to collect baseline data for neck function for F-15E aircrew and determine efficacy and feasibility of two separate exercise protocols in measuring short-term outcomes of subjective and objective neck function in order to inform future study design. METHODS: Randomized to either progressive (PRO) or general (GEN) exercise groups were 41 F-15E aircrew. Data collection occurred at baseline, 3 wk, and 3 mo. RESULTS: At baseline, 39% of the subjects reported current NP, 79.5% reported a history of NP attributed to flying, 12.8% reported being removed from flying duties due to NP, and 10% reported receiving medical care for NP. PRO and GEN group randomization showed similar baseline assessment data. Blinding was successful and exercise logs showed 31.6% compliance with prescribed exercise regimens. There were small but statistically significant increases in neck range of motion in both groups over the course of the study. Aircrew with current NP had significantly higher F-15E flight hours. DISCUSSION: This study supports the high prevalence of NP in aircrew, yet low frequency of seeking care for NP. Future studies to assess NP prevention and treatment in aircrew require an integrated approach that includes operational exercise policy and long-term data collection in flying units with dedicated resources for assessment and analysis. Lee MS, Briggs R, Scheirer V, Kearby G, Young BA. Exercise effects on neck function among F-15E aircrew. Aerosp Med Hum Perform. 2021; 92(10):815824.

Illusion-enhanced Virtual Reality Exercise for Neck Pain: A Replicated Single Case Series

OBJECTIVES

Body illusions have shown promise in treating some chronic pain conditions. We hypothesized that neck exercises performed in virtual reality (VR) with visual feedback of rotation amplified would reduce persistent neck pain.

METHODS

In a multiple-baseline replicated single case series, 8 blinded individuals with persistent neck pain completed a 4-phase intervention (initial n=12, 4 dropouts): (1) "baseline"; (2) "VR" during which participants performed rotation exercises in VR with no manipulation of visual feedback; (3) "VR enhanced" during which identical exercises were performed but visual feedback overstated the range of motion being performed; (4) "follow-up." Primary outcomes were twice-daily measures of pain-free range of motion and pain intensity. During the baseline and follow-up phases, measures were taken but no intervention took place.

RESULTS

No differences in primary outcomes were found between VR and baseline, VR enhanced and VR, or VR enhanced and follow-up.

DISCUSSION

Our hypothesis, that neck exercises performed in VR with visual feedback of rotation amplified, would reduce persistent neck pain was not supported. Possible explanations and future directions are discussed.

Changes in Muscle Morphology in Female Chronic Neck Pain Patients Using Magnetic Resonance Imaging

STUDY DESIGN

Population-based cross-sectional study.

OBJECTIVE

The aim of this study was to gain a better understanding of changes in muscle morphology in patients with chronic idiopathic neck pain (CINP) and chronic whiplash-associated disorder (CWAD).

SUMMARY OF BACKGROUND DATA

Worldwide, neck pain (NP) is a common health problem with high socioeconomic burden. A high percentage of these patients evolves toward chronic symptoms. Efficacy of treatments for these complaints remains variable. In current literature, changes in muscle morphology (muscle fat infiltration and cross-sectional area) have been reported in patients with NP, both CWAD and CINP. However, no strong conclusions could be made.

METHODS

In this study, magnetic resonance imaging was used to obtain data on muscle morphology from 14 cervical flexor and extensor muscles in 117 female subjects with NP (CWAD = 37; CINP = 45) and healthy controls (HC = 35).

RESULTS

The CWAD group had a significantly larger muscle fat infiltration in some extensor (semispinalis and splenius capitis, trapezius, obliquus capitis inferior) and flexor (sternocleidomastoid) muscles compared to the CINP and/or HC group. A significantly larger (muscle) cross-sectional area was found in some extensor (levator scapulae, semispinalis capitis, trapezius) and flexor (longus colli, longus capitis, sternocleidomastoid) muscles in the HC group compared to the CINP and/or CWAD group. No clear associations were found between group differences and factors as pain duration, kinesiophobia, and disability.

CONCLUSION

The results in this study suggest changes in muscle morphology in both NP cohorts. These results show some similarities with earlier findings in this research domain. Further studies based on controlled longitudinal designs are needed to facilitate data compilation, to draw stronger conclusions, and to integrate them into the treatment of patients with chronic NP.Level of Evidence: 4.

Enhanced Pronociceptive and Disrupted Antinociceptive Mechanisms in Nonspecific Chronic Neck Pain

OBJECTIVE

Evidence suggests altered pronociceptive and antinociceptive mechanisms in many chronic pain conditions. Knowledge about these mechanisms in nonspecific chronic neck pain (NSNP) would improve understanding of the causes and the design of more effective treatments. Pressure pain threshold (PPT) is often used to assess presence of altered nociceptive processing in NSNP; however, its usefulness to detect this is yet to be established. The purpose of this study was to determine the functional status of temporal summation of second pain (TSSP) and conditioned pain modulation (CPM) in NSNP and to characterize the association of both measures with PPT and clinical features of NSNP.

METHODS

Thirty-two participants with NSNP (mean [SD] age = 44 [11] years; 27 female) and 32 age- and sex-matched healthy controls were recruited. TSSP was assessed using an electrical stimulus at the dorsum of the hand, and CPM was evaluated with the Cold Pressor Test. PPT was assessed bilaterally at the neck and tibialis anterior muscles.

RESULTS

Participants with NSNP showed greater TSPP (mean difference = 0.23; 95% CI = 0.46-0.01; Cohen d = 0.51) and lower CPM (mean difference = 19.44; 95% CI = 10.42-28.46; Cohen d = 1.09). Pooled data from all participants showed lower PPTs at the neck than the tibialis anterior. However, PPT measures did not differ between groups at either location. PPT measures were not correlated with CPM and TSP.

CONCLUSION

NSNP is associated with enhanced pronociceptive and impaired antinociceptive mechanisms, which may explain long-lasting pain and failure of some treatments to resolve symptoms. However, due to the observational nature of this study, a clear cause-effect relationship cannot be established. Normal PPT values in the clinic should not be interpreted as absence of altered nociceptive processing.

IMPACT

This study fills in some gaps in knowledge. Changes in central nociceptive processing may explain persistent and recurrent symptoms in NSNP and failure of treatments to obtain long-lasting relief. Further research is required to ascertain if TSSP and CPM assessment in the clinic may help predict physical therapy treatment outcome. Whether symptomatic relief with physical therapy is mediated by an improvement in TSSP and CPM should also be explored. PPTs were unaltered in participants with NSNP despite evidence of impairment in the central pain modulatory systems. Normal PPTs should not be interpreted as evidence of unaltered central pain-related processing.

Microscopic changes in the spinal extensor musculature in patients experiencing chronic spinal pain: protocol for a systematic review

INTRODUCTION

Chronic spinal pain (CSP) is the most common musculoskeletal disorder and is a leading cause of disability as per the Global Burden of Diseases. Previous reviews of microscopic changes in the spinal extensor muscles of people with CSP have focused on the lumbar region only and the results have been inconclusive. Therefore, in this protocol, we aim to assess microscopic changes in the extensor muscles of all spinal regions, investigating regionally specific changes in muscle fibre types of the spinal extensor muscles in patients with non-specific CSP.

METHODS/ANALYSIS

This protocol was designed using Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines. Searches will use the following databases: MEDLINE, Embase, PubMed, CINAHL Plus and Web of Science along with relevant grey literature searches. Two reviewers will conduct the searches, perform data extraction, apply inclusion criteria and conduct risk of bias assessment using Newcastle-Ottawa Scale. Data will be synthesised and analysed independently. If there is sufficient homogeneity, then meta-analysis will be conducted by the reviewers jointly. If not, meta-synthesis or narrative reporting will be performed. The quality of the evidence will be assessed using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) guidelines.

ETHICS AND DISSEMINATION

The results of this study will be submitted for publication to a peer-reviewed journal and will be presented at conferences. Ethical approval for this systematic review was not required due to no patient data being collated.

PROSPERO REGISTRATION NUMBER

CRD42020198087.

Fluoroscopic Findings of Extra-Cervical Facet Joint Flow and Its Incidence on Cervical Facet Joint Arthrograms

Cervical facet joint (CFJ) syndrome is a common cause of neck pain. For its diagnosis and treatment, CFJ injection with arthrogram is generally performed. This study aimed to investigate the frequency of extra-CFJ flow on CFJ arthrograms during injections and its differences according to age, sex, and cervical vertebral level. We analyzed 760 CFJ arthrograms administrated to 208 patients diagnosed with CFJ syndrome. Arthrograms at each vertebral level were collected to evaluate the normal CFJ and extra-CFJ flow. The primary and secondary outcomes were frequency of extra-CFJ flow according to cervical vertebral level, age, and sex and according to pairwise cervical levels, respectively. Extra-CFJ flow at the cervical spine occurred during 179 injections, and the overall incidence was 3.3–36.2% at different cervical levels. The incidence of extra-CFJ flow at each cervical vertebral level according to age and sex was not significant. Extra-CFJ flow was the highest at C6 and C7, but there was no statistical significance. Extra-CFJ flow was higher at lower vertebral levels (C5–C7) than at upper levels (C3 and C4). Additional clinical studies and anatomical evaluations are needed to support its clinical value and enable the development of new injection techniques.

Spinal cord injury is not a feature of chronic whiplash-associated disorder: a magnetic resonance spectroscopy study

PURPOSE

Injury to the cervical spinal cord has been suggested as a mechanism that may underpin chronic whiplash-associated disorder (WAD). This study aimed to assess metabolite concentrations indicative of neuronal injury or pathology in the cervical cord in people with chronic WAD.

METHODS

Forty-one people with chronic WAD (mean [SD] age 39.6 [11.0] years, 25 females) and 14 healthy controls (39.2 [12.6] years, 9 females) underwent cervical spinal cord magnetic resonance spectroscopy to measure the metabolites N-acetylaspartate (NAA), creatine (Cr) and choline (Cho). Participants with WAD completed clinical questionnaires on pain intensity (Visual Analogue Scale), disability (Neck Disability Index) and psychological factors (Pain Catastrophising Scale, Post-traumatic Diagnostic Scale), and underwent cervical range of motion assessment and pain threshold testing to cold and pressure stimuli. Data were analysed using hypothesis testing and Spearman correlations (p < 0.05).

RESULTS

There were no differences between the WAD and control groups for NAA/Cr (median [IQR] WAD 1.73 [1.38, 1.97], controls 2.09 [1.28, 2.89], p = 0.37), NAA/Cho (WAD 1.50 [1.18, 2.01], controls 1.57 [1.26, 1.93], p = 0.91) or Cr/Cho (WAD 0.84 [0.64, 1.17], controls 0.76 [0.60, 0.91], p = 0.33). There were no significant correlations between NAA/Cr, NAA/Cho or Cr/Cho and any clinical variable (p ≥ 0.06).

CONCLUSIONS

Findings are consistent with major metabolic changes not being present in chronic WAD.

Small fibre pathology in chronic whiplash-associated disorder: A cross-sectional study

BACKGROUND

Mechanisms underpinning ongoing symptoms in chronic whiplash associated-disorder (WAD) are not well understood. People with chronic WAD can exhibit sensory dysfunction consistent with small nerve fibre pathology, including thermal hypoaesthesia and hyperalgesia. This study investigated small fibre structure and function in chronic WAD.

METHODS

Twenty-four people with chronic WAD (median [IQR] age 49 [15] years, 16 females) and 24 pain-free controls (50 [17] years, 16 females) were recruited. Intraepidermal nerve fibre density (IENFD) and dermal innervation were assessed by skin biopsy. This was performed at (a) the lateral index finger on the primary side of pain and (b) superior to the lateral malleolus on the contralateral side. Quantitative sensory testing was performed over the hand.

RESULTS

The WAD group exhibited lower IENFD at the finger (WAD: median [IQR] 4.5 [4.9] fibres/mm; control 7.3 [3.9]; p = .010), but not the ankle (WAD: mean [SD] 7.3 [3.7] fibres/mm; control 9.3 [3.8]; p = .09). Dermal innervation was lower in the WAD group at the finger (WAD: median [IQR] 3.7 [2.8] nerve bundles/mm² ; controls: 4.9 [2.1]; p = .017) but not the ankle (WAD: median [IQR] 2.1 [1.9] nerve bundles/mm² ; controls: 1.8 [1.8]; p = .70). In the WAD group, hand thermal and light touch detection were impaired, and heat pain thresholds were lowered (p ≤ .037).

CONCLUSIONS

Findings suggest small fibre structural and functional deficits in chronic WAD, implicating potential involvement of small fibre pathology.

SIGNIFICANCE

Our study found decreased intraepidermal nerve fibre density, reduced dermal innervation, thermal hypoaesthesia and hypersensitivity in people with chronic WAD, suggestive of small fibre pathology. This observation of peripheral nervous system pathology in chronic whiplash provides novel insights on mechanisms underpinning symptoms and challenges commonly held beliefs regarding this condition.

Age- and gender-related variations of cervical muscle composition using chemical shift encoding-based water-fat MRI

PURPOSE

To understand fat distribution patterns and ectopic fat deposition in healthy adults and to provide normative data, encompassing the borders of physiological regional muscle composition. For this purpose chemical shift encoding-based water-fat Magnetic Resonance Imaging (MRI) was used for proton density fat fraction (PDFF) calculations.

MATERIAL AND METHODS

91 volunteers were enrolled (male: n = 28, age = 36.6 ± 11.4 years; female: n = 63, age = 38.5 ± 15.1 years). PDFF values combined for the multifidus, semispinalis and spinalis cervicis muscles at the level of the 3rd cervical vertebral body (C3), the 5th cervical vertebral body (C5) and the first thoracic vertebral body (Th1) were extracted.

RESULTS

The paraspinal musculature at C3 (14.8 ± 10.1 % vs. 19.2 ± 11.0 %; p = 0.029) and Th1 (13.8 ± 7.0 % vs 17.7 ± 7.4 %; p = 0.011) showed significantly lower PDFF values in men compared to women. Partial correlation testing with BMI as control variable revealed highly significant correlations between the paraspinal musculature PDFF at C3 (men: r = 0.504, p = 0.007; women: r = 0.279, p = 0.028), C5 (men: r = 0.450, p = 0.019; women: r = 0.347, p = 0.006) and Th1 (men: r = 0.652, p < 0.0001; women: r = 0.443, p < 0.0001) with age in both genders.

CONCLUSION

The present data suggest gender and age-specific fat deposition patterns of the cervical and the upper cervicothoracic paraspinal muscles and may provide reference values for pathology detection.

Concussion in Combination With Whiplash-Associated Disorder May Be Missed in Primary Care: Key Recommendations for Assessment and Management

Whiplash and concussion may have similar presenting symptoms, biomechanical mechanisms, and neurophysiological sequelae, but neither enjoys a gold standard diagnostic test. Guidelines for whiplash and concussion are developed and implemented separately. This disparate process may contribute to misdiagnosis, delay appropriate primary care management, and impair patient outcomes. In our clinical commentary, we present 3 cases where signs and symptoms consistent with whiplash were identified in primary care. Symptoms in all cases included neck pain, headache, dizziness, and concentration deficits, raising suspicion of coexisting postconcussion syndrome. All cases were referred for specialist physical therapy. Characteristics consistent with poor recovery in both whiplash and postconcussion syndrome were confirmed, and multidisciplinary management, drawing from both whiplash and concussion guidelines, was implemented. All patients reported improvement in activities of daily living after tailored management addressing both neck and head injury-related factors, suggesting that these conditions were not mutually exclusive. Self-reported outcomes included reductions in neck disability and postconcussion symptoms of between 20% and 40%. It may be appropriate for whiplash and concussion guidelines to be amalgamated, enhanced, and mutually recognized on a patient-by-patient basis. Primary health care professionals might consider minimum screening to identify postconcussion syndrome in patients following motor vehicle collision by administering questionnaires and assessing cranial nerve function, balance, and cognition. Management should then incorporate principles from both whiplash and concussion guidelines and harmonize with available imaging guidelines for suspected spine and head trauma. J Orthop Sports Phys Ther 2019;49(11):819-828. doi:10.2519/jospt.2019.8946.

Does Overall Cervical Spine Pathology Relate to the Clinical Heterogeneity of Chronic Whiplash?

BACKGROUND AND PURPOSE

There remains limited evidence for the clinical importance of most imaging findings in whiplash. However, it is possible the type and number of findings on Computed Tomography (CT) may contribute to prognostic recovery models. The purpose is to interpret cervical spine pathologies in the context of known factors influencing recovery.

MATERIALS AND METHODS

This is a secondary analysis from a database of 97 acutely injured participants enrolled in a prospective inception cohort study. Thirty-eight participants underwent standard of care cervical spine CT in the emergency medicine department. All 38 participants were assessed at <1-week, 2-weeks, and 3-months post-injury and classified using percentage scores on the Neck Disability Index (recovered/mild (NDI of 0-28%) or moderate/severe (NDI ≥ 30%)). Between-group comparison of categorical variables (gender (male/female), presence of at least one CT finding (yes/no), and presence of ≥3 pathologies on CT (yes/no)) was conducted using 2-tailed Fisher's exact test.

RESULTS

Participants from both groups demonstrated at least one observable pathology. The group with persistent moderate/severe symptoms presented with significantly more pathology at baseline than those who later reported recovery or milder symptoms at 3-months post injury (p = 0.02).

CONCLUSIONS

This preliminary study, which needs replication in a larger cohort, provides foundation that the number of degenerative pathologies seen on initial post MVC CT may be associated with the subsequent clinical course of whiplash.