Chronic whiplash pain

Chronic neuropathic pain components in whiplash-associated disorders correlate with metabolite concentrations in the anterior cingulate and dorsolateral prefrontal cortex: a consensus-driven MRS re-examination

Introduction

Whiplash injury (WHI) is characterised by a forced neck flexion/extension, which frequently occurs after motor vehicle collisions. Previous studies characterising differences in brain metabolite concentrations and correlations with neuropathic pain (NP) components with chronic whiplash-associated disorders (WAD) have been demonstrated in affective pain-processing areas such as the anterior cingulate cortex (ACC). However, the detection of a difference in metabolite concentrations within these cortical areas with chronic WAD pain has been elusive. In this study, single-voxel magnetic resonance spectroscopy (MRS), following the latest MRSinMRS consensus group guidelines, was performed in the anterior cingulate cortex (ACC), left dorsolateral prefrontal cortex (DLPFC), and occipital cortex (OCC) to quantify differences in metabolite concentrations in individuals with chronic WAD with or without neuropathic pain (NP) components.

Materials and methods

Healthy individuals (n = 29) and participants with chronic WAD (n = 29) were screened with the Douleur Neuropathique 4 Questionnaire (DN4) and divided into groups without (WAD-noNP, n = 15) or with NP components (WAD-NP, n = 14). Metabolites were quantified with LCModel following a single session in a 3 T MRI scanner within the ACC, DLPFC, and OCC.

Results

Participants with WAD-NP presented moderate pain intensity and interference compared with the WAD-noNP group. Single-voxel MRS analysis demonstrated a higher glutamate concentration in the ACC and lower total choline (tCho) in the DLPFC in the WAD-NP versus WAD-noNP group, with no intergroup metabolite difference detected in the OCC. Best fit and stepwise multiple regression revealed that the normalised ACC glutamate/total creatine (tCr) (p = 0.01), DLPFC n-acetyl-aspartate (NAA)/tCr (p = 0.001), and DLPFC tCho/tCr levels (p = 0.02) predicted NP components in the WAD-NP group (ACC r 2 = 0.26, α = 0.81; DLPFC r 2 = 0.62, α = 0.98). The normalised Glu/tCr concentration was higher in the healthy than the WAD-noNP group within the ACC (p < 0.05), but not in the DLPFC or OCC. Neither sex nor age affected key normalised metabolite concentrations related to WAD-NP components when compared to the WAD-noNP group.

Discussion

This study demonstrates that elevated glutamate concentrations within the ACC are related to chronic WAD-NP components, while higher NAA and lower tCho metabolite levels suggest a role for increased neuronal-glial signalling and cell membrane dysfunction in individuals with chronic WAD-NP components.

Sleep architecture and the absence of trapezius muscle atonia in women with chronic whiplash-associated disorder: a pilot study

Sleep disturbances frequently occur in people with whiplash-associated disorder (WAD) and have been evaluated using questionnaires or actigraphy. It is not clear whether sleep architecture, as assessed by polysomnography (PSG), is altered in individuals with WAD. Additionally, in people with WAD, muscle dysfunction is observed during tasks performed during wakefulness. Thus, this study aimed to analyze the sleep architecture of patients with chronic WAD as well as to evaluate trapezius muscle activity during sleep. Nine women with chronic WAD and nine healthy age-matched women participated in the study. Two PSG recordings were conducted for each participant. Surface electromyography signal samples of the right and left trapezius, and mentonian muscles were obtained from N2, N3, and REM sleep stages for analysis. Significant differences were found in the percentages of total sleep time in the N1 and N2 stages between the two groups. While the muscle tone of the three muscles analyzed decreased progressively across the sleep stages in the healthy group, in the chronic WAD group, this decrement was observed only in the mentonian muscle, and the trapezius muscle continued to exhibit the same muscle tone throughout the sleep stages without atonia during REM sleep. The absence of trapezius muscle atonia during REM sleep in the WAD patients may be related to dysfunction of the mechanisms that regulate motor activity.

Does Pain Neuroscience Education and Cognition-Targeted Motor Control Training Improve Cervical Motor Output? Secondary Analysis of a Randomized Clinical Trial

BACKGROUND

In the context of interventions aimed at reducing pain, disability, and maladaptive pain cognitions in chronic neck pain, it is hypothesized that patients who have greater symptom reduction possibly also demonstrate greater improvement in cervical motor output. Therefore, the aim of this study was to examine the effect of pain neuroscience education plus cognition-targeted motor control training on cervical motor output.

METHODS

Impairments in cervical motor output were measured in 64 subjects with chronic neck pain using standardized tests. Cervical muscle strength, cervical mobility, balance, and cervical neuromuscular control were derived. To assess the differences between groups in response to treatment, a random-intercept linear mixed-models analysis, applying a diagonal covariance matrix, was used.

RESULTS

A significant treatment × time interaction effect was found for neuromuscular control of the deep cervical flexors, favoring the experimental treatment at 3 months' follow-up (mean group difference: 1.982; 95% confidence interval 0.779, 3.185; large effect size d = 0.82). Significant main effects of time were found for the neuromuscular capacity of scapulothoracic muscles and for cervical mobility. No significant effects were found for balance, cervical muscle strength, or endurance of cervical flexors.

CONCLUSION

Pain neuroscience education combined with cognition-targeted motor control training is not more effective than biomedically focused education and exercise therapy for improving cervical motor output in people with chronic neck pain. Our findings question the relative importance of factors such as pain, disability, and maladaptive pain cognitions on cervical motor output and the need to address it in treatment.

Diagnosis of Tinnitus Due to Auditory Radiation Injury Following Whiplash Injury: A Case Study

We report on a patient with tinnitus who showed injury of auditory radiation following whiplash injury, demonstrated by diffusion tensor tractography (DTT). A 48-year-old male patient suffered from a car crash resulting in flexion-hyperextension injury of his head after being hit from behind by a moving car while waiting at a signal while driving a car. Three days after the car crash, he began to feel tinnitus in both ears and his tinnitus became aggravated with the passage of time. No specific lesion was observed on a conventional brain MRI performed two weeks after the car crash. Although he visited several hospitals, the precise cause of his tinnitus was not detected. Two years after the car crash, he underwent evaluation for his tinnitus at the ear, nose and throat department of a university hospital. The pure tone audiometry was evaluated in a sound-proof room to screen his hearing status for the frequencies of 250-8000 Hz and no specific abnormality was detected. Although he was also tested for speech audiometry, there was also no specific abnormality. In order to assess his tinnitus, a tinnitogram was conducted to evaluate the frequency content and the loudness. His tinnitus was characterized at an intensity of 40 dB and a frequency of 4000 Hz. However, no abnormality was observed in either ear on physical examination. On DTT, the auditory radiation showed severe narrowing and tearing in both hemispheres. To summarize, neural injury of the auditory radiation was demonstrated in a patient with tinnitus following whiplash injury, using DTT.

Performance properties of health-related measurement instruments in whiplash: systematic review protocol

BACKGROUND

Whiplash is a common traumatic cervical injury which is most often a consequence of rear-end motor vehicle accidents. It has been estimated that up to 50% of the whiplash patients suffer from chronic symptoms, resulting in extensive individual and societal burden. Several measurement instruments are used for initial assessment of whiplash and evaluation of response to treatment. However, a comprehensive assessment of the performance of these measures is lacking. Furthermore, there is no consensus on the most relevant outcome domains and their corresponding measurement instruments of choice. This systematic review aims to identify, describe, and critically appraise the performance properties of health-related measurement instruments in whiplash population.

METHODS

The following literature databases will be searched from their date of establishment: PubMed, Embase®, MEDLINE, CINAHL Complete, PsycINFO, and HAPI. All original articles evaluating the reliability, validity, responsiveness, and feasibility of health-related measurement instruments in whiplash will be included, without additional restriction on their intended use, source of data, and structure. Risk of bias will be assessed using the COSMIN Risk of Bias checklist. Findings of the studies will be judged against the criteria for good measurement properties, and results from all studies will be qualitatively summarized to generate an overall quality of findings. Overall quality of evidence will be determined using a modified GRADE approach, which will be used in conjunction with the overall quality of results for generation of recommendations. Two reviewers will perform all steps of the review independently. Discrepancies will be discussed between the reviewers, and in case of remaining disagreement, the senior reviewer will make the final decision.

DISCUSSION

This systematic review will summarize the body of literature on health-related measurement instruments in whiplash, aiming to facilitate the selection of high-quality measurement instrument for researchers and physicians. Findings of this study will guide the ongoing efforts for development of a core outcome set.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO reference number CRD42018070901.

Motor impairment in patients with chronic neck pain: does the traumatic event play a significant role? A case-control study

BACKGROUND CONTEXT

Motor impairment is a key sign in patients with traumatic (whiplash-associated disorder [WAD]) and non-traumatic (idiopathic neck pain [INP]) neck pain.

PURPOSE

This study aimed to analyze differences in motor impairment between two patient groups and to assess the association between motor performance and self-reported symptoms.

STUDY DESIGN

This is a case-control study.

PATIENT SAMPLE

A total of 38 patients with chronic INP, 35 patients with chronic WAD, and 30 healthy pain-free controls were included in the study.

OUTCOME MEASURES

Outcome measures used in this study were mobility (°), strength (N), repositioning accuracy (°), endurance (seconds), sway velocity (cm/s), sway area (cm²), and neuromuscular control.

METHODS

Group differences of motor impairment, together with questionnaires to evaluate pain intensity, fear avoidance, pain catastrophizing, symptoms of central sensitization, and disability, were analyzed with analysis of covariance, including age as a covariate.

RESULTS

Motor impairment was observed in both patient groups with a higher degree in patients with chronic WAD. These impairments were moderately linked to self-reported disability and were in most cases associated with pain, fear avoidance, and symptoms of central sensitization (|ρ| ranging from 0.28 to 0.59).

CONCLUSIONS

Motor impairment should be addressed when treating both groups of patients, keeping in mind the association with self-reported pain and disability, fear-avoidance, and central sensitization.

Cervical extension traction as part of a multimodal rehabilitation program relieves whiplash-associated disorders in a patient having failed previous chiropractic treatment: a CBP® case report

[Purpose] To present the case of the non-surgical restoration of cervical lordosis in a patient suffering from chronic whiplash syndrome including chronic neck pain and daily headaches resulting from previous whiplash. [Subject and Methods] A 31 year old female presented with a chief complaint of chronic neck pain and headaches for 12 years, correlating temporally with a sustained whiplash. These symptoms were not significantly relieved by previous chiropractic spinal manipulative therapy. The patient had cervical hypolordosis and was treated with Chiropractic BioPhysics^® protocol including extension exercises, manual adjustments and cervical extension traction designed to increase the cervical lordosis. [Results] The patient received 30 treatments over approximately 5-months. Upon re-assessment, there was a significant increase in global C2–C7 lordosis, corresponding with the reduction in neck pain and headaches. [Conclusion] This case adds to the accumulating evidence that restoring lordosis may be key in treating chronic whiplash syndrome. We suggest that patients presenting with neck pain and/or headaches with cervical hypolordosis be treated with a program of care that involves cervical extension traction methods to restore the normal cervical lordosis.

A novel approach in the treatment of acute whiplash syndrome: Ultrasound-guided needle percutaneous electrolysis. A randomized controlled trial

INTRODUCTION

Whiplash associated disorders are currently a common musculoskeletal problem. Besides the high incidence in western countries, the costs derived from prolonged treatment and medicolegal compensation, make this entity a challenging problem for clinicians and insurance companies. To date, no conservative treatment has shown clear superiority in the management of acute cases.

HYPOTHESIS

Percutaneous needle electrolysis (PNE) is an effective approach for the treatment of Quebec type II acute whiplash syndrome (AWS). PNE consists in the application of brief galvanic currents into a damaged structure, producing a local controlled inflammatory response, with subsequent tissular healing enhancement.

MATERIALS AND METHODS

One hundred AWS patients were randomized into: (a) standard physiotherapy intervention for AWS; (b) a standardized PNE protocol for AWS. Both groups were assessed for treatment outcome at the 5th week mark.

RESULTS

Both groups showed a statistically significant improvement according to the Northwick Park Neck Questionnaire, visual analogic scale and pressure pain threshold. The improvement was similar in both groups, except for the pain pressure threshold, with a 56.6% reduction vs. 44.4% reduction in favour of the PNE group (P=0.035). In addition, the physio group consumed a mean treatment time of 20hours, while the PNE intervention averaged less than 1 hour in total.

DISCUSSION

PNE can be considered as an effective treatment option for AWS. Importantly, the technique is highly cost-effective, with limited equipment required and a notable treatment time reduction, compared to more comprehensive physiotherapy protocols.

TYPE OF STUDY

Randomized controlled trial.

LEVEL OF PROOF

1b.

The Physiological Basis of Cervical Facet-Mediated Persistent Pain: Basic Science and Clinical Challenges

Synopsis Chronic neck pain is a common condition and a primary clinical symptom of whiplash and other spinal injuries. Loading-induced neck injuries produce abnormal kinematics between the vertebrae, with the potential to injure facet joints and the afferent fibers that innervate the specific joint tissues, including the capsular ligament. Mechanoreceptive and nociceptive afferents that innervate the facet have their peripheral terminals in the capsule, cell bodies in the dorsal root ganglia, and terminal processes in the spinal cord. As such, biomechanical loading of these afferents can initiate nociceptive signaling in the peripheral and central nervous systems. Their activation depends on the local mechanical environment of the joint and encodes the neural processes that initiate pain and lead to its persistence. This commentary reviews the complex anatomical, biomechanical, and physiological consequences of facet-mediated whiplash injury and pain. The clinical presentation of facet-mediated pain is complex in its sensory and emotional components. Yet, human studies are limited in their ability to elucidate the physiological mechanisms by which abnormal facet loading leads to pain. Over the past decade, however, in vivo models of cervical facet injury that reproduce clinical pain symptoms have been developed and used to define the complicated and multifaceted electrophysiological, inflammatory, and nociceptive signaling cascades that are involved in the pathophysiology of whiplash facet pain. Integrating the whiplash-like mechanics in vivo and in vitro allows transmission of pathophysiological mechanisms across scales, with the hope of informing clinical management. Yet, despite these advances, many challenges remain. This commentary further describes and highlights such challenges. J Orthop Sports Phys Ther 2017;47(7):450-461. Epub 16 Jun 2017. doi:10.2519/jospt.2017.7255.