Potential processes involved in the initiation and maintenance of whiplash-associated disorders: discussion paper 3

Physical testing in patients with acute whiplash-associated disorders: A within session test-retest reliability study

BACKGROUND

People with whiplash-associated disorders (WAD) commonly present with a variety of physical impairments. However, the reliability of physical tests has not been established for patients with acute WAD.

OBJECTIVE

To assess test-retest reliability of different physical tests in acute WAD.

DESIGN

Intra-rater test-retest reliability.

METHODS

Patients with acute WAD were recruited. Physical tests were used to evaluate articular, muscular and neural systems in two blocks of measurements separated by 10 min. Bland-Altman plots were performed to assess intrarater agreement, which included calculation of the mean difference (d) between rates, the 95% CI for d, the standard deviation of the differences and the 95% limits of agreement. Reliability was calculated via the standard error of measurement, the minimal detectable change, percent of agreement, the intraclass-correlation coefficient, and kappa coefficient.

RESULTS

47 patients participated. Test-retest reliability was excellent or good for almost all measures, except for extension ROM, ULTT for the radial nerve, and active cervical extension and upper cervical rotation performed in 4-point kneeling, which presented moderate reliability. Systematic bias was found in cervical ROM in flexion, left and right lateral-flexion, left and right rotation; left ULTT for radial nerve; right trapezius, suboccipitalis and temporalis muscles, left temporalis; C3, both sides of C1-C2, left C3-C4.

CONCLUSION

The majority of physical tests achieved good or excellent test-retest intra-rater reliability when tested in patients with acute WAD. Findings must be considered with caution for those tests which demonstrated systematic bias. Additional research is warranted to evaluate inter-rater reliability.

Higher Neck Pain Intensity and the Presence of Psychosocial Factors Are More Likely When Headache is Present after a Whiplash Injury: A Case-Control Study

BACKGROUND

Several factors such as neck pain intensity, disability, anxiety, depression, female sex, or a previous history of headache are associated with post-whiplash headache. However, the possible role of psychosocial factors contributing to the presence of headache or worsening of headache after a whiplash trauma remains unclear. To address this gap in knowledge, there is the need to assess psychosocial factors concerning headache shortly after a whiplash injury.

OBJECTIVE

To evaluate psychological features, pain and disability in people with acute whiplash associated disorders (WAD) and compare these features between those with and without headache.

DESIGN

Case-control study.

SETTING

A secondary care traumatology center.

METHODS

Forty-seven people with acute WAD were recruited; 28 with headache, and 19 without. All participants completed self-reported questionnaires including Visual Analogue Scale (VAS) for neck pain intensity, the Neck Disability Index (NDI), Pain Catastrophizing Scale (PCS), Tampa Scale Kinesiophobia-11 (TSK-11), and State-Trait Anxiety Inventory.

RESULTS

Neck pain intensity (P < .001), neck disability (P < 0.001), pain catastrophizing (P < .001), kinesiophobia (P < .001), and anxiety state (P = .007) and trait (P = .05) were higher in those with headache when compared to those without. In addition, high levels of neck pain (P = .025), moderate levels of neck disability (P < .001), moderate levels of pain catastrophizing (P = .015), and moderate (P = .002) and severe (P = .016) levels of kinesiophobia were related to the presence of headache.

CONCLUSIONS

The level of neck pain intensity and disability, kinesiophobia, catastrophizing, and anxiety were all greater in people with acute WAD who presented with a headache compared to those without headache.

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.

Precollision Medical Diagnoses Predict Chronic Neck Pain Following Acute Whiplash Trauma

OBJECTIVES

The reason why some individuals develop chronic symptoms, whiplash-associated disorder, following whiplash trauma is poorly understood. We explored whether precollision pain-related diagnoses, medically unexplained symptoms, and psychiatric diagnoses are related to whiplash-associated disorder.

MATERIALS AND METHODS

A cohort of 719 individuals exposed to whiplash trauma and subsequently experiencing symptoms within 72 hours (whiplash-exposed cohort) and 3595 matched controls were included in this observational prospective study. At 12 months postcollision, the whiplash-exposed cohort rated their neck pain using the Visual Analog Scale. Data on health were obtained from the Danish National Patient Register for the whiplash-exposed cohort and for the controls for a 5-year period before collision.

RESULTS

The whiplash-exposed cohort had significantly increased incidences of precollision pain-related diagnoses: χ(1)=17.42, P<0.001 and medically unexplained symptoms: χ(1)=22.2, P<0.001 but not psychiatric diagnoses: χ(1)=3.60, P>0.05 compared with controls in the 5-year period. Participants from the whiplash-exposed cohort with precollision pain-related diagnoses (odds ratio=2.46; 95% confidence interval, 1.39; 4.35) and medically unexplained symptoms (odds ratio, 1.72; 95% confidence interval, 1.04; 2.84) had significantly increased odds for neck pain at follow-up.

DISCUSSION

Precollision pain and medically unexplained symptoms predict chronic neck pain following whiplash trauma. This may indicate that a sensitization process was initiated before the collision or that individuals with precollision low threshold for contacting health care services maintain this behavior postcollision. The collision may trigger existing individual vulnerabilities that constitute to be a risk factor for chronic whiplash.

Advancing imaging technologies for patients with spinal pain: with a focus on whiplash injury

BACKGROUND CONTEXT

Radiological observations of soft-tissue changes that may relate to clinical symptoms in patients with traumatic and non-traumatic spinal disorders are highly controversial. Studies are often of poor quality and findings are inconsistent. A plethora of evidence suggests some pathoanatomical findings from traditional imaging applications are common in asymptomatic participants across the life span, which further questions the diagnostic, prognostic, and theranostic value of traditional imaging. Although we do not dispute the limited evidence for the clinical importance of most imaging findings, we contend that the disparate findings across studies may in part be due to limitations in the approaches used in assessment and analysis of imaging findings.

PURPOSE

This clinical commentary aimed to (1) briefly detail available imaging guidelines, (2) detail research-based evidence around the clinical use of findings from advanced, but available, imaging applications (eg, fat and water magnetic resonance imaging and magnetization transfer imaging), and (3) introduce how evolving imaging technologies may improve our mechanistic understanding of pain and disability, leading to improved treatments and outcomes.

STUDY DESIGN/SETTING

A non-systematic review of the literature is carried out.

METHODS

A narrative summary (including studies from the authors' own work in whiplash injuries) of the available literature is provided.

RESULTS

An emerging body of evidence suggests that the combination of existing imaging sequences or the use of developing imaging technologies in tandem with a good clinical assessment of modifiable risk factors may provide important diagnostic information toward the exploration and development of more informed and effective treatment options for some patients with traumatic neck pain.

CONCLUSIONS

Advancing imaging technologies may help to explain the seemingly disconnected spectrum of biopsychosocial signs and symptoms of traumatic neck pain.

Lateral atlantoaxial joint meniscoid volume in individuals with whiplash associated disorder: A case-control study

BACKGROUND

Lateral atlantoaxial (LAA) joints are established sources of nociceptive input in chronic whiplash associated disorder (WAD). These joints contain intra-articular meniscoids that may be damaged in whiplash trauma. LAA joint meniscoid morphology has not been investigated comprehensively in a chronic WAD population, and it is unclear whether morphological differences exist compared to a pain-free population.

OBJECTIVES

This study examined LAA joint meniscoid volume in individuals with chronic WAD who report pain in a distribution consistent with LAA joint pain.

DESIGN

Case-control study.

METHOD

Fourteen individuals with chronic WAD with pain in an LAA joint distribution (mean [SD] age 38.1 [10.8] years; six female) and 14 age- and sex-matched pain-free controls (38.0 [10.5] years) underwent cervical spine magnetic resonance imaging. LAA joint images were inspected for meniscoids; meniscoid volume was calculated in mm³ and as a percentage of articular cavity volume. Symptom duration, location and intensity were recorded. Data were analysed using paired t-tests, Wilcoxon signed-rank testing, Spearman's rank testing, linear and logistic regression (α < 0.05).

RESULTS

Ventral and dorsal meniscoids (n = 112) were found in each LAA joint. Greater dorsal meniscoid volume as a percentage of articular cavity volume was associated with higher pain intensity (odds ratio 1.48, p = 0.03; likelihood ratio test chi-square₂ = 6.64, p = 0.04), however no significant differences existed between meniscoid volumes of WAD and control participants.

CONCLUSIONS

Findings indicate a potential link between dorsal LAA joint meniscoid volume and pain, suggesting larger meniscoid size may have pathoanatomical significance in WAD.

How Do We Meet the Challenge of Whiplash?

A previous special issue of JOSPT (October 2016) discussed whiplash in terms of the clinical problems and current research surrounding prevention, biomechanics of injury, emergent care, imaging advancements, recovery pathways and prognosis, pathogenesis of posttrauma pain, acute and chronic management, and new predictive clinical tools. While great strides have been made in the field of whiplash and are continuing in earnest, a key group of clinicians and academics have recognized that inconsistent outcomes in published literature hamper our ability to meaningfully synthesize research findings, leading to results of systematic reviews that provide very few concrete clinical recommendations. We are optimistic that improved outcomes for people with whiplash-associated disorder (WAD) are attainable in the near future, as interdisciplinary research efforts continue to align internationally, new mechanisms are identified and explored, and advanced statistical techniques allow complex questions to be answered in clinically meaningful ways. J Orthop Sports Phys Ther 2017;47(7):444-446. doi:10.2519/jospt.2017.0106.

Chronic neck pain patients with traumatic or non-traumatic onset: Differences in characteristics. A cross-sectional study

BACKGROUND AND AIMS

Patients with chronic neck pain can present with disability, low quality of life, psychological factors and clinical symptoms. It is unclear whether patients with a traumatic onset differ from those with a non-traumatic onset, by having more complex and severe symptoms. The purpose of this study was to investigate the clinical presentation of chronic neck pain patients with and without traumatic onset by examining cervical mobility, sensorimotor function, cervical muscle performance and pressure pain threshold in addition to the following self-reported characteristics: quality of life, neck pain and function, kinesiophobia, depression, and pain bothersomeness.

METHODS

This cross-sectional study included 200 participants with chronic neck pain: 120 with traumatic onset and 80 with non-traumatic onset. Participants were recruited from physiotherapy clinics in primary and secondary health care. For participants to be included, they were required to be at least 18 years of age, have had neck pain for at least 6 months, and experienced neck-related activity limitation as determined by a score of at least 10 on the Neck Disability Index. We conducted the following clinical tests of cervical range of motion, gaze stability, eye movement, cranio-cervical flexion, cervical extensors, and pressure pain threshold. The participants completed the following questionnaires: physical and mental component summary of the Short Form Health Survey, EuroQol-5D, Neck Disability Index, Patient-Specific Functional Scale, Pain Bothersomeness, Beck Depression Inventory-II, and TAMPA scale of kinesiophobia. The level of significance for all analyses was defined as p<0.01. Differences between groups for the continuous data were determined using either a Student's t-test or Mann Whitney U test.

RESULTS

In both groups, the majority of the participants were female (approximately 75%). Age, educational level, working situation and sleeping patterns were similar in both groups. The traumatic group had symptoms for a shorter duration (88 vs. 138 months p=0.001). Participants in the traumatic group showed worse results on all measures compared with those in the non-traumatic group, significantly on neck muscle function (cervical extension mobility p=0.005, cranio-cervical flexion test p=0.007, cervical extensor test p=0.006) and cervical pressure pain threshold bilateral (p=0.002/0.004), as well on self-reported function (Neck Disability Index p=0.001 and Patient-Specific Functional Scale p=0.007), mental quality of life (mental component summary of the Short Form Health Survey p=0.004 and EuroQol-5D p=0.001) and depression (Beck Depression Inventory-II p=0.001).

CONCLUSIONS

This study showed significant differences between chronic neck pain patients when differentiated into groups based on their onset of pain. However, no specific clinical test or self-reported characteristic could differentiate between the groups at an individual patient level.

IMPLICATIONS

Pressure pain threshold tests, cervical muscle performance tests and patient-reported characteristics about self-perceived function and psychological factors may assist in profiling chronic neck pain patients. The need for more intensive management of those with a traumatic onset compared with those with a non-traumatic onset should be examined further.

Morphology of Cervical Spine Meniscoids in Individuals With Chronic Whiplash-Associated Disorder: A Case-Control Study

Study Design Case-control study. Background Cervical spine meniscoids are thought to contribute to neck pain and hypomobility in individuals with chronic whiplash-associated disorder (WAD); however, their morphology has not been studied in a clinical population. Objectives To investigate cervical spine meniscoid morphology in individuals with chronic WAD. Methods Twenty volunteers with chronic WAD (mean ± SD age, 39.3 ± 11.0 years; 10 female) and 20 age- and sex-matched controls (age, 39.1 ± 10.6 years) underwent cervical spine magnetic resonance imaging. Lateral atlantoaxial and zygapophyseal joints (C2-3 to C6-7) were inspected for meniscoids. Length of meniscoid protrusion was measured and composition (adipose/fibrous/fibroadipose) assessed. Data were analyzed using Wilcoxon signed-rank tests and linear and logistic regression (P<.05). Results Meniscoids were identified in the chronic WAD (n = 317) and control (n = 296) groups. At the lateral atlantoaxial joints, median meniscoid length was greater in the control group (ventral, 6.07 mm; dorsal, 7.24 mm) than the WAD group (ventral, 5.01 mm; P = .06 and dorsal, 6.48 mm; P<.01). At the dorsal aspect of zygapophyseal joints, meniscoids were more frequently fibrous in the chronic WAD group (odds ratio = 2.38, P<.01; likelihood ratio test: χ²₂, 9.02; P = .01). Conclusion In individuals with chronic WAD, lateral atlantoaxial meniscoids were shorter and dorsal cervical zygapophyseal meniscoids were more fibrous, suggesting alterations in meniscoid composition. This may have pathoanatomical implications in chronic WAD. J Orthop Sports Phys Ther 2016;46(10):902-910. Epub 3 Sep 2016. doi:10.2519/jospt.2016.6702.

Methodology of AA CRASH: a prospective observational study evaluating the incidence and pathogenesis of adverse post-traumatic sequelae in African-Americans experiencing motor vehicle collision

INTRODUCTION

A motor vehicle collision (MVC) is one of the most common life-threatening events experienced by individuals living in the USA. While most individuals recover following MVC, a significant proportion of individuals develop adverse post-traumatic sequelae such as post-traumatic stress disorder or persistent musculoskeletal pain. Adverse post-traumatic sequelae are common, morbid and costly public health problems in the USA and other industrialised countries. The pathogenesis of these disorders following MVC remains poorly understood. In the USA, available data suggest that African-Americans experience an increased burden of adverse post-traumatic sequelae after MVC compared to European Americans, but to date no studies examining the pathogenesis of these disorders among African-Americans experiencing MVC have been performed.

METHODS AND ANALYSIS

The African-American CRASH (AA CRASH) study is an NIH-funded, multicentre, prospective study that enrols African-Americans (n=900) who present to the emergency department (ED) within 24 hours of MVC. Participants are enrolled at 13 ED sites in the USA. Individuals who are admitted to the hospital or who report a fracture or tissue injury are excluded. Participants complete a detailed ED interview that includes an assessment of crash history, current post-traumatic symptoms and health status prior to the MVC. Blood samples are also collected in the ED using PAXgene DNA and PAXgene RNA tubes. Serial mixed-mode assessments 6 weeks, 6 months and 1 year after MVC include an assessment of adverse sequelae, general health status and health service utilisation. The results from this study will provide insights into the incidence and pathogenesis of persistent pain and other post-traumatic sequelae in African-Americans experiencing MVC.

ETHICS AND DISSEMINATION

AA CRASH has ethics approval in the USA, and the results will be published in a peer-reviewed journal.

Endogenous pain inhibition is unrelated to autonomic responses in acute whiplash-associated disorders

Patients with acute whiplash-associated disorder (WAD) demonstrate an inefficient endogenous pain inhibition and may experience a dysfunction in autonomic nervous system reactivity to pain. This study compared the autonomic response to painful stimuli between patients with acute and chronic WAD and healthy controls. In addition, the role of the autonomic nervous system for explaining inefficient endogenous pain inhibition was examined in acute WAD. Seventeen patients with acute WAD, 30 patients with chronic WAD, and 31 healthy controls participated in an experiment evaluating the autonomic nervous system at rest and during painful stimuli. Skin conductance and heart rate variability (HRV) parameters were monitored continuously during conditioned pain modulation. A significant autonomic response to pain was present for skin conductance and two HRV parameters in all experimental groups. There was an interaction effect in the skin conductance response to pain but not in HRV responses in any of the groups. In patients with acute WAD, no significant correlations were present between pain, pressure pain thresholds, pain inhibition, and any of the autonomic parameters. This study refutes autonomic dysfunction at rest and in response to pain in acute WAD. The dysfunctional conditioned pain modulation appears unrelated to autonomic responses to pain.

The pain drawing as an instrument for identifying cervical spine nerve involvement in chronic whiplash-associated disorders

Objective

The aim of the study was to investigate the psychometric properties of a standardized assessment of pain drawing with regard to clinical signs of cervical spine nerve root involvement.

Design

This cross-sectional study included data collected in a randomized controlled study. Patients: Two hundred and sixteen patients with chronic (≥6 months) whiplash-associated disorders, grade 2 or 3, were included in this study.

Methods

The validity, sensitivity, and specificity of a standardized pain drawing assessment for determining nerve root involvement were analyzed, compared to the clinical assessment. In addition, we analyzed the interrater reliability with 50 pain drawings.

Results

Agreement was poor between the standardized pain drawing assessment and the clinical assessment (kappa =0.11, 95% CI: −0.03 to 0.20). Sensitivity was high (93%), but specificity was low (19%). Interrater reliability was good (kappa =0.64, 95% CI: 0.53 to 0.76). Conclusion: The standardized pain drawing assessment of nerve root involvement in chronic whiplash-associated disorders was not in agreement with the clinical assessment. Further research is warranted to optimize the utilization of a pain/discomfort drawing as a supportive instrument for identifying nerve involvement in cervical spinal injuries.

Pain and pain tolerance in whiplash-associated disorders: A population-based study

Background

Pain is a cardinal symptom in individuals with whiplash‐associated disorders (WAD). We aimed to compare pain characteristics between individuals with WAD and individuals reporting chronic pain from other causes, and to determine whether potential differences were accounted for by experimental pain tolerance.

Methods

Data from the 6th Tromsø Study (2007–2008, n = 12,981) were analysed. The number of painful locations was compared between individuals with WAD and individuals reporting chronic pain from other causes using negative binomial regression, pain frequency using multinomial logistic regression and pain intensity using multiple linear regression. Differences in experimental pain tolerance (cold pressor test) were tested using Cox regression; one model compared individuals with WAD to those with chronic pain from other causes, one compared the two groups with chronic pain to individuals without chronic pain. Subsequently, regression models investigating clinical pain characteristics were adjusted for pain tolerance.

Results

Of individuals with WAD, 96% also reported other causes for pain. Individuals with WAD reported a higher number of painful locations [median (inter‐quartile range): 5 (3.5–7) vs. 3 (2–5), p < 0.001] and higher pain intensity (crude mean difference = 0.78, p < 0.001) than individuals with chronic pain from other causes. Pain tolerance did not differ between these two groups. Compared to individuals without chronic pain, individuals with WAD and individuals with chronic pain from other causes had reduced pain tolerance.

Conclusions

Individuals with WAD report more additional causes of pain, more painful locations and higher pain intensity than individuals with chronic pain from other causes. The increased pain reporting was not accounted for by pain tolerance.

Potential associations between chronic whiplash and incomplete spinal cord injury

STUDY DESIGN

This research utilized a cross-sectional design with control group inclusion.

OBJECTIVES

Preliminary evidence suggests that a portion of the patient population with chronic whiplash may have sustained spinal cord damage. Our hypothesis is that in some cases of chronic whiplash-associated disorders (WAD), observed muscle weakness in the legs will be associated with local signs of a partial spinal cord injury of the cervical spine.

SETTING

University based laboratory in Chicago, IL, USA.

METHODS

Five participants with chronic WAD were compared with five gender/age/height/weight/body mass index (BMI) control participants. For a secondary investigation, the chronic WAD group was compared with five unmatched participants with motor incomplete spinal cord injury (iSCI). Spinal cord motor tract integrity was assessed using magnetization transfer imaging. Muscle fat infiltration (MFI) was quantified using fat/water separation magnetic resonance imaging. Central volitional muscle activation of the plantarflexors was assessed using a burst superimposition technique.

RESULTS

We found reduced spinal cord motor tract integrity, increased MFI of the neck and lower extremity muscles and significantly impaired voluntary plantarflexor muscle activation in five participants with chronic WAD. The lower extremity structural changes and volitional weakness in chronic WAD were comparable to participants with iSCI.

CONCLUSION

The results support the position that a subset of the chronic whiplash population may have sustained partial damage to the spinal cord.

SPONSORSHIP

NIH R01HD079076-01A1, NIH T32 HD057845 and the Foundation for Physical Therapy Promotion of Doctoral Studies program.

The Effectiveness of Conservative Management for Acute Whiplash Associated Disorder (WAD) II: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

OBJECTIVE

To evaluate the effectiveness of conservative management (except drug therapy) for acute Whiplash Associated Disorder (WAD) II.

DESIGN

Systematic review and meta-analysis of Randomised Controlled Trials (RCTs) using a pre-defined protocol. Two independent reviewers searched information sources, decided eligibility of studies, and assessed risk of bias (RoB) of included trials. Data were extracted by one reviewer and checked by the other. A third reviewer mediated any disagreements throughout. Qualitative trial and RoB data were summarised descriptively. Quantitative syntheses were conducted across trials for comparable interventions, outcome measures and assessment points. Meta-analyses compared effect sizes with random effects, using STATA version 12.

DATA SOURCES

PEDro, Medline, Embase, AMED, CINAHL, PsycINFO, and Cochrane Library with manual searching in key journals, reference lists, British National Bibliography for Report Literature, Center for International Rehabilitation Research Information & Exchange, and National Technical Information Service were searched from inception to 15th April 2015. Active researchers in the field were contacted to determine relevant studies.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

RCTs evaluating acute (<4 weeks) WADII, any conservative intervention, with outcome measures important to the International Classification of Function, Disability and Health.

RESULTS

Fifteen RCTs all assessed as high RoB (n=1676 participants) across 9 countries were included. Meta-analyses enabled 4 intervention comparisons: conservative versus standard/control, active versus passive, behavioural versus standard/control, and early versus late. Conservative intervention was more effective for pain reduction at 6 months (95%CI: -20.14 to -3.38) and 1-3 years (-25.44 to -3.19), and improvement in cervical mobility in the horizontal plane at <3 months (0.43 to 5.60) compared with standard/control intervention. Active intervention was effective for pain alleviation at 6 months (-17.19 to -3.23) and 1-3 years (-26.39 to -10.08) compared with passive intervention. Behavioural intervention was more effective than standard/control intervention for pain reduction at 6 months (-15.37 to -1.55), and improvement in cervical movement in the coronal (0.93 to 4.38) and horizontal planes at 3-6 months (0.43 to 5.46). For early (<4 days) versus late (>10 days) interventions, there were no statistically significant differences in all outcome measures between interventions at any time.

CONCLUSIONS

Conservative and active interventions may be useful for pain reduction in patients with acute WADII. Additionally, cervical horizontal mobility could be improved by conservative intervention. The employment of a behavioural intervention (e.g. act-as-usual, education and self-care including regularly exercise) could have benefits for pain reduction and improvement in cervical movement in the coronal and horizontal planes. The evidence was evaluated as low/very low level according to the Grading of Recommendations Assessment, Development and Evaluation system.

The Rapid and Progressive Degeneration of the Cervical Multifidus in Whiplash: An MRI Study of Fatty Infiltration

STUDY DESIGN

Single-center prospective longitudinal study.

OBJECTIVE

To study the (1) temporal development of muscle fatty infiltrates (MFI) in the cervical multifidi after whiplash, (2) differences in multifidi MFI between those who recover or report milder pain-related disability and those who report moderate/severe symptoms at 3 months, and (3) predictive value of multifidi MFI outcomes.

SUMMARY OF BACKGROUND DATA

The temporal development of MFI on conventional magnetic resonance image has been shown to be associated with specific aspects of pain and psychological factors. The replication of such findings has yet to be explored longitudinally.

METHODS

Thirty-six subjects with whiplash injury were enrolled at less than 1 week postinjury and classified at 3 months using percentage scores on the Neck Disability Index as recovered/mild (0%-28%) or severe (≥30%). A fat/water magnetic resonance imaging measure, patient self-report of pain-related disability, and post-traumatic stress disorder were collected at less than 1 week, 2 weeks, and 3 months postinjury. The effects of time and group (per Neck Disability Index) and the interaction of time by group on MFI were determined. Receiver operating characteristic curve analysis was used to determine a cut-point for MFI at 2 weeks to predict outcome at 3 months.

RESULTS

There was no difference in MFI across groups at enrolment. MFI values were significantly higher in the severe group than those in the recovered/mild group at 2 weeks and 3 months. The receiver operating characteristic curve analysis indicated that MFI levels of 20.5% or above resulted in a sensitivity of 87.5% and a specificity of 92.9% for predicting outcome at 3 months.

CONCLUSION

Consistent with previous evidence, muscle degeneration occurs soon after injury but only in those patients with poor functional recovery. This study provides further evidence that (1) multifidi MFI occur in tandem with known predictive risk factors (older age, pain-related disability, and post-traumatic stress disorder) and (2) routine imaging protocols may need to be reconsidered in the vast majority of patients after whiplash.

LEVEL OF EVIDENCE

3.

The geography of fatty infiltrates within the cervical multifidus and semispinalis cervicis in individuals with chronic whiplash-associated disorders

STUDY DESIGN

Cross-sectional.

OBJECTIVES

To quantify the magnitude and distribution of muscle fat infiltration (MFI) within the cervical multifidus and semispinalis cervicis muscles in participants with chronic whiplash-associated disorders (WADs) compared to those who have fully recovered from a whiplash injury and healthy controls.

BACKGROUND

Previous research has established the presence of increased MFI throughout the cervical extensor muscles of individuals with WAD when compared to healthy controls. These changes appear to be greater in the deepest muscles (eg, multifidus and semispinalis cervicis) than in the more superficial muscles. A detailed analysis of the distribution of MFI within these deep extensor muscles in chronic WAD, recovered, and control groups would provide a foundation for further investigation of specific mechanisms, etiologies, and targets for treatments.

METHODS

Fifteen participants (WAD, n = 5; recovered, n = 5; and control, n = 5) were studied using a 3-D fat-water separation magnetic resonance imaging sequence. Bilateral measures of cervical multifidus and semispinalis cervicis MFI in 4 quartiles (1 [medial] to 4 [lateral]) at cervical levels C3 through C7 were included in the analysis. Intrarater and interrater reliability were established. A mixed-model analysis was performed to control for covariates, identify interaction effects, and compare MFI distribution between groups.

RESULTS

The limits of agreement confirmed strong intrarater and interrater agreement at all levels (C3-C7). Sex, age, and body mass index were identified as significant covariates for MFI. Significant interactions were found between group and muscle quartile (P<.001) and between muscle quartile and cervical level (P<.001). Pairwise comparisons for intraquartile MFI between groups revealed significantly greater MFI in the WAD group when compared to the recovered group in the first quartile (P<.001), second quartile (P<.001), and third quartile (P = .03). When compared to the control group, the WAD group had significantly greater MFI in the first quartile (P = .002) and the second quartile (P = .045). The control group had significantly higher MFI in comparison to the recovered group in the first quartile (P = .048).

CONCLUSION

This study provides preliminary data mapping the spatial distribution of MFI in the cervical multifidus and semispinalis cervicis muscles in individuals with chronic WAD, those who have recovered from a whiplash injury, and healthy controls. Muscle fat infiltration is more concentrated in the medial portion of the muscles in all participants. However, the magnitude of MFI in the medial quartiles (1 and 2) is greatest in the chronic WAD group.

Factors related to non-recovery from whiplash. The Nord-Trøndelag Health Study (HUNT)

BACKGROUND

Whiplash injuries show a variable prognosis which is difficult to predict. Most individuals experiencing whiplash injuries rapidly recover but a significant proportion develop chronic symptoms and ongoing disability.

PURPOSE

By employing longitudinal data, we investigated how psychological and physical symptoms, self-rated health, use of health services and medications, health behavior and demographic factors predict recovery from whiplash.

METHOD

Data from two waves of a large, Norwegian, population-based study (The Nord-Trøndelag Health Study: HUNT2 and HUNT3) were used. Individuals reporting whiplash in HUNT2 (baseline) were identified in HUNT3 11 years later. The characteristics of individuals still suffering from whiplash in HUNT3 were compared with the characteristics of individuals who had recovered using Pearson's chi-squared test, independent sample t-tests and logistic regression.

RESULTS

At follow-up, 31.6 % of those reporting whiplash at baseline had not recovered. These individuals (n = 199) reported worse health at baseline than recovered individuals (n = 431); they reported poorer self-rated health (odds ratio [OR] = 3.12; 95 % confidence interval [CI], 2.20-4.43), more symptoms of anxiety (OR = 1.70; 95 % CI, 1.15-2.50), more diffuse somatic symptoms (OR = 2.38; 95 % CI, 1.61-3.51) and more musculoskeletal symptoms (OR = 1.21; 95 % CI, 1.13-1.29). Individuals still suffering from whiplash also visited more health practitioners at baseline (OR = 1.18; 95 % CI, 1.06-1.32) and used more medications (OR = 1.24; 95 % CI, 1.09-1.40).

CONCLUSION

Poor self-rated health seems to be a strong risk factor for whiplash injuries becoming chronic. Diffuse somatic symptoms, musculoskeletal symptoms and symptoms of anxiety at baseline are important prognostic risk factors. Knowledge of these maintaining risk factors enables identification of individuals at risk of non-recovery, facilitating adequate treatment for this vulnerable group.

Mechanisms underlying chronic whiplash: contributions from an incomplete spinal cord injury?

OBJECTIVE

To explore the association between findings on advanced, but available, magnetic resonance imaging (MRI) sequences of the cervical spinal cord and muscular system, in tandem with biomechanical measures of maximum volitional plantar flexion torques as a proxy for a mild incomplete spinal cord injury.

DESIGN

Observational case series.

SETTING

University research laboratory.

SUBJECTS

Three patients with chronic whiplash and one patient with history of whiplash injury but no current symptoms.

METHODS

We measured lower extremity muscle fat, morphological changes in descending spinal cord pathways with advanced MRI applications and maximal activation of the plantar flexors.

RESULTS

Larger magnitudes of lower extremity muscle fat corresponded to altered spinal cord anatomy and reductions in the ability to maximally activate plantar flexor torques in the three subjects with chronic whiplash. Such findings were not present in the recovered participant.

CONCLUSIONS

The potential value of MRI to quantify neuromuscular degeneration in chronic whiplash is recognized. Larger scaled prospective studies are warranted before stronger conclusions can be drawn.

The prevalence of temporomandibular disorders in patients with late whiplash syndrome who experience orofacial pain: a case-control series study

BACKGROUND

The authors conducted a study to compare the frequency of specific temporomandibular disorder (TMD) diagnoses in patients who had late whiplash syndrome (LWS) with that in a control group.

METHODS

The authors recruited 65 patients who had orofacial pain and a previous diagnosis of LWS and 65 age- and sex-matched control patients who had chronic orofacial pain without a history of whiplash injury (WI) for a case-control series study. All patients completed a questionnaire pertaining to the Research Diagnostic Criteria for Temporomandibular Disorders and underwent a clinical examination.

RESULTS

The authors compared the frequency of TMD diagnoses in case patients with that in control patients by using a χ(2) test; they set the α level a priori at .05. The number of patients diagnosed with myofascial pain (MP) and disk displacement with reduction (DDWR) was significantly higher in the case group than in the control group (P = .002 and P = .001, respectively).

CONCLUSIONS

The results of this study show a higher frequency of MP and DDWR in patients with LWS than in patients with chronic orofacial pain and no history of WI. Practical Implications. Clinicians should be knowledgeable about the correlation between WI and TMD so they can inform and treat patients accurately.

In vivo cervical facet joint capsule deformation during flexion-extension

STUDY DESIGN

Nonrandomized controlled cohort.

OBJECTIVE

To characterize subaxial cervical facet joint kinematics and facet joint capsule (FJC) deformation during in vivo, dynamic flexion-extension. To assess the effect of single-level anterior arthrodesis on adjacent segment FJC deformation.

SUMMARY OF BACKGROUND DATA

The cervical facet joint has been identified as the most common source of neck pain, and it is thought to play a role in chronic neck pain related to whiplash injury. Our current knowledge of cervical facet joint kinematics is based on cadaveric mechanical testing.

METHODS

Fourteen asymptomatic controls and 9 C5-C6 arthrodesis patients performed full range of motion flexion-extension while biplane radiographs were collected at 30 Hz. A volumetric model-based tracking process determined 3-dimensional vertebral position with submillimeter accuracy. FJC fibers were modeled and grouped into anterior, lateral, posterior-lateral, posterior, and posterior-medial regions. FJC fiber deformations (total, shear, and compression-distraction) relative to the static position were determined for each cervical motion segment (C2-C3 through C6-C7) during flexion-extension.

RESULTS

No significant differences in the rate of fiber deformation in flexion were identified among motion segments (P = 0.159); however, significant differences were observed among fiber regions (P < 0.001). Significant differences in the rate of fiber deformation in extension were identified among motion segments (P < 0.001) and among fiber regions (P = 0.001). The rate of FJC deformation in extension adjacent to the arthrodesis was 45% less than that in corresponding motion segments in control subjects (P = 0.001).

CONCLUSION

In control subjects, FJC deformations are significantly different among vertebral levels and capsule regions when vertebrae are in an extended orientation. In a flexed orientation, FJC deformations are different only among capsule regions. Single-level anterior arthrodesis is associated with significantly less FJC deformation adjacent to the arthrodesis when the spine is in an extended orientation.

LEVEL OF EVIDENCE

4.

Targeting chronic recurrent low back pain from the top-down and the bottom-up: a combined transcranial direct current stimulation and peripheral electrical stimulation intervention

BACKGROUND

Mechanisms such as neural sensitization and maladaptive cortical organization provide novel targets for therapy in chronic recurrent low back pain (CLBP).

OBJECTIVE

We investigated the effect of a transcranial direct current stimulation (tDCS) and peripheral electrical stimulation (PES) treatment on pain, cortical organization, sensitization and sensory function in CLBP.

METHODS

Using a placebo-controlled crossover design, 16 individuals received four treatments in separate sessions: (i) anodal tDCS/PES; (ii) anodal tDCS/sham PES; (iii) sham tDCS/PES; or (iv) sham tDCS/sham PES. Pain was assessed at baseline, immediately following, and at 1 and 3 days after treatment. Motor cortical organization, sensitization and sensory function were measured before and immediately after treatment.

RESULTS

Combined tDCS/PES reduced pain and sensitization, normalized motor cortical organization and improved sensory function. The reduction in pain was greater in individuals with more pronounced sensitization. Applied alone, tDCS or PES also reduced pain. However, with the exception of improved sensory function and reduced map volume following PES, clinical and neurophysiological outcomes were unaltered by tDCS or PES applied separately. No changes were observed following sham treatment.

CONCLUSION

Our data suggest a combined tDCS/PES intervention more effectively improves CLBP symptoms and mechanisms of cortical organization and sensitization, than either intervention applied alone or a sham control.

An early intervention programme had no detectable influence on the health status of people with musculoskeletal injuries following road traffic crashes: comparative study

OBJECTIVE

To compare the health status of people with minor injuries from road traffic crashes that are exposed to an early, active intervention programme (intervention group) with those receiving usual care (control group) over a 12 month period.

DESIGN

Prospective comparative study using sequential cohorts.

SUBJECTS

People presenting to hospital emergency departments with mild to moderate musculoskeletal injuries following road traffic crashes.

MAIN OUTCOME MEASURES

Physical Component Score (PCS) and Mental Component Score (MCS) of the Short Form 36 (SF-36) health status measure; Hospital Anxiety and Depression Scale (HADS) and the Functional Rating Index (FRI) recorded immediately post-crash, at 6 months and at 12 months after injury.

RESULTS

There were 95 participants allocated to the control group and 98 allocated to the intervention group. Participants were enrolled at a mean of 9.3 days following the crash. There were no significant differences in baseline health measures between the groups. Apart from a small improvement in anxiety for the intervention group, there were no significant differences in health status between the groups. Twenty percent of participants in the intervention group received treatment from external healthcare providers that was inconsistent with the recommendations of the intervention programme.

CONCLUSIONS

The intervention programme failed to result in a clinically significant improvement in health outcomes compared with usual care. There is some evidence to suggest that the intervention had some psychological benefits, as evidenced by the small improvement in anxiety levels. Limited adherence, frequent use of co-interventions, or other factors (such as intervention content or intensity) may have reduced its effect.

Predictive capacity of pain beliefs and catastrophizing in Whiplash Associated Disorder

INTRODUCTION

Beliefs about pain are known to be important factors in recovery, most notably in LBP. Relatively less is known about the role of pain beliefs in Whiplash Associated Disorder (WAD). The widely advocated cognitive-behavioural approach to pain management necessitates cognitive factors such as pain beliefs be examined, even early after injury. The primary purpose of this study was to explore the predictive capacity of early post-injury pain beliefs and catastrophizing in patients with WAD.

METHODS

Patients (n=72) undergoing treatment for acute WAD in physical therapy and chiropractic clinics were invited to participate in the study. Research participants were asked to complete measures of beliefs (Survey of Pain Attitudes (SOPA) and Pain Beliefs and Perception Inventory (PBPI)) and catastrophizing (Pain Catastrophizing Scale) at baseline (within 6 weeks of injury), and 3 and 6 months post-injury. In addition, pain severity and self-reported disability using the Whiplash Disability Questionnaire (WDQ) were recorded at each measurement occasion. Baseline belief and catastrophizing scores were examined for their relationship with future pain and disability using multiple linear regression.

RESULTS

Expectancy beliefs (PBPI Permanence and SOPA Medical Cure) were negatively correlated with pain intensity at 6-months and uniquely accounted for 16% and 14% of explained variance, respectively, after controlling for baseline pain intensity, age, sex and history of WAD. Consistent with previous research, catastrophizing was also found to be predictive of future pain. The amount of unique variance explained by beliefs in the prediction of future disability was modest after controlling for baseline disability, age, sex and history of WAD.

DISCUSSION

These results suggest that expectancy beliefs are potentially important constructs to include in future explanatory prognosis studies. The Medical Cure and Permanence subscales of the SOPA and PBPI are tools that could be used to measure these expectancy constructs.

Content not quantity is a better measure of muscle degeneration in whiplash

Whiplash associated disorder (WAD) represents an enormous economic, social and personal burden. Five out of 10 people with WAD never fully recover and up to 25% continue to have moderate to severe pain-related disability. Unfortunately, clear and definitive reasons as to why half of individuals with WAD recover uneventfully and the other half do not, remain elusive. Identifying the factors that can reliably predict outcome holds considerable importance for not only WAD, but arguably for other acute musculoskeletal traumas. The precise pathology present in WAD has been controversial and often biased by outdated models. Fortunately, a combination of new measurement technology that illuminates pain processing, physical and social functioning and post-traumatic stress responses (and possibly markers of altered muscle size/shape/physiology) is providing a clearer picture of the multisystem pathophysiology in individuals with persistent WAD. The aim of this professional issues paper is to illuminate the clinical and research communities with regards to the growing body of knowledge for determining the trajectory of a patient with whiplash.

Somatic symptoms beyond those generally associated with a whiplash injury are increased in self-reported chronic whiplash. A population-based cross sectional study: the Hordaland Health Study (HUSK)

BACKGROUND

Chronic whiplash leads to considerable patient suffering and substantial societal costs. There are two competing hypothesis on the etiology of chronic whiplash. The traditional organic hypothesis considers chronic whiplash and related symptoms a result of a specific injury. In opposition is the hypothesis that chronic whiplash is a functional somatic syndrome, and related symptoms a result of society-induced expectations and amplification of symptoms. According to both hypotheses, patients reporting chronic whiplash are expected to have more neck pain, headache and symptoms of anxiety and depression than the general population. Increased prevalence of somatic symptoms beyond those directly related to a whiplash neck injury is less investigated. The aim of this study was to test an implication derived from the functional hypothesis: Is the prevalence of somatic symptoms as seen in somatization disorder, beyond symptoms related to a whiplash neck injury, increased in individuals self-reporting chronic whiplash? We further aimed to explore recall bias by comparing the symptom profile displayed by individuals self-reporting chronic whiplash to that among those self-reporting a non-functional injury: fractures of the hand or wrist. We explored symptom load, etiologic origin could not be investigated in this study.

METHODS

Data from the Norwegian population-based "Hordaland Health Study" (HUSK, 1997-99); N = 13,986 was employed. Chronic whiplash was self-reported by 403 individuals and fractures by 1,746. Somatization tendency was measured using a list of 17 somatic symptoms arising from different body parts and organ systems, derived from the research criteria for somatization disorder (ICD-10, F45).

RESULTS

Chronic whiplash was associated with an increased level of all 17 somatic symptoms investigated (p<0.05). The association was moderately strong (group difference of 0.60 standard deviation), only partly accounted for by confounding. For self-reported fractures symptoms were only slightly elevated. Recent whiplash was more commonly reported than whiplash-injury a long time ago, and the association of interest weakly increased with time since whiplash (r = 0.016, p = 0.032).

CONCLUSIONS

The increased prevalence of somatic symptoms beyond symptoms expected according to the organic injury model for chronic whiplash, challenges the standard injury model for whiplash, and is indicative evidence of chronic whiplash being a functional somatic syndrome.