A contemporary neuroscience approach compared to biomedically focused education combined with symptom-contingent exercise therapy in people with chronic whiplash associated disorders: a randomized controlled trial protocol

Gray Matter Adaptations to Chronic Pain in People with Whiplash-Associated Disorders are Partially Reversed After Treatment: A Voxel-based Morphometry Study

Gray matter (GM) changes are often observed in people with chronic spinal pain, including those with chronic whiplash-associated disorders (CWAD). These GM adaptations may be reversed with treatment, at least partially. Pain neuroscience education combined with exercise (PNE+Exercise) is an effective treatment, but its neural underlying mechanisms still remain unexplored in CWAD. Here, we performed both cross-sectional and longitudinal voxel-based morphometry to 1) identify potential GM alterations in people with CWAD (n = 63) compared to age- and sex-matched pain-free controls (n = 32), and 2) determine whether these GM alterations might be reversed following PNE+Exercise (compared to conventional physiotherapy). The cross-sectional whole-brain analysis revealed that individuals with CWAD had less GM volume in the right and left dorsolateral prefrontal cortex and left inferior temporal gyrus which was, in turn, associated with higher pain vigilance. Fifty individuals with CWAD and 29 pain-free controls were retained in the longitudinal analysis. GM in the right dorsolateral prefrontal cortex increased after treatment in people with CWAD. Moreover, the longitudinal whole-brain analysis revealed that individuals with CWAD had decreases in GM volumes of the left and right central operculum and supramarginal after treatment. These changes were not specific to treatment modality and some were not observed in pain-free controls over time. Herewith, we provide the first evidence on how GM adaptations to CWAD respond to treatment. PERSPECTIVE: This article presents which gray matter adaptations are present in people with chronic pain after whiplash injuries. Then, we examine the treatment effect on these alterations as well as whether other neuroplastic effects on GM following treatment occur.

Exercise-Induced Hypoalgesia in Patients with Chronic Whiplash-Associated Disorders: Differences between Subgroups Based on the Central Sensitization Inventory

BACKGROUND

Physical exercise is an important element in the rehabilitation of chronic whiplash-associated disorders, with the physiological process underlying pain reduction called exercise-induced hypoalgesia. In chronic whiplash-associated disorders, exercise-induced hypoalgesia appears impaired, and the research suggests a relationship with symptoms of dysfunctional nociceptive processing, such as central sensitization. This study improves our understanding of exercise-induced hypoalgesia in chronic whiplash-associated disorders by examining the differences between the extent of exercise-induced hypoalgesia in subgroups based on scores on the central sensitization inventory (CSI).

METHODS

Data were collected from 135 participants with chronic whiplash-associated disorders who completed a set of questionnaires. Pain pressure thresholds and temporal summations were assessed before and after a submaximal aerobic bicycle exercise test.

RESULTS

We observed no interaction effect between exercise-induced hypoalgesia and the CSI scores for both pain pressure threshold and temporal summation. No overall statistical effect was measured in the analysis of the effect of time. The pain pressure threshold significantly related to the CSI. The temporal summation showed no correlation.

CONCLUSIONS

During this study, we did not find evidence for a difference in the presence of exercise-induced hypoalgesia when the subgroups were created based on the central sensitization cluster calculator. Limited evidence was found for the influence of CSI scores on the delta pain pressure threshold.

Neural processing of pain-related distress to neck-specific movements in people with chronic whiplash-associated disorders

ABSTRACT

Pain-related distress contributes to long-term disability in chronic whiplash-associated disorders. Recently, neuroimaging studies have revealed altered neural responses to viewing pictures of movements associated with back pain in key regions for threat and affective processing. In this study, we examined neural correlates of imagining neck-specific movements designed to elicit pain-related distress in individuals with whiplash-associated disorders (n = 63) when compared with that in sex-matched pain-free controls (n = 32). In the scanner, participants were presented with neck-specific movement-related pictures divided into 3 categories (high fear, moderate-fear, and neutral control pictures) and asked to imagine how they would feel if they were performing the movement. Whole-brain analyses revealed greater differential activation (high-fear vs neutral) in individuals with whiplash-associated disorders when compared with that in pain-free controls in 6 clusters including right and left postcentral gyri, left parietal operculum, dorsal precuneus, left superior frontal gyrus/anterior cingulate cortex, and posterior cingulate cortex/ventral precuneus. For the contrast moderate-fear vs neutral, patients showed greater differential activation than controls in the right and left posterolateral cerebellum. Activation patterns in the precuneus and posterior cingulate cortex were negatively associated with pain-related fear, but no other correlations were observed. Together, the findings suggest that when conceptualizing neck-specific movements associated with pain, people with chronic whiplash-associated disorders may predict-and potentially amplify-their sensory and affective consequences and therewith trigger dysfunctional affective and/or behavioral responses. Herewith, we provide new insights into the neural mechanisms underlying chronic pain in people with whiplash-associated disorders, pointing towards a complex interplay between cognitive/affective and sensorimotor circuitry.

A guide to identify cervical autonomic dysfunctions (and associated conditions) in patients with musculoskeletal disorders in physical therapy practice

BACKGROUND

Differential diagnosis is a hot topic in physical therapy, especially for those working in a direct access setting dealing with neck pain and its associated disorders. All international guidelines agree in recommending to first rule out non-musculoskeletal pathologies as the cause of signs and symptoms in the patient. Although the autonomic nervous system (ANS) has a crucial role and is also involved in pain conditions, coverage of it in neuroscience textbooks and educational programmes is limited and most healthcare professionals are unfamiliar with it. Although autonomic conditions are benign in nature, they are clinically of great importance as they may be a 'red flag' warning of an injury along the sympathetic pathway. Therefore, sound knowledge of the ANS system is essential for clinicians.

OBJECTIVE

To develop physical therapists' knowledge of and confidence in understanding cervical ANS function and dysfunction, thus enhancing clinical reasoning skills and the pattern recognition process, and performing and interpreting objective examinations.

METHODS

This master class provides an introductory guide and essential knowledge to facilitate clinicians to understand cervical autonomic dysfunctions and their clinical evaluation. The optimal referral method is also handled.

CONCLUSIONS

Gaining knowledge and understanding of the ANS, its function, its dysfunction, and the related clinical manifestations is likely to lead to a decision-making process driven by 'science and conscience'. This will empower physical therapists to be aware of subtle clues that may be offered by patients during the interview and history intake leading to the appropriate physical examination and triage.

Combining Stress Management With Pain Neuroscience Education and Exercise Therapy in People With Whiplash-Associated Disorders: A Clinical Perspective

Individuals classified as having whiplash-associated disorder (WAD) grade II, which reflects approximately 93% of people with WAD who are commonly managed by health care professionals, exhibit both physical (eg, pain and disability) and psychological (eg, fear of movement, anxiety, posttraumatic stress) problems that, in approximately 50% of cases, persist beyond 3 months. There is still much ongoing debate regarding factors predictive of poor recovery. The strongest associations have been found for high initial pain and disability following whiplash injury. In addition, a growing body of evidence supports the clinical importance of characteristic features, such as disturbed nociceptive processing (eg, local or general hyperalgesia to cold and mechanical stimuli), inefficient cognitions and beliefs about pain/movement/recovery, and posttraumatic stress symptoms, in the development and maintenance of physical and psychological manifestations in individuals with WAD. For this reason, the field shifted away from single interventions that mainly follow a biomedical approach, such as exercise therapy and activity programs, to gold standard multimodal care (at least 2 distinct therapeutic modalities given by 1 or more health care professionals) that acknowledges the biopsychological nature of WAD. To date, there exist several multimodal care approaches to managing WAD; however, for most, the efficacy has been found to be rather limited. One may argue that the limited success of some approaches can be attributed to the fact that they focused mainly on rehabilitating the physical symptoms (eg, pain, disability) rather than also the associated cognitive (eg, catastrophizing) and psychological (eg, posttraumatic stress symptoms) symptoms of the condition, leaving much room for improvement. In this article, current and previous evidence is used to explain why and how a comprehensive and multimodal treatment for people with WAD-consisting of a combination of pain neuroscience education, cognition-targeted exercise therapy, and stress management-can be applied in clinical practice.