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.

Disability and return to work after a multidisciplinary intervention for (sub)acute low back pain: A systematic review.

OBJECTIVE: This systematic review aimed to examine pain, functional status and return to work after a multidisciplinary intervention, with or without additional workplace intervention, for (sub)acute low back pain among adults. DATA SOURCES: A comprehensive search was completed (November 2022) in six electronic databases (Embase, MEDLINE, Web of Science, Cochrane, CENTRAL and Scopus) and in the reference list of all identified studies. REVIEW METHODS: The search results were screened against predefined eligibility criteria by two independent researchers. Included articles were systematic reviews or randomized controlled trials examining the effect of a multidisciplinary intervention, with or without workplace intervention, in working adults with (sub)acute low back pain. Relevant information was summarized and clustered, and the methodological quality and certainty of evidence were assessed respectively using the RoB 2-tool, the ROBIS tool and the GRADE criteria. RESULTS: The search resulted in a total of 3020 articles. After the screening process, 12 studies remained (11 randomized controlled trials and 1 systematic review), which studied overall 2751 patients, with a follow-up period of at least 12 months. CONCLUSIONS: A multidisciplinary intervention is favorable compared to usual care for pain intensity and functional status but this is less clear for return to work. Comparable work-related effects were found when comparing a multidisciplinary intervention with a less extensive intervention, whereas uncertainties exist regarding outcomes of pain intensity and functional status. Furthermore, adding a workplace intervention to usual care and subdividing patients based on work-related characteristics seems beneficial for return to work.

Temporal changes in pain processing after whiplash injury, based on Quantitative Sensory Testing: A systematic review.

BACKGROUND AND OBJECTIVE: After whiplash injury, some patients develop chronic whiplash-associated disorders. The exact pathophysiology of this chronification is still unclear and more knowledge is needed regarding the different post-injury phases. Therefore, studies were searched that examined temporal changes in pain processing, measured by Quantitative Sensory Testing (QST). DATABASES AND DATA TREATMENT: This systematic review searched three electronic databases (Medline, Web of Science and Embase) for articles meeting the eligibility requirements. Risk of bias was assessed according to a modified Newcastle-Ottawa Scale. RESULTS: The 12 included studies presented moderate to good methodological quality. These studies showed altered pain processing within the first month after injury and normalization within 3 months in 59%-78% of the patients. After 3 months, recovery stagnates during the following years. Thermal and widespread mechanical hyperalgesia occur already in the acute phase, but only in eventually non-recovered patients. CONCLUSIONS: Differences in pain processing between recovering and non-recovering patients can be observed already in the acute phase. Early screening for signs of altered pain processing can identify patients with high risk for chronification. These insights in temporal changes show the importance of rehabilitation in the acute phase. Future research should target to develop a standardized (bed-site) QST protocol and collect normative data which could, in relation with self-reported pain parameters, allow clinicians to identify the risk for chronification. SIGNIFICANCE: Altered pain processing is present soon after whiplash injury, but usually recovers within 3 months. Non-recovering patients show little to no improvements in the following years. Differences between recovering and non-recovering patients can be observed by Quantitative Sensory Testing already in the acute phase. Therefore, it is considered a feasible and effective tool that can contribute to the identification of high-risk patients and the prevention of chronification.

Are Reports of Pain, Disability, Quality of Life, Psychological Factors, and Central Sensitization Related to Outcomes of Quantitative Sensory Testing in Patients Suffering From Chronic Whiplash Associated Disorders?

BACKGROUND: Chronic whiplash associated disorders (CWAD) are characterized by long-lasting symptoms of neck pain occurring after an acceleration-deceleration injury. Central sensitization (CS) has been suggested as the possible underlying mechanism for these symptoms, and is characterized by changes in the central nervous system. Besides CS, psychological factors are believed to play an important role in the experience of (chronic) pain. OBJECTIVE: Investigating the relationships between self-reported pain, disability, quality of life, psychological factors, and symptoms of CS; and electrical-based quantitative sensory testing (QST) outcomes in CWAD patients. Secondly, to investigate the differences in QST between CWAD patients and pain-free controls. METHODS: Seventy-two individuals with CWAD and 55 pain-free controls underwent electrical stimuli-based QST. Detection and pain thresholds (EPT), temporal summation (TS), and conditioned pain modulation were examined. Spearman correlation and linear mixed models analyses were performed to assess, respectively, the hypothesized associations and group differences in QST. RESULTS: The Pain Catastrophizing magnification subscale correlated with the left wrist EPT (r=-0.332; P=0.004), and the Pain Anxiety Symptom Scale-20 with the left wrist (r=-0.325; P=0.005) and ankle (r=-0.330; P=0.005) EPT. TS at the ankle correlated with the CS inventory (r=0.303; P=0.010), Short Form 36 pain subscale (r=-0.325; P=0.005), and Illness Perception Questionnaire revised consequences subscale (r=0.325; P=0.005). EPTs left (P=0.011) and right wrist (P=0.023) were lower in the CWAD group, but conditioned pain modulation and TS did not differ between groups. CONCLUSION: QST outcomes relate to psychological constructs, rather than to self-reported pain intensity and distribution. Local hyperalgesia was found in individuals with CWAD, but no differences in endogenous pain facilitation nor inhibition.