Online Exercise Programs for Chronic Nonspecific Neck Pain: A Randomized Controlled Trial Reveals Comparable Effects of Global, Local, and Combined Approaches.

OBJECTIVE: Specific neck exercises are recommended in the rehabilitation of chronic nonspecific neck pain (CNNP). They are unfortunately often accompanied by acute pain flare-ups. Global exercises might be a beneficial addition, as they activate endogenous analgesia without overloading painful structures. However, it is still unclear which type of exercise is most effective. This randomized controlled trial was done to evaluate the effect of an online blended program of global and specific neck exercises, compared to programs including only 1 of both types of exercise. METHODS: Forty-eight patients with CNNP were randomized into 3 groups. Online questionnaires were collected at baseline, at midtreatment, immediately after treatment, and at the 3-month follow-up. Quantitative sensory testing and actigraphy were assessed at baseline and after treatment. Linear mixed-model analyses were performed to evaluate treatment effects within and between groups. Neck pain-related disability after treatment was considered the primary outcome. RESULTS: No time × treatment interaction effects were found. All groups improved in neck pain-related disability, pain intensity, self-reported symptoms of central sensitization, local pain sensitivity, physical activity, and pain medication use. No effects were found on quality of life, sleep quality, depression, anxiety, stress, widespread pain sensitivity, health economics, or actigraphy measurements. A higher global perceived effect was reported after performing the blended program, compared to the other groups. CONCLUSION: A blended exercise program was not superior to the stand-alone programs in reducing disability. Nevertheless, the global perceived effect of this type of exercise was higher. Future research necessitates larger sample sizes to adequately explore the optimal type of exercise for patients with CNNP. IMPACT: Exercise therapy should be an important part of the rehabilitation of patients with CNNP, regardless of the type of exercise.

Exploration of Somatosensory Function of Patients With Acute Nonspecific Neck Pain, Through Quantitative Sensory Testing and Self-reported Symptoms.

OBJECTIVES: Adaptations in somatosensory function characterize several chronic pain conditions, including nonspecific neck pain (NNP). Early signs of central sensitization (CS) contribute to pain chronification and poor treatment responses after conditions such as whiplash injury and low back pain. Despite this well-established association, the prevalence of CS in patients with acute NNP, and accordingly, the potential impact of this association, is still unclear. Therefore, this study aimed to investigate whether changes in somatosensory function occur during the acute phase of NNP. METHODS: This cross-sectional study compared 35 patients with acute NNP with 27 pain-free individuals. All participants completed standardized questionnaires and an extensive multimodal Quantitative Sensory Testing protocol. A secondary comparison was made with 60 patients, with chronic whiplash-associated disorders, a population wherein CS is well-established. RESULTS: Compared with pain-free individuals, pressure pain thresholds (PPTs) in remote areas and thermal detection and pain thresholds were unaltered. However, patients with acute NNP showed lower cervical PPTs and conditioned pain modulation, higher temporal summation, Central Sensitization Index scores, and pain intensity. Compared with the group with chronic whiplash-associated disorders, PPTs did not differ at any location, yet the Central Sensitization Index scores were lower. DISCUSSION: Changes in somatosensory function occur already in acute NNP. Local mechanical hyperalgesia demonstrated peripheral sensitization, while enhanced pain facilitation, impaired conditioned pain modulation, and self-reported symptoms of CS suggest adaptations in pain processing already early in the stage of NNP.

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.

Immediate effects of dry needling on pain sensitivity and pain modulation in patients with chronic idiopathic neck pain: a single-blinded randomized clinical trial.

BACKGROUND: Dry needling is frequently used for the treatment of neck pain but knowledge about its neurophysiological central effects is scarce. OBJECTIVES: To compare the immediate effects of a single session of dry needling (DN) and sham needling (SN) on local and distant pressure pain thresholds and conditioned pain modulation in patients with chronic idiopathic neck pain. METHOD: Participants with chronic idiopathic neck pain were randomly allocated to a DN or SN group. The primary outcome measure was the pressure pain threshold (PPT) at one peripheral location: quadriceps muscle (Q). Secondary outcome measures were local PPTs at the treated (most painful) (tUT) and non-treated upper trapezius muscle (ntUT), absolute and relative conditioned pain modulation (CPM) effects and pain during hot water immersion. Patients were assessed at baseline and immediately post intervention. Linear mixed models were used to examine interaction effects as well as between- and within-group differences. RESULTS: Fifty-four participants were included for statistical analysis. Linear mixed model analyses showed no significant "group X time" interaction effects for any of the outcome measures. The relative CPM effect at the Q was significantly higher post-intervention, compared to baseline within the DN group (mean difference= 13.52%; 95% CI: 0.46, 26.59). CONCLUSION: The present study shows no superior effect of DN, compared to SN, in the immediate effect on local and distant PPTs and CPM in patients with chronic idiopathic neck pain.

Individual Patterns and Temporal Trajectories of Changes in Fear and Pain during Exposure In Vivo: A Multiple Single-Case Experimental Design in Patients with Chronic Pain.

Exposure in vivo (EXP) is an effective treatment to reduce pain-related fear and disability in chronic pain populations. Yet, it remains unclear how reductions in fear and pain relate to each other. This single-case experimental design study attempted to identify patterns in the individual responses to EXP and to unravel temporal trajectories of fear and pain. Daily diaries were completed before, during and after EXP. Multilevel modelling analyses were performed to evaluate the overall effect. Temporal effects were scrutinized by individual regression analyses and determination of the time to reach a minimal clinically important difference. Furthermore, individual graphs were visually inspected for potential patterns. Twenty patients with chronic low back pain and complex regional pain syndrome type I were included. On a group level, both fear and pain were reduced following EXP. Individually, fear was significantly reduced in 65% of the patients, while pain in only 20%. A decrease in fear was seen mostly in the first weeks, while pain levels reduced later or remained unchanged. Daily measurements provided rich data on temporal trajectories of reductions in fear and pain. Overall, reductions in fear preceded pain relief and seemed to be essential to achieve pain reductions.

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.