Clinically assessed lumbopelvic sensorimotor control tests in low back pain: are they actually valid? A systematic review according to COSMIN guidelines.

BACKGROUND: Impairments in lumbopelvic sensorimotor control (SMC) are thought to be one of the underlying mechanisms for the recurrence and persistence of low back pain (LBP). As such, lumbopelvic SMC tests are frequently included in the clinical examination of patients with LBP. OBJECTIVE: To evaluate convergent and known-groups validity of clinically assessed lumbopelvic SMC tests in patients with LBP according to COSMIN guidelines. DESIGN: Systematic review METHODS: Five electronic databases were searched until December 2023. Studies examining convergent or known-groups validity of lumbopelvic SMC tests assessed via inspection or palpation in patients with LBP were included. Known-groups validity had to be assessed between patients with LBP and pain-free persons. Two independent researchers appraised risk of bias and quality of evidence (QoE) using the COSMIN Risk of Bias checklist and modified GRADE approach, respectively. Results for known-groups validity were reported separately for single tests and test-clusters. RESULTS: Twelve studies (946 participants) were included. Three studies investigated convergent validity of three single tests. Regarding known-groups validity, six studies evaluated six single tests and four studies investigated two test-clusters. For only one test, both convergent and known-groups were assessed. The QoE for tests showing sufficient convergent or known-groups validity was (very) low, whereas QoE was moderate for single tests or test-clusters with insufficient known-groups validity. CONCLUSION: All clinically assessed lumbopelvic SMC tests with sufficient convergent or known-groups validity had (very) low QoE. Therefore, test outcomes should be interpreted cautiously and strong reliance on these outcomes for clinical decision-making can currently not be recommended.

The Role of Anxiety and Depression in Shaping the Sleep-Pain Connection in Patients with Nonspecific Chronic Spinal Pain and Comorbid Insomnia: A Cross-Sectional Analysis.

(1) Background: This exploratory study aims to explore the relationship between nonspecific chronic spinal pain (nCSP) and insomnia symptoms, by examining the interconnections, strengths, and directional dependence of the symptoms. In addition, we aim to identify the key symptoms of the nCSP-insomnia relationship and shed light on the bidirectional nature of this relationship. (2) Methods: This study is a secondary analysis of the baseline data (cross-sectional) from a randomized controlled trial, which examined the added value of Cognitive Behavioral Therapy for Insomnia (CBT-I) combined with cognition-targeted exercise therapy, conducted in collaboration with the Universiteit Gent and Vrije Universiteit Brussel (Belgium). One hundred and twenty-three nCSP patients with comorbid insomnia were recruited through the participating hospitals, advertisements, announcements in local newspapers, pharmacies, publications from support groups, and primary care. To explore the interconnections and directionality between symptoms and the strengths of the relationships, we estimated a regularized Gaussian graphical model and a directed acyclic graph. (3) Results: We found only one direct, but weak, link between sleep and pain, namely, between average pain and difficulties maintaining sleep. (4) Conclusions: Despite the lack of strong direct links between sleep and pain, pain and sleep seem to be indirectly linked via anxiety and depression symptoms, acting as presumable mediators in the network of nCSP and comorbid insomnia. Furthermore, feeling slowed down and fatigue emerged as terminal nodes, implying their role as consequences of the network.

Does movement preparation enhance attending to bodily sensations in the back in people with persistent low back pain?

Attention has been proposed to play an important role in persisting pain, with excessive attentional processes towards pain information leading to worse pain outcomes and maladaptive behaviors. Nevertheless, research on somatosensory attending during the anticipation of pain-related movements is still scarce. This study investigated if individuals with chronic and recurrent lower back pain compared to pain-free controls, show enhanced attending to somatosensory information in the back while anticipating back-recruiting movements. 43 healthy control, 33 recurrent (RLBP) and 33 chronic low back (CLBP) pain sufferers were asked to perform back-recruiting movements. Before the movement initiation cue, a task-irrelevant tactile stimulus was administered to participants' lower back to elicit somatosensory evoked potentials (SEPs), used as an index of somatosensory attending. In contrast to our hypothesis, most identified SEP components did not differ across groups. The only exception was the P175 amplitude which was larger for the CLBP group compared to individuals with RLBP and healthy controls. The current study did not find robust evidence of enhanced somatosensory attending to the back in people with persisting lower back pain. The finding that CLBP, but not RLBP individuals, had larger amplitudes to the P175 component, is discussed as possibly reflecting a higher state of emotional arousal in these patients when having to prepare the back-recruiting movements.

Maximal Exercise Tolerance, Objective Trunk Strength, and Mobility Measurements in Axial Spondyloarthritis.

OBJECTIVE: Although exercise therapy is safe, effective, and recommended as a nonpharmacological treatment for axial spondyloarthritis (axSpA), there is a lack of guidelines regarding type and dosage. Insufficient knowledge about physical and physiological variables makes designing effective exercise programs challenging. Therefore, the goal of this study was to simultaneously assess trunk strength, spinal mobility, and the cardiorespiratory fitness of patients with axSpA. METHODS: In a cross-sectional study, 58 patients with axSpA (mean age 40.8 yrs, 50% male, mean symptom duration 10.3 yrs) performed maximal cervical and trunk mobility and isometric strength tests in all planes (using David Back Concept devices) and a maximal cardiopulmonary bicycle exercise test (n = 25). Mobility and strength data were compared to healthy reference data. Cut-off values for clinical cardiopulmonary exercise testing interpretation were used to judge normality. Patients were compared based on radiographic involvement and symptom duration. RESULTS: Both strength (P ≤ 0.02) and mobility (P ≤ 0.001) were significantly lower for the patients with axSpA compared to the reference. Strength deficits were comparable between the radiographic and nonradiographic groups (P > 0.05, except trunk extension [P = 0.03]), whereas mobility showed higher deficits in the radiographic group (cervical extension [P = 0.02] and rotation [P = 0.01], and trunk extension [P = 0.03] and rotation [P = 0.03]), regardless of symptom duration. Similarly, symptom duration positively affected oxygen pulse (P = 0.03), relative anaerobic threshold (P = 0.02), and aerobic capacity (P = 0.02). CONCLUSION: In patients with axSpA, strength is more affected than mobility when compared to healthy controls. Likewise, mainly the metabolic component of aerobic capacity is impaired, affecting cardiopulmonary fitness. These findings indicate that future personalized exercise programs in patients with axSpA should incorporate exercises for cardiopulmonary fitness next to strength and mobility training.

Comparing physical therapy students' attitudes and beliefs regarding chronic low back pain and knee osteoarthritis: an international multi-institutional comparison between 2013 and 2020 academic years.

BACKGROUND: In 2013, physical therapy students demonstrated low guideline-adherent recommendations regarding chronic low back pain (CLBP) for spinal pathology, activity, and work. OBJECTIVES: To assess the differences in physical therapy students' attitudes, beliefs, and adherence to guideline recommendations regarding CLBP and knee osteoarthritis between 2013 and 2020. METHODS: In 2013 and 2020, second and fourth-year physical therapy students were recruited from 6 Belgian and 2 Dutch institutions. Attitudes and beliefs regarding CLBP and knee OA were evaluated using the Pain Attitudes and Beliefs Scale for Physiotherapists (PABS-PT), the Health Care Providers' Pain and Impairment Relationship Scale (HC-PAIRS), and a questionnaire regarding therapeutic exercise and knee osteoarthritis. A clinical vignette was used to measure guideline-adherent recommendations regarding spinal pathology, activity, and work. RESULTS: In 2013, 927 second-year and 695 fourth-year students; in 2020, 695 second-year and 489 fourth-year students; were recruited to participate in the study. Compared to 2013, students had less biomedical and stronger biopsychosocial attitudes and beliefs regarding CLBP, more guideline-adherent recommendations for activity, and more biopsychosocial beliefs regarding the benefits of exercise for patients with knee osteoarthritis in both the second and fourth year. Only fourth-year students in 2020 scored significantly better on HC-PAIRS and guideline-adherent recommendation relating to spinal pathology. No differences were found regarding work recommendations. CONCLUSIONS: Between 2013 and 2020, physical therapy students made a positive shift towards a more biopsychosocial approach to CLBP and knee osteoarthritis management. Guideline-adherent recommendations for CLBP concerning activity improved, however, concerning work and spinal pathology, it remained low.

Nociceptive, neuropathic, or nociplastic low back pain? The low back pain phenotyping (BACPAP) consortium's international and multidisciplinary consensus recommendations.

The potential to classify low back pain as being characterised by dominant nociceptive, neuropathic, or nociplastic mechanisms is a clinically relevant issue. Preliminary evidence suggests that these low back pain phenotypes might respond differently to treatments; however, more research must be done before making specific recommendations. Accordingly, the low back pain phenotyping (BACPAP) consortium was established as a group of 36 clinicians and researchers from 13 countries (five continents) and 29 institutions, to apply a modified Nominal Group Technique methodology to develop international and multidisciplinary consensus recommendations to provide guidance for identifying the dominant pain phenotype in patients with low back pain, and potentially adapt pain management strategies. The BACPAP consortium's recommendations are also intended to provide direction for future clinical research by building on the established clinical criteria for neuropathic and nociplastic pain. The BACPAP consortium's consensus recommendations are a necessary early step in the process to determine if personalised pain medicine based on pain phenotypes is feasible for low back pain management. Therefore, these recommendations are not ready to be implemented in clinical practice until additional evidence is generated that is specific to these low back pain phenotypes.

Exploring Interactions Between Sex, Pain Characteristics, Disability, and Quality of Life in People With Chronic Spinal Pain: A Structural Equation Model.

In people with nonspecific chronic spinal pain (nCSP), disability and quality of life are associated with clinical, cognitive, psychophysical, and demographic variables. However, evidence regarding the interactions between these variables is only limited to this population. Therefore, this study aims to explore path models explaining the multivariate contributions of such variables to disability and quality of life in people with nCSP. This secondary analysis uses baseline data from a randomized controlled trial including 120 participants with nCSP. Structural equation modeling was used to explore path models for the Pain Disability Index (PDI), the Short Form 36-item physical (SF-36 PC), and mental (SF-36 MC) component scores. All models included sex, pain catastrophizing, kinesiophobia, hypervigilance, and pain intensity. Additionally, the PDI and SF-36 PC models included pressure pain thresholds (PPTs) at the dominant pain site (ie, neck or low back). Significant associations were found between sex, pain cognitions, pain intensity, and PPTs. Only pain catastrophizing significantly directly influenced the PDI (P ≤ .001) and SF-36 MC (P = .014), while the direct effects on the SF-36 PC from kinesiophobia (P = .008) and pain intensity (P = .006) were also significant. However, only the combined effect of all pain cognitions on the SF-36 PC was mediated by pain intensity (P = .019). Our findings indicate that patients' pain-related cognitions have an adverse effect on their physical health-related quality of life via a negative influence on their pain intensity in people with nCSP. PERSPECTIVE: This secondary analysis details a network analysis confirming significant interactions between sex, pain cognitions, pain intensity, and PPTs in relation to disability and health-related quality of life in people with chronic spinal pain. Moreover, its findings establish the importance of pain cognitions and pain intensity for these outcomes. TRIALS REGISTRATION: Clinicaltrials.gov (NCT02098005).

Do Patients with Chronic Spinal Pain and Comorbid Insomnia Have More Features of Central Sensitization? A Case-Control Study.

BACKGROUND: Chronic spinal pain (CSP) is a major public health problem worldwide, frequently related to sleep problems. Central sensitization (CS) may worsen the clinical picture of CSP patients with insomnia. The aim of this study was to compare self-reported and objectively measured clinical outcomes between insomniac CSP patients with comorbid insomnia with and without symptoms of CS. METHODS: A case-control study on baseline self-reported sleep, functioning, and psychological distress through online questionnaires. Objective sleep and physical activity parameters and pressure pain thresholds (PPTs) were assessed through polysomnography, actigraphy, and digital algometry, respectively. Independent sample t-test and Mann-Whitney U tests were used to examine possible differences in the outcome measures between the groups. RESULTS: Data from 123 participants were included and revealed no statistically significant group for objective sleep and physical activity parameters. The CS group, however, presented with worse self-reported sleep (quality sleep, insomnia severity, and dysfunctional beliefs about sleep), increased mental and physical fatigue, and higher psychological distress (anxiety and depressive symptoms), and reported lower PPTs. CONCLUSIONS: symptoms of CS may influence perceived sleep and affect functional health and well-being perception but do not seem to affect objective sleep and physical activity.

The Role of Back Muscle Dysfunctions in Chronic Low Back Pain: State-of-the-Art and Clinical Implications.

Changes in back muscle function and structure are highly prevalent in patients with chronic low back pain (CLBP). Since large heterogeneity in clinical presentation and back muscle dysfunctions exists within this population, the potential role of back muscle dysfunctions in the persistence of low back pain differs between individuals. Consequently, interventions should be tailored to the individual patient and be based on a thorough clinical examination taking into account the multidimensional nature of CLBP. Considering the complexity of this process, we will provide a state-of-the-art update on back muscle dysfunctions in patients with CLBP and their implications for treatment. To this end, we will first give an overview of (1) dysfunctions in back muscle structure and function, (2) the potential of exercise therapy to address these dysfunctions, and (3) the relationship between changes in back muscle dysfunctions and clinical parameters. In a second part, we will describe a framework for an individualised approach for back muscle training in patients with CLBP.

Relationship, differences, and agreement between objective and subjective sleep measures in chronic spinal pain patients with comorbid insomnia: a cross-sectional study.

ABSTRACT: Sleep disturbances are one of the most frequent reported problems in people with nonspecific chronic spinal pain (nCSP) and presents an additional treatment challenge. Interventions targeting sleep problems are mainly based on subjective sleep complaints and do not take objective sleep into consideration. The aim of this cross-sectional study was to evaluate the relationship and conformity between self-reported and objectively measured sleep parameters (ie, questionnaire vs polysomnography and actigraphy). The baseline data of 123 people with nCSP and comorbid insomnia who are participating in a randomized controlled trial were analyzed. Pearson correlations were used to investigate the relationship between objective and subjective sleep parameters. Differences between objective and subjective sleep parameters were analyzed using t tests. Bland-Altman analyses were performed to quantify and visualize agreement between the different measurement methods. Except for the significant moderate correlation between perceived time in bed (TIB) and actigraphic TIB ( r = 0.667, P < 0.001), all other associations between subjective and objective measures were rather weak ( r < 0.400). Participants underestimated their total sleep time (TST) (mean difference [MD] = -52.37 [-67.94, -36.81], P < 0.001) and overestimated sleep onset latency (SOL) (MD = 13.76 [8.33, 19.20], P < 0.001) in general. The results of this study suggest a discrepancy (differences and lack of agreement) between subjective and objective sleep parameters in people with nCSP and comorbid insomnia. No or weak associations were found between self-reported sleep and objectively measured sleep. Findings suggest that people with nCSP and comorbid insomnia tend to underestimate TST and overestimate SOL. Future studies are necessary to confirm our results.

Predictors for physical activity and its change after active physical therapy in people with spinal pain and insomnia: Secondary analysis of a randomized controlled trial.

BACKGROUND: In healthy people and people with nonspecific chronic spinal pain (nCSP) and/or insomnia, participation in physical activity on a regular basis has several physical and psychological health benefits. However, people with chronic conditions often tend to reduce physical activity participation which can lead to deconditioning over time. Currently, there are no known predictors for an (in)active lifestyle (before and after physical therapy treatment) in people with chronic spinal pain and comorbid insomnia. OBJECTIVE: To examine predictors of pre-treatment moderate-to-vigorous physical activity (MVPA) and to examine determinants for a change in MVPA in response to 14-weeks of active physical therapy treatment in people with nonspecific chronic spinal pain (nCSP) and comorbid insomnia. METHODS: Baseline data and post-treatment data were analyzed for 66 participants. A linear multiple regression analysis was conducted to examine which factors predict MVPA at baseline. Linear mixed-effects modeling was used to identify determinants for change in MVPA in response to an active physical therapy treatment. RESULTS: Physical fatigue (b = -0.9; 95%CI: -1.59, -0.15), less limitations in functioning as a result of emotional problems (b = 0.1; 95%CI: 0.03, 0.10), mental fatigue (b = -1.0; 95%CI: -1.67, -0.43), lower general sleep quality (b= 0.7; 95%CI: 0.22, 1.17), and body mass index (b = -0.5; 95%CI: -0.93, -0.16) were significant predictors of baseline MVPA. The regression model explained 33.3% of the total variance in baseline MVPA. The change of MVPA in response to the treatment ranged from a decrease of 17.5 to an increase of 16.6 hours per week. No determinants for change in MVPA after treatment could be identified. CONCLUSION: People with nCSP and comorbid insomnia are more likely to engage in MVPA if they report, at baseline, lower sleep quality, fewer limitations in functioning resulting from emotional problems, lower body mass index, as well as less physical and mental fatigue.

The Relationship Between Pain-Related Psychological Factors and Maximal Physical Performance in Low Back Pain: A Systematic Review and Meta-Analysis.

Theoretical frameworks explain how pain-related psychological factors may influence the physical performance. In this systematic review and meta-analysis, we evaluated the evidence regarding the relationship between the pain-related psychological factors and the maximal physical performance in patients with low back pain (LBP). Pubmed, Embase, CINAHL and Web of Science databases were searched from inception to May 2022. Cross-sectional or longitudinal studies reporting cross-sectional measures of association between at least one pain-related psychological factor and a quantitatively measured outcome of maximal physical performance in patients with LBP were eligible for inclusion. Thirty-eight studies (n = 2,490; 27 cross-sectional studies, n = 1,647 (66%); 11 longitudinal studies, n = 843 (34%)) were included, with 92% of participants (n = 2,284) having chronic LBP. Results showed that pain-related fear, pain catastrophizing, and anticipated pain were consistently and negatively associated with the maximal physical performance in chronic LBP, whereas pain-self efficacy showed positive correlations. Overall, magnitudes of absolute pooled r-values were small (r ≤ 0.25), except for anticipated pain, which was moderately associated with maximal physical performance (r = -0.34 to -0.37). Subanalyses and sensitivity analyses yielded similar pooled correlation coefficients. Certainty of evidence using the GRADE recommendations was very low to moderate for pain-related fear, and very low to low for the other pain-related psychological factors. Prospero registration: CRD42021227486. PERSPECTIVE: Overall, small pooled correlation coefficients were shown between pain-related psychological factors and maximal physical performance in chronic LBP. Certainty of evidence was very low to low for all pain-related psychological factors other than pain-related fear. Future studies taking into account limitations of the current literature may therefore change these conclusions.

Combining Cognitive Behavioral Therapy for Insomnia and Chronic Spinal Pain Within Physical Therapy: A Practical Guide for the Implementation of an Integrated Approach.

Most people who have nonspecific chronic spinal pain (nCSP) report comorbid insomnia. However, in current treatment strategies for nCSP, insomnia is usually not addressed. Considering the bidirectional interaction between pain and sleep and its underlying psychophysiological mechanisms, insomnia may increase the risk of developing adverse physical and psychological health outcomes and should thus no longer be left untreated. As suggested by previous pilot studies, adding cognitive behavioral therapy for insomnia to the contemporary evidence-based biopsychosocial physical therapy approach may also improve pain outcomes in nCSP. This manuscript aims to provide practical guidelines on hybrid physical therapy, including the combination of the following components: (1) pain neuroscience education (eg, to reconceptualize pain) and cognition-targeted exercise therapy (eg, graded exposure to functional daily life movements), and (2) cognitive behavioral therapy for insomnia (sleep psychoeducation, behavioral and cognitive therapy, correction of sleep hygiene, and relaxation therapy) can be deployed for the management of patients who have chronic spinal pain. Impact. Due to the major impact sleep disturbances have on pain and disability, insomnia as a comorbidity should no longer be ignored when treating patients with chronic spinal pain.

Reliability and discriminative validity of a screening tool for the assessment of neuromuscular control and movement control in patients with neck pain and healthy individuals.

BACKGROUND: To evaluate the reliability and discriminative validity of a proposed adapted tool for the assessment of movement control in patients with and without neck pain. METHOD: A cross-sectional study at a University hospital center involving 25 pain-free healthy controls and 25 patients suffering from neck pain. Participants were assessed by two raters for inter-rater reliability and 1 week afterwards by a same rater for intra-rater reliability. The assessment involved a test for the axioscapular (adapted scapular holding test; SHT) and craniocervical (adapted craniocervical flexion test; CCFT) region for which intra-class correlation coefficients (ICCs) were computed to define the reliability. Discriminative validity to distinguish patients from controls was assessed by cross-validated computation of sensitivity, specificity, positive and negative likelihood ratios, overall accuracy, and area under the curve. RESULTS: The proposed tool was able to reliably assess sensorimotor impairment in participants at the craniocervical region (ICCintra = [0.52-0.82]; ICCinter = [0.60-0.85]), left axioscapular region (ICCintra = [0.43-0.77]; ICCinter = 0.71-0.90), and right axioscapular region (ICCintra = [0.47-0.79]; ICCinter = [0.42-0.77]). Furthermore, the tool yielded a sensitivity of 0.86, a specificity of 0.57, and accuracy of 0.71 (based on cross-validation). CONCLUSION: The proposed tool is able to reliably evaluate patients based on their sensorimotor performance in the craniocervical and axioscapular region.Implications for rehabilitationNeck pain is related to sensorimotor impairment including neuromuscular differences and atypical sensormimotor control strategies.Clinicians should not avoid the challenging task of screening for sensorimotor impairment in patients reporting neck pain.The proposed tool supplemented with other tools might guide clinicians in the evaluation of sensorimotor impairment.

Influence of education level on the effectiveness of pain neuroscience education: A secondary analysis of a randomized controlled trial.

BACKGROUND: Current evidence supports the use of pain neuroscience education (PNE) in several chronic pain populations. However, the effects of PNE at group level are rather small and little is known about the influence of personal factors (e.g. level of education [LoE]). OBJECTIVE: To examine whether the effectiveness of PNE differs in chronic spinal pain (CSP) patients with high LOE (at least a Bachelor's degree) versus lower educated patients. METHOD: A total of 120 Belgian CSP patients were randomly assigned to the experimental (PNE) or control group (biomedical-focused neck/back school). Participants within each group were further subcategorized based on highest achieved LoE. ANOVA and Bonferroni post-hoc analyses were used to evaluate differences in effectiveness of the interventions between higher and lower educated participants. RESULTS: No differences between higher and lower educated participants were identified for pain-related disability. Significant interactions (P < .05) were found for kinesiophobia and several illness perceptions components. Bonferroni post-hoc analysis revealed a significant improvement in kinesiophobia (P < .001 and P < .002, medium effect sizes) and perceived negative consequences (P < .001 and P < .008, small effect sizes) in the PNE groups. Only the higher education PNE group showed a significant improvement in perceived illness cyclicity (P = .003, small effect size). Post-treatment kinesiophobia was significant lower in the higher educated PNE group compared to the higher educated control group (p < .001). CONCLUSION: Overall, the exploratory findings suggest no clinical meaningful differences in effectiveness of PNE between higher and lower educated people. PNE is effective in improving kinesiophobia and several aspects of illness perceptions regardless of LoE.

Modulation of the nociceptive flexion reflex by conservative therapy in patients and healthy people: a systematic review and meta-analysis.

ABSTRACT: The nociceptive flexion reflex (NFR) is a spinally mediated withdrawal response and is used as an electrophysiological marker of descending modulation of spinal nociception. Chemical and pharmacological modulation of nociceptive neurotransmission at the spinal level has been evidenced by direct effects of neurotransmitters and pharmacological agents on the NFR. Largely unexplored are, however, the effects of nonpharmacological noninvasive conservative interventions on the NFR. Therefore, a systematic review and meta-analysis was performed and reported following the PRISMA guidelines to determine whether and to what extent spinal nociception measured through the assessment of the NFR is modulated by conservative therapy in patients and healthy individuals. Five electronic databases were searched to identify relevant articles. Retrieved articles were screened on eligibility using the predefined inclusion criteria. Risk of bias was investigated according to Version 2 of the Cochrane risk-of-bias assessment tool for randomized trials. The evidence synthesis for this review was conducted in accordance with the Grading of Recommendations Assessment, Development and Evaluation. Thirty-six articles were included. Meta-analyses provided low-quality evidence showing that conservative therapy decreases NFR area and NFR magnitude and moderate-quality evidence for increases in NFR latency. This suggests that conservative interventions can exert immediate central effects by activating descending inhibitory pathways to reduce spinal nociception. Such interventions may help prevent and treat chronic pain characterized by enhanced spinal nociception. Furthermore, given the responsiveness of the NFR to conservative interventions, the NFR assessment seems to be an appropriate tool in empirical evaluations of treatment strategies.PROSPERO registration number: CRD42020164495.

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.

Reduced Parasympathetic Reactivation during Recovery from Exercise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Although autonomic nervous system (ANS) dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) has been proposed, conflicting evidence makes it difficult to draw firm conclusions regarding ANS activity at rest in ME/CFS patients. Although severe exercise intolerance is one of the core features of ME/CFS, little attempts have been made to study ANS responses to physical exercise. Therefore, impairments in ANS activation at rest and following exercise were examined using a case-control study in 20 ME/CFS patients and 20 healthy people. Different autonomous variables, including cardiac, respiratory, and electrodermal responses were assessed at rest and following an acute exercise bout. At rest, parameters in the time-domain represented normal autonomic function in ME/CFS, while frequency-domain parameters indicated the possible presence of diminished (para)sympathetic activation. Reduced parasympathetic reactivation during recovery from exercise was observed in ME/CFS. This is the first study showing reduced parasympathetic reactivation during recovery from physical exercise in ME/CFS. Delayed HR recovery and/or a reduced HRV as seen in ME/CFS have been associated with poor disease prognosis, high risk for adverse cardiac events, and morbidity in other pathologies, implying that future studies should examine whether this is also the case in ME/CFS and how to safely improve HR recovery in this population.