Lower Pressure Pain Thresholds Research Articles

Pain Sensitization and Neuropathic Pain-like Symptoms Associated with Effectiveness of Exercise Therapy in Patients with Hip and Knee Osteoarthritis.

Pain sensitization and neuropathic pain-like symptoms are some of the common pain symptoms in patients with lower limbs, including hip and knee, osteoarthritis (HOA/KOA). Exercise therapy has been the first-line treatment; however, the effects differ for each patient. This prospective cohort study investigated the relationship between the effectiveness of exercise therapy and pretreatment characteristics (radiologic severity, pain sensitization, and neuropathic pain-like symptoms) of patients with HOA/KOA. We assessed the pain intensity using a numerical rating scale (NRS) before and after 12 weeks of exercise therapy in patients with HOA/KOA (n = 101). Before treatment, the Kellgren–Lawrence (K-L) grade; minimum joint space width (mJSW); pressure pain threshold (PPT) and temporal summation of pain (TSP) at the affected joint, tibia, and forearm; Central Sensitization Inventory-9; and painDETECT questionnaire (PDQ) were assessed. Cluster analysis was based on the pretreatment NRS and change in NRS with exercise therapy to identify the subgroups of pain reduction. The pretreatment characteristics of each cluster were compared. According to the results of the cluster analyses, patients in cluster 1 had severe pain that did not improve after exercise therapy, patients in cluster 2 had severe pain that improved, and those in cluster 3 had mild pain that improved. The patients in cluster 1 exhibited lower PPT at all measurement sites, higher TSP at the affected joint, and higher PDQ scores than those in other clusters. There was no difference in the K-L grade and mJSW among the clusters. The subgroup with severe pain and pain sensitization or neuropathic pain-like symptoms at pretreatment, even with mild joint deformity, may have difficulty in achieving improvement in pain after 12 weeks of exercise therapy. These findings could be useful for prognosis prediction and for planning exercise therapy and combining with other treatment.

Chronic postoperative pain after total knee arthroplasty: The potential contributions of synovitis, pain sensitization and pain catastrophizing-An explorative study.

BackgroundA subset of osteoarthritis patients will experience chronic postoperative pain after total knee arthroplasty (TKA), but the source of pain is unclear. The aim of this exploratory study was to assess patients with and without postoperative pain after TKA using magnetic resonance imaging (MRI), quantitative sensory testing (QST), clinical assessment of pain and assessments of catastrophizing thoughts.MethodsForty‐six patients completed the 6‐month postoperative assessment. MRI findings were scored according to the MRI Osteoarthritis Knee Score recommendation for Hoffa synovitis, effusion size and bone marrow lesions. QST included assessment of pressure pain thresholds (PPTs), temporal summation of pain (TSP) and conditioned pain modulation (CPM). Pain catastrophizing was assessed using the Pain Catastrophizing Scale (PCS). Clinical pain assessment was conducted using a visual analogue scale (VAS, 0–10 cm), and groups of moderate‐to‐severe (VAS > 3) and none‐to‐mild postoperative pain (VAS ≤ 3) were identified.ResultsPatients with moderate‐to‐severe postoperative pain (N = 15) demonstrated higher grades of Hoffa synovitis (p < 0.001) and effusion size (p < 0.001), lower PPTs (p = 0.039), higher TSP (p = 0.001) and lower CPM (p = 0.014) when compared with patients with none‐to‐mild postoperative pain (N = 31). No significant difference was found in PCS scores between the two groups. Multiple linear regression models found synovitis (p = 0.036), effusion size (p = 0.003), TSP (p = 0.013) and PCS (p < 0.001) as independent parameters contributing to the postoperative pain intensity.ConclusionThese exploratory findings could indicate that chronic postoperative pain after TKA is a combination of joint‐related synovitis and effusion, sensitization of central pain mechanisms and potentially pain catastrophizing thoughts, but larger studies are needed to confirm this.SignificanceThe end‐stage treatment of knee osteoarthritis is total knee arthroplasty. Some patients experience chronic postoperative pain after total knee arthroplasty, but the mechanism for chronic postoperative pain is widely unknown. The current study indicates that higher levels postoperative of synovitis and effusion, higher temporal summation of pain and higher pain catastrophizing scores could be associated with higher chronic postoperative pain.

Applying the Rapid OPPERA Algorithm to Predict Persistent Pain Outcomes Among a Cohort of Women Undergoing Breast Cancer Surgery

Persistent postmastectomy pain after breast surgery is variable in duration and severity across patients, due in part to interindividual variability in pain processing. The Rapid OPPERA Algorithm (ROPA) empirically identified 3 clusters of patients with different risk of chronic pain based on 4 key psychophysical and psychosocial characteristics. We aimed to test this type of group-based clustering within in a perioperative cohort undergoing breast surgery to investigate differences in postsurgical pain outcomes. Women (N = 228) scheduled for breast cancer surgery were prospectively enrolled in a longitudinal observational study. Pressure pain threshold (PPT), anxiety, depression, and somatization were assessed preoperatively. At 2-weeks, 3, 6, and 12-months after surgery, patients reported surgical area pain severity, impact of pain on cognitive/emotional and physical functioning, and pain catastrophizing. The ROPA clustering, which used patients’ preoperative anxiety, depression, somatization, and PPT scores, assigned patients to 3 groups: Adaptive (low psychosocial scores, high PPT), Pain Sensitive (moderate psychosocial scores, low PPT), and Global Symptoms (high psychosocial scores, moderate PPT). The Global Symptoms cluster, compared to other clusters, reported significantly worse persistent pain outcomes following surgery. Findings suggest that patient characteristic-based clustering algorithms, like ROPA, may generalize across diverse diagnoses and clinical settings, indicating the importance of “person type” in understanding pain variability. PerspectiveThis article presents the practical translation of a previously developed patient clustering solution, based within a chronic pain cohort, to a perioperative cohort of women undergoing breast cancer surgery. Such preoperative characterization could potentially help clinicians apply personalized interventions based on predictions concerning postsurgical pain.

Total tenderness score and pressure pain thresholds in persistent post-traumatic headache attributed to mild traumatic brain injury

ObjectiveTo investigate whether persistent post-traumatic headache attributed to mild traumatic brain injury (TBI) is associated with more pronounced pericranial tenderness and lower pressure pain thresholds (PPTs) in the head and neck region, compared with healthy controls.MethodsPatients with persistent post-traumatic headache (n = 100) and age- and gender-matched healthy controls (n = 100) were included between July 2018 and June 2019. Total tenderness score (TTS) was used to assess pericranial tenderness by bilateral manual palpation in eight muscles or tendon insertions. Summation was then used to calculate a TTS from 0 to 48 based on individual right- and left-sided scores; higher TTS score indicated more pronounced pericranial tenderness. PPTs were examined in m. temporalis and m. trapezius (upper and middle part) using an electronic pressure algometer that applies increasing blunt pressure at a constant rate.ResultsThe TTS score was higher in patients with persistent post-traumatic headache (median, 21; IQR, 12–31), compared with healthy controls (median, 10; IQR, 6–17; P < .001). PPTs were lower in patients with persistent post-traumatic headache than in controls in both the left-sided m. temporalis (mean ± SD, 157.5 ± 59.9 vs. 201.1 ± 65.2; P < .001) and right-sided m. temporalis (mean ± SD, 159.5 ± 63.8 vs. 212.3 ± 61.9; P < .001). Furthermore, patients with persistent post-traumatic headache also had lower left- and right-sided PPTs in the upper as well as middle part of m. trapezius, compared with healthy controls; all P values were .05 or less.ConclusionsAmong patients with persistent post-traumatic headache, pericranial tenderness was more pronounced and PPTs in the head and neck region were lower than in healthy controls free of headache and mild TBI. Further research is needed to better understand the involvement of pericranial myofascial nociceptors in the disease mechanisms underlying post-traumatic headache.

Susceptibility to movement-evoked pain following resistance exercise.

ObjectiveTo investigate the: (1) role of basic muscle pain sensitivity and psychological factors in the prediction of movement-evoked pain (MEP) following delayed onset muscle soreness (DOMS), and (2) association of MEP with changes in systemic muscle pain sensitivity following DOMS induction.MethodsFifty-one participants were assigned to either eccentric resistance exercise or control groups. They completed questionnaires evaluating psychological distress and underwent muscle pain sensitivity evaluation by the pressure pain threshold (PPT) test at the exercised and remote muscles, before and 24 hours following the intervention. MEP intensity was determined in response to lifting a 3kg canister using a visual analogue scale (VAS).ResultsThe exercise group demonstrated MEP intensity of 5/10 on VAS and reduced PPTs at the main exercised muscle (p<0.001). A regression tree analyses revealed that the level of anxiety trait predicted a higher MEP intensity. A secondary analysis showed that 53% participants who were DOMS responders (MEP > mild intensity; ≥ 3/10 VAS) exhibited decreased PPTs in the exercised (p<0.001) and remote (p = 0.027) muscles following eccentric exercise. Characterization of DOMS responders revealed that, at baseline, they had lower PPTs in the exercised (p = 0.004) and remote (p = 0.001) muscles and reported higher psychological distress i.e., anxiety trait and depression symptoms (p<0.05), compared to non-responders. A regression analysis revealed that lower PPT or high levels of anxiety trait increased the probability to become a responder (p = 0.001).ConclusionsSusceptibility to MEP following DOMS is determined by muscle pain hypersensitivity and high levels of anxiety trait. MEP at the early stage of DOMS is linked with an increase in systemic muscle pain sensitivity suggestive of central mechanisms. This knowledge is valuable in translating science into clinical musculoskeletal pain management.

The association of the localized pain sensitivity in the residual limb and prosthesis use in male veterans with transtibial amputation

ABSTRACT The association of localized pain sensitivity in the residual limb and prosthesis use has clinical implications, however, rarely been assessed. This study aimed to investigate pain sensitivity and explore its range, variability, and association with prosthesis use alongside other demographic and clinical characteristics of veterans with transtibial amputation. Pain sensitivity was determined as pressure pain threshold (PPT) and pressure tolerance (PT) in 19 male veterans with a mean age of 49.5 years using pressure algometry at 12 anatomical locations on‎ the residual limb. A comparison of pain sensitivity at each location, and among anatomical locations and participants was explored using independent t-test, analysis of variance, and Kruskal–Wallis tests, respectively. Pain sensitivity range (PSR), the difference between PT and PPT, was significantly different (p < 0.05) at mid-patellar tendon, medial tibial flare, and the distal end of the tibia. The lowest PPT and PT (20.5 and 33 Ncm−2, p = 0.13) were recorded at the distal end of the residual limb, and the highest PPT and PT (73.4 and 94.3 Ncm−2, p = 0.03) were recorded at the mid-patellar tendon. Pain sensitivity was significantly different among anatomical locations and participants. The correlation tests (Pearson and partial eta squared) showed non-significant associations of pain sensitivity with participants’ demographic and clinical characteristics except for daily prosthesis use. The mid-patellar tendon, medial tibial flare, and distal end of the tibia revealed the lowest pain hypersensitivity ‎due to higher PSR. Longer daily prosthesis use was associated with increased pain sensitivity.

Association between pelvic pain bothersomeness and pain sensitivity: A community-based cross-sectional study of young adult females in the Raine Study.

Pelvic pain has been associated with augmented nociceptive processing, but large studies controlling for multiple potential confounding factors are lacking. This study investigated the association between pelvic pain bothersomeness and pain sensitivity in young adult women, accounting for potential confounding factors. Cross-sectional study. Community-dwelling sample. The Raine Study Gen2-22 year follow-up (n=475). The experience of bothersomeness related to pelvic pain was determined from a question in the Urogenital Distress Inventory short form. Pain sensitivity was measured using pressure pain and cold pain thresholds. Potential confounding factors included ethnicity, marital status, highest level of education, income, waist-hip ratio, level of activity, sleep quality, smoking, comorbidity history, C-reactive protein level, musculoskeletal pain experience and psychological distress. Three hundred and sixty-two women (76.2%) reported no pelvic pain bothersomeness, 74 (15.6%) reported mild pelvic pain bothersomeness and 39 (8.2%) reported moderate-severe pelvic pain bothersomeness. After adjusting for marital status (and test site), moderate-severe pelvic pain bothersomeness was associated with a lower pressure pain threshold (i.e. greater pressure pain sensitivity) (coefficient -51.46, 95%CI -98.06 to -4.86, p=0.030). After adjusting for smoking, moderate-severe pelvic pain bothersomeness was also associated with a higher cold pain threshold (i.e. greater cold pain sensitivity) (coefficient 4.35, 95%CI 0.90-7.79, p=0.014). This study suggests augmented nociceptive processing as a contributing factor in pelvic pain bothersomeness for some women. Thorough assessment of women who present clinically with pelvic pain should consider pain sensitivity as a potential contributing factor to their presentation.

Application of painDETECT in Pediatric Chronic Pain: How Well Does It Identify Neuropathic Pain and Its Characteristics?

Pediatric neuropathic pain is difficult to diagnose, and when undetected is associated with functional disability, mental health concerns, and decreased quality of life. PainDETECT is a screening tool developed to differentiate neuropathic from nociceptive pain components, thus guiding treatment decision-making and improving outcomes. Therefore, the purpose of this study was to evaluate how well painDETECT can identify neuropathic pain and its characteristics in a pediatric population. Adolescents (10-24yo) were recruited from two major children's hospitals. Participants completed painDETECT and two quantitative sensory tasks (QST) that assess mechanical allodynia (brush) and pressure pain (algometer) as part of an ongoing study. Pain diagnoses were collected via parent report and participant medical chart, when unclear. Descriptive statistics and ANOVAs were used to characterize participants and assess painDETECT in relation to diagnosis and QST measures. Participants with chronic pain diagnoses (N=110, Mage=15.05±2.4, Nfemale=88) and peers without pain (N=55, Mage=15.84±3.9, Nfemale=39) were included. As expected, painDETECT scores for participants with pain (M=11.51±6.59) were higher than peers without pain (M=1.42±2.15). Among those diagnosed with neuropathic pain, painDETECT identified 88.5% as having neuropathic pain. Among those diagnosed with abdominal, endometriosis, and fibromyalgia, 75% were identified as having nociceptive pain and 0% as having neuropathic pain. For those diagnosed with musculoskeletal and pain amplification, 61% were identified as having nociceptive pain and 19.6% as having neuropathic pain. Individuals in the neuropathic pain category had significantly higher mechanical allodynia (p=.021) and lower pressure pain thresholds (p=.059). PainDETECT differentiated participants with pain from their peers without pain and demonstrated accuracy in identifying participants as having nociceptive vs. neuropathic pain, consistent with their existing pain diagnosis. Moreover, QST results were consistent with a positive neuropathic screening. Taken together, results support the use of painDETECT as a pediatric neuropathic pain screening tool. Grant support from 5R01HD83270.

Evaluating the Relationship Between Acute Pain Perception and Gut Microbiota Among Female University Students in Japan: A Prospective Cohort Study.

The gut microbiota (GM) plays an important role in gut-brain communication, and the ‘gut-brain axis’ has attracted much attention as a factor influencing human host health. We previously reported that pain perception may be associated with GM composition in males. The aim of this study was to investigate the relationship between GM composition and pain perception among 42 healthy female university students in Japan. Pain perception was evaluated by pressure pain threshold (PPT), current perception threshold (CPT), temporal summation of pain (TSP), conditioned pain modulation (CPM), and a questionnaire on psychological state. CPT was stimulated at 5, 250, and 2,000 Hz, which reflected the thresholds of the C, Aδ, and Aβ fibers, respectively. Also, GM composition was estimated using 16S rRNA analysis. The lower alpha diversity was associated with, the lower PPT (rs = 0.330, P < 0.05) and CPT of 2000 Hz (re = 0.339, P < 0.05). Furthermore, alpha diversity was identified as an explanatory variable for PPT (β = 0.424, P < 0.01) and TSP (β = -0.317, P < 0.05), alpha diversity and state anxiety for CPT of 2000 Hz (β = 0.321, P < 0.05), and state anxiety for CPT of 250 Hz (β = 0.320, P < 0.05). However, there was no relationship between the rate of major phylum and pain perception.

Pain sensitivities predict prophylactic treatment outcomes of flunarizine in chronic migraine patients: A prospective study.

We aimed to assess the differences in quantitative sensory testing between chronic migraine and healthy controls and to explore the association between pain sensitivities and outcomes in chronic migraine following preventive treatment. In this prospective open-label study, preventive-naïve chronic migraine and healthy controls were recruited, and cold, heat, mechanical punctate, and pressure pain thresholds over the dermatomes of first branch of trigeminal nerve and first thoracic nerve were measured by quantitative sensory testing at baseline. Chronic migraines were treated with flunarizine and treatment response was defined as ≥50% reduction in the number of monthly headache days over the 12-week treatment period. Eighty-four chronic migraines and fifty age-and-sex-matched healthy controls were included in the analysis. The chronic migraine had higher cold pain thresholds over the dermatomes of the first branch of trigeminal nerve and the first thoracic nerve (p < 0.001 and < 0.001), lower pressure pain thresholds over the dermatomes of the first thoracic nerve (p = 0.003), heat pain thresholds over the dermatomes of the first branch of the trigeminal nerve and the first thoracic nerve (p < 0.001 and p = 0.015) than healthy controls. After treatment, 24/84 chronic migraine had treatment response. The responders with relatively normal pain sensitivity had higher heat pain thresholds over the dermatome of the first branch of the trigeminal nerve (p = 0.002), mechanical punctate pain thresholds over the dermatomes of the first branch of the trigeminal nerve (p = 0.023), and pressure pain thresholds over the dermatomes of the first branch of the trigeminal nerve (p = 0.026) than the hypersensitive non-responders. Decision tree analysis showed that patients with mechanical punctate pain threshold over the dermatomes of the first branch of the trigeminal nerve > 158 g (p = 0.020) or heat pain threshold over the dermatome of the first branch of the trigeminal nerve > 44.9°C (p = 0.002) were more likely to be responders. Chronic migraine were generally more sensitive compared to healthy controls. Preventive treatment with flunarizine should be recommended particularly for chronic migraine who have relatively normal sensitivity to mechanical punctate or heat pain.Trial registration: This study was registered on ClinicalTrials.gov (Identifier: NCT02747940).

Signs Indicative of Central Sensitization Are Present but Not Associated with the Central Sensitization Inventory in Patients with Focal Nerve Injury.

Objective: Carpal tunnel syndrome (CTS) is the most common focal nerve injury. People with CTS may show alterations in central processing of nociceptive information. It remains unclear whether the central sensitization inventory (CSI) is capable of detecting such altered central pain processing. Methods: Thirty healthy volunteers were matched with 30 people with unilateral CTS from the orthopaedic waitlist. Changes to central pain processing were established through psychophysical sensory testing (bilateral pressure pain thresholds (PPT), conditioned pain modulation, temporal summation) and pain distribution on body charts. Patients also completed pain severity and function questionnaires, psychological questionnaires and the CSI. Results: Compared to healthy volunteers, patients with CTS have lower PPTs over the carpal tunnel bilaterally (t = −4.06, p < 0.0001 ipsilateral and t = −4.58, p < 0.0001 contralateral) and reduced conditioned pain modulation efficacy (t = −7.31, p <0.0001) but no differences in temporal summation (t = 0.52, p = 0.60). The CSI was not associated with psychophysical measures or pain distributions indicative of altered central pain processing. However, there was a correlation of the CSI with the Beck Depression Inventory (r = 0.426; p = 0.019). Conclusion: Patients with CTS show signs of altered central pain mechanisms. The CSI seems unsuitable to detect changes in central pain processing but is rather associated with psychological factors in people with focal nerve injuries.

Significant other interactions in people with chronic low back pain: Subgrouping and multidimensional profiles.

Background: Back pain is complex. Social support and significant other interactions influence the pain experience. Purpose: To statistically derive subgroups of people with chronic low back pain based upon their interactions with significant others, and profile subgroups across multidimensional variables. Research Design: Longitudinal cohort study. Study Sample: People with chronic axial low back pain (n = 262). Data Collection and Analysis: Latent class analysis of significant other interaction data was used to derive subgroups of people with chronic low back pain. Subgroups were profiled across baseline multidimensional variables and one-year follow-up pain intensity, disability and bothersomeness. Results: Three clusters were identified: Cluster 1 (7.6%) characterised by the lowest distracting, punishing and solicitous interactions. Cluster 2 (16.0%) characterised by the highest distracting and solicitous responses and social support. Cluster 3 (76.3%) characterised by the highest punishing and lowest social support. Cluster 1 reported less disability than Clusters 2 and 3. Mindfulness was significantly different across all subgroups with Cluster 1 being most mindful and Cluster 3 least mindful. Depression, anxiety and stress were significantly higher in Cluster 3 than Cluster 1. Pain catastrophising was higher for Cluster 2 than Clusters 1 and 3. Cluster 2 had lower pressure pain threshold than Clusters 1 and 3. Conclusions: These results support the association between significant other interactions and the experience of back pain. Considering significant other interactions in clinical practice may be important for managing some people's presentation.

Signs of Central Hypersensitivity, Stress, and Anxiety following Treatment for Breast Cancer: A Case Control Study.

Background With treatment for breast cancer, women treated may present significant sensory abnormalities in the upper extremity. However, there are no conclusive studies that have evaluated pressure pain thresholds (PPT) in the shoulder of postoperated women for breast cancer. The aim of this study was to compare PPT in the shoulder, stress, anxiety, depression symptoms, and quality of sleep among postoperated women for breast cancer (PO group) and asymptomatic women of shoulder pain (control group). Methods 40 women participated (n = 20, PO group, age: average ± standard deviation, 49.2 ± 8.3 years; body mass index (BMI): 27.5 ± 3.0 kg/cm2; surgery time: 22.2 ± 34.4 months; n = 20, control group, 46.9 ± 8.1 years; BMI: 26.8 ± 3.5 kg/cm2). The PPT was evaluated with a digital algometer at 32 points in the shoulder region and one control point in the tibialis anterior. Stress, anxiety, and depression were evaluated with the Depression, Anxiety and Stress Scale 21 (DASS-21) and the quality of sleep by the Pittsburgh Sleep Quality Index. Results Significant differences were observed over 1.5 kgf/cm2 in 33 points evaluated (p < 0.01) with a small to high effect size (Cliff's delta range = 0.16; 0.92) and higher levels of anxiety and stress in the PO group (anxiety: median [first; third quartile], 5[3; 12.5]; stress: 9.7 ± 4.7 (7.8; 11.8)) in comparison with the control group (anxiety: 2.5[1; 4.8]; stress: 6.7 ± 3.31 (5.2; 8.3), (p < 0.05)). No significant differences were found between the groups in depression and sleep quality (p > 0.05). Conclusion Postoperated women for breast cancer present hyperalgesia in the shoulder anterior and posterior region, low PPT in the tibialis anterior, and higher levels of stress and anxiety compared to the control group.

Patients with symptomatic permanent atrial fibrillation show quantitative signs of pain sensitisation

Abstract Background/Introduction Most patients with atrial fibrillation (AF) report symptoms, while around one-third are asymptomatic. We hypothesized that sensory processing, in particular pain, differs in patients with symptomatic and asymptomatic AF. Purpose To assess differences in pain sensitisation in patients with symptomatic and asymptomatic AF. Methods Thirty individuals with permanent AF (15 symptomatic, 15 asymptomatic) completed the AF6 and SF-36 questionnaires and underwent quantitative pain sensitisation testing using pressure algometry at the sternum (referred pain area) and the tibialis anterior muscle (generalized pain area). The primary objective was to assess differences in pressure pain thresholds (PPT), temporal summation of pain (TSP), and conditioned pain modulation (CPM) in the two groups. The secondary objective was to determine association of demographic and clinical parameters to quantitative measures of pain sensitisation. Results The symptomatic group had lower PPTs at both tibialis (p=0.004) and sternum (p=0.01), as well as impaired CPM (p=0.025) and facilitated TSP (p=0.008) at the tibialis but not sternum, compared to the asymptomatic group. The AF6 sum score was negatively correlated to PPT on both tibialis (r=−0.50, p=0.005) and sternum (r=−0.42, p=0.02) and positively correlated to TSP of both tibialis (r=0.57, p=0.001) and sternum (r=0.45, p=0.01), but not to CPM. The physical component summary score was positively correlated to the PPT on both tibialis (r=0.52, p=0.003) and sternum (r=0.40, p=0.03) and negatively to TSP on the tibialis (r=−0.53, p=0.003) but not sternum. Conclusions Patients with symptomatic AF exhibit lower pain tolerance than patients with asymptomatic AF, as well as impaired pain inhibitory control and facilitated summation of pain, indicating that pain sensitisation may be of importance in symptomatic AF. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Department of Cardiology, Örebro University, Sweden PPTs tibialis anterior musclePPTs sternum

Associations between joint pathologies and central sensitization in persons with hand osteoarthritis: results from the Nor-Hand study.

ObjectivePain sensitization is associated with pain severity in persons with hand OA. What contributes to pain sensitization is unclear. This study explores whether hand OA pathologies and symptom duration are related to central sensitization.MethodParticipants with hand OA in the Nor-Hand study underwent bilateral hand radiography and US examination. Central sensitization was assessed with pressure pain thresholds (PPT) at remote sites (wrist, trapezius and tibialis anterior muscles) and temporal summation. We examined whether hand OA pathologies, independent of each other, including structural severity (Kellgren–Lawrence sum score, presence of erosive hand OA), inflammatory severity (greyscale synovitis and power Doppler activity sum scores) and symptom duration, were related to central sensitization, adjusting for age, sex, BMI, comorbidities and OA-severity of knee/hip.ResultsIn 291 participants (88% women, median age 61 years, interquartile range 57–66 years) Kellgren–Lawrence, greyscale synovitis and power Doppler activity sum scores were not associated with lower PPTs at remote sites. Persons with erosive hand OA had lower PPTs at the wrist (adjusted beta −0.75, 95% CI −1.32, −0.19) and tibialis anterior (adjusted beta −0.82, 95% CI −1.54, −0.09) and had greater temporal summation (adjusted beta 0.56, 95% CI 0.12, 1.01) compared with persons with non-erosive disease. No associations were found for symptom duration.ConclusionsA person’s overall amount of structural or inflammatory hand OA pathologies was not associated with central sensitization. Although persons with erosive hand OA showed greater signs of central sensitization, the small differences suggest that central sensitization is mainly explained by factors other than joint pathologies.

Cognitive, emotional, and somatosensory behavior in professional dancers with acute and chronic pain.

Dance has been linked in a complex manner to pain and the physical and psychological peculiarities of this discipline could influence pain perception and chronicity of pain. To determine the differences in cognitive, emotional, and somatosensory symptoms between dancers with acute versus chronic pain. A cross-sectional study of professional dancers with pain. Higher conservatory of dance. Thirty-four professional dancers experiencing pain were included. The cohort was divided into two subgroups: those with acute pain (<3months duration) and those with chronic pain (>3months duration). Not applicable. Pain intensity (as measured by the visual analogue scale or VAS), pressure pain threshold (PPT), Pain Catastrophizing Scale (PCS), pain-related fear of movement (Tampa Scale of Kinesiophobia [TSK-11]), fear avoidance beliefs (Fear-Avoidance Beliefs Questionnaire [FABQ]), self-efficacy (Chronic Pain Self-Efficacy Scale [CPSS]). and chronic pain severity (Chronic Pain Graded Scale [CPGS]). Dancers with chronic pain reported higher levels of pain intensity in daily activities (p < .01; t=3.42; d =1.17) and during exercise/dance (p=.02; t=2.82; d =0.82), as well as lower PPT in lumbar (p=.03; t=3.22; d =1.1) and tibialis regions (p=.01; t=2.51; d =0.86). Dancers with acute pain experienced worse psychological symptoms indicated by the fear of harm subscale of TSK-11 (p=.04; t=-2.08; d =0.72), physical activity subscale of FABQ (p=.03; t=-2.27; d =0.78), and pain management subscale of CPSS (p=.01; t=-2.76; d =0.94) and lower scores for CPGS scale (p=.01; t=2.99; d =0.7 to 1.26). The results showed differences in pain intensity and PPT revealing higher values in dancers with chronic pain. It is possible that the physical and psychological characteristics of dancers, as well as the sociocultural aspects of this discipline, could influence the way in which this population interprets pain.

Do Sex and Pain Characteristics Influence the Effectiveness of Pain Neuroscience Education in People Scheduled for Total Knee Arthroplasty? Secondary Analysis of a Randomized Controlled Trial.

This explorative study investigates the moderating effect of sex and baseline pain characteristics on the effectiveness of preoperative pain neuroscience education (PNE) plus knee joint mobilization versus biomedical education plus knee joint mobilization in patients who have knee osteoarthritis and are scheduled to undergo total knee arthroplasty (TKA). After baseline assessment of self-reported questionnaires (pain intensity, disability, symptoms of central sensitization and pain cognitions) and quantitative sensory testing, 44 participants with knee osteoarthritis were randomized into the PNE plus knee joint mobilization or biomedical education plus knee joint mobilization group. The questionnaires were retaken directly after and 1month after 4 sessions of treatment and at 3months after surgery. Based on baseline quantitative sensory testing results, the sample was subdivided into a high (showing high experimental pain levels and low pressure pain thresholds) and low pain cluster using principal components analysis and cluster analysis. Therapy effects over time were evaluated using 3-way analysis of variance, with time as the within factor and treatment, sex, and baseline pain cluster as between factors. Women benefited significantly more from the PNE intervention compared with the control intervention in terms of self-reported symptoms of central sensitization. For both pain clusters, differences in therapeutic effects concerning pain intensity and pain cognitions were found, with higher superiority of the PNE intervention in the high-pain cluster subgroup compared with the low-pain cluster. Based on these explorative analyses, it can be concluded that sex and preoperative pain measures may influence the effectiveness of preoperative PNE for some specific outcome measures in people scheduled to undergo TKA. Although further research on this topic is needed, the potential influence of sex and preoperative pain measures on the effectiveness of preoperative PNE should be considered when implementing this intervention in people undergoing TKA.

Mouth opening, jaw disability, neck disability, pressure pain thresholds, and myofascial trigger points in patients with disc displacement with reduction: A descriptive and comparative study

ABSTRACT Objective To assess jaw and neck function, pressure pain threshold (PPT), and the presence of trigger points (TrPs) in disc displacement with reduction (DDWR) subjects compared to healthy subjects. Methods One hundred DDWR subjects and 100 matched controls were studied. Clinical evaluations included demographic data, range of motion, jaw and neck disability, PPT, and muscle TrPs. Results DDWR subjects have limited pain-free opening limitation (p < 0.001), jaw and neck disability limitation (p < 0.001), and higher presence of active and latent TrPs limitation (p < 0.001) compared to healthy subjects. Conclusion DDWR subjects present a limited pain-free mouth opening, higher jaw and neck disability, lower PPT, and major presence of active and latent TrPs compared to healthy subjects. Cervical spine and TMJ evaluation and treatment should be considered in DDWR patients.

Association of temporomandibular disorders with pain sensitivity: A cohort study.

Pain related to temporomandibular disorders (TMD) can be linked with multiple site pain (MSP), and may associate with increased pain sensitivity, more frequently among women than men. The aim of the study was to examine the associations of pressure pain threshold (PPT) and tolerance (PPTo) with TMD and associated MSP in the Northern Finland Birth Cohort 1966 (NFBC1966) study. Altogether 1961 NFBC1966 subjects attended clinical medical and dental examination at the Institute of Dentistry, University of Oulu in 2012-2013. Clinical examinations were carried out using a modified Diagnostic Criteria for TMD protocol (DC/TMD). MSP was defined based on questions regarding body pain sites. Additionally, PPT and PPTo were assessed using algometer measurements. Mann-Whitney U-test and Tobit regression models were used to analyse associations between TMD sub-diagnoses, MSP, PPT and PPTo, stratified by sex. Further models were adjusted with anxiety and depressive symptoms, which were assessed using Hopkins Symptom Checklist-25 (HSCL-25) and two-way interaction terms. Among females, lower PPT and PPTo were associated with myalgia and arthralgia. Among males, lower PPT and PPTo were associated with MSP-linked TMD. Tobit regression analysis showed significantly lower PPT and PPTo values in the myalgia and arthralgia subgroups among female TMD subjects. Among females, disc displacement with reduction had an inverse association with PPT and PPTo. Among males, lower PPTo was associated with degenerative joint disease and MSP-linked TMD. The pain regulatory mechanisms behind TMD act differently between the genders as local TMD among females and MSP-linked TMD among males were associated with pain sensitivity. The study shows that there are differences in the associations of painful TMD with pressure pain tolerance, pressure pain sensitivity and MSP between male and female subjects.

The Effects of Gender, Functional Condition, and ADL on Pressure Pain Threshold in Stroke Patients

BackgroundSomatosensory impairments and pain are common symptoms following stroke. However, the condition of perception and pain threshold for pressure stimuli and the factors that can influence this in individuals with stroke are still unclear. This study aimed to investigate the gender differences in pressure pain threshold (PPT) and positive somatosensory signs for pressure stimuli, and explore the effects of joint pain, motor function, and activities of daily living (ADL) on pain threshold in post-stroke patients.DesignA cross-sectional study.MethodsA total of 60 participants with stroke were recruited, and their pain condition, motor functions, and ADL were evaluated by the Fugl-Meyer assessment of joint pain scale, motor function scale, and Barthel index, respectively. PPTs in eight tested points at the affected and unaffected sides were assessed.ResultsSignificant differences in PPTs were found between male and female patients in all measured muscles (p < 0.05). Positive somatosensory signs for pressure stimuli, including hypoalgesia and hyperalgesia, were frequently found at the affected side, particularly in the extremity muscles, but such signs were not significantly influenced by gender (p > 0.05). More equal PPTs between both sides and relatively lower PPTs at the affected side in the trunk and medial gastrocnemius muscles (p < 0.05) were observed in patients with less pain, better motor functions, and ADL.ConclusionGender differences widely exist in post-stroke survivors either at the affected or unaffected side, which are multifactorial. Sensory loss and central and/or peripheral sensitization, such as hypoalgesia and hyperalgesia for pressure stimuli, caused by a brain lesion are common signs in male and female stroke patients. Moreover, patients who are in a better condition show a more symmetrical pain sensitivity between both sides in the trunk and in female lower extremities, indicating the bidirectional improvement of somatosensory abnormalities caused by a possible neural plasticity.