Search

Yingxuan Hu,1,* Junqin Ma,1,* Bingmei Chen,2 Jiahui Pang,1 Wen Liang,2 Wen Wu1 1Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China; 2Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Wen Wu; Wen Liang, Email wuwen66@163.com; liangwendoc@163.comPurpose: This study was conducted to explore the differences in functional changes in the pain matrix in patients with chronic back pain (CBP) at different stages and identify whether these brain changes were related to the pain duration.Patients and Methods: In this study, 29 healthy individuals and 54 patients with CBP were recruited. According to the pain duration, 25 patients (3 to 12 months) were divided into the CBP-S group and 29 patients (≥ 24 months) were divided into the CBP-L group. All subjects completed clinical pain-related measurement and functional magnetic resonance imaging (fMRI) scans. Moreover, the amplitude of low-frequency fluctuation (ALFF), functional connectivity (FC), and correlation analysis were conducted in this study.Results: Compared with healthy controls, patients in the CBP-L group showed significantly decreased ALFF in the left precuneus. In the FC analysis, patients in the CBP-S and CBP-L groups showed significantly decreased FC in several regions in the bilateral orbitofrontal cortices (OFC) and the left ventral posterior insula. Moreover, there were significant differences in the FC between the left hyper granular insula and the probabilistic area in OFC in pairwise group comparisons. The correlation analysis results demonstrated that pain duration was correlated with these functional brain changes, and the ANCOVA results revealed that pain intensity and pain interference scores did not affect the FC analysis results.Conclusion: There are different changes in the pain neural matrix in patients with chronic pain at different stages. Furthermore, the pain duration is related to brain functional changes.Keywords: chronic back pain, pain duration, fMRI, resting-state, pain matrix

Objective: To assess pain outcomes, stress levels and body awareness among patients with chronic pain and explore potential associations between these variables. Design: An explorative study. Methods: Patients with chronic pain in primary and specialist care were assessed regarding pain intensity using the Numerical Rating Scale (NRS; 0–10 point scale) and stress levels using the Stress and Crisis Inventory (SCI-93; 0–140). To assess body awareness, multidimensional assessment of interoceptive awareness (MAIA; 0–5), a widely used self-report measure of interoceptive bodily awareness was used. Results: Participants (n = 42) reported an average NRS of 4.4, elevated stress levels and low body awareness. Stress levels were moderately correlated with pain intensity (r = 0.53; p

Background: Time elapsed since pain onset might affect the likelihood of neuropathic component in low back pain. The aim of this study was to investigate the relationship between neuropathic pain component and pain duration in patients with low back pain and to identify factors associated with neuropathic pain component. Methods: Patients with low back pain who received treatment at our clinic were enrolled. Neuropathic component was assessed using the painDETECT questionnaire at the initial visit. PainDETECT scores and the results for each item were compared according to pain duration category (< 3 months, 3 months to 1 year, 1 year to 3 years, 3 years to 10 years, and ≥ 10 years). A multivariate analysis was used to identify factors associated with neuropathic pain component (painDETECT score ≥ 13) in low back pain. Results: A total of 1957 patients, including 255 patients who reported neuropathic‐like pain symptoms (13.0%), fully satisfied the study criteria for analysis. No significant correlation between painDETECT score and pain duration was observed (ρ = −0.025, p = 0.272), and there were no significant differences between median painDETECT score or trend of change in the proportion of patients with neuropathic component and the pain duration category (p = 0.307, p = 0.427, respectively). The electric shock‐like pain symptom was frequently reported in patients with acute low back pain, and the persistent pain pattern with slight fluctuations was predominant in chronic low back pain. The pattern of attacks with pain between them was much less common in patients with pain for 10 years or longer. Multivariate analysis revealed that a history of lumbar surgery, severe maximum pain, opioid use, lumbosacral radiculopathy, and sleep disturbance were significantly associated with a neuropathic component in low back pain. Conclusion: Time elapsed since current pain onset did not correlate with neuropathic pain component in patients with low back pain. Therefore, diagnostic and therapeutic approaches for this condition should be based on a multidimensional evaluation at assessment and not on pain duration alone. [ABSTRACT FROM AUTHOR]

Purpose: Pain catastrophizing is one of the most important factors contributing to pain experience and duration of action. This study aimed to explore the moderator role of pain duration in the hypothetical relation between pain catastrophizing and pain intensity in patients with chronic musculoskeletal pain syndrome (CMPS). Material and Methods: Seven hundred and eight patients with CMPS (mean age: 28.52 ± 7.75 years) participated in this cross-sectional and descriptive study. The pain intensity and catastrophizing of the patients was assessed with the Visual Analog Scale (VAS) and Pain Catastrophizing Scale (PCS), respectively. The time elapsed since the participants' first experience of pain (number of days) was recorded as pain duration. Results: There was a positive correlation between pain duration (r=0.181, p<0.001), pain intensity (r=0.432, p<0.001) and total score of pain catastrophizing. According to univariate and multivariate regression analysis, pain duration adjusting for pain catastrophizing maintained its predictor effect on pain intensity (p<0.001). According to hierarchical model, the effect of pain catastrophizing on pain intensity was 44.7%, its effect increases to 48.5% adding pain duration. Conclusion: The results of this study supports that pain duration has no critical effect on the relation between pain catastrophization to pain intensity in patients with CMPS. [ABSTRACT FROM AUTHOR]

Abstract Background Chronic inflammatory joint diseases (CIJD) have been linked to increased cardiovascular morbidity and mortality. A decisive reason could be a dysregulation of the autonomic nervous system, which is responsible for the control of cardiovascular function. So far, the cause of changes in autonomic nervous system functions remains elusive. In this study, we investigate the role of chronic pain and the insular cortex in autonomic control of cardiac functioning in patients with CIJD. Methods We studied the autonomic nervous system through the assessment of heart rate and heart rate variability (HRV) at rest and under cognitive stimulation. Furthermore, we investigated insular cortex volume by performing surface-based brain morphometry with FreeSurfer. For this study, 47 participants were recruited, 22 individual age- and sex-matched pairs for the magnetic resonance imaging analyses and 14 for the HRV analyses. All available patients’ data were used for analysis. Results Pain duration was negatively correlated with the resting heart rate in patients with chronic inflammatory joint diseases (n = 20). In a multiple linear regression model including only CIJD patients with heart rate at rest as a dependent variable, we found a significant positive relationship between heart rate at rest and the volume of the left insular cortex and a significant negative relationship between heart rate at rest and the volume of the right insular cortex. However, we found no significant differences in HRV parameters or insular cortex volumes between both groups. Conclusions In this study we provide evidence to suggest insular cortex involvement in the process of ANS changes due to chronic pain in CIJD patients. The study was preregistered with the German Clinical Trials Register ( https://www.drks.de ; DRKS00012791; date of registration: 28 July 2017).

Background: Temporomandibular disorder (TMD) is a common condition that frequently transitions to chronic symptoms. Experimental pain models that mimic the symptoms of clinical TMD may be useful in understanding the mechanisms, and sex differences, present in this disorder. Here we aimed to comprehensively characterise the nature and time-course of pain, functional impairment and hyperalgesia induced by repeated intramuscular injection of nerve growth factor (NGF) into the masseter muscle, and to investigate sex differences in the NGF-induced pain experience. Methods: 94 healthy individuals participated in a longitudinal study with 30-day follow-up. NGF was injected into the right masseter muscle on Day 0 and Day 2. Participants attended laboratory sessions to assess pain (Numerical Rating Scale; NRS), functional limitation (mouth opening distance, Jaw Functional Limitation Scale; JFLS) and mechanical sensitization (pressure pain thresholds; PPTs) on Days 0, 2 and 5 and completed twice daily electronic pain dairies from Day 0 to day 30. Results: Peak pain averaged 2.0/10 (95 % CI: 1.6–2.4) at rest and 4.3/10 (95 % CI: 3.9–4.8) on chewing. Pain-free mouth opening distance reduced from 5.0 cm (95 % CI: 4.8–5.1 cm) on Day 0 to 3.7 cm (95 % CI: 3.5–3.9 cm) on Day 5. The greatest reduction in PPTs was observed over the masseter muscle. Females experienced higher pain, greater functional impairment, and greater sensitivity to mechanical stimuli than males. Conclusion: Intramuscular injection of NGF is a useful model with which to explore the mechanisms, and sex differences, present in clinical TMD.

Background Context: Physical activity in its various forms are the most recommended prevention and treatment strategy for chronic low back pain (CLBP). Standing postural stability is a prerequisite for many types of physical activities. Systematic reviews have investigated the evidence for an association between CLBP and postural stability but results remain inconclusive.Purpose: Our primary objective was to compare postural stability between pain-free controls and subjects with CLBP with or without leg pain and single and multisite chronic musculoskeletal pain subjects. The secondary objectives were to evaluate the association between postural stability with CLBP intensity and duration, demographics, physical characteristics and validated health and pain-related patient-reported outcome measures (PROMs).Study Design/setting: Cross-sectional study in a private chiropractic clinic setting PATIENT SAMPLE: Subjects included 42 pain-free controls and 187 patients with chronic musculoskeletal pain divided into CLBP with or without leg pain and single and multisite pain groups.Outcome Measures: Pain intensity was measured using the numerical pain rating scale, PROMs Central Sensitization Inventory, Tampa Scale of Kinesiophobia, The Depression Scale, EuroQol-5D, Roland-Morris Disability Questionnaire, and Pain and Sleep Questionnaire Three-Item Index disability. Group differences were measured using area and velocity of sway on the force plate.Methods: Postural stability was assessed using a force plate on four 60-second bipedal quiet stance tests: eyes open on a stable surface, eyes closed on a stable surface, eyes open on an unstable foam surface, eyes closed on an unstable foam surface. Following the clinic visit, subjects completed an online web-based data entry detailing pain history, demographic data, physical characteristics, pain intensity via the numerical pain rating scale, and PROMS.Results: Postural sway parameters did not differ between pain-free controls and subjects with CLBP with or without leg pain and single and multisite chronic musculoskeletal pain subjects. Furthermore, severity and duration of CLBP pain in addition to central sensitization, kinesiophobia, depression, quality of life, disability, and effect of pain on sleep only had very weak associations with postural stability.Conclusions: Chronic musculoskeletal pain appears not to influence bipedal postural stability. [ABSTRACT FROM AUTHOR]

In this cross-sectional study, it was planned to examine the relationship between age, gender, daily life activity habits, clinical examination findings and treatment sessions number of the patients with chronic low back pain who applied for chiropractic treatment. After examination of the patient files, who were treated at Private Clinic between January 2010 and December 2017, 408 patients' data were accepted into study. Patients; demographic characteristics, physical examination findings and imaging results were examined. Age, gender, sedentary time (sitting), activity level, stress level, pain duration, spinal dysfunction segments and treatment number were included. Patients' mean age was 43.1 ± 12.6 years, 205 were male (50.2%) and 203 (49.8%) were female. When the total number of received treatment sessions were examined, the average for all patients was 3.5±2.9. The number of treatments were significantly higher in the groups with pain duration of 6-10 years and 11 years and above, compared to the group with 0-5 years of pain (p = 0.009). There was a significant difference between the patients' pain duration and number of treatment sessions. However, there was no significant difference in age, gender, daily life activity habits, clinical examination findings and number of treatment sessions in our study. [ABSTRACT FROM AUTHOR]

Background: Chronic inflammatory joint diseases (CIJD) have been linked to increased cardiovascular morbidity and mortality. A decisive reason could be a dysregulation of the autonomic nervous system, which is responsible for the control of cardiovascular function. So far, the cause of changes in autonomic nervous system functions remains elusive. In this study, we investigate the role of chronic pain and the insular cortex in autonomic control of cardiac functioning in patients with CIJD.Methods: We studied the autonomic nervous system through the assessment of heart rate and heart rate variability (HRV) at rest and under cognitive stimulation. Furthermore, we investigated insular cortex volume by performing surface-based brain morphometry with FreeSurfer. For this study, 47 participants were recruited, 22 individual age- and sex-matched pairs for the magnetic resonance imaging analyses and 14 for the HRV analyses. All available patients' data were used for analysis.Results: Pain duration was negatively correlated with the resting heart rate in patients with chronic inflammatory joint diseases (n = 20). In a multiple linear regression model including only CIJD patients with heart rate at rest as a dependent variable, we found a significant positive relationship between heart rate at rest and the volume of the left insular cortex and a significant negative relationship between heart rate at rest and the volume of the right insular cortex. However, we found no significant differences in HRV parameters or insular cortex volumes between both groups.Conclusions: In this study we provide evidence to suggest insular cortex involvement in the process of ANS changes due to chronic pain in CIJD patients. The study was preregistered with the German Clinical Trials Register ( https://www.drks.de ; DRKS00012791; date of registration: 28 July 2017). [ABSTRACT FROM AUTHOR]

Objective: To assess pain outcomes, stress levels and body awareness among patients with chronic pain and explore potential associations between these variables., Design: An explorative study., Methods: Patients with chronic pain in primary and specialist care were assessed regarding pain intensity using the Numerical Rating Scale (NRS; 0-10 point scale) and stress levels using the Stress and Crisis Inventory (SCI-93; 0-140). To assess body awareness, multidimensional assessment of interoceptive awareness (MAIA; 0-5), a widely used self-report measure of interoceptive bodily awareness was used., Results: Participants ( n = 42) reported an average NRS of 4.4, elevated stress levels and low body awareness. Stress levels were moderately correlated with pain intensity ( r = 0.53; p < 0.001; 95% confidence interval [CI] 0.25-0.72) and number of pain sites ( r = 0.58; p < 0.001; 95% CI 0.32-0.76). The regression analysis showed that pain outcomes predicted stress level scores and explained almost 50% of variance ( R 2 < 0.001). Moreover, shorter pain duration predicted a higher body awareness ( p < 0.001). Moreover, shorter pain duration predicted a higher body awareness ( p = 0.04)., Conclusion: In patients with chronic pain, high pain intensity and multiple painful sites seem to be associated with impaired stress regulation. The patients had low body awareness, which was negatively influenced by pain duration., Competing Interests: The authors have no conflicts of interest to declare., (© 2024 The Author(s).)

Objectives: Increased evidence indicates that pain location affects central sensitization (CS)‐related symptoms. In addition, pain location and pain duration may be intricately related to CS‐related symptoms. However, these factors have been investigated separately. This study aimed to investigate the association between CS‐related symptoms and pain location and/or pain duration in patients with musculoskeletal disorders. Methods: Six hundred thirty‐five participants with musculoskeletal disorders were included in this cross‐sectional study. All participants were assessed for pain location, pain duration, central sensitization inventory (CSI), EuroQol‐5 dimension, and brief pain inventory. The participants were categorized into 3 groups based on pain location (spinal, limb, and both spinal and limb pain) and into 2 groups based on pain duration (acute and chronic pain). Results: The interaction between pain location and pain duration were not significant on CSI score (P > 0.05). The odds ratio for higher CSI score (≥ 40) in patients with both spinal and limb pain vs. those with spinal or limb pain was 2.64 (P < 0.01) and that in patients with chronic pain vs. those with acute pain was 1.31 (P = 0.52). In addition, the prevalence of higher CSI scores in the combination of chronic and "both spinal and limb" pain was high (23.1%, adjusted residual = 4.48). Conclusions: Pain location independently influenced CSI scores, and the combination of both spinal and limb pain and chronic pain indicated high CSI scores. The combination of pain location and pain duration is an important clue that points to CS‐related symptoms. [ABSTRACT FROM AUTHOR]

It is important to validate self-reported musculoskeletal pain used in epidemiological studies for evaluation of pain outcome measures. The main objective of this paper was to assess the association between self-reported neck/shoulder/upper limb pain and clinical signs of disorders in the region, especially by comparing a measure that only used pain intensity with a measure that combined pain intensity and pain duration. Four hundred and twenty technical school students of both genders were included with a median age of 17 years (16–28). The students stated the pain in four intensity grades and the pain duration in four period lengths within the preceding four weeks period. A pain severity index was calculated by multiplying the pain intensity (0–3) and the duration (1–4). A clinical examination was performed within a week after completing the form. The associations were evaluated by agreement, correlation and symmetric strength of association (contingency). The study found low correlation and low positive agreement for neck/shoulder and upper limb pain related to clinical signs of disorders in the region. However, the relationship showed high negative agreement and high contingency. The negative agreement increased for the neck/shoulder region with higher cut-off points for dichotomization, but not for the upper limb region. The index combining reports of pain intensity with pain duration, do not improve agreement, correlation or contingency with clinical signs compared to use of pain intensity alone. This study showed an association between self-reported neck/shoulder/upper limb pain intensity and clinical signs of musculoskeletal disorders of the region. An index combining pain intensity and duration (Pain Severity Index) did not increase this association. From the results we suggest using pain intensity reports alone and if dichotomizing is wanted, choosing a cut-off point at high pain levels, especially for neck and shoulder pain. [ABSTRACT FROM AUTHOR]

Study Design: A cross-sectional study of the Northern Finland Birth Cohort 1966 (NFBC1966).Objective: The aim of this study was to evaluate the association between the type, size, and location of lumbar Modic changes (MC), and prolonged disabling low back pain (LBP).Summary Of Background Data: LBP is the leading cause of disability worldwide and it affects all age- and socioeconomical groups. Only a small proportion of LBP patients are diagnosed with a specific cause: In most cases no single nociceptive cause for the pain can be identified. MC are visualized in magnetic resonance imaging (MRI) as a signal intensity change in vertebral bone marrow and have been proposed to represent a specific degenerative imaging phenotype associated with LBP. MC can be classified into several subtypes, of which inflammatory Type 1 (MC1) is suggested as being more likely to be associated with LBP.Methods: We assessed lumbar MRI (n = 1512) for the presence, type, and size of MC. The associations of MC characteristics with prolonged (≥30 days during the past year) and disabling (bothersomeness of LBP at least 6 on a 0-10 Numeric Rating Scale) LBP, evaluated at the time of imaging at 47 years, were analyzed using binary logistic regression, adjusted for sex, BMI, smoking, educational status, lumbar disc degeneration, and disc herniations.Results: Any MC and MC1 were associated with prolonged disabling LBP (odds ratio [OR] after full adjustments 1.50 [95% confidence interval, CI 1.05-2.15] and 1.50 [95% CI 1.10-2.05], respectively). Furthermore, MC covering the whole anterior-posterior direction or the whole endplate, as well as the height of MC, were significantly associated with prolonged disabling LBP (OR after full adjustments 1.59 [95% CI 1.14-2.20], 1.67 [95% CI 1.13-2.46] and 1.26 [95% CI 1.13-1.42], respectively).Conclusion: Our study showed a significant and independent association between MC and clinically relevant LBP.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Copyright of Der Schmerz is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Accumulating evidence from neuroimaging studies has supported that chronic pain could induce changes in brain function. However, few studies have focused on the dynamic regional homogeneity (dReHo) of trigeminal neuralgia (TN). In this study, twenty-eight TN patients and 28 healthy controls (HC) were included. Based on the resting-state fMRI (rsfMRI), we detected abnormalities in dReHo in the TN patients. Patients with TN had decreased dReHo in the left middle temporal gyrus, superior parietal lobule, and precentral gyrus, and increased dReHo in the thalamus. Furthermore, the increase in dReHo in the thalamus was positively correlated with duration of TN (r = 0.485, p = 0.012). These results provide compelling evidence for abnormal resting-state brain activity in TN and suggest that the duration of TN may play a critical role in brain function.

Accumulating evidence from neuroimaging studies has supported that chronic pain could induce changes in brain function. However, few studies have focused on the dynamic regional homogeneity (dReHo) of trigeminal neuralgia (TN). In this study, twenty-eight TN patients and 28 healthy controls (HC) were included. Based on the resting-state fMRI (rsfMRI), we detected abnormalities in dReHo in the TN patients. Patients with TN had decreased dReHo in the left middle temporal gyrus, superior parietal lobule, and precentral gyrus, and increased dReHo in the thalamus. Furthermore, the increase in dReHo in the thalamus was positively correlated with duration of TN (r = 0.485, p = 0.012). These results provide compelling evidence for abnormal resting-state brain activity in TN and suggest that the duration of TN may play a critical role in brain function. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: This case‐control study aimed to compare patients with temporomandibular disorders (TMD) and healthy controls in terms of oral health‐related quality of life (OHRQoL) considering Graded Chronic Pain Scale (GCPS) scores, pain duration, psychological impairment and demographic characteristics. Methods: A total of 75 patients with TMD and 75 healthy controls were recruited. The short version of Oral Health Impact Profile (OHIP‐14) was administered for evaluating the OHRQoL. Psychosocial impairments were assessed using the General Health Questionnaire‐28 (GHQ‐28). The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) axis I and II were also used for patient diagnosis and collecting GCPS scores, pain duration, age and gender. Independent‐sample t tests, Pearson's chi‐square tests and multiple logistic and linear regression models were applied for statistical analysis. Results: The mean age of the patients was 34.3±12.4 years. A female‐to‐male ratio of 6:1 was seen in the TMD group. The prevalence and severity of the OHIP were significantly different between the TMD and control groups (66.7% vs 12.0% and 18.0 vs 9.2, respectively). According to multiple logistic regression for OHIP prevalence and multiple linear regression for OHIP severity in the TMD group, GCPS scores and pain duration, followed by psychological impairment, were the most important predictors of the OHRQoL. Conclusion: TMD negatively affected the OHRQoL, particularly in patients with psychological impairments. Meanwhile, age and gender did not seem to have a serious effect. Hence, promoting the quality of life of patients with TMD requires emphasis on chronic pain management and maintaining good mental health. [ABSTRACT FROM AUTHOR]

Study Design: Cross-sectional design.Objective: Here we aimed to determine whether motor cortical reorganization in low back pain (LBP) can be identified using noninvasive surface electromyographic (EMG) recordings of back muscles at different lumbar levels, and whether cortical reorganization is related to clinical features of LBP.Summary Of Background Data: Reorganization of motor regions of the brain may contribute to altered motor control, pain, and disability in chronic LBP. However, data have been limited by the need for invasive recordings of back muscle myoelectric activity. The relationship between altered cortical organization and clinical features of LBP remains unclear.Methods: In 27 individuals with recurrent, nonspecific LBP and 23 pain-free controls, we mapped the motor cortical representation of the paraspinal muscles using transcranial magnetic stimulation in conjunction with noninvasive surface EMG recordings at L3 and L5 levels. Clinical measures of pain severity, location, and duration were made.Results: The results demonstrate a loss of discrete motor cortical organization of the paraspinal muscles in chronic LBP that can be identified using noninvasive EMG recordings. A loss of discrete cortical organization was clearer when surface electrodes were positioned at L3 rather than L5. A novel finding was that altered motor cortical organization (number of discrete peaks and map volume) was associated with the severity and location of LBP.Conclusion: These data suggest that surface EMG positioned at L3 is appropriate for the identification of changes in the motor cortex in LBP. Furthermore, our data have implications for treatment strategies that aim to restore cortical organization in LBP.Level Of Evidence: 2. [ABSTRACT FROM AUTHOR]

Background and Objective: The treatment of neuropathic pain due to low-back (lumbosacral) radiculopathies, a common source of neuropathic pain, is challenging and often requires a multimodal therapeutic approach. The capsaicin 8% patch is the first topical analgesic licensed for peripheral neuropathic pain. To evaluate this treatment, a subset of patients with painful radiculopathy (lumbar and cervical, including ventral and dorsal rami) enrolled into the multicenter, non-interventional QUEPP study (Qutenza 2 - safety and effectiveness in peripheral neuropathic pain) was analyzed.Methods: Of the 1044 study participants, 50 were diagnosed with painful radiculopathy as only peripheral neuropathic pain syndrome and were eligible for evaluation. Patients received a single treatment (visit 1) with follow-up visits 2-5 at weeks 1-2, 4, 8 and 12. Parameters assessed at all visits included pain intensity, neuropathy symptoms and side effects. Quality of life (SF-12) and painDETECT 1 questionnaires were completed at baseline and final visit. Data was analyzed by patch application site and duration of pain.Results: Topical treatment led to a significant decrease of pain intensity between weeks 1/2 and week 12 versus baseline at the application sites representing dermatomes of ventral (N = 26) and dorsal rami (N = 13) of spinal nerves. A significant decline (p ≤ .001) of numeric pain rating scale scores was observed between weeks 1/2 following patch application and the end of observation (week 12) in the overall radiculopathy group (N = 50), and the groups with either 3 months to 2 years (N = 14) or >2 years (N = 23) duration of pain. Pain relief of at least 30% was observed in 50.0%, 71.4% and 39.1% of patients in the respective groups. Four patients experienced in total seven adverse drug reactions (application site pain or pruritus).Conclusion: Effective neuropathic pain relief was observed after patch application within the innervation territories of both dorsal and ventral branches of the spinal nerve. Further controlled randomized trials are indicated. [ABSTRACT FROM AUTHOR]

Background Patients with chronic pain conditions such as neuropathic pain frequently experience delays in diagnosis and treatment. Ideally, all patients should be treated in a timely manner, but in those patients with more established disease it is important to know that approved treatments remain effective. Methods This was a pooled analysis of 19 randomized placebo-controlled trials of pregabalin for peripheral neuropathic pain conditions, including diabetic peripheral neuropathy, postherpetic neuralgia, and post-traumatic/postsurgical pain. Patients were divided into 5 pain duration categories based on time since onset of pain (< 6 months, 6 months to < 1 year, 1 year to < 2 years, 2 years to < 5 years, and ≥ 5 years). Mean change in pain score at endpoint, vs. placebo, was assessed for each category, together with changes in Patient Global Impression of Change ( PGIC) responders ('very much' or 'much' improved at endpoint). Results The analysis included 5,783 patients ( n = 3,619 pregabalin; n = 2,164 placebo). Mean baseline pain scores were similar across the pain duration categories (range 6.3 to 6.5). Pregabalin significantly improved pain score at endpoint, vs. placebo, in all patients together (treatment difference [95% confidence interval], −0.59 [−0.67, −0.52], P < 0.0001) and similarly in each pain duration category ( P < 0.0001 for each). There were significantly more PGIC responders with pregabalin, vs. placebo, for all patients (45.0% vs. 30.9%, P < 0.0001) and each category separately ( P < 0.001 for each). There were no consistent, significant differences in treatment response between the different pain duration categories. Conclusions Pregabalin significantly improves pain irrespective of the length of time since onset of neuropathic pain. [ABSTRACT FROM AUTHOR]

The quality of life (QOL) has been defined as ‘‘a person’s sense of well-being that stems from satisfaction or dissatisfaction with the areas of life that are important to him/her’’. It is generally accepted that pain intensity and duration have a negative impact on the QOL. One specific type of control is “self-efficacy”, or the belief that one has the ability to successfully engage in specific actions. The ability to adapt to pain may play an important role in maintaining the QOL. In this study, we investigated the role of self-efficacy, pain intensity, and pain duration in various domains of quality of life such as physical, psychological, social and environmental domains. In this study, 290 adult patients (146 men, 144 women) completed coping self-efficacy and the WHOQOL-BREF Questionnaire. Moreover, we illustrated numerical rating scale for pain intensity. The results were analyzed using SPSS version of 19.0 and means, descriptive correlation, and regression were calculated. Our data revealed that self-efficacy but not the pain duration could significantly anticipate the QOL and its four related domains (P

Unlabelled: Compelling evidence has shown chronic widespread and exaggerated pain experience in chronic musculoskeletal pain (MSKP) conditions. In addition, neuroimaging research has revealed morphological and functional brain alterations in these patients. It is hypothesized that brain alterations play a role in the persistent pain complaints of patients with chronic MSKP. Nevertheless, lack of overview exists regarding the relations between brain alterations and clinical measures of pain. The present systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, to investigate the relations between structural or functional brain alterations, using magnetic resonance imaging scans, and clinical pain measures in patients with chronic MSKP. PubMed, Web of Science, Cinahl, and Cochrane databases were searched. First, the obtained articles were screened according to title and abstract. Second, the screening was on the basis of full-text. Risk of bias in included studies was investigated according to the modified Newcastle-Ottawa Scale. Twenty studies met the inclusion criteria. Moderate evidence shows that higher pain intensity and pressure pain sensitivity are related to decreased regional gray matter (GM) volume in brain regions encompassing the cingulate cortex, the insula, and the superior frontal and temporal gyrus. Further, some evidence exists that longer disease duration in fibromyalgia is correlated with decreased total GM volume. Yet, inconclusive evidence exists regarding the association of longer disease duration with decreased or increased regional GM volume in other chronic MSKP conditions. Inconclusive evidence was found regarding the direction of the relation of pain intensity and pressure pain sensitivity with microstructural white matter and functional connectivity alterations. In conclusion, preliminary to moderate evidence demonstrates relations between clinical pain measures, and structural and functional connectivity alterations within brain regions involved in somatosensory, affective, and cognitive processing of pain in chronic MSKP. Nevertheless, inconclusive results exist regarding the direction of these relations. Further research is warranted to unravel whether these brain alterations are positively or negatively correlated to clinical pain measures.Perspective: Structural and functional brain alterations within regions involved in somatosensory, affective, and cognitive pain processing play a crucial role in the persistent pain of chronic MSKP patients. Accordingly, these brain alterations have to be taken into account when assessing and treating patients with chronic MSKP. [ABSTRACT FROM AUTHOR]

Background: Temporomandibular disorder (TMD) is a common condition that frequently transitions to chronic symptoms. Experimental pain models that mimic the symptoms of clinical TMD may be useful in understanding the mechanisms, and sex differences, present in this disorder. Here we aimed to comprehensively characterise the nature and time-course of pain, functional impairment and hyperalgesia induced by repeated intramuscular injection of nerve growth factor (NGF) into the masseter muscle, and to investigate sex differences in the NGF-induced pain experience., Methods: 94 healthy individuals participated in a longitudinal study with 30-day follow-up. NGF was injected into the right masseter muscle on Day 0 and Day 2. Participants attended laboratory sessions to assess pain (Numerical Rating Scale; NRS), functional limitation (mouth opening distance, Jaw Functional Limitation Scale; JFLS) and mechanical sensitization (pressure pain thresholds; PPTs) on Days 0, 2 and 5 and completed twice daily electronic pain dairies from Day 0 to day 30., Results: Peak pain averaged 2.0/10 (95 % CI: 1.6-2.4) at rest and 4.3/10 (95 % CI: 3.9-4.8) on chewing. Pain-free mouth opening distance reduced from 5.0 cm (95 % CI: 4.8-5.1 cm) on Day 0 to 3.7 cm (95 % CI: 3.5-3.9 cm) on Day 5. The greatest reduction in PPTs was observed over the masseter muscle. Females experienced higher pain, greater functional impairment, and greater sensitivity to mechanical stimuli than males., Conclusion: Intramuscular injection of NGF is a useful model with which to explore the mechanisms, and sex differences, present in clinical TMD., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: This project was funded by grant 1R61NS113269-01 from The National Institutes of Health to DAS, SMS and SC. DAS is an advisor to Empower Therapeutics. The other authors have no conflicts to declare., (© 2023 The Authors.)

Objectives: The aim of this study was to assess the influence of the shaping technique on incidence, intensity, duration and type of postoperative pain (PP). Methods: Root canal treatments were carried out with rotary instrumentation (n = 80) during a single-visit, and data about pre-treatment conditions were collected. Patients were given a questionnaire to record the presence or absence of post-endodontic pain, its duration and level of discomfort. A matching patient (same pre-treatment conditions but manual instrumentation) was randomly selected from a pool (n = 374) and assigned to the control group. A total of 44 pairs of patients matched completely and were included in the study. Incidence (yes/no) of PP was assessed using Chi-square tests, intensity (mild, moderate, severe) with trend tests and duration (days) with Mann-Whitney U tests. Results: A significantly greater proportion of the patients in the control group reported pain than did patients in the rotary shaping group (p < 0.05). However, pain duration was shorter (p = 0.008) in the control group. Differences in level of discomfort were not statistically significant. Conclusions: The results of this prospective in vivo study suggest that a higher incidence of PP should be expected after manual root canal preparation. However a second major finding of the study is that when present, PP after a rotary canal preparation is expected to last longer. Clinical significance: There has been an increase in the use of rotary techniques among dentists in recent years. The present study analyses the differences in the incidence and characteristics of postoperative pain that should be expected after rotary canal preparation compared to traditional manual methods that had not been reported yet. [ABSTRACT FROM AUTHOR]

Background: Temporomandibular pain disorder (TMD) is a common pain condition in the face. People with TMD report multiple pain comorbidities. The presence of fibromyalgia and migraine in people with TMD is associated with an increase in TMD pain intensity and duration. However, data on the relationship between increasing number of pain comorbidities and TMD pain are rare. The aims of this study were: firstly to evaluate the extent to which increasing number of comorbidities is associated with increasing TMD pain intensity and duration; and secondly to evaluate the extent to which the presence of specific comorbidities is associated with increasing TMD pain intensity and duration. Methods: The sample included 180 people seeking TMD treatment at Boston and Montreal clinics. TMD was diagnosed using the Research Diagnostic Criteria for TMD. A Numerical Pain Rating Scale assessed TMD pain intensity and participants provided their TMD pain duration in a study questionnaire. The comorbidities of migraine, chronic fatigue syndrome, irritable bowel syndrome, interstitial cystitis and restless leg syndrome were diagnosed by 5 validated diagnostic questionnaires. The associations were analyzed by linear regression, controlling for confounders. Results: There was a positive association between the number of comorbidities present and TMD pain intensity (p < 0.01) and between the number of comorbidities present and TMD pain duration (p < 0.01). Also, the presence of migraine was positively associated with TMD pain intensity (p < 0.01) and the presence of chronic fatigue syndrome was positively associated with TMD pain intensity (p < 0.05) and with TMD pain duration (p < 0.01). When TMD patients were separated into groups, these associations did not change for the myofascial pain group, whereas in the non-myofascial pain group, the relationship between number of comorbidities and TMD pain duration was the only one still present. Conclusion: This study shows that the number of comorbidities is positively associated with TMD pain duration and intensity. The presence of specific conditions, such as migraine and chronic fatigue syndrome, is associated with an increase in TMD intensity and duration. [ABSTRACT FROM AUTHOR]