Multimodal therapeutic intervention program associated with photobiomodulation therapy for individuals with chronic nonspecific neck pain: protocol for a clinical trial.

BACKGROUND: Neck pain is a prevalent global musculoskeletal issue, significantly contributing to the loss of years of healthy life due to disability. Chronic nonspecific neck pain (CNNP) involves diverse symptoms impacting mobility and quality of life. While therapeutic exercises demonstrate efficacy, the role of photobiomodulation therapy (PBMT) remains uncertain. This study aims to assess the additional effects of PBMT within a multimodal therapeutic intervention for CNNP. METHODS: A randomized, two-arm, controlled, blind clinical trial follows CONSORT and SPIRIT guidelines. Participants diagnosed with CNNP will receive a stand-alone multimodal therapeutic intervention or the same program with additional PBMT. The primary outcomes will be assessed by the functional disability identified through applying the NDI (Neck Disability Index). Secondary outcomes will be pain intensity during rest and active neck movement, catastrophizing and kinesiophobia, functionality, and disability assessed at baseline, after 8 weeks, and at a 4-week follow-up. Both groups receive pain education before personalized interventions, including resistance exercises, neuromuscular activities, mobility, and body balance. The PBMT group undergoes low-level light therapy. Intention-to-treat analysis, using linear mixed models, employs data presented as mean, standard deviation, and differences with a 95% confidence interval. Non-normally distributed variables transform. Statistical significance is set at 5%. DISCUSSION: This study addresses a critical gap in understanding the combined effects of PBMT and therapeutic exercises for CNNP. The findings aim to guide clinicians, researchers, and CNNP sufferers through rigorous methodology and diverse outcome assessments, offering valuable insights into evidence-based practices for CNNP management. Data confidentiality is maintained throughout, ensuring participant privacy during statistical analysis. TRIAL REGISTRATION: Effects of adding photobiomodulation to a specific therapeutic exercise program for the treatment of individuals with chronic nonspecific neck pain, registration number: NCT05400473, on 2022-05-27.

Beyond pain: the influence of psychological factors on functional status in fibromyalgia.

OBJECTIVES: Fibromyalgia (FM) is characterised by chronic widespread pain, often associated with fatigue, sleep disturbance, cognitive and mood impairment. Pain is a complex and multidimensional experience that significantly impacts personal, social, and professional functioning. Psychological factors related to chronic pain include catastrophising and self-efficacy in managing the painful condition. Therefore, this study explores the influence of chronic pain and related psychological factors on functional outcomes in FM patients. METHODS: In this study, 91 Italian patients with FM were assessed using an online questionnaire. The questionnaire included instruments to assess pain, such as the Numerical Rating Scale (NRS) and the Brief Pain Inventory (BPI), psychological characteristics, such as the Pain Self-Efficacy Questionnaire (PSEQ) and the Pain Catastrophizing Scale (PCS), and health-related quality of life with the 12-item Short Form Survey (SF-12). Multiple regression models were run, using the Interference subscale of the BPI and the physical and mental components of the SF-12 as outcomes, and the NRS, PCS and PSEQ scales as predictors. RESULTS: Our analysis revealed that in our model, both PCS and PSEQ were significant predictors of BPI-Interference (PCS: ß=0.29; p=0.001; PSEQ: ß=-0.36; p<0.001); NRS and PSEQ significantly predicted SF-12-Physical score (NRS: ß=-0.32; p=<0.001; PSEQ: ß=.50; p<0.001); PCS was found to be the only significant predictor of SF-12-Mental scores (ß=-0.53; p<0.001). CONCLUSIONS: Our results suggested that psychological variables such as catastrophic thinking and self-efficacy play a significant role in determining daily functioning and physical and mental health status in FM patients, showing greater influence than pain intensity.

Mendelian randomization highlights sleep disturbances mediated the effect of depression on chronic pain.

INTRODUCTION: Depression and chronic pain are significant contributors to the global burden of disease. Previous research has revealed complex relationships between these two conditions, which may be influenced by sleep quality. However, observational studies have limitations, including confounding factors and reverse causation. This study aims to explore the mediating effects of sleep on the relationship between depression and chronic pain using Mendelian randomization (MR). METHODS: We conducted a two-step, two-sample MR study using mediation analysis. We obtained major depressive disorder (MDD) Genome-Wide Association Studdies (GWAS) data from Wray et al.'s GWAS meta-analysis. Phenotypic data related to sleep were collected from the UK Biobank. Chronic pain data were obtained from the Finnish database. RESULTS: MR analysis revealed significant genetic associations between MDD and chronic localized pain [IVW: odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.16-1.38, p = 2.52 × 10-7] as well as fibromyalgia (IVW: OR = 2.17, 95% CI = 1.34-3.52, p = .002). Genetic susceptibility for MDD was also associated with insomnia (IVW: OR = 1.10, 95% CI = 1.06-1.13, p = 3.57 × 10-8) and self-reported short sleep duration (IVW: OR = 1.03, 95% CI = 1.00-1.06, p = .047). The mediating effects of insomnia and fibromyalgia on the pathway from depression to chronic regional pain were 1.04 and 1.03, respectively, with mediation proportions of 12.8% and 15.2%. Insomnia mediated the pathway between depression and fibromyalgia with an effect of 1.12, accounting for 15.2% of the total effect. CONCLUSION: This two-step MR analysis strengthens the evidence of genetic predictive associations between depression and chronic pain, highlighting the mediating roles of insomnia and short sleep duration. It further elucidates the specific roles of distinct sleep disorders, differentiating insomnia and short sleep duration from other sleep-related phenotypes.

Chronic Pain and Joint Hypermobility: A Brief Diagnostic Review for Clinicians and the Potential Application of Infrared Thermography in Screening Hypermobile Inflamed Joints.

Joint hypermobility syndromes, particularly chronic pain associated with this condition, including Hypermobile Ehlers-Danlos Syndrome (hEDS) and Hypermobility Spectrum Disorders (HSD), present diagnostic challenges due to their multifactorial origins and remain poorly understood from biomechanical and genomic-molecular perspectives. Recent diagnostic guidelines have differentiated hEDS, HSD, and benign joint hypermobility, providing a more objective diagnostic framework. However, incorrect diagnoses and underdiagnoses persist, leading to prolonged journeys for affected individuals. Musculoskeletal manifestations, chronic pain, dysautonomia, and gastrointestinal symptoms illustrate the multifactorial impact of these conditions, affecting both the physical and emotional well-being of affected individuals. Infrared thermography (IRT) emerges as a promising tool for joint assessment, especially in detecting inflammatory processes. Thermal distribution patterns offer valuable insights into joint dysfunctions, although the direct correlation between pain and inflammation remains challenging. The prevalence of neuropathies among hypermobile individuals accentuates the discordance between pain perception and thermographic findings, further complicating diagnosis and management. Despite its potential, the clinical integration of IRT faces challenges, with conflicting evidence hindering its adoption. However, studies demonstrate objective temperature disparities between healthy and diseased joints, especially under dynamic thermography, suggesting its potential utility in clinical practice. Future research focused on refining diagnostic criteria and elucidating the underlying mechanisms of hypermobility syndromes will be essential to improve diagnostic accuracy and enhance patient care in this complex and multidimensional context.

Modulating Neural Circuits of Pain in Preclinical Models: Recent Insights for Future Therapeutics.

Chronic pain is a pathological state defined as daily pain sensation over three consecutive months. It affects up to 30% of the general population. Although significant research efforts have been made in the past 30 years, only a few and relatively low effective molecules have emerged to treat chronic pain, with a considerable translational failure rate. Most preclinical models have focused on sensory neurotransmission, with particular emphasis on the dorsal horn of the spinal cord as the first relay of nociceptive information. Beyond impaired nociceptive transmission, chronic pain is also accompanied by numerous comorbidities, such as anxiety-depressive disorders, anhedonia and motor and cognitive deficits gathered under the term "pain matrix". The emergence of cutting-edge techniques assessing specific neuronal circuits allow in-depth studies of the connections between "pain matrix" circuits and behavioural outputs. Pain behaviours are assessed not only by reflex-induced responses but also by various or more complex behaviours in order to obtain the most complete picture of an animal's pain state. This review summarises the latest findings on pain modulation by brain component of the pain matrix and proposes new opportunities to unravel the mechanisms of chronic pain.

Chronic Neuropathic Pain and Comorbid Depression Syndrome: From Neural Circuit Mechanisms to Treatment.

Chronic neuropathic pain and comorbid depression syndrome (CDS) is a major worldwide health problem that affects the quality of life of patients and imposes a tremendous socioeconomic burden. More than half of patients with chronic neuropathic pain also suffer from moderate or severe depression. Due to the complex pathogenesis of CDS, there are no effective therapeutic drugs available. The lack of research on the neural circuit mechanisms of CDS limits the development of treatments. The purpose of this article is to provide an overview of the various circuits involved in CDS. Notably, activating some neural circuits can alleviate pain and/or depression, while activating other circuits can exacerbate these conditions. Moreover, we discuss current and emerging pharmacotherapies for CDS, such as ketamine. Understanding the circuit mechanisms of CDS may provide clues for the development of novel drug treatments for improved CDS management.

Post-polio syndrome - somatosensory dysfunction and its relation to pain: a pilot study with quantitative sensory testing.

OBJECTIVE: To explore and characterize somatosensory dysfunction in patients with post-polio syndrome and chronic pain, by conducting examinations with Quantitative Sensory Testing. DESIGN: A cross-sectional, descriptive, pilot study conducted during 1 month. SUBJECTS/PATIENTS: Six patients with previously established post-polio syndrome and related chronic pain. METHODS: All subjects underwent a neurological examination including neuromuscular function, bedside sensory testing, a thorough pain anamnesis, and pain drawing. Screening for neuropathic pain was done with 2 questionnaires. A comprehensive Quantitative Sensory Testing battery was conducted with z-score transformation of obtained data, enabling comparison with published reference values and the creation of sensory profiles, as well as comparison between the study site (more polio affected extremity) and internal control site (less affected extremity) for each patient. RESULTS: Derived sensory profiles showed signs of increased prevalence of sensory aberrations compared with reference values, especially Mechanical Pain Thresholds, with significant deviation from reference data in 5 out of 6 patients. No obvious differences in sensory functions were seen between study sites and internal control sites. CONCLUSION: Post-polio syndrome may be correlated with a mechanical hyperalgesia/allodynia and might be correlated to a somatosensory dysfunction. With lack of evident side-to-side differences, the possibility of a generalized dysfunction in the somatosensory system might be considered.

Yoga as a complementary therapy for rheumatoid arthritis: a case-based review.

Rheumatoid arthritis (RA) presents patients with chronic pain and functional limitations due to its autoimmune nature. Despite symptomatic and pharmaceutical interventions, many patients experience inadequate relief, prompting exploration into non-pharmacological approaches such as yoga. This study aims to evaluate the effectiveness of yoga as an adjunctive therapy for RA by examining clinical data from patients experiencing chronic pain and limitations. This study analyzed several clinical cases at the Shymkent City Regional Clinical Hospital. Ten RA patients, irrespective of various demographic factors, were enrolled. Parameters including pain intensity, inflammation activity, systolic blood pressure, joint function, and morning stiffness were assessed to gauge the impact of yoga. The findings demonstrated notable positive changes following a three-month yoga program. These changes encompassed enhanced joint health, reduced pain severity, and decreased disease activity. Particularly noteworthy was the reduction in morning stiffness by an average of 31 min, alongside a decrease in the average pain index from 80 mm to 41.5 mm. The mean RA activity level decreased from 5.8 to 4.7. Furthermore, mean systolic blood pressure decreased by 15.5 mmHg, and mean cholesterol levels decreased from 5.3 mmol/L to 4.8 mmol/L. These results underscore the potential significance of yoga as a supplementary intervention for RA. Yoga practice may enhance patients' quality of life and alleviate disease symptoms. Nevertheless, the study's limited sample size necessitates caution, and further research is warranted to validate these findings.

The positive effect of pulse electromagnetic field therapy on pain and disability in chronic low back pain: a comparative study.

BACKGROUND: Low back pain that lasts longer than three months is called chronic low back pain. Chronic low back pain is among the most common problems in the world, causing severe disability and loss of employment in patients. OBJECTIVE: To investigate the effect of pulse electromagnetic field therapy (PEMFT) added to routine physical therapy on pain and functional status in patients with chronic low back pain. METHODS: This retrospective comparative study included 69 patients with chronic low back pain. The patients were divided into two groups: those who received lumbar transcutaneous electrical nerve stimulation, infrared, and ultrasound treatments, and those who additionally received PEMFT. The files of patients with chronic low back pain were reviewed, and those who had been evaluated using the Quebec Back Pain Disability Scale (QBPDS) in terms of functional capacity and effects of low back pain and the Visual Analogue Scale (VAS) for pain both before and after treatment were included in the study. RESULTS: No significant difference was detected between the two groups' pretreatment VAS and QBPDS scores (p > 0.05). The second-and-third measurement scores of both groups were significantly lower than their first-measurement VAS and QBPDS scores (p ˂ 0.001), but there was no significant difference between their second- and third-measurement scores (p > 0.05). According to the inter-group comparison of the VAS and QBPDS scores, the second and third-measurement scores of the PEMFT group were significantly lower than those of the control group (p ˂ 0.001). CONCLUSIONS: PEMFT seems to be able to alleviate pain intensity and ameliorate disability in patients with chronic low back pain. PEMFT can be considered an effective and safe option that can be added to routine physical therapy modalities for relieving chronic low back pain frequently encountered in clinical practice. Further studies validating the effectiveness of PEMFT could strengthen its position in the management of chronic low back pain.

A study on the effects of visual condition on postural stability in adults with and without chronic low back pain.

This study was conducted to compare postural stability during repeated unilateral standing tasks between adults with and without chronic low back pain (LBP) while considering visual input. The study involved 26 participants with LBP and 39 control participants. Each participant performed three trials of standing tasks on the dominant limb using a stable platform. The Falls Efficacy Scale was utilized to assess fall-related self-efficacy and fear of falling due to potential physical frailty. The center of pressure (COP) sway excursion was analyzed at 10 mm and 20 mm thresholds for the time-in-boundary (TIB). The results indicated a significant fear of falling difference in the LBP group compared to the control group (t = 3.27, p = 0.001). The LBP group demonstrated a significant interaction between visual condition and TIB (F = 8.45, p = 0.01), particularly in the LBP group, which demonstrated a notable decrease in TIB at 10 mm (54.02 % compared to the control group's 70.40 %) and 20 mm (70.93 % compared to the control group's 85.92 %) thresholds during the second trial and at 10 mm (59.73 % compared to the control group's 73.84 %) during the third trial in the eyes open condition. Overall, visual condition demonstrated significant interactions on thresholds (F = 15.80, p = 0.001, η2p = 0.21) as well as trials  ×  thresholds (F = 4.21, p = 0.04, η2p = 0.07). These findings indicate a potential adaptation in postural control among the LBP group with visual feedback. Further research is warranted to explore group differences when considering visual conditions and sway excursion thresholds.

Evaluation of the segmental distribution of pain sensitivity among patients with central sensitization associated with chronic subacromial pain syndrome: A cross-sectional study.

INTRODUCTION: Pain sensitivity is the main finding of central sensitization (CS) and can occur in patients with chronic shoulder pain. However, there is limited evidence concerning the distribution of pain sensitivity in shoulders, forearms, and legs in patients with CS associated with chronic shoulder pain. The present study aimed to determine the distribution of pain sensitivity in patients with CS associated with chronic subacromial pain syndrome (SPS). METHOD: This cross-sectional study included 58 patients with chronic SPS and CS (patient group) and 58 healthy participants (control group). The presence of CS was determined using the Central Sensitization Inventory (CSI). To determine the distribution of pain sensitivity, pressure pain threshold (PPT) measurements were performed from the shoulders, forearms, and legs. RESULTS: There was no significant difference between the two groups in terms of sociodemographic data (p > 0.05). The patient group had a significantly higher CSI score (p < 0.001) and lower PPTs in all regions (p < 0.05) than the control group. Unlike the control group, the patient group had lower PPTs on the affected side for the shoulder [mean difference (MD) 95% confidence interval (CI): 1.2 (-1.7 to -0.6)], forearm [MD 95% CI: 1.1 (-1.7 to -0.6)], and leg [MD 95% CI: 0.9 (-1.4 to -0.3)] compared with the contralateral side (p < 0.001). CONCLUSION: Pain sensitivity is more pronounced in the affected shoulder and the forearm and leg located on this side than in those on the contralateral side in patients with CS associated with chronic SPS.

Risk of unfavorable pain prognosis impacts walking physiomechanical parameters and psychophysiological workload in sufferers of chronic low back pain.

BACKGROUND: Tolerating physical tasks depends not only on task-specific characteristics but also on an individual's psychophysiological capacity to respond to the imposed load. People suffering from chronic low back pain (CLBP) may experience reduced psychophysiological capacity and are at risk for poor pain prognosis, which could lead to an increased walking workload. AIM: To investigate how the risk of unfavorable pain prognosis in CLBP can impact walking physiomechanical parameters and psychophysiological workload. METHODS: A cross-sectional observational study. The study classified 74 volunteers into four groups based on their prognosis for pain: pain-free control (CG/n = 20), low (LrG/n = 21), medium (MrG/n = 22), and high (HrG/n = 11) risk of poor prognosis for CLBP. The ground assessments identified the self-selected (SSW) and optimal (OWS) walking speeds, as well as the locomotor rehabilitation index (LRI). Treadmill assessments were conducted at two different speeds (0.83 and 1.11 m s-1, SSW and OWS) to record physiomechanical parameters. Psychophysiological workloads during walking were measured via workload impulse for the session (TRIMP), determined by variations in heart rate. RESULTS: CLBP groups exhibited slower SSW and lower LRI compared to the CG. The TRIMP was lower in the LrG. However, both MrG and HrG exhibited a comparable overload to the CG, even while walking at a lower intensity with a psychophysical demand. SSW and OWS displayed an increased TRIMP compared to fixed speeds. CONCLUSION: Psychosocial factors may affect SSW in people with CLBP but not among the risk strata. An unfavorable prognosis for pain could jeopardize the psychophysiological capacity to withstand walking demands.

The role of attention bias malleability in experiencing pain and associated disability.

Background: Attentional processing of pain has been theorized to play a key role in the severity of pain and associated disability. In particular attentional bias towards pain information, resulting in poor pain outcomes, has been extensively researched. Recently, the idea was put forward that attention bias malleability (AM), i.e., the readiness to acquire an attentional bias irrespective of its direction, may be key in predicting poor pain outcomes. We tested this hypothesis in two studies. Methods: In Study 1, 55 healthy participants completed an AM paradigm, followed by an experimental heat pain paradigm probing pain experience and pain-related task interference. In Study 2, 71 people with chronic pain completed an AM paradigm and questionnaires probing pain experience and associated disability. Results: In Study 1, including healthy participants, no relationship was found between AM indices and experimental pain outcomes. In Study 2, including chronic pain patients, results indicated that higher levels of overall AM were related to higher levels of pain experience and disability. Conclusion: This study partially supports the hypotheses that the degree to which individuals can adapt their attentional preference in line with changing environmental conditions is associated with poor pain outcomes. However, future research is needed to clarify inconsistent findings between healthy volunteers and chronic pain patients as well as to determine the causal status of AM in poor pain outcomes.

[THE MUSCULAR COMPONENT OF FIBROMYALGIA PATHOPHYSIOLOGY].

INTRODUCTION: Fibromyalgia syndrome (FMS) is a chronic pain syndrome, prevalent in women more than men. The main symptoms are widespread musculoskeletal pain, fatigue, and weakness. To date, the pathophysiological mechanisms are unclear, and there are several pathogenic theories elucidating this condition. In this review, we summarized articles published in the past few years, regarding the effect of musculoskeletal dysfunction on FMS. We focused on the musculoskeletal system and central nervous system (CNS) disarrays.

Improving Function and Quality of Life in Patients with Chronic Neck Pain, Tension-Type Headache, and Forward Head Posture: The Role of Eyeball Exercise and Cervical Stabilization Programs.

BACKGROUND The purpose of this study was to investigate the effects of eyeball exercise and cervical stabilization programs to patients with chronic neck pain, tension-type headache (TTH), and forward head posture (FHP). MATERIAL AND METHODS The design of this study was a randomized controlled trial. A total of 40 participants were randomly divided into 2 groups: the experimental group (n=20) and the control group (n=20). Both groups received cervical manual therapy and biofeedback-guided stabilization exercises (30 min/session, 3 sessions/week, 6 weeks). In addition to the regular treatments, the participants in the experimental group also performed eyeball exercises for 20 minutes per session, 3 sessions per week, for a total of 6 weeks. Changes in neck pain (numeric rating scale, NRS), neck disability index (NDI), quality of life (Short Form-12 Health Survey Questionnaire, SF-12), headache impact test-6 (HIT-6), craniovertebral angle (CVA), cranial rotation angle (CRA), and muscle tone were measured. RESULTS Both groups showed significant improvements in NRS, NDI, SF-12, HIT-6 scores, CVA, CRA, and muscle tone (p<0.05). The experimental group had significant differences in NDI, SF-12, HIT-6 scores, and suboccipital muscle tone compared to the control (p<0.05). CONCLUSIONS Combining the eyeball exercise program with commonly used manual therapy and stabilization exercises for patients with chronic neck pain can help reduce nerve compression and promote muscle relaxation in the eye and neck areas. The method is thus proposed as an effective intervention to enhance function and quality of life in patients with chronic neck pain patients, TTH, and FHP.

Pain perception as hierarchical Bayesian inference: A test case for the theory of constructed emotion.

An intriguing perspective about human emotion, the theory of constructed emotion considers emotions as generative models according to the Bayesian brain hypothesis. This theory brings fresh insight to existing findings, but its complexity renders it challenging to test experimentally. We argue that laboratory studies of pain could support the theory because although some may not consider pain to be a genuine emotion, the theory must at minimum be able to explain pain perception and its dysfunction in pathology. We review emerging evidence that bear on this question. We cover behavioral and neural laboratory findings, computational models, placebo hyperalgesia, and chronic pain. We conclude that there is substantial evidence for a predictive processing account of painful experience, paving the way for a better understanding of neuronal and computational mechanisms of other emotions.

One spinal manipulation session reduces local pain sensitivity but does not affect postural stability in individuals with chronic low back pain: a randomised, placebo-controlled trial.

BACKGROUND: Clinical practice guidelines recommend spinal manipulation for patients with low back pain. However, the effects of spinal manipulation have contradictory findings compared to placebo intervention. Therefore, this study investigated the immediate effects of lumbar spinal manipulation on pressure pain threshold (PPT) and postural stability in people with chronic low back pain (cLBP). Second, we investigated the immediate effect of lumbar spinal manipulation on pain intensity and the interference of the participant beliefs about which treatment was received in the PPT, postural stability, and pain intensity. METHODS: A two-arm, randomised, placebo-controlled, double-blind trial was performed. Eighty participants with nonspecific cLPB and a minimum score of 3 on the Numeric Pain Rating Scale received one session of lumbar spinal manipulation (n = 40) or simulated lumbar spinal manipulation (n = 40). Primary outcomes were local and remote PPTs and postural stability. Secondary outcomes were pain intensity and participant's perceived treatment allocation. Between-group mean differences and their 95% confidence intervals (CIs) estimated the treatment effect. One-way analysis of covariance (ANCOVA) was performed to assess whether beliefs about which treatment was received influenced the outcomes. RESULTS: Participants had a mean (SD) age of 34.9 (10.5) years, and 50 (62.5%) were women. Right L5 [between-group mean difference = 0.55 (95%CI 0.19 to 0.90)], left L5 [between-group mean difference = 0.45 (95%CI 0.13 to 0.76)], right L1 [between-group mean difference = 0.41 (95%CI 0.05 to 0.78)], left L1 [between-group mean difference = 0.57 (95%CI 0.15 to 0.99)], left DT [between-group mean difference = 0.35 (95%CI 0.04 to 0.65)], and right LE [between-group mean difference = 0.34 (95%CI 0.08 to 0.60)] showed superior treatment effect in the spinal manipulation group than sham. Neither intervention altered postural stability. Self-reported pain intensity showed clinically significant decreases in both groups after the intervention. A higher proportion of participants in the spinal manipulation group achieved more than two points of pain relief (spinal manipulation = 90%; sham = 60%). The participants' perceived treatment allocation did not affect the outcomes. CONCLUSION: One spinal manipulation session reduces lumbar pain sensitivity but does not affect postural stability compared to a sham session in individuals with cLPB. Self-reported pain intensity lowered in both groups and a higher proportion of participants in the spinal manipulation group reached clinically significant pain relief. The participant's belief in receiving the manipulation did not appear to have influenced the outcomes since the adjusted model revealed similar findings.

Association of demographics, lumbar active range of motion and disability in chronic low back: a baseline data analysis of a randomized controlled trial from Pakistan.

BACKGROUND: The disability and significant economic costs accredited to Low back pain (LBP) are likely to rise which is an essential problem in low and middle-income countries like Pakistan. The associated factors of LBP are age, sex, and race including physical activity, high spinal load, lifting, bending, and twisting occupations. The literature highlighted there is substantial differences in associated factors of LBP within available studies in developing countries. The objective is to investigate the association of demographic factors and lumbar range of motion with disability in patients with chronic low back. METHODS: A baseline data analysis was performed as an analytical cross-sectional study among 150 patients with chronic low back in a randomized controlled trial with a duration from March 2020 and January 2021. After recording demographics, Modified-Modified Schober's test was used to measure lumbar flexion and extension and Oswestry disability index for disability. After the descriptive analysis the continuous variables, age and pain were analyzed with Spearman's correlation. Variables that were significant in bivariate analysis were then fitted in a multivariable linear regression. The Kruskal-Wallis test was used to analyze variations of disability in gender, marital status, work status, education level, and duration of pain. The p-value of 0.05 was significant. RESULTS: The results showed a significant correlation between age and pain in sitting (rh=-0.189, p = 0.021 and rh = 0.788, p < 0.001) with the disability but no significant effects of age and pain in sitting (B=-0.124, p = 0.212 and B = 1.128, p = 0.082) on disability were found. The decrease in lumbar flexion and extension was found to increase disability (B=-6.018 and - 4.032 respectively with p < 0.001). Female gender (x2(1) = 15.477, p = < 0.001) and unmarried marital status (x2(1) = 4.539, p = 0.033) had more disability than male gender and married marital status, respectively. There was a significance between groups of the duration of pain regarding disability (x2 (2) = 70.905, p < 0.001). Age, education level, and work status showed no significance (p > 0.05). CONCLUSIONS: The female gender and unmarried marital status are associated with functional disability. Decreased lumbar range of motion accompanies more disability, while age, education level, and work status do not effect on disability.

An Innovative EEG-Based Pain Identification and Quantification: A Pilot Study.

OBJECTIVE: The present pilot study aimed to propose an innovative scale-independent measure based on electroencephalographic (EEG) signals for the identification and quantification of the magnitude of chronic pain. METHODS: EEG data were collected from three groups of participants at rest: seven healthy participants with pain, 15 healthy participants submitted to thermal pain, and 66 participants living with chronic pain. Every 30 s, the pain intensity score felt by the participant was also recorded. Electrodes positioned in the contralateral motor region were of interest. After EEG preprocessing, a complex analytical signal was obtained using Hilbert transform, and the upper envelope of the EEG signal was extracted. The average coefficient of variation of the upper envelope of the signal was then calculated for the beta (13-30 Hz) band and proposed as a new EEG-based indicator, namely Piqß, to identify and quantify pain. MAIN RESULTS: The main results are as follows: (1) A Piqß threshold at 10%, that is, Piqß ≥ 10%, indicates the presence of pain, and (2) the higher the Piqß (%), the higher the extent of pain. CONCLUSIONS: This finding indicates that Piqß can objectively identify and quantify pain in a population living with chronic pain. This new EEG-based indicator can be used for objective pain assessment based on the neurophysiological body response to pain. SIGNIFICANCE: Objective pain assessment is a valuable decision-making aid and an important contribution to pain management and monitoring.

Parvalbumin gates chronic pain through the modulation of firing patterns in inhibitory neurons.

Spinal cord dorsal horn inhibition is critical to the processing of sensory inputs, and its impairment leads to mechanical allodynia. How this decreased inhibition occurs and whether its restoration alleviates allodynic pain are poorly understood. Here, we show that a critical step in the loss of inhibitory tone is the change in the firing pattern of inhibitory parvalbumin (PV)-expressing neurons (PVNs). Our results show that PV, a calcium-binding protein, controls the firing activity of PVNs by enabling them to sustain high-frequency tonic firing patterns. Upon nerve injury, PVNs transition to adaptive firing and decrease their PV expression. Interestingly, decreased PV is necessary and sufficient for the development of mechanical allodynia and the transition of PVNs to adaptive firing. This transition of the firing pattern is due to the recruitment of calcium-activated potassium (SK) channels, and blocking them during chronic pain restores normal tonic firing and alleviates chronic pain. Our findings indicate that PV is essential for controlling the firing pattern of PVNs and for preventing allodynia. Developing approaches to manipulate these mechanisms may lead to different strategies for chronic pain relief.