The Pain Descriptors Used by Individuals with Musculoskeletal Pain from Northern India.

Background: Chronic pain is a common health problem worldwide that results in significant costs to society and has negative impacts on the individuals with chronic pain. In order to study and treat pain, valid and reliable pain assessment is necessary, including assessment of pain quality. However, all of the most commonly used measures of pain quality were developed in Western countries. Evidence has shown that some of these measures are not content valid for use in non-Western countries. Moreover, it remains unclear which pain descriptors are universal across people from different countries who speak different languages, and which are specific to individuals from a particular country or even from a particular region within one country. Aim: The current study sought to: (1) identify the number and frequency of words used by native speakers of Hindi in northern India to describe their pain; (2) compare the rates of descriptor use in these individuals with samples of individuals from Nepal and the USA; and (3) investigate the content validity of the most commonly used pain quality measures for measuring pain in this Hindi-speaking population. Methods: Two hundred and forty individuals with chronic musculoskeletal pain who speak and understand Hindi were asked to describe their pain. Results: The results showed overlap as well as differences in the words used to describe pain with samples of individuals with pain from other countries. Moreover, none of the pain quality measures examined were found to be content valid in the Hindi-speaking sample, suggesting that these measures need to be adapted to assess pain quality in this population. Conclusion: The study findings confirm the conclusion that pain quality measures developed in one country or in one pain population are not necessarily valid for assessing pain quality in a population from another country. The findings also suggest the possibility that a measure could be developed which would allow for more valid assessment of pain quality in individuals with pain from different countries.

Mean of Daily Versus Single Week Recall-Based Pain Quality Assessments in Neuropathic Pain Trials: Implications for Assay Sensitivity.

Patients with neuropathic pain often present with variable pain and nonpainful sensory qualities that could serve as outcomes in randomized clinical trials (RCTs). This study aimed to investigate the within-participant variability in the severity of these sensory qualities and whether the means of 7 daily pain quality assessments provide better assay sensitivity (ie, more sensitivity to treatment effects) than single-week recall-based assessments. This secondary analysis used data from an RCT of transcutaneous electrical nerve stimulation for chemotherapy-induced peripheral neuropathy (N = 142). Participants rated the severity of painful and nonpainful sensory qualities using 0 to 10 numeric rating scales daily for 1 week (24-hour recall) and 1 time at the end of each week (week recall) at trial baseline and endpoint (after 6 weeks of treatment). For pain quality assay sensitivity analyses, the 2 types of measures were used to 1) define the study sample (ie, how many participants met minimum baseline pain quality severity) and 2) calculate the observed effect sizes (ie, between-group differences in mean pain qualities) using analysis of covariances. The projected sample sizes required to detect the observed effect sizes in future clinical trials for hot/burning pain and cramping were substantially smaller using the daily mean outcome compared with week recall (ie, hot/burning pain: 153 vs 388, cramping: 121 vs 349), and only marginally larger for sharp/shooting pain (22 participants) with the daily mean outcome. Compared with single-week recall-based assessments of pain qualities, the mean of daily assessments may improve RCT assay sensitivity when used to define entry criteria and assess outcomes. PERSPECTIVES: This study suggests that means of daily pain quality assessments may improve assay sensitivity when used to define entry criteria and assess outcomes in clinical trials. This work may inform design of future clinical trials evaluating the intensity of different pain qualities.

Multimodal approach to address the multifaceted nature of Chronic Musculoskeletal Disorders: Bridging the gap between research and clinical practice.

Musculoskeletal (MSK) disorders encompass various conditions impacting bones, muscles, tendons, ligaments, and nerves. An estimated 1.71 billion individuals globally have MSK disorders, causing disability and reduced quality of life. Literature contradicts the notion that musculoskeletal pain and disability solely arise from physical impairments; psychological, behavioural, and social factors contribute significantly. These facets influence pain perception and chronic impairment development. Common interventions-medication, exercise, manual and hydrotherapy, electro-thermal modalities, behavioural and alternative therapies-address pain individually, yet lack the comprehensive response required. In contrast, a multimodal approach combines diverse therapies tailored to individual needs. It ensures lasting symptom relief, prevents recurrence, and improves function. Although proven effective, clinical implementation of this approach remains limited. This mini-review discusses the reasons behind this gap, underscores multimodal approach importance, and enlightens rehabilitation professionals on its potential for managing chronic musculoskeletal issues.

Pain Characteristics of Patients With Fibromyalgia: A Comparison Between Gender and Different Emotional States.

BACKGROUND: Generalized pain is the core symptom of fibromyalgia (FM). Few studies have described FM's different pain characteristics under various conditions. OBJECTIVE: To explore the pain characteristics of patients with FM of different gender and emotional states. STUDY DESIGN: A cross-sectional study. SETTING: A medical center in Beijing, People's Republic of China. METHODS: A total of 197 patients with FM were recruited from an outpatient clinic. Three distinct instruments were used to assess their pain characteristics: the Numeric Rating Scale (NRS-11) to assess pain severity, the Widespread Pain Index (WPI) to assess the number of pain regions, and the Short Form-McGill Pain Questionnaire-2 (SF-MPQ-2) to assess pain qualities. The Zung Self-Rating Anxiety Scale and Zung Self-Rating Depression Scale were used to assess patients' emotional states. An independent 2-sample t test, chi-squared test, and Mann-Whitney U test were used to analyze gender pain characteristics differences and different emotional states (with/without anxiety, with/without depression). RESULTS: Pain severity on the NRS-11 was 7 (5-8), the number of pain regions determined by WPI was 13 (10-16), and the total score of different pain qualities from the SF-MPQ-2 was 2.36 (1.68-3.73) in all patients with FM. The most frequently reported regions of pain were the right shoulder girdle (89.34%), left shoulder girdle (88.32%), upper back (85.28%), and neck (81.73%). The most frequently reported pain qualities were tiredness/exhaustion (97.46%), aching pain (94.42%), numbness (78.68%), cold/freezing pain (75.63%), and tenderness (75.13%). Women patients reported more severe pain and numbness, less frequent chest pain, and shooting pain than men patients did. Patients with FM and anxiety experienced more frequent and more severe feelings of punishing/cruel thoughts, fearfulness, sickening, and tenderness; more frequent jaw pain and cold-freezing pain; more severe pain caused by light touch and tiredness/exhaustion; less frequent lower leg pain than those without anxiety did. Patients with FM and depression reported more frequent and more severe pain caused by light touch; more frequent tenderness; more severe feelings of tiredness/exhaustion, sickening,fearfulness, and punishing/cruel thoughts; and less frequent and less severe piercing pain than those without depression did. LIMITATIONS: The limitations of this study are its single-center design and lack of objective pain indicators. CONCLUSION: Gender significantly affected pain severity, chest pain, numbness, and shooting pain. Jaw pain, lower leg pain, cold/freezing pain, tenderness, pain caused by light touch, piercing pain, and pain-affective descriptors are closely related to emotional states in FM. A comprehensive understanding of pain characteristics in patients with FM would be helpful for disease education, diagnosis, and treatment.

Pain quality patterns in delayed onset muscle soreness of the lower back suggest sensitization of fascia rather than muscle afferents: a secondary analysis study.

Delayed onset muscle soreness (DOMS) of the lower back is considered a surrogate for acute low back pain (aLBP) in experimental studies. Of note, it is often unquestioningly assumed to be muscle pain. To date, there has not been a study analyzing lumbar DOMS in terms of its pain origin, which was the aim of this study. Sixteen healthy individuals (L-DOMS) were enrolled for the present study and matched to participants from a previous study (n = 16, L-PAIN) who had undergone selective electrical stimulation of the thoracolumbar fascia and the multifidus muscle. DOMS was induced in the lower back of the L-DOMS group using eccentric trunk extensions performed until exhaustion. On subsequent days, pain on palpation (100-mm analogue scale), pressure pain threshold (PPT), and the Pain Sensation Scale (SES) were used to examine the sensory characteristics of DOMS. Pain on palpation showed a significant increase 24 and 48 h after eccentric training, whereas PPT was not affected (p > 0.05). Factor analysis of L-DOMS and L-PAIN sensory descriptors (SES) yielded a stable three-factor solution distinguishing superficial thermal ("heat pain ") from superficial mechanical pain ("sharp pain") and "deep pain." "Heat pain " and "deep pain" in L-DOMS were almost identical to sensory descriptors from electrical stimulation of fascial tissue (L-PAIN, all p > 0.679) but significantly different from muscle pain (all p < 0.029). The differences in sensory description patterns as well as in PPT and self-reported DOMS for palpation pain scores suggest that DOMS has a fascial rather than a muscular origin.

Utilization of PROMIS Neuropathic Pain Quality for Detection and Monitoring Neuropathic Pain in Heel Pain Patients.

Background: Diagnosis and management of neuropathic pain (NP) in foot and ankle patients remain challenging. We investigated the plausibility of using Patient-Reported Outcomes Measurement Information System (PROMIS) Neuropathic Pain Quality (PQ-Neuro) as an initial screening tool to detect NP and track the treatment effects. Methods: Patients with heel pain were prospectively recruited and grouped to no-NP, mild-NP, and severe-NP based on the initial PROMIS PQ-Neuro t scores. Pain Interference (PI), Physical Function (PF), and Self-Efficacy (SE) scores were evaluated at baseline, 30-day, and 90-day follow-up. Other factors such as age, smoking, body mass index (BMI), low back/neck pain, anxiety/depression, and medications were analyzed. Linear mixed modeling was used to assess the main effects of time and NP on PROMIS t scores, comparing minimal clinically important difference (MCID). Results: Forty-eight patients with mean age of 52.4 years were recruited. Using the PROMIS PQ-Neuro as the assessment tool, 33 patients (69%) were detected to have NP at baseline-23 (48%) mild and 10 (21%) severe. BMI was the only independent factor associated with NP (P = .011). Higher baseline PQ-Neuro t score was significantly associated with higher follow-up PQ-Neuro (P < .001), PI (P = .005), and lower SE (P = .04) across time points. Patients with NP showed lower PF at baseline with significantly less improvement in PF (3 vs 9.9, P = .035) and did not meet MCID. Conclusion: Baseline PROMIS PQ-Neuro ≥46 was significantly associated with worse PI and SE across all time points, with less clinically significant improvements in PF. Prevalence of NP in heel pain patients was high. The PROMIS PQ-Neuro may serve as a valuable tool for detection of NP and guiding clinical treatment decision pathways for heel pain patients. Level of Evidence: Level III, prospective cohort study.

Examining the use of cannabidiol and delta-9-tetrahydrocannabinol-based medicine among individuals diagnosed with dementia living within residential aged care facilities: Results of a double-blind randomised crossover trial.

OBJECTIVE: Dementia affects individuals older than 65 years. Currently, residential aged care facilities (RACF) use psychotropic medications to manage behavioural and neuropsychiatric symptoms of dementia (BPSD), which are recommended for short-term use and have substantial side effects, including increased mortality. Cannabinoid-based medicines (CBM) have some benefits that inhibit BPSD and cause minimal adverse effects (AEs), yet limited research has been considered with this population. The study aimed to determine a tolerable CBM dose (3:2 delta-9-tetrahydrocannabinol:cannabidiol), and assessed its effect on BPSD, quality of life (QoL) and perceived pain. METHODS: An 18-week randomised, double-blinded, crossover trial was conducted. Four surveys, collected on seven occasions, were used to measure changes in BPSD, QoL and pain. Qualitative data helped to understand attitudes towards CBM. General linear mixed models were used in the analysis, and the qualitative data were synthesised. RESULTS: Twenty-one participants (77% female participants, mean age 85) took part in the trial. No significant differences were seen between the placebo and CBM for behaviour, QOL or pain, except a decrease in agitation at the end of treatment in favour of CBM. The qualitative findings suggested improved relaxation and sleep among some individuals. Post hoc estimates on the data collected suggested that 50 cases would draw stronger conclusions on the Neuropsychiatric Inventory. CONCLUSIONS: The study design was robust, rigorous and informed by RACF. The medication appeared safe, with minimal AEs experienced with CBM. Further studies incorporating larger samples when considering CBM would allow researchers to investigate the sensitivity of detecting BPSD changes within the complexity of the disease and concomitant with medications.

Quantitative and Qualitative Pain Evaluation in Response to OnabotulinumtoxinA for Chronic Migraine: An Observational Real-Life Study.

(1) Background: Randomized controlled trials and real-life studies demonstrated the efficacy of OnabotulinumtoxinA (OBT-A) for CM prevention. However, no studies specifically addressed its effect on pain's quantitative intensity and qualitative characteristics. (2) Methods: This is an ambispective study: a post-hoc retrospective analysis of real-life prospectively collected data from two Italian headache centers on CM patients treated with OBT-A over one year (i.e., Cy1-4). The primary endpoint was the changes in pain intensity (Numeric Rating Scale, NRS; the Present Pain Intensity (PPI) scale, the 6-point Behavioral Rating Scale (BRS-6)) and quality scale (the short-form McGill Pain Questionnaire (SF-MPQ)) scores. We also assessed the relationship between changes in intensity and quality of pain and disability scale (MIDAS; HIT-6) scores, monthly headache days (MHDs), and monthly acute medication intake (MAMI) (3) Results: We retrieved 152 cases (51.5 years SD 11.3, 80.3% females). From baseline to Cy-4, MHDs, MAMI, NRS, PPI, and BRS-6 scores decreased (consistently p < 0.001). Only the throbbing (p = 0.004), splitting (p = 0.018), and sickening (p = 0.017) qualities of pain collected in the SF-MPQ were reduced. Score variations in MIDAS related to those in PPI scales (p = 0.035), in the BRS-6 (p = 0.001), and in the NRS (p = 0.003). Similarly, HIT-6 score changes related to PPI score modifications (p = 0.027), in BRS-6 (p = 0.001) and NRS (p = 0.006). Conversely, MAMI variation was not associated with qualitative or quantitative pain score modifications except BRS-6 (p = 0.018). (4) Conclusions: Our study shows that OBT-A alleviates migraine by reducing its impact on multiple aspects, such as frequency, disability, and pain intensity. The beneficial effect on pain intensity seems specific to pain characteristics related to C-fiber transmission and is associated with a reduction in migraine-related disability.

Automated Extraction of Pain Symptoms: A Natural Language Approach using Electronic Health Records.

BACKGROUND: Pain costs more than $600 billion annually and affects more than 100 million Americans, but is still a poorly understood problem and one for which there is very often limited effective treatment. Electronic health records (EHRs) are the only databases with a high volume of granular pain information that allows for documentation of detailed clinical notes on a patient's subjective experience. OBJECTIVES: This study applied natural language processing (NLP) technology to an EHR dataset as part of a pilot study to capture pain information from clinical notes and prove its feasibility as an efficient method. STUDY DESIGN: Retrospective study. SETTING: All data were from UConn Health John Dempsey Hospital (JDH) in Farmington, CT. METHODS: The JDH EHR dataset contains 611,355 clinical narratives from 359,854 patients from diverse demographic backgrounds from 2010 through 2019. These data were processed through a customized NLP pipeline. A training set of 100 notes was annotated based on focus group-generated ontology and used to generate and evaluate an NLP model that was later tested on the remaining notes. Validation of the model was evaluated externally and performance was analyzed. RESULTS: The model identified back pain as the most common location of experienced pain with 40,369 term frequencies. Patients most commonly experienced decreased mobility with their pain with 7,375 term frequencies. Pain was most commonly found to be radiating with 26,967 term frequencies and patients most commonly rated their pain as 8/10 with 2,375 term frequencies. All parameters studied had statistical F-scores greater than 0.85. LIMITATIONS: A single-center, pilot study subject to reporting bias, recording bias, and missing patient data. CONCLUSIONS: Our customized NLP model demonstrated good and successful performance in extracting granular pain information from clinical notes in electronic health records.

Pain quality of thermal grill illusion is similar to that of central neuropathic pain rather than peripheral neuropathic pain.

OBJECTIVES: Application of spatially interlaced innocuous warm and cool stimuli to the skin elicits illusory pain, known as the thermal grill illusion (TGI). This study aimed to discriminate the underlying mechanisms of central and peripheral neuropathic pain focusing on pain quality, which is considered to indicate the underlying mechanism(s) of pain. We compared pain qualities in central and peripheral neuropathic pain with reference to pain qualities of TGI-induced pain. METHODS: Experiment 1:137 healthy participants placed their hand on eight custom-built copper bars for 60 s and their pain quality was assessed by the McGill Pain Questionnaire. Experiment 2: Pain quality was evaluated in patients suffering from central and peripheral neuropathic pain (42 patients with spinal cord injury, 31 patients with stroke, 83 patients with trigeminal neuralgia and 131 patients with postherpetic neuralgia). RESULTS: Experiment 1: Two components of TGI-induced pain were found using principal component analysis: component 1 included aching, throbbing, heavy and burning pain, component 2 included itching, electrical-shock, numbness, and cold-freezing. Experiment 2: Multiple correspondence analysis (MCA) and cross tabulation analysis revealed specific pain qualities including aching, hot-burning, heavy, cold-freezing, numbness, and electrical-shock pain were associated with central neuropathic pain rather than peripheral neuropathic pain. CONCLUSIONS: We found similar qualities between TGI-induced pain in healthy participants and central neuropathic pain rather than peripheral neuropathic pain. The mechanism of TGI is more similar to the mechanism of central neuropathic pain than that of neuropathic pain.

Diet quality and perceived effects of dietary changes in Dutch endometriosis patients: an observational study.

RESEARCH QUESTION: What is the current diet of women with endometriosis, in terms of adherence to dietary guidelines and use of diets, and what are the perceived effects of dietary modifications? DESIGN: In this online explorative observational study, the Dutch Healthy Diet 2015 index (DHD-15) and quality of life (QoL) with the Endometriosis Health Profile-30 questionnaire (EHP-30) were used to assess diet quality. RESULTS: The questionnaires were completed by 157 participants. Many participants made one or more dietary adaptations for their endometriosis, in the form of a specific diet (46.5%), with the use of dietary supplements (56.1%), with other dietary adjustments (64.3%), or all. Endometriosis patients had a significantly lower DHD-15 score, indicating a lower diet quality than a healthy reference group (P = 0.004). In the endometriosis group, diet users had a significantly higher total DHD-15 score than non-diet users (P < 0.0001). Diet quality was not correlated with QoL (Pearson's r = -0.010, P = 0.904). Many specific dietary adjustments (71.3%), however, were reported to reduce endometriosis pain-related symptoms. The removal of gluten, dairy or soy, as well as the addition of vegetables, showed the greatest perceived reductions of symptoms in participants. CONCLUSIONS: Although no specific dietary adjustment was found to increase QoL, endometriosis patients do feel that dietary adjustments have a beneficial effect on their symptoms. Therefore, more research is needed to gain evidence about the specific effects of nutrients on endometriosis symptoms.

Acute experimentally-induced pain replicates the distribution but not the quality or behaviour of clinical appendicular musculoskeletal pain. A systematic review.

OBJECTIVES: Experimental pain is a commonly used method to draw conclusions about the motor response to clinical musculoskeletal pain. A systematic review was performed to determine if current models of acute experimental pain validly replicate the clinical experience of appendicular musculoskeletal pain with respect to the distribution and quality of pain and the pain response to provocation testing. METHODS: A structured search of Medline, Scopus and Embase databases was conducted from database inception to August 2020 using the following key terms: "experimental muscle pain" OR "experimental pain" OR "pain induced" OR "induced pain" OR "muscle hyperalgesia" OR ("Pain model" AND "muscle"). Studies in English were included if investigators induced experimental musculoskeletal pain into a limb (including the sacroiliac joint) in humans, and if they measured and reported the distribution of pain, quality of pain or response to a provocation manoeuvre performed passively or actively. Studies were excluded if they involved prolonged or delayed experimental pain, if temporomandibular, orofacial, lumbar, thoracic or cervical spine pain were investigated, if a full text of the study was not available or if they were systematic reviews. Two investigators independently screened each title and abstract and each full text paper to determine inclusion in the review. Disagreements were resolved by consensus with a third investigator. RESULTS: Data from 57 experimental pain studies were included in this review. Forty-six of these studies reported pain distribution, 41 reported pain quality and six detailed the pain response to provocation testing. Hypertonic saline injection was the most common mechanism used to induce pain with 43 studies employing this method. The next most common methods were capsaicin injection (5 studies) and electrical stimulation, injection of acidic solution and ischaemia with three studies each. The distribution of experimental pain was similar to the area of pain reported in clinical appendicular musculoskeletal conditions. The quality of appendicular musculoskeletal pain was not replicated with the affective component of the McGill Pain Questionnaire consistently lower than that typically reported by musculoskeletal pain patients. The response to provocation testing was rarely investigated following experimental pain induction. Based on the limited available data, the increase in pain experienced in clinical populations during provocative maneuvers was not consistently replicated. CONCLUSIONS: Current acute experimental pain models replicate the distribution but not the quality of chronic clinical appendicular musculoskeletal pain. Limited evidence also indicates that experimentally induced acute pain does not consistently increase with tests known to provoke pain in patients with appendicular musculoskeletal pain. The results of this review question the validity of conclusions drawn from acute experimental pain studies regarding changes in muscle behaviour in response to pain in the clinical setting.

Eficácia da estabilização central e fortalecimento supervisionado do quadril na osteoartrite de joelho: um protocolo de ensaio clínico randomizado / Efficacy of core stability and supervised hip strengthening on knee osteoarthritis: a Randomized study protocol

INTRODUÇÃO: A osteoartrite (OA) é um problema significativo associado à dor, que reduz a funcionalidade e prejudica a qualidade de vida. Apenas alguns estudos prévios estabeleceram o efeito comparativo da estabilização e do exercício de fortalecimento do quadril. OBJETIVO: Investigar a estabilização e sua relação com o exercício supervisionado de fortalecimento do quadril no tratamento da OA do joelho. METODOLOGIA: Este é um projeto de ensaio clínico centralizado, dois grupos, pré-teste pós-teste, randomizado, onde quarenta e seis pacientes com OA de joelho serão alocados aleatoriamente em dois grupos. Grupo A (grupo experimental 1) e B (grupo experimental 2) receberão exercícios de estabilização e fortalecimento do quadril três dias por semana durante quatro semanas, respectivamente, em doze sessões de tratamento. A medida de desfecho primário será a medida de desfecho de lesão no joelho e osteoartrite (KOOS), ambas as versões em inglês e hindi, e as medidas de desfecho secundário serão o teste Timed Up and Go (TUG), o teste de suporte da cadeira para quantidade pré e pós efeito da intervenção. RESULTADOS ESPERADOS: Este estudo planejou avaliar a eficácia e a importância da estabilização e exercícios de fortalecimento do quadril na redução da dor, melhorando a função e a qualidade de vida em pacientes com OA de joelho. NÚMERO DE REGISTRO DO PROTOCOLO / TESTE: CTRI/2020/06/025973

INTRODUCTION: Osteoarthritis (OA) is a significant problem associated with pain; it reduces function, and hampered the quality of life. Only a few previous studies have established the comparative effect of core stability and hip strengthening exercise. OBJECTIVE: To investigate core stability and its relationship with supervised hip strengthening exercise in the management of knee OA. METHODS: This is a single centered project, two-group, pretest, a post-test, randomized clinical trial where Forty-six patients with knee OA will be randomly allocated into two groups, Group A (experimental group 1) and B (experimental group 2) will receive core stability and hip strengthening exercise on three days a week for four weeks respectively across twelve treatment sessions. The primary outcome measure will be Knee Injury and Osteoarthritis Outcome measure (KOOS) in both English and Hindi versions, and secondary outcome measures will be Timed Up and Go test (TUG), Chair stand test to quantity pre and post effect of the intervention. EXPECTED RESULTS: This study planned to assess the efficacy and importance of core stability and hip strengthening exercise in reducing pain, improving function and quality of life in patients with knee OA. PROTOCOL/TRIAL REGISTRATION NUMBER: CTRI/2020/06/025973

A novel diclofenac gel (AMZ001) applied once or twice daily in subjects with painful knee osteoarthritis: A randomized, placebo-controlled clinical trial.

PURPOSE: Osteoarthritis Research Society International (OARSI) Expert Consensus Guidelines recommend topical non-steroidal anti-inflammatory drugs as first-line medications for osteoarthritis (OA) knee pain, but several voluminous daily applications are required to achieve efficacy. There is a need to develop new and improved topical analgesics with a faster onset, longer duration of action, and the requirement to apply less gel. This trial investigated the safety and efficacy of a new 3.06% diclofenac gel (AMZ001) in subjects with knee OA. METHODS: In total, 444 subjects (AMZ001 twice daily (BID) [n = 121], AMZ001 once daily (QD) + placebo QD [n = 121], placebo BID [n = 121], or Voltaren 1% 4-times daily [n = 81]) were enrolled. All except Voltaren 1% (single-blinded) were applied topically in a double-blind manner for a total of 4-weeks. The primary endpoint was the change from baseline to week 4 in the WOMAC pain sub-score in the target knee. Secondary and exploratory endpoints included additional efficacy measures (WOMAC total score, WOMAC function and stiffness sub-scores, WOMAC pain weight-bearing and non-weight-bearing sub-scores, ICOAP, chair-stand test, OMERACT-OARSI responder rate, PGA, WPAI, EQ-5D, rescue medication use, satisfaction questionnaire) and safety. RESULTS: Treatment with AMZ001 QD was effective at reducing WOMAC pain sub-scores vs placebo (estimated treatment difference [ETD]: -4.61 [95% confidence interval (CI): -9.09, -0.12]; p = 0.0440); however, BID application was not (ETD: -3.76 [95% CI: -8.21, 0.68]; p = 0.0969). For several secondary endpoints, changes from baseline to week 4 conferred nominally statistically significant improvements in favor of AMZ001 vs placebo, including PGA score (AMZ001 BID vs placebo, ETD: -0.61 [95% CI: -1.11, -0.11]; p = 0.0162; AMZ001 QD vs placebo, ETD: -0.63 [95% CI: -1.13, -0.13]; p = 0.0134), WPAI overall work impairment score (AMZ001 QD vs placebo, ETD: -10.44 [95% CI: -20.84, -0.04]; p = 0.0492), and EQ-5D VAS score (AMZ001 BID vs placebo, ETD: 4.70 [95% CI: 0.55, 8.85]; p = 0.0264). Post-hoc analysis excluding 11-14 subjects per group with pain scores that decreased between screening and baseline suggests a consistent effect of both AMZ001 QD (ETD: -5.84 [95% CI: -10.71, -0.97]; p = 0.0189) and BID (ETD: -5.35 [95% CI: -10.16, -0.54]; p = 0.0292) in reducing WOMAC pain sub-scores vs placebo. In general, treatment satisfaction was high, as measured by the satisfaction questionnaire. The frequency and incidence of adverse events (AEs) was greatest in the placebo group. Most AEs (>99%) were of mild or moderate severity. There were no serious AEs. There were no notable effects of any treatment on vital signs, ECGs, physical examination findings, or other laboratory assessments. CONCLUSIONS: Treatment with AMZ001 BID for 4 weeks improved WOMAC pain sub-scores; however, only QD application conferred nominally statistically significant improvements vs placebo. AMZ001 was generally well tolerated.

Epiduroscopic intervention in patients with a failed back surgery syndrome.

BACKGROUND: Epiduroscopy is a percutaneous endoscopic technique with an interesting diagnostic and therapeutic potential. AIM: The study was aimed to evaluate the effectiveness of this modern minimally invasive method in treating pain together with the accompanying neurological symptoms of patients with a failed back surgery syndrome (FBSS). RESULTS: In the retrospective multicentre clinical study, we monitored the effect of epiduroscopic performance in 40 patients with FBSS before epiduroscopy and after 6 and 12 months. The results of the study indicated a significant improvement in back pain after 6 months, at p<0.05. At the same time, a significant improvement was observed in pain radiating to the lower limbs after 6 and 12 months at p<0.05, as well as a significant improvement in the Oswestry Disability Index of the limbs after 6 months and after 12 months (p<0.05). CONCLUSION: The current summarised results indicate a significant positive effect of epiduroscopy in the treatment of chronic back pain with a reduction in radiating pain to the lower extremities and an increase in patients' quality of life after the procedure (Tab. 2, Fig. 1, Ref. 23).

Pain in tones - Is it possible to hear the pain quality? A pilot trial.

OBJECTIVE: The adequate treatment of chronic pain also calls for measuring its quality not only its intensity. For this reason, this pilot study investigated the non-verbal description of pain quality based on tones, distinguishing between nociceptive and neuropathic pain. METHODS: A nociceptive and a neuropathic pain stimulus were applied to 80 chronic pain patients and 80 healthy subjects. Using a tone generator, all participants matched both pain stimuli to an appropriate tone (in Hz). The stimulus intensity was measured using the NRS-scale, and the PainDETECT questionnaire was completed. RESULTS: Both groups matched a significantly higher tone to the neuropathic than to the nociceptive pain stimulus. Compared to healthy participants, chronic pain patients allocated higher tones to both pain stimuli. Higher values were also shown for the neuropathic pain stimulus, and chronic pain patients indicated an overall higher intensity of pain as healthy participants. CONCLUSIONS: It is possible to differentiate pain stimuli non-verbally through tones, however, whether quality or intensity, was the key factor remains unknown. Future studies could investigate the influence of additional factors. PRACTICAL IMPLICATIONS: A practical tool using tones should be developed to detect pain quality in patients - without verbal descriptions - quickly and more precisely.

Assessment of pain quality reveals distinct differences between nociceptive innervation of low back fascia and muscle in humans.

INTRODUCTION/OBJECTIVES: Verbal descriptors are an important pain assessment parameter. The purpose of this study was to explore the ability to discriminate deep muscle pain and overlying fascia pain according to verbal descriptors and compare the pattern with skin stimulation (from previously published data). METHODS: In 16 healthy human subjects, electrical stimulation was chosen to excite a broad spectrum of nociceptive primary afferents innervating the respective tissues. The 24-item Pain Perception Scale (Schmerzempfindungsskala [SES]) was used to determine the induced pain quality. RESULTS: Overall, affective (P = 0.69) and sensory scores (P = 0.07) were not significantly different between muscle and fascia. Factor analysis of the sensory descriptors revealed a stable 3-factor solution distinguishing superficial thermal ("heat pain" identified by the items "burning," "scalding," and "hot") from superficial mechanical ("sharp pain" identified by the items "cutting," "tearing," and "stinging") and "deep pain" (identified by the items "beating," "throbbing," and "pounding"). The "deep pain" factor was more pronounced for muscle than fascia (P < 0.01), whereas the other 2 factors were more pronounced for fascia (both P < 0.01). The patterns of skin and fascia matched precisely in sensory factors and on single-item level. CONCLUSION: The differences in sensory descriptor patterns between muscle and fascia may potentially guide treatment towards muscle or fascia in low back pain physiotherapeutic regimes. The similarity of descriptor patterns between fascia and skin, both including the terms "burning" and "stinging," opens the possibility that neuropathic back pain (when the dorsal ramus of the spinal nerve is affected) may be confused with low back pain of fascia origin.

Age- and sex-related differences in the presentation of paediatric migraine: A retrospective cohort study.

Introduction Although migraine is a common headache complaint in children and adolescents there remains a significant gap in understanding the unique aspects of the disease in these age groups and their evolution with development. The aim of this retrospective cohort study was to identify migraine features that are influenced by age and sex. Methods The headache characteristics of 359 paediatric patients with a clinical diagnosis of migraine from a tertiary paediatric headache clinic were assessed. Patients retrospectively reported headache characteristics during a structured intake interview and clinical exam. Headache characteristics, description and associated symptoms were compared between children (age ≤ 12 years) and adolescents (age > 12 years), and between male and female migraineurs. Results Several migraine features differed significantly with age and/or sex, including: (i) a marked change from a 1:1 sex ratio in children to a 2:1 predominance of girls in adolescents; (ii) a higher frequency of headache attacks per month in adolescents and female migraineurs; (iii) a higher proportion of adolescents endorsed a 'throbbing' pain quality; (iv) a higher proportion of children reporting nausea and vomiting; and (v) a higher proportion of adolescents, particularly female migraineurs, had a diagnosis of a co-morbid anxiety. Conclusion The presentation of migraine, both in terms of its headache characteristics and associated symptoms, appear to vary as a function of age and sex. Given that migraine symptoms have a neural basis, it is not surprising that during the key period of neurodevelopment from childhood to adolescence this may impact their presentation.

Valence and Arousal Value of Visual Stimuli and Their Role in the Mitigation of Chronic Pain: What Is the Power of Pictures?

The present study investigated the pain-reducing effects of various pictures in a sample of 88 patients receiving inpatient treatment for chronic pain. We investigated whether the pain-attenuating effects of the pictures were mediated by picture valence, arousal, or change in subjective social support. The study was carried out over 4 consecutive days. Patients were presented with photographs of loved ones, strangers, landscapes, or optical illusions via digital albums and were asked to rate their pain intensity and their sensory and affective experience of pain immediately before and after viewing the pictures. They also evaluated the valence of the pictures and the extent to which they were arousing. Before and after participation in the study, patients provided information on their subjective social support. The valence attributed to the pictures varied; photographs of loved ones elicited the greatest pleasure. Pictures of varying emotional content and arousal value all reduced affective and sensory perceptions of pain. Viewing photographs of loved ones reduced pain intensity more than viewing other picture types. The association between picture type and decrease in pain intensity was mediated by picture valence. These findings suggest an easy to implement supplementary intervention that could be used in multidisciplinary pain treatment. PERSPECTIVE: To our knowledge, this is the first demonstration that pictures mitigate pain in chronic pain patients receiving treatment in a multidisciplinary pain center. The procedure could be used routinely to treat pain, particularly severe pain.