Central pain mechanisms in chronic pain states--maybe it is all in their head

Pain Sensitivity Questionnaire: Cross-cultural adaptation and validation of the Greek version

INTRODUCTION

The Pain Sensitivity Questionnaire (PSQ) was developed to assess general pain sensitivity.

OBJECTIVE

This study aimed to validate the Greek version of PSQ.

METHODS

The questionnaire was translated into Greek (PSQ-GR) and piloted in a small sample of patients with chronic pain (n = 35). A total of 146 chronic pain patients and healthy volunteers completed the PSQ-GR, the Pain Catastrophizing Scale (PCS), Hospital Anxiety and Depression Scale (HADS) and Central Sensitization Inventory (CSI). To evaluate the test-retest reliability, 36 volunteers completed the PSQ-GR twice over 7 ± 2 days.

RESULTS

Internal consistency was excellent (Cronbach's alpha 0.90-0.96) for PSQ-total, PSQ-minor, and PSQ-moderate. The Intraclass Correlation Coefficient was estimated at 0.90-0.96 for PSQ-total, PSQ-minor and PSQ-moderate and the SEM was 0.59-0.90 for PSQ-total, PSQ-minor and PSQ-moderate approximately. The smallest detectable change was 0.48 for PSQ-total, 0.47 for PSQ-minor and 0.44 for PSQ-moderate. Positive and significant correlations were observed between PSQ-GR and HADS (r = 0.38, p < 0.01), PCS (r = 0.41, p < 0.01) and CSI (r = 0.30, p < 0.01). Statistically significant differences in PSQ-GR scores were identified between the healthy volunteers and the chronic pain patients.

CONCLUSION

The PSQ-GR is a reliable and valid tool that can assess pain sensitivity in healthy individuals and chronic musculoskeletal pain patients.

Laryngeal and Global Somatosensation in Primary Muscle Tension Dysphonia

INTRODUCTION

Primary muscle tension dysphonia (pMTD) is a functional voice disorder that reduces communicative abilities and adversely impacts occupational productivity and quality of life. Patients with pMTD report increased vocal effort, fatigue, discomfort, and odynophonia. Although laryngeal and paralaryngeal muscle tension and hyperfunction are the most commonly proposed mechanisms underlying these symptoms, recent studies suggest pMTD may have more to do with the somatosensory system. However, relationships between voice symptoms and somatosensory mechanisms are poorly understood, creating challenges for mechanistic-based pMTD management. The first objective was to compare laryngeal, paralaryngeal, and global somatosensation between subjects with and without pMTD. The second was to determine relationships between pMTD symptoms and somatosensation.

METHODS

Fifty-two (20 pMTD and 32 control) subjects underwent laryngeal sensory testing with aesthesiometers, as well as peripheral mechanosensory and dynamic temporal summation testing to paralaryngeal and limb regions. Voice symptom severities (vocal effort, fatigue, discomfort, and odynophonia) were collected on 100-mm visual analog scales before and after laryngeal sensory testing. Participants also completed the Central Sensitization Inventory.

RESULTS

Patients with pMTD reported significantly higher laryngeal sensations (P = 0.0072) and voice symptom severities (P < 0.001) compared with the control group, and had significantly more vocal tract discomfort postlaryngeal sensory testing compared with the prelaryngeal sensory testing timepoint (P = 0.0023). However, there were no significant group differences in laryngeal airway protection responses suggestive of peripheral laryngeal hypersensitivities (P = 0.444). There were also no significant group differences on paralaryngeal or global sensitivities (P > 0.05), and no correlations between severity of voice symptoms and perceptual laryngeal sensations or hypersensitivities (P > 0.05).

CONCLUSION

Patients with pMTD perceive more sensitivities in the larynx and feel more sensations related to the voice (vocal effort, fatigue, discomfort, and pain). However, in general, patients with pMTD do not have abnormal peripheral laryngeal hypersensitivities, increased global somatosensation, or heightened central sensitivity. The lack of significant correlations between peripheral laryngeal hypersensitivities and voice symptom severity ratings suggests these outcome variables target distinct mechanistic constructs.

From fibrositis to fibromyalgia to nociplastic pain: how rheumatology helped get us here and where do we go from here?

Rheumatologists and rheumatology have had a prominent role in the conceptualisation of nociplastic pain since the prototypical nociplastic pain condition is fibromyalgia. Fibromyalgia had been previously known as fibrositis, until it became clear that this condition could be differentiatied from autoimmune disorders because of a lack of systemic inflammation and tissue damage. Nociplastic pain is now thought to be a third descriptor/mechanism of pain, in addition to nociceptive pain (pain due to peripheral damage or inflammation) and neuropathic pain. Nociplastic pain can occur in isolation, or as a co-morbidity with other mechanisms of pain, as commonly occurs in individuals with autoimmune disorders. We now know that the cardinal symptoms of nociplastic pain are widespread pain (or pain in areas not without evidence of inflammation/damage), accompanied by fatigue, sleep and memory issues. There is objective evidence of amplification/augmentation of pain, as well as of non-painful stimuli such as the brightness of lights and unpleasantness of sound or odors. Nociplastic pain states can be triggered by a variety of stressors such as trauma, infections and chronic stressors. Together these features suggest that the central nervous system (CNS) is playing a major role in causing and maintaining nociplastic pain, but these CNS factors may in some be driven by ongoing peripheral nociceptive input. The most effective drug therapies for nociplastic pain are non-opioid centrally acting analgesics such as tricyclics, serotonin-norepinephrine reuptake inhibitors and gabapentinoids. However the mainstay of therapy of nociplastic pain is the use of a variety of non-pharmacological integrative therapies, especially those which improve activity/exercise, sleep and address psychological co-morbidities.

Can the Assessment of the Circadian Rhythm of Pain Be Shortened? A Study of Community-Dwelling Participants with Chronic Pain

Purpose

This study aimed to juxtapose the circadian rhythm of pain with the conventional 7-day assessment and ascertain the feasibility of condensing the evaluation of the circadian rhythm of pain into a 3-day timeframe.

Patients and Methods

Seventy-three patients with pain persisting for a minimum of 3 months and a numerical rating scale (NRS) score of ≥2 were recruited from three medical centers. The circadian patterns of pain were appraised over a 7-day period by quantifying the intensity of pain at six temporal junctures each day using a 10-cm visual analog scale (VAS). Cluster analysis was performed using six standardized variables derived from the VAS score of each participant at six designated time points to identify cohorts with analogous circadian rhythms of pain. The clusters were discerned for the 7- and 3-day assessments (Tuesday-Thursday, Friday-Sunday, and Sunday-Tuesday), according to the research objectives. Cohen's kappa coefficient was calculated to gauge the intra-observer variability to assess the consistency between the outcomes of the cluster analysis for the 7-day assessment and each of the 3-day assessments.

Results

The highest Cohen's kappa coefficient was observed for the 3-day evaluation spanning from Friday to Sunday, indicating a substantial concordance with the results of the 7-day assessment.

Conclusion

Our results suggest that it may be prudent to consider implementing a condensed 3-day evaluation of the circadian rhythm of pain that is tailored to individual characteristics. This approach will allow a better understanding of the diurnal rhythms of chronic pain in patients and implement more targeted and specific pain management strategies. Furthermore, it will contribute to increased patient satisfaction through early intervention.

Expert Consensus on Ion Channel Drugs for Chronic Pain Treatment in China

Ion channel drugs have been increasing used for chronic pain management with progress in the development of selective calcium channel modulators. Although ion channel drugs have been proven safe and effective in clinical practice, uncertainty remains regarding its use to treat chronic pain. To standardize the clinical practice of ion channel drug for the treatment of chronic pain, the National Health Commission Capacity Building and Continuing Education Center for Pain Diagnosis and Treatment Special Ability Training Project established an expert group to form an expert consensus on the use of ion channel drugs for the treatment of chronic pain after repeated discussions on existing medical evidence combined with the well clinical experience of experts. The consensus provided information on the mechanism of action of ion channel drugs and their recommendations, caution use, contraindications, and precautions for their use in special populations to support doctors in their clinical decision-making.

Pain improvement after three weeks of daily self-executed cross-friction massage using a fascia ball in a patient with recent-onset plantar heel pain: a case report

BACKGROUND

Plantar heel pain is described as sharp pain at the medial plantar aspect of the calcaneus and medial longitudinal arch of the foot. There are various treatment options that usually need a clinician or a therapist for application. The present case report aimed to describe the outcomes of self-executed cross-friction massage using a fascia ball in a patient with recent-onset plantar heel pain.

CASE DESCRIPTION

The patient was a 42-year-old man who reported plantar heel pain during the first steps in the morning along with decreased function of the foot and ankle lasting about three months. He was instructed to self-execute cross-friction massage using a fascia ball daily in the evening at home for six weeks.

OUTCOMES

Pain during treatment decreased from a Numeric Pain Rating Scale (NPRS)-score of 8/10 and from a Short-Form McGill Pain Questionnaire (SF-MPQ)-score of 34/60 at initial treatment to NPRS- and SF-MPQ-scores of 0/10 and 0/60, respectively, after about three weeks. The patient reported no pain and restored function after six weeks of treatment, and in the follow-up measurements.

DISCUSSION

Daily self-executed cross-friction massage using a fascia ball may be a useful alternative intervention for treating recent-onset plantar heel pain.

The effectiveness of a combined exercise and psychological treatment programme on measures of nervous system sensitisation in adults with chronic musculoskeletal pain - a systematic review and meta-analysis

BACKGROUND

Quantitative sensory testing (QST) offers information regarding underlying mechanisms contributing to chronic pain (CP) in adults with musculoskeletal disorders. This review examined the use of QST measures in adults with CP following participation in a combined exercise and psychological intervention.

METHODS

The review was conducted in accordance with the PRISMA guidelines. Five databases were searched from inception to November 2022. All study designs which evaluated the effects of a combined exercise and psychological treatment on measures of nervous system sensitivity in adults with chronic musculoskeletal pain were included.

RESULTS

A total of 13 studies met the selection criteria, 10 of which were included in a meta-analysis. Local pressure pain thresholds were the most frequently used measure (n = 12 studies). Meta-analysis revealed statistically significantly improvements in favour of the combined exercise and psychological intervention group, compared to a control group, for local pressure pain threshold measures [SMD = 0.44, 95% CI 0.08-0.81, I2 = 84%], pain intensity scores [SMD=-0.89, 95% CI -1.66- -0.13, I2 = 94%] and the Central Sensitisation Inventory [SMD=-0.69, 95% CI -1.37- -0.02, I2 = 87%]. There were no significant differences found between groups for remote pressure pain thresholds, temporal summation or conditioned pain modulation.

CONCLUSIONS

The results suggest that a combined exercise and psychological intervention may lead to greater improvements in local pressure pain threshold, pain intensity and Central Sensitisation Inventory scores when compared to a control intervention in adults with CP, however these findings must be interpreted with caution as a large degree of heterogeneity was present in these results (I2: 84-94%). Further large, longitudinal studies are required using standardised QST measurement procedures and patient reported outcome measures to explore changes in nervous system sensitisation.

TRIAL REGISTRATION

This systematic review is registered with PROSPERO, ID Number CRD42022380464.

Comorbidity of Lifetime History of Abuse and Trauma With Opioid Use Disorder: Implications for Nursing Assessment and Care

BACKGROUND

Opioid use disorder (OUD) is a public health crisis and is challenging to treat. Previous research has shown correlations between OUD, abuse/trauma, and chronic pain.

AIMS

The purpose of this study was to investigate history of lifetime sexual, physical, and/or emotional abuse among participants in a medication-assisted treatment (MAT) program for OUD, and to investigate associations between abuse history and chronic pain.

METHODS

This is a secondary analysis of intake data from a 2-year, nonexperimental cohort treatment program of patients with OUD in rural Colorado. De-identified data were provided by 476 adult MAT patients using the Adult Addiction Severity Index (ASI-6). The ASI-6 includes three yes/no questions about history of abuse (emotional, physical, and sexual), with separate scoring for "past 30 days" and "lifetime" abuse.

RESULTS

Lifetime history among MAT program for OUD patients was 23% for sexual abuse, 43% for physical abuse, and 58% for emotional abuse. History of physical abuse was significantly associated with having a chronic pain diagnosis, χ2 = 4.49, p = .03, and also with higher reported pain levels, t(460) = 2.71, p = .007.

CONCLUSION

Lifetime history of physical abuse was associated with OUD and chronic pain, yet standard pain assessments do not assess these factors. In health care settings, the implementation of standardized trauma-informed screening tools, prompt recognition of abuse/trauma history, and adjunct psychological interventions may reduce stigma, reduce opioid use escalation, and help patients overcome OUD.

The multi-generational familial aggregation of interstitial cystitis, other chronic nociplastic pain disorders, depression, and panic disorder

BACKGROUND

Interstitial cystitis/painful bladder syndrome (IC) is a chronic pelvic pain condition which has high comorbidity with other nociplastic, or unexplained, pain disorders [e.g. fibromyalgia (FM), irritable bowel syndrome (IBS), and myalgic encephalomyelitis/chronic fatigue (ME/CFS)] and some psychiatric conditions [major depressive disorder (MDD) and panic disorder (PD)]. Here we investigated the shared familiality of IC and these other nociplastic and psychiatric conditions.

METHODS

Subjects were identified in the Utah Population Database, which links genealogy data back to the 1800s to medical record diagnosis billing code data back to 1995. We computed the relative risk of each of these disorders among first (FDR), second (SDR), and third-degree relatives (TDR) of six proband groups: IC, FM, IBS, ME/CFS, PD, and MDD. Given the known familial aggregation of each of these disorders, we conducted our analyses to test for heritable interrelationships using proband subgroups whose members did not have the diagnosis assessed in their relatives.

RESULTS

We observed strong evidence for heritable interrelationships among all six disorders. Most analyses indicated significantly increased risk for each of the six disorders in FDR, SDR, and TDR of all or most proband groups. Out of 30 possible bidirectional disorder interrelationships, 26 were significant among FDR, 23 were significant among SDR, and 7 were significant among TDR. Clustering was observed in both close and distant relatives.

CONCLUSIONS

Our results support a common, heritable component to IC and other nociplastic and psychiatric conditions.

Efficacy of Tuina in chronic low back pain with anxiety: study protocol for a randomised controlled trial

INTRODUCTION

Chronic low back pain (cLBP) is one of the largest and most frequent public health problems worldwide. Tuina is a physical therapy commonly used in China to treat musculoskeletal diseases. Compared with traction, there is little high-quality scientific evidence that can demonstrate the effectiveness of Tuina in the treatment of patients with cLBP. Therefore, the purpose of this clinical trial is to evaluate the effect of massage on cLBP patients compared with traction.

METHODS AND ANALYSES

This is a single-centre, assessor-blinded and analyst-blinded prospective randomised controlled trial with two parallel arms. Ninety-four patients with cLBP will be recruited. Three treatments were given every week for a total of 4 weeks. In the Traction group, participants were given traction therapy in the Tuina group, participants will receive a four-step physiotherapy including kneading, rolling, plucking and oblique pulling. The outcomes will be measured at baseline, at the end of treatment, as well as 1 and 2 months after treatment. The primary outcome will be the Hamilton Anxiety Scale after 12 sessions of treatment. The secondary outcomes will be the Visual Analogue Scale, the medical outcomes study Short Form 36, Serum Quantitative Index and genetic testing after 12 sessions of treatment.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of Yueyang Hospital of Integrated Traditional Chinese and Western Medicine affiliated with Shanghai University of Traditional Chinese Medicine.

TRIAL REGISTRATION NUMBER

ChiCTR2200065448.

Prevalence and interference of neuropathic pain in the quality of life in patients with knee osteoarthritis

OBJECTIVE

With the aging of the population, more patients have complained of pain due to knee Osteoarthritis (OA), and the number of arthroplasties has also increased. The objective of this study is to evaluate the prevalence of the neuropathic pain component in candidates for Total Knee Replacement and the effects of this component on their quality of life.

METHODS

In this cross-sectional study, patients with OA candidates for knee arthroplasty in the present institution were evaluated using the pain detection questionnaire and the Visual Analog Pain (VAS) scale to measure the pain index and the presence of associated neuropathic pain. In addition, evaluation of the quality of life and functionality using the EQ5D and SF12 questionnaires and their relationship with cases of neuropathic pain were performed.

RESULTS

One hundred twenty-six patients were evaluated, and 71.4 % were female. The age ranged from 46 to 85 years, and about 70 % of the patients had some associated clinical comorbidity. Neuropathic pain was present in 28.6 % of the patients evaluated. Patients with neuropathic pain presented worse results in the VAS evaluation, in the care, pain, and anxiety domains of the EQ5D, and in the physical and mental scores of the SF12.

CONCLUSION

Neuropathic pain was present in 28.6 % of the patients with knee OA who are candidates for arthroplasty. Patients with associated neuropathic pain present a higher level of pain and worse quality of life scores. Recognizing this type of pathology is extremely important in fully monitoring gonarthrosis.

Chronic non-cancer pain management - insights from Australian general practitioners: a qualitative descriptive study

BACKGROUND

The study explored the experiences and perceptions of GPs regarding the management of chronic non-cancer pain (CNCP). Specifically, participants were asked to identify perceived enablers and barriers to CNCP care and how the care of patients with CNCP may be improved.

METHODS

The study utilised a qualitative descriptive methodology. General practice in Western Australia. The sample was purposive with 12 Australian GPs from predominantly metropolitan locations and with experience in managing CNCP. Semi structured interviews were conducted. Each interview was of 45-60min duration. All interviews were audio recorded and transcribed using a secure transcription service. Thematic analysis developed themes inductively and deductively.

RESULTS

Themes emerged regarding: the importance of a holistic and personalised approach; the important role of a coordinating GP; the need for an evidence-based approach to opioid management; concerns relating to access to multidisciplinary services; the importance of clinician and patient education regarding CNCP; and an acknowledgement of the challenges for doctors and patients in managing CNCP.

CONCLUSIONS

Currently, the management of CNCP in Australia is challenging. Notable challenges include: difficulties with continuity of patient care; challenges with patient expectations of treatment, in particular opioid medications; difficulty with access to the health services required to enable holistic care; and the need for improved pain education in the community. The breadth of these challenges suggests there is a need for supportive organisational and structural considerations in the healthcare system to enable optimal care of CNCP in the community.

Adolescents and Young Adults With Sickle Cell Disease: Nociplastic Pain and Pain Catastrophizing as Predictors of Pain Interference and Opioid Consumption

OBJECTIVES

Some patients with sickle cell disease (SCD) have features of nociplastic pain. While research suggests that many patients with nociplastic pain consume more opioids due to opioid nonresponsiveness, little is known about the impact of nociplastic pain and pain catastrophizing on opioid consumption and pain interference among adolescents and young adults (AYA) with SCD. The purpose of this study was to (1) characterize nociplastic pain and pain catastrophizing among AYA with SCD, and (2) determine whether these characterizations are associated with subsequent opioid consumption and pain interference 1 month after characterization.

METHODS

Participants completed surveys characterizing nociplastic pain and catastrophizing at a routine clinic visit (baseline). Thereafter, participants received weekly text messages that included pain interference and opioid consumption surveys. Multipredictor 2-part models were used to evaluate the predictive relationships between baseline characterizations and subsequent pain interference, and opioid consumption.

RESULTS

Forty-eight AYA aged 14 to 35 completed baseline measures. Twenty-five percent of participants had scores suggestive of nociplastic pain. Greater nociplastic pain features significantly increased the odds of consuming opioids (odds ratio=1.2) and having greater interference from pain (odds ratio=1.46). Regression analyses found that greater baseline nociplastic pain characteristics were significantly associated with opioid consumption (β=0.13) and pain interference (β=0.061); whereas higher pain catastrophizing scores predicted less opioid consumption (β=-0.03) and less pain interference (β=-0.0007).

DISCUSSION

In this sample of AYA with SCD, features of nociplastic pain predicted higher subsequent opioid consumption and pain interference. Being aware of nociplastic pain features in patients with SCD may better guide individualized pain management.

Impact of Electronic Chronic Pain Questions on patient-reported outcomes and healthcare utilization, and attitudes toward eCPQ use among patients and physicians: prospective pragmatic study in a US general practice setting

Objective

The Electronic Chronic Pain Questions (eCPQ) has been developed to help healthcare providers systematically capture chronic pain data. This study evaluated the impact of using the eCPQ on patient-reported outcomes (PROs) and healthcare resource utilization (HCRU) in a primary care setting, and patient and physician perceptions regarding use of, and satisfaction with, the eCPQ.

Methods

This was a prospective pragmatic study conducted at the Internal Medicine clinic within the Henry Ford Health (HFH) Detroit campus between June 2017 and April 2020. Patients (aged ≥18 years) attending the clinic for chronic pain were allocated to an Intervention Group to complete the eCPQ in addition to regular care, or a control group to receive regular care only. The Patient Health Questionnaire-2 and a Patient Global Assessment were assessed at baseline, 6-months, and 12-months study visits. HCRU data were extracted from the HFH database. Telephone qualitative interviews were conducted with randomly selected patients and physicians who used the eCPQ.

Results

Two hundred patients were enrolled, 79 in each treatment group completed all 3 study visits. No significant differences (p > 0.05) were found in PROs and HCRU between the 2 groups. In qualitative interviews, physicians and patients reported the eCPQ as useful, and using the eCPQ improved patient-clinician interactions.

Conclusion

Adding the eCPQ to regular care for patients with chronic pain did not significantly impact the PROs assessed in this study. However, qualitative interviews suggested that the eCPQ was a well-accepted and potentially useful tool from a patient and physician perspective. By using the eCPQ, patients were better prepared when they attended a primary care visit for their chronic pain and the quality of patient-physician communication was increased.

MOF-Fabric Composites Based on a Multi-Functional MOF as Luminescent Sensors for a Neurotransmitter and an Anti-Cancer Drug

A biocompatible, reliable, fast, and nanomolar-level dual-functional sensor for a neurotransmitter (e.g., adrenaline) and an anti-cancer drug (e.g., 6-mercaptopurine (6-MP)) is still far away from the hand of modern-day researchers. To address this issue, we synthesized an aqua-stable, bio-friendly, thiourea-functionalized Zr(IV) metal-organic framework (MOF) for selective, rapid sensing of adrenaline and 6-MP with ultra-low limit of detection (LOD for adrenaline = 1.9 nM and LOD for 6-MP = 28 pM). This is the first MOF-based fluorescent sensor of both the targeted analytes. The sensor not only can detect adrenaline in HEPES buffer medium but also in different bio-fluids (e.g., human urine and blood serum) and pH media. It also exhibited 6-MP sensing ability in aqueous medium and in various wastewater specimens and pH solutions. For the quick and on-site detection of this neuro-messenger (adrenaline) and the drug (6-MP), cost-effective sensor-coated cotton fabric composites were fabricated. The MOF@cotton fabric composite is capable of detecting both the analytes up to the nanomolar level by the naked eye under UV light. The sensor can be recycled up to five times without significantly losing its efficiency. The Förster resonance energy transfer in the presence of adrenaline and inner-filter effect in the presence of 6-MP are the most likely reasons behind the quenching of the MOF's fluorescence intensity, which were proved with the help of appropriate instrumental techniques.

Emerging Advances in Nanocarriers Approaches in the Effective Therapy of Pain Related Disorders: Recent Evidence and Futuristic Needs

Pain disorders are the primary cause of disability nowadays. These disorders, such as rheumatoid arthritis (RA) and osteoarthritis (OA), cause loss of function, joint pain and inflammation and deteriorate the quality of life. The treatment of these inflammatory diseases includes anti-inflammatory drugs administered via intra-articular, topical or oral routes, physical rehabilitation or surgery. Owing to the various side effects these drugs could offer, the novel approaches and nanomaterials have shown potential to manage inflammatory diseases, prolonged half-life of anti-inflammatory drugs, reduced systemic toxicity, provide specific targeting, and refined their bioavailability. This review discusses in brief about the pain pathophysiology and its types. The review summarizes the conventional therapies used to treat pain disorders and the need for novel strategies to overcome the adverse effects of conventional therapies. The review describes the recent advancements in nanotherapeutics for inflammatory diseases using several lipids, polymers and other materials and their excellent efficiency in improving the treatment over conventional therapies. The results of the nanotherapeutic studies inferred that the necessity to use nanocarriers is due to their controlled release, targeting drug delivery to inflamed tissues, low toxicity and biocompatibility. Therefore, it is possible to assert that nanotechnology will emerge as a great tool for advancing the treatment of pain disorders in the near future.

Machine learning algorithms distinguish discrete digital emotional fingerprints for web pages related to back pain

Back pain is the leading cause of disability worldwide. Its emergence relates not only to the musculoskeletal degeneration biological substrate but also to psychosocial factors; emotional components play a pivotal role. In modern society, people are significantly informed by the Internet; in turn, they contribute social validation to a "successful" digital information subset in a dynamic interplay. The Affective component of medical pages has not been previously investigated, a significant gap in knowledge since they represent a critical biopsychosocial feature. We tested the hypothesis that successful pages related to spine pathology embed a consistent emotional pattern, allowing discrimination from a control group. The pool of web pages related to spine or hip/knee pathology was automatically selected by relevance and popularity and submitted to automated sentiment analysis to generate emotional patterns. Machine Learning (ML) algorithms were trained to predict page original topics from patterns with binary classification. ML showed high discrimination accuracy; disgust emerged as a discriminating emotion. The findings suggest that the digital affective "successful content" (collective consciousness) integrates patients' biopsychosocial ecosystem, with potential implications for the emergence of chronic pain, and the endorsement of health-relevant specific behaviors. Awareness of such effects raises practical and ethical issues for health information providers.

Characterization of visual processing in temporomandibular disorders using functional magnetic resonance imaging

BACKGROUND AND PURPOSE

Many patients with chronic pain report hypersensitivity not only to noxious stimuli, but also to other modalities including innocuous touch, sound, and light, possibly due to differences in the processing of these stimuli. The goal of this study was to characterize functional connectivity (FC) differences between subjects with temporomandibular disorders (TMD) and pain-free controls during a visual functional magnetic resonance imaging (fMRI) task that included an unpleasant, strobing visual stimulus. We hypothesized the TMD cohort would exhibit maladaptations in brain networks consistent with multisensory hypersensitivities observed in TMD patients.

METHODS

This pilot study included 16 subjects, 10 with TMD and 6 pain-free controls. Clinical pain was characterized using self-reported questionnaires. Visual task-based fMRI data were collected on a 3T MR scanner and used to determine differences in FC via group independent component analysis.

RESULTS

Compared to controls, subjects with TMD exhibited abnormally increased FC between the default mode network and lateral prefrontal areas involved in attention and executive function, and impaired FC between the frontoparietal network and higher order visual processing areas.

CONCLUSIONS

The results indicate maladaptation of brain functional networks, likely due to deficits in multisensory integration, default mode network function, and visual attention and engendered by chronic pain mechanisms.

A Latin American consensus meeting on the essentials of mixed pain

OBJECTIVES

The term "mixed pain" has been established when a mixture of different pain components (e.g. nociceptive, neuropathic, and nociplastic) are present. It has gained more and more acceptance amongst pain experts worldwide, but many questions around the concept of mixed pain are still unsolved. The sensation of pain is very personal. Cultural, social, personal experiences, idiomatic, and taxonomic differences should be taken into account during pain assessment. Therefore, a Latin American consensus committee was formed to further elaborate the essentials of mixed pain, focusing on the specific characteristics of the Latin American population.

METHODS

The current approach was based on a systematic literature search and review carried out in Medline. Eight topics about the definition, diagnosis, and treatment of mixed pain were discussed and voted for by a Latin American consensus committee and recommendations were expressed.

RESULTS

At the end of the meeting a total of 14 voting sheets were collected. The full consensus was obtained for 21 of 25 recommendations (15 strong agreement and 6 unanimous agreement) formulated for the above described 8 topics (7 of the 8 topics had for all questions at least a strong agreement - 1 topic had no agreement for all 4 questions).

CONCLUSION

In a subject as complex as mixed pain, a consensus has been reached among Latin American specialists on points related to the definition and essence of this pain, its diagnosis and treatment. Recommendations for diagnosis and treatment of mixed pain in Latin America were raised.

Pain and aging: A unique challenge in neuroinflammation and behavior

Chronic pain is one of the most common, costly, and potentially debilitating health issues facing older adults, with attributable costs exceeding $600 billion annually. The prevalence of pain in humans increases with advancing age. Yet, the contributions of sex differences, age-related chronic inflammation, and changes in neuroplasticity to the overall experience of pain are less clear, given that opposing processes in aging interact. This review article examines and summarizes pre-clinical research and clinical data on chronic pain among older adults to identify knowledge gaps and provide the base for future research and clinical practice. We provide evidence to suggest that neurodegenerative conditions engender a loss of neural plasticity involved in pain response, whereas low-grade inflammation in aging increases CNS sensitization but decreases PNS sensitivity. Insights from preclinical studies are needed to answer mechanistic questions. However, the selection of appropriate aging models presents a challenge that has resulted in conflicting data regarding pain processing and behavioral outcomes that are difficult to translate to humans.

Pain Widespreadedness, and Not Primary Pain Location, is Associated With Comorbid Symptoms in Children With Chronic Pain

OBJECTIVES

Pediatric chronic pain represents heterogeneous diagnoses; often, primary pain location informs research classifications and treatment. In contrast, recent research has highlighted the role of widespread pain and this perspective has been adopted in assessments in specialty pediatric pain clinics. The lack of direct comparison between these 2 methods of categorizing pediatric chronic pain may hinder the adoption of evidence-based practices across the spectrum of care. Therefore, this study aimed to compare whether primary pain location or pain widespreadedness is more informative for pain-related symptoms in pediatric chronic pain.

METHODS

Youth (n=223) between the ages of 8 to 23 years (M=15.93, SD=2.11, 83% female) completed surveys upon intake at the pediatric chronic pain clinic. Free-text entries of primary pain location were coded into categories: headache, abdominal pain, and musculoskeletal pain. Additional domains assessed included widespread pain, pain interference, kinesiophobia, catastrophizing, anxiety, depression, sleep, and fatigue.

RESULTS

Differences based on primary pain location only emerged for kinesiophobia, F(2150)=8.20, P<0.001, with the highest scores among those with musculoskeletal pain. In contrast, controlling for sex, age, and pain intensity, pain widespreadedness was associated with pain interference, pain catastrophizing, fatigue, anxiety, and depression (P<0.05).

DISCUSSION

Pain widespreadedness was more consistently associated with pain-related outcomes among pediatric chronic pain patients than primary pain location, and body maps may be useful in determining a nociplastic pain mechanism to inform treatment. Improved assessment of pediatric pain mechanisms may help advance more precise treatment delivery.

Non-invasive brain stimulation and pain neuroscience education in the cognitive-affective treatment of chronic low back pain: Evidence and future directions

Chronic low back pain (CLBP) is among the leading causes of disability worldwide. Beyond the physical and functional limitations, people's beliefs, cognitions, and perceptions of their pain can negatively influence their prognosis. Altered cognitive and affective behaviors, such as pain catastrophizing and kinesiophobia, are correlated with changes in the brain and share a dynamic and bidirectional relationship. Similarly, in the presence of persistent pain, attentional control mechanisms, which serve to organize relevant task information are impaired. These deficits demonstrate that pain may be a predominant focus of attentional resources, leaving limited reserve for other cognitively demanding tasks. Cognitive dysfunction may limit one's capacity to evaluate, interpret, and revise the maladaptive thoughts and behaviors associated with catastrophizing and fear. As such, interventions targeting the brain and resultant behaviors are compelling. Pain neuroscience education (PNE), a cognitive intervention used to reconceptualize a person's pain experiences, has been shown to reduce the effects of pain catastrophizing and kinesiophobia. However, cognitive deficits associated with chronic pain may impact the efficacy of such interventions. Non-invasive brain stimulation (NIBS), such as transcranial direct current stimulation (tDCS) or repetitive transcranial magnetic stimulation (rTMS) has been shown to be effective in the treatment of anxiety, depression, and pain. In addition, as with the treatment of most physical and psychological diagnoses, an active multimodal approach is considered to be optimal. Therefore, combining the neuromodulatory effects of NIBS with a cognitive intervention such as PNE could be promising. This review highlights the cognitive-affective deficits associated with CLBP while focusing on current evidence for cognition-based therapies and NIBS.

The impact of nociplastic pain features on the response to physical therapy in patients with primary myofascial pain

BACKGROUND

Myofascial pain is a common, but poorly understood multifactorial condition.

OBJECTIVE

This study analyzed how the degree of central sensitization (nociplastic pain) can impact the response to physical therapy for patients with myofascial pain.

METHODS

This prospective, observational cohort study compared pain phenotyping and functional measures in 30 participants with non-acute neck/shoulder girdle primary myofascial pain following 3-months of physical therapy. The Fibromyalgia Survey Questionnaire Score served as a surrogate of central sensitization.

RESULTS

All participants demonstrated some benefit from physical therapy; however, those with moderate levels of nociplastic pain features were less likely to have clinically significant improvements on the Neck Disability Index, PEG score, or pain catastrophizing measures. Those with higher levels of nociplastic pain had a similar chance of showing improvement as those with lower levels, except regarding catastrophizing. Significant improvements were independent of the type or amount of therapy received.

CONCLUSION

The degree of nociplastic pain in patients with myofascial pain appears to be inversely related to improvements from a peripherally based treatment. This is not to say that individuals with moderate to higher levels of nociplastic pain do not benefit from physical therapy, but they proportionally benefit less.

Assessment of systemic joint laxity in the clinical context: Relevance and replicability of the Beighton score in chronic fatigue

BACKGROUND

Persistent symptoms in patients with systemic joint laxity (SJL) are often equivalent with complications. Screening for SJL is an important part of the assessment of musculoskeletal phenotype. The common measuring tool, the Beighton score (BS), still has unclear evidence.

OBJECTIVE

To assess the Beighton score in a clinical context for (1) ability to classify SJL as absent or present (criterion validity), and (2) interrater reliability (physician-physiotherapist), for a dichotomous cut-off (yes/no), as well as for interpretation in categories (no, some, clear SJL).

METHODS

This real-world observational study included 149 consecutive patients seeking secondary care for investigation of possible myalgic encephalomyelitis/chronic fatigue syndrome. Assessment was done during a routine examination. Data were evaluated with Cohen's kappa and Spearman's rho.

RESULTS

BS criterion validity showed poor agreement with the assessment of SJL: percentage agreement was 74 % and kappa 0.39 (3-cut level), 73 % and kappa 0.39/0.45 (4-/5-cut level). The best interrater reliability was moderate (rho 0.66) for interpretation in categories.

CONCLUSIONS

The BS alone was not a reliable proxy for SJL and should be supplemented with a targeted history. Nevertheless, its interrater reliability was acceptable, and the categorised score appears to have greater clinical relevance than the dichotomous score.

At Least 5-Year Outcomes of Whiplash-Induced Chronic Neck Pain Following Response to Intra-Articular Facet Joint Corticosteroid Injection

Objective

To investigate whether the response to intra-articular facet joint corticosteroid injection can determine the long-term prognosis (at least 5 years after injury) of whiplash injury-related neck pain sustained 3–12 months after injury.

Methods

Of 65 patients who visited a university hospital for persistent whiplash injury-induced axial neck pain sustained 3–12 months after injury (numeric rating scale score ≥3) and had received intra-articular facet joint corticosteroid injection, 40 completed the telephone interview. We divided the patients into “good response group” (≥50% pain reduction at 1 month after the injection) and “poor response group” (<50% pain reduction at 1 month after the injection). We asked participants regarding the presence and degree of neck pain, its impact on work, and the use of oral pain medication or injection treatment.

Results

A follow-up at least 5 years after the injury found that the number of patients with persistent whiplash injury-related neck pain was significantly lower in the good response group than in the poor response group. The number of patients taking oral pain medications prescribed by a medical doctor or receiving injection treatments in a pain clinic or hospital for neck pain was lower in the good response group than in the poor response group. The number of patients who answered that their work was affected by neck pain was lower in the good response group than in the poor response group.

Conclusion

The response to intra-articular corticosteroid injection might be helpful in determining at least 5-year outcomes of chronic whiplash injury-induced pain.

Are menstrual symptoms associated with central sensitization inventory? A cross-sectional study

BACKGROUND

Dysmenorrhea is a prevalent pain condition that affects women of reproductive age, who are monthly exposed to this pain, usually until they reach the adult age, or even after that, which can predispose them to Central Sensitization. The present study aimed to observe the association between menstrual characteristics and central sensitivity symptoms in women.

METHODS

Cross-sectional study. Brazilian women (n=10,402) answered an online form comprised of questions regarding their gynecological history, the Numerical Rating Scale for pain and the Central Sensitization Inventory, part A. For the analysis, we separated women into two groups: Central Sensitivity Symptoms group (n=5,200) and No-Central Sensitivity Symptoms group (n=5,202). We performed a binary logistic regression with the backward insertion method for the variables with p<0.05 in the bivariate analysis between groups. The significance level was set at 5%.

RESULTS

Prevalence of dysmenorrhea was 67.3%, and 32.2% of women in the Central Sensitivity Symptoms group reported pain >8 during their menstrual period. The logistic regression showed that greater levels of menstrual pain (Odds Ratio 1.12), gynecological diseases (Odds Ratio 1.51), presence of dysmenorrhea since adolescence (Odds Ratio 1.20) and irregular menstrual cycles (Odds Ratio 1.47) increased the likelihood of women presenting with Central Sensitivity Symptoms (p<0.05 for all comparisons).

CONCLUSIONS

The present study shows that Central Sensitivity Symptoms are present in about 50% of women and are associated with menstrual characteristics such as dysmenorrhea-related pain intensity, cycle regularity, presence of dysmenorrhea since adolescence accompanied by gynecological diseases.

SIGNIFICANCE

Central sensitivity symptoms occur in 50% of women, and are more present in women with dysmenorrhea. They are associated with cycle regularity, presence of dysmenorrhea since adolescence, and gynecological diseases.

LIMITATIONS

Women that suffer from dysmenorrhea and of higher socioeconomic and educational levels may have been more propense to respond to the invitation; as such, the findings of the present study should be carefully interpreted.

Intermittent Fasting: Potential Utility in the Treatment of Chronic Pain across the Clinical Spectrum

Dietary behavior can have a consequential and wide-ranging influence on human health. Intermittent fasting, which involves intermittent restriction in energy intake, has been shown to have beneficial cellular, physiological, and system-wide effects in animal and human studies. Despite the potential utility in preventing, slowing, and reversing disease processes, the clinical application of intermittent fasting remains limited. The health benefits associated with the simple implementation of a 12 to 16 h fast suggest a promising role in the treatment of chronic pain. A literature review was completed to characterize the physiologic benefits of intermittent fasting and to relate the evidence to the mechanisms underlying chronic pain. Research on different fasting regimens is outlined and an overview of research demonstrating the benefits of intermittent fasting across diverse health conditions is provided. Data on the physiologic effects of intermittent fasting are summarized. The physiology of different pain states is reviewed and the possible implications for intermittent fasting in the treatment of chronic pain through non-invasive management, prehabilitation, and rehabilitation following injury and invasive procedures are presented. Evidence indicates the potential utility of intermittent fasting in the comprehensive management of chronic pain and warrants further investigation.

Cortical mechanisms of visual hypersensitivity in women at risk for chronic pelvic pain

ABSTRACT

Increased sensory sensitivity across non-nociceptive modalities is a common symptom of chronic pain conditions and is associated with chronic pain development. Providing a better understanding of the brain-behavior relationships that underlie multimodal hypersensitivity (MMH) may clarify the role of MMH in the development of chronic pain. We studied sensory hypersensitivity in a cohort of women (n = 147) who had diary confirmation of menstrual status and were enriched with risk factors for chronic pelvic pain, such as dysmenorrhea and increased bladder sensitivity. We administered 2 experimental tasks to evaluate the cross-modal relationship between visual and visceral sensitivity. Visual sensitivity was probed by presenting participants with a periodic pattern-reversal checkerboard stimulus presented across 5 brightness intensities during electroencephalography recording. Self-reported visual unpleasantness ratings for each brightness intensity were simultaneously assessed. Visceral sensitivity was evaluated with an experimental bladder-filling task associated with early clinical symptoms of chronic pelvic pain. Visually evoked cortical activity increased with brightness intensity across the entire scalp, especially at occipital electrode sites. Visual stimulation-induced unpleasantness was associated with provoked bladder pain and evoked primary visual cortex activity. However, the relationship between unpleasantness and cortical activity was moderated by provoked bladder pain. These results demonstrate that activity in the primary visual cortex is not greater in individuals with greater visceral sensitivity. We hypothesize that downstream interpretation or integration of this signal is amplified in individuals with visceral hypersensitivity. Future studies aimed at reducing MMH in chronic pain conditions should prioritize targeting of cortical mechanisms responsible for aberrant downstream sensory integration.

It Hurts to Move! Intervention Effects and Assessment Methods for Movement-Evoked Pain in Patients With Musculoskeletal Pain: A Systematic Review with Meta-analysis

OBJECTIVES

To estimate the effects of musculoskeletal rehabilitation interventions on movementevoked pain and to explore the assessment methods/protocols used to evaluate movement-evoked pain in adults with musculoskeletal pain.

DESIGN

Systematic review with meta-analysis.

LITERATURE SEARCH

Three electronic databases (PubMed, Web of Science, and Scopus) were searched.

STUDY SELECTION CRITERIA

Randomized controlled trials investigating musculoskeletal rehabilitation interventions for movement-evoked pain in adults with musculoskeletal pain were included.

DATA SYNTHESIS

Meta-analysis was conducted for outcomes with homogeneous data from at least 2 trials. The mean change in movementevoked pain was the primary outcome measure. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation framework.

RESULTS

Thirty-eight trials were included, and 60 different interventions were assessed. There was moderate-certainty evidence of a beneficial effect of exercise therapy compared to no treatment (standardized mean difference [SMD], -0.65; 95% confidence interval [CI]: -0.83, -0.47; P<.001) on movement-evoked pain in adults with musculoskeletal pain. There was low-certainty evidence of a beneficial effect of transcutaneous electrical nerve stimulation compared to no treatment (SMD, -0.46; 95% CI: -0.71, -0.21; P = .0004). There was no benefit of transcutaneous electrical nerve stimulation when compared to sham transcutaneous electrical nerve stimulation (SMD, -0.28; 95% CI: -0.60, 0.05; P = .09; moderate-certainty evidence).

CONCLUSION

There was moderate-certainty evidence that exercise therapy is effective for reducing movement-evoked pain in patients with musculoskeletal pain compared to no treatment. Consider exercise therapy as the first-choice treatment for movement-evoked pain in clinical practice. J Orthop Sports Phys Ther 2022;52(6):345-374. Epub: 05 Feb 2022. doi:10.2519/jospt.2022.10527.

Implications of Obstructive Sleep-related Breathing Disorder in Dentistry: Focus on Snoring and Obstructive Sleep Apnea

Obstructive sleep-related breathing disorder (SRBD) is an umbrella term that encompasses various types of upper airway dysfunctions during sleep characterized by increased respiratory effort secondary to snoring and/or increased upper airway resistance and pharyngeal collapse. Obstructive sleep apnea (OSA) is a representative SRBD that involves a significant decrease in or cessation of airflow despite the presence of respiratory effort. While snoring is considered a normal condition, it can cause serious noise disturbance to sleep partners and is considered a predictor of OSA. Snoring and OSA are highly correlated with obesity. SRBDs can lead to cardiovascular disease, hypertension, decreased quality of life, decreased work efficiency, daytime sleepiness, decreased neurocognitive activity, and psychological impairments. In dentistry, research on sleep problems has focused on temporomandibular disorder (TMD)/orofacial pain. The relationship between OSA and TMD/orofacial pain has been reported, but it is not clear whether it is a simple correlation or a causal relationship. Therefore, we aimed to review the causes of SRBDs including snoring and OSA and to review and infer the relationship between these SRBDs and TMD/orofacial pain. The effects of snoring and OSA extend beyond sleep disturbances and are worthy of future research, especially with regard to TMD.

Association between temporal summation and conditioned pain modulation in chronic low back pain: baseline results from 2 clinical trials

Introduction

Temporal summation (TS) and conditioned pain modulation (CPM) represent different aspects of central pain processing. Their relationship and differential performance within distinct body locations are not well understood.

Objectives

To examine the association between TS and CPM in chronic low back pain and the influence of testing location on this relationship.

Methods

We analyzed baseline data from 2 clinical trials on participants with chronic low back pain (n = 264; 47.3% female; mean age = 41 years, SD = 12; mean pain = 5.3/10, SD = 1.4). Measures used included questionnaires assessing pain and negative affect, phasic thermal TS at the hand (thenar) and the lower back (lumbar), followed by CPM that included a thermal testing stimulus (Heat-6, the temperature where pain rating is 6/10) and a cold-pressor conditioning stimulus. Nonparametric, proportional odds logistic regression was used to model thenar, and separately, lumbar TS, using CPM, Heat-6, negative affect, and demographics.

Results

Our models revealed a small association (βs = 0.17, P = 0.01) between reduced CPM and heightened TS at both testing sites, regardless of demographics or negative affect.

Conclusion

Results suggest a modest association between TS and CPM, irrespective of anatomical testing location, demographics, and negative affect. These findings will help improve the methodology and interpretation of TS and CPM measurement in clinical pain populations.

Central sensitization and severity of gastrointestinal symptoms in irritable bowel syndrome, chronic pain syndromes, and inflammatory bowel disease

BACKGROUND

Central sensitization has been suggested as an explanation of the wide range of gastrointestinal and extraintestinal symptoms commonly seen in irritable bowel syndrome (IBS). In this study, the presence and level of central sensitization, and its association to gastrointestinal (GI) symptoms were explored in IBS in comparison with control groups.

METHODS

We investigated patients with IBS (n = 215), chronic pain disorders (n = 36), and inflammatory bowel disease (IBD) (n = 40) and volunteers without chronic diseases (n = 112). The Central Sensitization Inventory (CSI) was translated and validated in Swedish and used together with the Highly Sensitive Person (HSP) scale to measure the presence and level of central sensitization. Furthermore, severity of GI symptoms (GSRS-IBS and IBS-SSS), and anxiety and depression (HAD) were determined.

KEY RESULTS

The Swedish translation of CSI demonstrated excellent validity. Central sensitization, defined by validated cut-off levels for CSI and HSP, was common in the whole cohort (40% and 28%) and in IBS (57% and 35%). Study participants with central sensitization had more severe GI symptoms, anxiety and depression, than participants without central sensitization. Strong associations were seen between CSI and GI symptom severity in the whole cohort (GSRS-IBS: partial η²  = 0.455, p < 0.001; IBS-SSS: partial η²  = 0.408, p < 0.001), with decreasing strength in patients with chronic pain, IBD, IBS, and volunteers.

CONCLUSION AND INFERENCES

Central sensitization was common in IBS and associated with GI symptom severity, but with stronger associations in chronic pain disorders and IBD. This implies that other mechanisms may be of equal or greater importance for GI symptom severity in IBS.

The influence of physical exercise on behavioral habits, kinesiophobia, and disability in people with low back pain: A retrospective cross-sectional study

INTRODUCTION

Physical exercise improves physical fitness and health, helping to reduce pain and prevent low back pain. This study aims to compare the intensity of low back pain (LBP), behavioral habits, and the level of disability and kinesiophobia among exercising and non-exercising subjects with LBP.

METHODS

Consecutive sample of 102 individuals was divided into exercising group (EG) and non-exercising group (NEG). The data was extracted from the answers to the questionnaires Back Pain and Body Posture Evaluation Instrument (BackPEI-A), Oswestry Disability Index (ODI) and Fear-avoidance Beliefs Questionnaire (FABQ-Brazil). For statistical analysis, the chi-square test was used, α ≤ 0.05.

RESULTS

Both groups presented predominance of mild to moderate pain intensity and absence of kinesiophobia in the practice of physical activity, with no statistically significant difference. However, there was significant difference between the groups for the risk of occurrence of LBP and for levels of incapacity and kinesiophobia related to work.

CONCLUSION

Exercising individuals appear to present with a lower risk for occurrence of LBP, lower level of disability, and absence of work-related kinesiophobia.

Central sensitisation in chronic fatigue syndrome and fibromyalgia; a case control study

INTRODUCTION

Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are both complex conditions that are challenging to treat. This may be related to an incomplete understanding of their pathophysiology, itself obfuscated by their heterogeneity. The symptomatic overlap between them and their common comorbidity suggests a shared vulnerability, which might be explained by central sensitisation.

METHODS

19 CFS cases, 19 FM cases and 20 age and sex matched healthy controls (HC) were recruited primarily from secondary care clinics in London. Those with other pain disorders, psychiatric diagnoses and those taking centrally acting or opiate medications were excluded. Participants were asked to abstain from alcohol and over the counter analgaesia 48 h prior to assessment by static and dynamic quantitative sensory tests, including measures of temporal summation (TS) and conditioned pain modulation (CPM).

RESULTS

CS, as defined by the presence of both enhanced TS and inefficient CPM, was present in 16 (84%) CFS cases, 18 (95%) FM cases, and none of the HC (p < 0.001). Pressure pain thresholds were lower in CFS (Median222kPaIQR 146-311; p = 0.04) and FM cases (Median 189 kPa; IQR 129-272; p = 0.003) compared to HC (Median 311 kPa; IQR 245-377). FM cases differed from HC in cold-induced (FM = 22.6 °C (15.3-27.7) vs HC = 14.2 °C (9.0-20.5); p = 0.01) and heat-induced (FM = 38.0 °C (35.2-44.0) vs HC = 45.3 °C (40.1-46.8); p = 0.03) pain thresholds, where CFS cases did not.

CONCLUSION

Central sensitisation may be a common endophenotype in chronic fatigue syndrome and fibromyalgia. Further research should address whether central sensitisation is a cause or effect of these disorders.

Complex Regional Pain Syndrome: Thalamic GMV Atrophy and Associations of Lower GMV With Clinical and Sensorimotor Performance Data

Results on gray matter alterations in complex regional pain syndrome (CRPS) showed heterogeneous findings. Since CRPS is a rare disease, most studies included only small and heterogeneous samples resulting in a low reliability of findings between studies. We investigated 24 CRPS patients with right upper limb affection in the chronic stage of disease using structural MRI and clinical testing. We focused on gray matter volume (GMV) alterations of the brain in comparison to 33 age matched healthy controls, their association to clinical characteristics (duration of pain syndrome and pain intensity ratings) and sensorimotor performance (finger dexterity and spatiotactile resolution). When applying an explorative whole brain analysis CRPS patients showed lower GMV in the bilateral medial thalamus. No other areas showed a relevant GMV difference for the group comparisons. When applying a region of interest driven approach using anatomical masks of the thalamus, ACC/mPFC, putamen, and insula we found relevant associations of clinical and behavioral data in ACC and insula. Whereas, the GMV in ACC showed negative associations with pain intensity and CRPS duration, the GMV of the left posterior insula was negatively associated with sensorimotor performance of the affected hand side. Overall, our results are in accordance to results of others describing a thalamic reduction of GMV in patients with neuropathic pain and are also in accordance with associations of pain intensity and duration with reduced ACC in general in patients with chronic pain syndromes. Sensorimotor performance seems to be related to posterior insula GMV reduction, which has not been described yet for other patient groups.

Effects of safinamide on pain in patients with fluctuating Parkinson's disease

BACKGROUND

Non-motor symptoms (NMS) are integral to Parkinson's Disease (PD) and management remains a challenge. Safinamide is a novel molecule in relation to addressing NMS due to its multifocal mechanism of action with both dopaminergic and non-dopaminergic properties.

OBJECTIVE

To investigate the efficacy of safinamide on NMS and its burden in PD patients with motor fluctuations after 6 months of treatment.

METHODS

This observational, multicenter, open-label, pilot study assessed a wide range of NMS using the following rating scales, NMSS (non-motor symptom scale), KPPS (King's PD pain scale), HADS (hospital anxiety and depression scale), PDQ-8 (Parkinson's disease quality of life questionnaire), and PDSS-2 (Parkinson's disease sleep scale), EuroQol-5D 3 level version (EQ-5D-3L), CGI-I (clinical global impression of improvement), and PGI-C (patient global impression of change). Motor examination using UPDRS part III (Unified Parkinson's disease rating scale, motor examination), UPDRS IV (complications of therapy) and Hoehn and Yahr staging were also obtained.

RESULTS

27 patients were included in the analysis and were evaluated at baseline and ≥ 6 months after safinamide treatment. 26 patients had a daily maintenance dose of 100 mg and 1 patient a daily dose of 50 mg. Significant improvements in UPDRS IV, KPPS item 5 (region-specific "off" dystonia), KPPS domain 3 (items 4-6, fluctuation related pain) and KPPS total score were observed after treatment with safinamide, while maintaining stable dopaminergic medication. No statistically significant differences were found in NMSS, HADS, PDSS-2, EQ-5D-3L, and PDQ-8 after treatment.

CONCLUSIONS

Our results suggest that safinamide may have a beneficial effect on pain, a key unmet need in fluctuating PD patients.

Why It Is Important to Consider the Effects of Analgesics on Sleep: A Critical Review

We review the known physiological mechanisms underpinning all of pain processing, sleep regulation, and pharmacology of analgesics prescribed for chronic pain. In particular, we describe how commonly prescribed analgesics act in sleep-wake neural pathways, with potential unintended impact on sleep and/or wake function. Sleep disruption, whether pain- or drug-induced, negatively impacts quality of life, mental and physical health. In the context of chronic pain, poor sleep quality heightens pain sensitivity and may affect analgesic function, potentially resulting in further analgesic need. Clinicians already have to consider factors including efficacy, abuse potential, and likely side effects when making analgesic prescribing choices. We propose that analgesic-related sleep disruption should also be considered. The neurochemical mechanisms underlying the reciprocal relationship between pain and sleep are poorly understood, and studies investigating sleep in those with specific chronic pain conditions (including those with comorbidities) are lacking. We emphasize the importance of further work to clarify the effects (intended and unintended) of each analgesic class to inform personalized treatment decisions in patients with chronic pain. © 2021 American Physiological Society. Compr Physiol 11:1-31, 2021.

From One Pain to Many: The Emergence of Overlapping Pains in Children and Adolescents

OBJECTIVES

The objective of this study was to compare children and adolescents with overlapping chronic pains (OCP) to those with single chronic pains (SCP) among youth presenting in specialized clinical settings, in an effort to identify potential risk factors for developing overlapping pains.

METHODS

A total of 1235 youth ages 8 to 18 seen in a tertiary care multidisciplinary pain clinic or a multidisciplinary headache clinic completed self-report measures of pain, disability, psychological functioning and clinical history and characteristics at the time of initial clinic visit. Information was captured in a chronic pain data repository and accessed for the current study.

RESULTS

Subsequent pain symptoms developed on average 11.9 months (SD=24.5 mo) after onset of the first pain symptom. Compared with patients with SCP, patients with OCP report more medical comorbidity, more developmental issues, and poorer current sleep and school functioning. They also scored significantly higher than patients with SCP on self-reported functional disability, pain catastrophizing, fear of pain, depression, anxiety, and psychological stress and lower quality of life (all Ps<0.001). In multivariate analysis, variables most strongly associated with presenting with OCP were age (odds ratio [OR]: 1.1, P<0.001), having a clinically significant high functional disability (OR: 1.4, P=0.3), and low quality of life (OR: 2.5, P<0.001).

DISCUSSION

Given their tendency toward more psychological and medical comorbidities, patients with OCP may require more intense and diverse treatment approaches. Some early life experiences may be a risk factor for development of OCP. Longitudinal studies are needed to fully evaluate the heightened risk for OCP associated with some of these factors.

Comparative safety review of current pharmacological treatments for interstitial cystitis/ bladder pain syndrome

Introduction: Interstitial cystitis (IC)/bladder pain syndrome (BPS) is a frustrating disease of chronic bladder pain associated with lower urinary tract symptoms. Although there are many proposed treatment algorithms, the uncertainty as to their etiology has a negative impact on the therapeutic outcome. Oftentimes combination therapy of drugs with different mechanisms of action will be utilized to relieve the symptoms. With the various treatment options available to patients and providers, there is an ever-growing need to implement drug efficacy as well as safety to promote best practice in use of the approved drug.Areas covered: This review will focus on guideline-based pharmacotherapies as described by the AUA and EAU, specifically oral, and intravesical therapies with the most up-to-date published literature. Pharmacotherapies targeting bladder, and/or systemic factors in the overall treatment of IC/BPS are discussed with a particular focus on efficacy and drug safety evaluation.Expert opinion: IC/BPS is a syndrome that requires bladder targeting agents to restore the urothelium barrier function and inhibit bladder hypersensitivity as well as various drugs with anti-inflammatory effects, and immune modulation effects. Current pharmacotherapies for IC/BPS have various therapeutic effects and adverse effects depending on the dose and individual response.

Pain Phenotypes in Rare Musculoskeletal and Neuromuscular Diseases

For patients diagnosed with a rare musculoskeletal or neuromuscular disease, pain may transition from acute to chronic; the latter yielding additional challenges for both patients and care providers. We assessed the present understanding of pain across a set of ten rare, noninfectious, noncancerous disorders; Osteogenesis Imperfecta, Ehlers-Danlos Syndrome, Achondroplasia, Fibrodysplasia Ossificans Progressiva, Fibrous Dysplasia/McCune-Albright Syndrome, Complex Regional Pain Syndrome, Duchenne Muscular Dystrophy, Infantile- and Late-Onset Pompe disease, Charcot-Marie-Tooth Disease, and Amyotrophic Lateral Sclerosis. Through the integration of natural history, cross-sectional, retrospective, clinical trials, & case studies we described pathologic and genetic factors, pain sources, phenotypes, and lastly, existing therapeutic approaches. We highlight that while rare diseases possess distinct core pathologic features, there are a number of shared pain phenotypes and mechanisms that may be prospectively examined and therapeutically targeted in a parallel manner. Finally, we describe clinical and research approaches that may facilitate more accurate diagnosis, monitoring, and treatment of pain as well as elucidation of the evolving nature of pain phenotypes in rare musculoskeletal or neuromuscular illnesses.

The Importance of a Multi-Disciplinary Approach to the Endometriotic Patients: The Relationship between Endometriosis and Psychic Vulnerability

Endometriosis is a chronic inflammatory condition, which is distinguished by the presence of the endometrial-like glands and stroma outside the uterine cavity. Pain and infertility are the most commonly expressed symptoms, occurring in 60% and 40% of cases, respectively. Women with endometriosis, especially those with pelvic pain, also have a greater vulnerability to several psychiatric disorders. There is, in particular, a tendency to contract affective or anxiety disorders as well as panic-agoraphobic and substance use disorders. Endometriosis with pelvic pain, infertility and psychic vulnerability usually leads to disability and a markedly lower quality of life for women of reproductive age. Thus, the burden of endometriosis is not limited to the symptoms and dysfunctions of the disease; it extends to the social, working and emotional spheres, leading to a severe impairment of global functioning. An analysis of scientific literature revealed a close relationship between specific temperamental traits, the expression of several psychiatric symptoms, chronicity of pain, risk of substance use and lower probability of a positive outcome. Endometriosis symptoms and the impact of related psychological consequences, increased vulnerability and the possible onset of psychiatric symptoms may influence coping strategies and weaken resilience, so triggering a vicious cycle leading to a marked deterioration in the quality of life. A multidisciplinary approach consisting of a medical team composed of gynecologists, psychologists, psychiatrists, experts in Dual Disorder, algologists and sexologists, would guarantee the setting of a target and taking the best decision on a personalized treatment plan. That approach would allow the prompt detection of any psychopathological symptoms and improve the endometriosis-related physical symptoms, bringing a healthier quality of life and a greater likelihood of a positive outcome.

Chronic Pain Among Patients With an Opioid Use Disorder

BACKGROUND AND OBJECTIVES

Chronic pain is not well understood in opioid-dependent populations. We report the prevalence of chronic pain and pain characteristics in an opioid-dependent population by treatment type and gender.

METHODS

This cross-sectional study opportunistically recruited 569 patients (32% women) receiving treatment for opioid use disorder (DSM-5) in Norway during 2016-2018 (83% received opioid maintenance treatment, 17% received treatment without medication). We asked about chronic pain (≥3 months; ICD-11), pain severity (NRS-11), and other pain characteristics.

RESULTS

Overall, 55% reported chronic pain (≥3 months), with a higher prevalence among women (61% vs 52%, P = .041) and patients receiving methadone (66%) compared with buprenorphine or no medication (46% and 45%, P < .001). Chronic pain was associated with higher age (P < .001) and higher doses of methadone (P = .048). The average duration of pain was 11 years. The most frequently reported pain locations were the lower extremities (59%) and the back (54%), and 69% reported more than one pain location. Constant pain and migrating pain were significantly associated with both moderate (adjusted odds ratio [aOR]: 2.04, confidence interval [CI]: 1.12-3.74 and aOR: 2.44, CI: 1.09-5.43) and severe pain intensity (aOR: 2.08, CI: 1.14-3.80 and aOR: 2.46, CI: 1.10-5.47). Reporting no effect of analgesics was associated with severe pain intensity (aOR: 0.54, CI: 0.29-0.99).

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Over half reported chronic pain, and rates were highest among women and patients receiving methadone. New contributions to the field are descriptions of pain characteristics by gender and pain severity, and interactions between medication type and age. (© 2021 The Authors. The American Journal on Addictions published by Wiley Periodicals LLC on behalf of The American Academy of Addiction Psychiatry). (Am J Addict 2021;00:00-00).

Erectile Dysfunction in Migraine in Indian Patients

Background:

Migraine is one of the common causes of primary headache worldwide. Migraine headaches significantly affect family and social activities. Migraine also impacts the sexual function of the sufferers. There are no published studies in India so far where they have studied the erectile function in male migrainers. This study is done to look for erectile dysfunction in male migrainers.

Materials and Methods:

This case-control study was done to look for presence of erectile dysfunction in male migrainers and the factors affecting it. Thirty age matched males with migraine and without migraine were studied. The International Headache Society's International Classification of Headache Disorders, 3^rd Edition, was used to diagnose migraine with or without aura. Migraine disability assessment scale was used to assess migraine-related disability, Numerical Rating Scale was used assess to the severity of headaches, Migraine-Specific Quality of Life Questionnaire to assess the quality of life, and International Index of Erectile Function score was used to assess the erectile function.

Results:

The mean age of the cases was 38.83 ± 5.7 years and that of the controls was 38.63 ± 5.3 years. The erectile dysfunction was seen in 80% of migrainers and none in the control group had erectile dysfunction. Those with erectile dysfunction had more severe headache which were severely disabling.

Conclusion:

Erectile dysfunction is common in migraine. There is a significant negative correlation of erectile dysfunction with severe disabling migraine.

Dysmenorrhea Symptom-Based Phenotypes: A Replication and Extension Study

BACKGROUND

Dysmenorrhea is a prevalent pain condition among women and a risk factor for other chronic pain conditions. Individuals vary in dysmenorrhea pain severity, the number of painful sites, and co-occurring gastrointestinal symptoms. Three dysmenorrhea symptom-based phenotypes were previously identified using latent class analysis; however, there is a need to validate these in an independent sample, so they can be used in mechanistic and interventional research. There is also a need to further characterize dysmenorrhea symptom-based phenotypes in terms of demographic, clinical, and psychobehavioral characteristics so they can be used to inform precision dysmenorrhea treatment.

OBJECTIVES

The study objectives were to (a) determine whether the same dysmenorrhea symptom-based phenotypes would be found in a new sample; (b) determine whether including demographic, clinical, and psychobehavioral covariates in latent class analyses would change individuals' phenotype memberships; and (c) investigate relationships between dysmenorrhea symptom-based phenotypes and demographic, clinical, and psychobehavioral characteristics.

METHODS

This cross-sectional survey study included 678 women (aged 14-42 years) with dysmenorrhea. Participants reported dysmenorrhea symptom severity, demographic, clinical (comorbid chronic pain and gynecological conditions), and psychobehavioral characteristics (perceived stress, anxiety, depression, sleep disturbance, and pain catastrophizing). We used latent class analysis to identify symptom-based phenotypes. We compared analyses with and without covariates (i.e., demographic, clinical, and psychobehavioral characteristics) to determine if individuals' phenotype memberships changed. We then examined associations between phenotypes and demographic, clinical, and psychobehavioral characteristics.

RESULTS

We reproduced three dysmenorrhea symptom-based phenotypes: the "mild localized pain" phenotype (characterized by mild abdominal cramps), the "severe localized pain" phenotype (characterized by severe abdominal cramps), and the "multiple severe symptoms" phenotype (characterized by severe pain at multiple locations and gastrointestinal symptoms). Analyses with and without covariates had little effect on individuals' phenotype membership. Race, comorbid chronic pain condition, endometriosis, and pain catastrophizing were significantly associated with the dysmenorrhea phenotypes.

DISCUSSION

Findings provide a foundation to further study mechanisms of dysmenorrhea symptom heterogeneity and develop dysmenorrhea precision treatments. The three dysmenorrhea symptom-based phenotypes were validated in a second sample. Demographic, clinical, and psychobehavioral factors were associated with dysmenorrhea symptom-based phenotypes.

Cortical Mechanisms of Visual Hypersensitivity in Women at Risk for Chronic Pelvic Pain

Multisensory hypersensitivity (MSH), which refers to persistent discomfort across sensory modalities, is a risk factor for chronic pain. Developing a better understanding of the neural contributions of disparate sensory systems to MSH may clarify its role in the development of chronic pain. We recruited a cohort of women (n=147) enriched with participants with menstrual pain at risk for developing chronic pain. Visual sensitivity was measured using a periodic pattern-reversal stimulus during EEG. Self-reported visual unpleasantness ratings were also recorded. Bladder pain sensitivity was evaluated with an experimental bladder-filling task associated with early clinical symptoms of chronic pelvic pain. Visual stimulation induced unpleasantness was associated with bladder pain and evoked primary visual cortex excitation; however, the relationship between unpleasantness and cortical excitation was moderated by bladder pain. Thus, future studies aimed at reversing the progression of MSH into chronic pain should prioritize targeting of cortical mechanisms responsible for maladaptive sensory input integration.

Understanding the Impact of Sex and Gender in Osteoarthritis: Assessing Research Gaps and Unmet Needs

Osteoarthritis (OA) affects more than 300 million individuals globally, with higher prevalence in women than in men. In addition, OA affects women and men differently, with women demonstrating both increased disease severity and disability. The Society for Women's Health Research (SWHR) convened an interdisciplinary group of expert researchers and clinicians for a roundtable meeting to review the current state of the science on OA and to identify knowledge gaps in the scientific literature, especially as they relate to the topics of sex and gender. The current review summarizes discussions from the roundtable and prioritizes areas of need that warrant further attention in OA research, diagnosis, care, and education. Improvements in basic and clinical research, clinical practice, patient education, and policy are needed to allow for better understanding as to the pathogenesis of sex- and gender-related disparities in OA.

Embodiment in Virtual Reality for the Treatment of Chronic Low Back Pain: A Case Series

Purpose

We describe two case studies that use embodiment in virtual reality as a treatment for chronic low back pain. The purpose of this case series was to determine the feasibility of a novel virtual reality-based digital therapeutic for the treatment of chronic pain.

Patients and Methods

Two patients with chronic low back pain received seven sessions, two sessions per week, of a novel digital therapeutic that combines virtual embodiment with graded motor imagery to deliver functional rehabilitation exercises using an off-the-shelf virtual reality system. Pain intensity was measured using a visual analog scale before and after each session to get an indication whether individual sessions of virtual embodiment training decrease pain intensity. Pain catastrophizing scale was assessed before the first session and after the seventh session to determine the extent to which virtual embodiment training can improve psychological symptoms of chronic low back pain.

Results

In both patients, pain intensity was improved after individual sessions of virtual embodiment training as measured by a paired t-test: (Patient A: t = 2.890, P < 0.05) and (Patient B: t = 5.346, P < 0.005). This indicates that individual sessions of virtual embodiment training decrease pain intensity. In both patients, improvements were observed in three subscales of the pain catastrophizing scale (rumination, magnification, and helplessness). This indicates that virtual embodiment training may have benefits for chronic pain symptoms such as pain intensity, pain-related mobility impairment, and disability.

Conclusion

This case series provides evidence that embodiment in virtual reality improves symptoms of persistent chronic low back pain. We propose a mechanism by which virtual embodiment may improve chronic pain symptoms by recontextualizing sensory feedback from the body as patients engage in functional rehabilitation exercises while in virtual reality.