Nociplastic Pain Research Articles

Pain in Inflammatory and Degenerative Joint Diseases

The International Association for the Study of Pain (IASP) agreed in 2020 on a revised definition of pain: “An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage”. Patients with rheumatic diseases frequently report pain as a primary symptom. However, rheumatology healthcare providers often lack the training to adequately differentiate between different causes of pain, which are mandatory for optimal treatment. IASP classifies pain into 3 descriptive categories: nociceptive, neuropathic, and nociplastic pain. A recent review (Murphy AE et al, Arthritis Care & Research, 2023) gives a nice overview of these different forms of pain. Nociceptive pain derives from tissue injury, with subsequent sensation of pain by nociceptors. It is usually well-localized and can be precisely described by patients (i.e. rheumatoid arthritis, primary osteoarthritis) and there are localized pathologies that explain the pain symptoms. Neuropathic pain occurs with injury or insult to a peripheral or central nerve. There may be pressure on the nerve as in carpal tunnel syndrome, or changes in nerves caused by diabetes or other causes of nerve pathologies like mononeuritis multiplex. The pain and paresthesia typically follow the distribution of peripheral nerves in a dermatomal distribution. Nociplastic pain describes pain characterized by altered nociceptive processing (e.g., hypersensitivity), suggestive of dysregulation of CNS pain processing pathways. Nociplastic pain likely encompasses many different CNS pathways that lead to amplified processing of pain signals, decreased inhibition of pain, or both. Prototypical nociplastic pain conditions include both widespread (e.g., fibromyalgia) and localized conditions (e.g., chronic temporomandibular pain disorders and irritable bowel syndrome). Patients with inflammatory or degenerative joint diseases may have one, two or three of the presently described forms of pain, and an important objective for the rheumatologists is to understand which types of pain our patients are suffering from. About one-quarter of the patients with inflammatory rheumatic joint diseases have additional fibromyalgia causing increased scores of patient-reported outcomes like patient’s global VAS and number of tender joints, and this results in elevated composite scores independent on the degree of inflammation. Thus, rheumatologists must try to differentiate between nociceptive pain caused by inflammatory or degenerative pathologies which may be treated by different ant-inflammatory treatments, neuropathic pain which may need operative of medical treatment, or nociplastic pain which should be non-medically treated.

Precuneal hyperperfusion in patients with attention-deficit/hyperactivity disorder-comorbid nociplastic pain.

Nociplastic pain (NP), a third category of chronic pain, offers a framework for elucidating its pathophysiology and treatment strategies. One of the characteristics of NP is comorbidity of symptoms other than pain, such as psychological and cognitive problems; therefore, these can be clues to understanding NP. Recently, we reported several cases with comorbid symptoms of attention-deficit/hyperactivity disorder (ADHD). Notably, ADHD medications, including methylphenidate (MP) and atomoxetine, improved chronic pain as well as the symptoms of ADHD. However, in clinical settings, identifying comorbid ADHD in patients with chronic pain is challenging, and underlying mechanisms have not been elucidated. To explore the common characteristics of brain function in patients with ADHD-comorbid NP, we identified brain regions where cerebral blood flow (CBF) distributions changed between pre- and post-treatment using single-photon emission computed tomography (SPECT). Additionally, we examined brain regions where CBF values correlated with clinical scores. We retrospectively studied 65 patients (mean age 53 ± 14years; 30 males and 35 females) with ADHD-comorbid NP who underwent CBF-SPECT before and after ADHD medication initiation. Clinical scores included the clinical global impression severity (CGI-S), pain numerical rating scale, hospital anxiety and depression scale, pain catastrophizing scale, and Conners' adult ADHD rating scale-self report scores. Voxel-based statistical methods were used to compare pre- and post-treatment CBF-SPECT images to identify significant differences and investigate brain regions correlated with clinical scores. The CBF was higher in the precuneus, insular gyrus, and thalamus before treatment than after treatment (paired t-test, cluster-definition p < 0.001, cluster-extent threshold p < 0.05, with family-wise error [FWE] correction). The hyperperfusion in the precuneus was positively correlated with the CGI-S score and significantly reduced after treatment with MP (paired t-test, cluster-definition p < 0.005, cluster-extent threshold p < 0.05, with FWE correction). The finding of precuneal hyperperfusion may provide insight into the mechanisms of NP and help identify patients who would benefit most from ADHD medications.

Влияние ноципластической боли на клинические проявления и качество жизни у пациентов с аксиальным псориатическим артритом

The purpose — to determine clinical and laboratory features of axial psoriatic arthritis (AxPsA); to study the impact of nociplastic pain (NP) on the clinical features and quality of life (QoL) in patients with AxPsA. Material and methods. 127 adult patients with psoriatic arthritis (PsA) were included. The number of tender (TJ) and swollen joints (SJ), patient global assessment and severity of pain, C-reactive protein (CRP) were determined. Activity of PsA was assessed with DAPSA, ASDAS, and BASDAI. NP was determined by screening using the CSI and neurologist’s examination. Sacroiliitis (SI) was determined with MRI. QoL was assessed with PsAID-12 and ASAS-HI. Results. SI was found in 60 (47.2%) patients with PsA (AxPsA). The TJ, SJ, CRP, DAPSA, ASDAS were found in higher values and values of CRP above normal, erosive peripheral arthritis and enthesitis were more often found in patients with AxPsA. NP was found in 30 (50%) patients with AxPsA who showed worse pain scores, BASDAI, ASDAS, and QoL. The indicators of TJ, SJ, and CRP in the groups did not differ. Conclusion. SI in PsA is associated with more severe peripheral and laboratory manifestations, but not with more severe pain. Patients with AxPsA with NP have higher rates of disease activity which are associated with degradation of patient reported outcomes including QoL without degradation of inflammation signs. For improving the QoL of patients with PsA it is necessary to study the mechanisms of chronic pain.

Relationship between Nociplastic Pain Involvement and Medication use, Symptom Relief, and Adverse effects Among People using Medical Cannabis for Chronic Pain.

Cannabis is commonly used for chronic pain management, but cannabis' effects remain poorly characterized in chronic nociplastic pain (NPP), which is posited to be caused by disturbances in nervous system pain processing. In this cross-sectional study (n=1,213), we used the 2011 Fibromyalgia (FM) Survey Criteria as a surrogate measure for degree of NPP among individuals using medical cannabis for chronic pain. Using a quartile-split, we investigated associations between degree of NPP and medication use, cannabis use characteristics, and symptom relief. Continuous variables were assessed using one-way analysis of variance (ANOVA) and categorical variables with Pearson's Chi-square test (2) and binomial logistic regression for calculation of odds ratios (OR). Participants were predominately female (59%), with mean ±SD age 49.4±13.6 years. Higher FM scores were associated with less self-reported improvement in pain and health since initiating medical cannabis use, as well as more cannabis-related side effects. Paradoxically, higher FM scores were also associated with higher usage of concomitant medication use (including opioids and benzodiazepines) but also with substituting cannabis for significantly more medication classes, including opioids and benzodiazepines. This article presents evidence that individuals in higher NPP quartiles have higher analgesic intake, higher odds of substituting cannabis for medications, higher side effect burden, and lower therapeutic effect from cannabis. These seemingly contradictory findings may reflect higher symptom burden, polypharmacy at baseline, or that NPP may be challenging to treat with cannabis. Further research is necessary to further explain cannabinoid effects in NPP.

Contextualization of the concept of nociplastic pain in irritable bowel syndrome.

The objective of this letter to the editor is to contextualize the concept of "nociplastic pain" in functional digestive disorders, especially in irritable bowel syndrome (IBS); and try to differentiate it from the term central sensitization, increasingly used in the literature, and with notable relevance in the pathophysiology of IBS.

Nociplastic pain: challenges and future perspectives

Nociplastic pain: challenges and future perspectives

Natural polyphenolic coffee extract administration relieves chronic nociplastic pain in a reserpine-induced fibromyalgia-like female mouse model.

Nociplastic pain involves reflexive and nonreflexive pain responses and it is a core symptom of fibromyalgia (FM). The increasing prevalence of this health condition and the low rates of patients' quality of life, combined with the lack of suitable pharmacologic treatments, evidence the demand to research new alternatives. Polyphenols may be potential therapeutic candidates as they have been reported to exert pathological pain modulation in preclinical models. In that context, this work was aimed to study the antinociceptive effects of a polyphenolic extract obtained from decaffeinated ground roasted coffee, in the RIM6 FM-like mouse model. To this end, RIM6 adult ICR-CD1 female mice were administered daily once a week with either 10 or 15mg/kg of extract, and reflexive pain responses were evaluated for up to 3 weeks. At the end, the depressive-like behavior was assessed as a nonreflexive pain response, and spinal cord and serum samples were collected for immunohistochemical and toxicological analyses. These findings showed that the repeated administration of the coffee polyphenolic extract (CE) modulated reflexive pain responses, depressive-like behavior, and spinal cord gliosis in a dose-dependent manner, without signs of systemic toxicity. Thus, the CE may be a potential pharmacological treatment suitable to relieve nociplastic pain responses characteristic of FM.

Pain phenotypes in caregivers of children with cerebral palsy.

To determine the phenotypes of chronic pain seen in individuals caring for children with cerebral palsy (CP). A current classification system was used to determine the prevalence of predominant pain phenotypes in caregivers of children with CP. To this end, the Visual Analog Scale, Margolis pain diagram, Central Sensitization Inventory, and Short Form-36 questionnaire were administered to the participants. In addition, the participants underwent a quantitative sensory examination. This study was concluded with 60 individuals. The predominant pain phenotype was nociceptive pain in 30% of the participants, nociplastic pain in 25%, and neuropathic pain in 5%. The pain duration (p=0.365) and quality of life of the individuals did not significantly differ according to the predominant pain phenotypes (p>0.05). However, there was a statistically significant difference between the pain phenotypes in terms of pain severity (p=0.016) and the Central Sensitization Inventory scores (p<0.001). Nociceptive pain was the most common pain phenotype in caregivers of children with CP. We also concluded that among the pain phenotypes, pain intensity was highest in neuropathic pain. There is a need for further studies in this area to demonstrate the validity and reliability of the evaluated mechanism-based classification system in order for it to be included in clinical guidelines.

The problem of residual pain in the assessment of rheumatoid arthritis activity.

Residual pain is a major unmet medical need observed in patients suffering from rheumatoid arthritis (RA), which decreases their quality of life, even after achieving remission or low disease activity. The article has two aims: 1) to present mechanisms involved in the pathophysiology of residual pain, both inflammatory and non-inflammatory, i.e. neuropathic and nociplastic pain, as well as secondary pain syndromes, i.e. osteoarthritis and fibromyalgia, which can contribute to residual pain; 2) to show the limitations of current disease activity measures recommended by European Alliance of Associations for Rheumatology (EULAR) and American College of Rheumatology (ACR), which raise the need for a separate assessment of pain, and examples of methods that could be used by medical professionals to assess the pain and make a differential diagnosis. In conclusion, establishing a valid method to assess pain is essential to identify the pathomechanism of residual pain and to create treatments tailored specifically to individual RA patients.

Exploring the psychopathological profile of fibromyalgia: insights from the personality assessment inventory and its association with disease impact.

Fibromyalgia (FM) is a complex rheumatic disorder characterized by chronic nociplastic pain and central sensitization. Psychopathological conditions can influence FM symptoms, which worsen their condition. However, not all patients with FM have psychopathological disorders, indicating a heterogeneous population. To investigate the psychopathological profile and personality disorders in patients with FM and its relationship impact on this disease. An observational and cross-sectional comparative study was conducted with a sample of 90 women, mean age 48.7 years (SD = 8.12), from Hospital del Mar, Barcelona. The Personality Assessment Inventory (PAI) and the Fibromyalgia Impact Questionnaire (FIQ) were used for assessment. FM patients predominantly exhibited psychopathological profiles resembling affective disorders (37.7%) and Cluster C personality disorders (58.8%). The severity of FM's impact was related to affective disorder symptoms, hypervigilance, derealization, somatization, and Cluster B personality disorder (emotional instability). Different rheumatic symptoms correlated with specific psychopathological patterns. Increased somatic symptoms on the FIQ were related to an unstable and dependent personality, while heightened emotional symptoms on the FIQ were associated with avoidance, borderline traits, and passive-aggressive reactions. Recognizing psychopathological aspects is crucial for managing FM. The PAI is a valuable tool for establishing its psychopathological multidimensional profile, which predominantly shows an affective spectrum conditions and comorbid Cluster C personality disorder, exacerbating the disease's impact.

Research progress of nociplastic pain in the clinical treatment of chronic pain diseases

Chronic pain is increasingly developing into a worldwide health problem. Due to the money and treatment required for care and rehabilitation, as well as the complexity of the various types of pain, chronic pain sufferers often bear a huge financial burden as well as a psychological one. According to statistics, 23% of chronic pain sufferers have suicidal thoughts. In 2017, the third category pain named "nociplastic pain" was proposed for the first time by the International Association for the Study of Pain (IASP) which is disparate with the first kind nociceptive pain and the second pain neuropathic. The physiological mechanisms behind this type of pain are not known. However, it is commonly thought to be associated with a hypersensitivity response in the central nervous system and can be resulted in chronic nociceptive pain, so nociplastic pain is able to occur by itself, and can combine with other pain. At the same time, this type of pain affects the central system and produces other derived symptoms. Examples include stimulation of the limbic system, including impaired processing of emotions by the amygdala, amplified pain perception, sleep disturbances, increased fatigue and sensitivity to external environmental stimuli. There are no very clear and obvious diagnostic criteria or methods, and clinical detection is difficult. Due to the many symptoms, patients usually undergo multiple tests, with high medical costs and a poor prognosis. Patients suffer both physical and psychological distress. The disease with its complexity characteristic leads the difficulty for doctors to diagnosis it plagues patients with the condition, while increasing the difficulty of medical diagnosis and the cost of medical treatment. This article synthesizes the existing developments in outcomes in nociplastic pain from introduction and classification to diagnosis and treatment, it discusses the existing research findings.

Exploring the complexities of pain phenotypes: OMERACT 2023 chronic pain working group workshop

ObjectiveTo educate and discuss pain mechanisms (nociceptive, neuropathic, nociplastic) illuminating its possible impact when measuring different outcomes, which may modify, confound and potentially bias the outcome measures applied across various aspects of Rheumatic Musculoskeletal Diseases (RMDs) clinical trials. MethodsIn the plenary presentations, PM lectured on different pain mechanisms and impact on disease activity assessment. Data from two data sets of RMDs patients, which assessed the prevalence and impact of nociplastic pain were presented and reviewed. Audience breakout group sessions and polling were conducted. ResultsMixed pain etiologies may differentially influence disease activity assessment and therapeutic decision-making. Polling demonstrated a consensus on the need to assess different types of pain as a phenotype, as it constitutes an important contextual factor (a variable that is not an outcome of the trial, but needs to be recognized [and measured] to understand the study results), and to standardize across RMDs. ConclusionThere is need for a standardized pain measure that can differentiate underlying pain mechanisms.

Gabapentin for Pain in Pediatric Palliative Care

ObjectiveGabapentin is commonly used to treat pain in children receiving pediatric palliative care. This study describes the real-world use of gabapentin and the associated benefits and adverse effects/events (AEs). MethodsA prospective, multicenter cohort of standardized data collection after a clinical decision was made to use gabapentin for managing neuropathic or nociplastic pain in children attended on by a pediatric palliative care service. It was conducted across 11 sites in seven countries including hospital, inpatient, and outpatient services. Clinical outcomes were graded using pain scales validated for age and cognitive ability and the National Cancer Institute Common Terminology Criteria for Adverse Events (NCICTCAE) at baseline, 14 days, 28 days, six weeks and 12 weeks after initiation of gabapentin. Ad-hoc safety reporting continued throughout the study. ResultsData were collected from 127 children with a median age of 4.7 years (IQR 0.1–17.9); 61% had a neurological disorder, 21% advanced cancer and the cohort had a high level of disability (Lansky/Karnofsky performance score 37.1). Gabapentin was prescribed at standard pediatric doses. On average, 76% of children had a reduction in pain and 42% experienced a potential AE. The mean pain score decreased from 6.0 (SD 2.6) at baseline to 3.3 (SD 2.4) at 14 days and 1.8 (SD 1.8) after 12-weeks of gabapentin therapy. Ten percent had increased pain at each time point. AEs did not increase when individual changes over time were accounted for except for somnolence (7%). Serious AEs attributable to gabapentin were possible or probable in 3% of children. ConclusionsGabapentin prescribed at standard doses for advanced cancer and severe neurological injury in children under a pediatric palliative care service was associated with generally improved pain intensity at previously described levels of adverse effects.

Exercise Therapy for Chronic Neck Pain: Tailoring Person-Centred Approaches within Contemporary Management.

Exercise therapy is considered the best evidence-based approach for managing chronic neck pain. However, the implementation of exercise therapy presents several challenges. Systematic reviews indicate that it has modest effectiveness, while clinical practice guidelines offer limited guidance on the exercise parameters required to optimise clinical outcomes. Moreover, recommendations often fail to differentiate between different types of neck pain. This article addresses the challenges associated with the prescription of exercise for chronic neck pain and provides recommendations for exercise therapy specific to chronic nociceptive, neuropathic, and nociplastic neck pain. The goal of this article is to facilitate the implementation of high-value evidence-based exercise therapy for these distinct types of chronic neck pain with the aim to improve its outcomes and to reduce the related individual and societal burdens.

Can Myofascial Trigger Points Involve Nociplastic Pain? A Scoping Review on Animal Models.

Nociplastic pain is a non-specific, regional pain lasting more than three months, characterised by the onset of hypersensitivity, despite no clear evidence of tissue damage. It is a relatively new classified type of pain. As a result, there has not yet been much work describing its precise modelling. The mechanism of its formation needs to be clearly explained. Authors point out that the occurrence of myofascial trigger points (MTrPs) can lead to this type of pain as one possibility. This paper summarises the available literature on modelling nociplastic pain and MTrPs. It complies with studies describing animal model creation and presents the results of performed experiments. The literature search was conducted in December 2022 and included the following databases: PubMed, Scopus, and Web of Science. In this scoping review, six studies were included. Two described the creation of animal models of nociplastic pain, one adapted old models to nociplastic pain, and three described the modelling of MTrPs. This is the first paper pointing in the possible direction of detecting and studying the correlation between MTrPs and nociplastic pain in animal models. However, there is currently insufficient evidence to describe MTrPs as nociplastic, as few studies with animal models exist.

Nociplastic pain

Nociplastic pain refers to pain arising from altered nociception without evidence of tissue or somatosensory damage. It encompasses various clinical conditions with shared neurophysiological mechanisms involving different organ systems. Nociplastic pain can occur independently or alongside chronic pain conditions with a nociceptive or neuropathic origin. This review introduces the concept of nociplastic pain, its clinical manifestations and the underlying pathophysiology. Taking a biopsychosocial approach can lead to a better understanding of nociplastic pain and improved treatment outcomes for affected individuals.

The potent analgesia of intrathecal 2R, 6R-HNK via TRPA1 inhibition in LF-PENS-induced chronic primary pain model

BackgroundChronic primary pain (CPP) is an intractable pain of unknown cause with significant emotional distress and/or dysfunction that is a leading factor of disability globally. The lack of a suitable animal model that mimic CPP in humans has frustrated efforts to curb disease progression. 2R, 6R-hydroxynorketamine (2R, 6R-HNK) is the major antidepressant metabolite of ketamine and also exerts antinociceptive action. However, the analgesic mechanism and whether it is effective for CPP are still unknown.MethodsBased on nociplastic pain is evoked by long-term potentiation (LTP)-inducible high- or low-frequency electrical stimulation (HFS/LFS), we wanted to develop a novel CPP mouse model with mood and cognitive comorbidities by noninvasive low-frequency percutaneous electrical nerve stimulation (LF-PENS). Single/repeated 2R, 6R-HNK or other drug was intraperitoneally (i.p.) or intrathecally (i.t.) injected into naïve or CPP mice to investigate their analgesic effect in CPP model. A variety of behavioral tests were used to detect the changes in pain, mood and memory. Immunofluorescent staining, western blot, reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and calcium imaging of in cultured dorsal root ganglia (DRG) neurons by Fluo-8-AM were used to elucidate the role and mechanisms of 2R, 6R-HNK in vivo or in vitro.ResultsIntrathecal 2R, 6R-HNK, rather than intraperitoneal 2R, 6R-HNK or intrathecal S-Ketamine, successfully mitigated HFS-induced pain. Importantly, intrathecal 2R, 6R-HNK displayed effective relief of bilateral pain hypersensitivity and depressive and cognitive comorbidities in a dose-dependent manner in LF-PENS-induced CPP model. Mechanically, 2R, 6R-HNK markedly attenuated neuronal hyperexcitability and the upregulation of calcitonin gene-related peptide (CGRP), transient receptor potential ankyrin 1 (TRPA1) or vanilloid-1 (TRPV1), and vesicular glutamate transporter-2 (VGLUT2) in peripheral nociceptive pathway. In addition, 2R, 6R-HNK suppressed calcium responses and CGRP overexpression in cultured DRG neurons elicited by the agonists of TRPA1 or/and TRPV1. Strikingly, the inhibitory effects of 2R, 6R-HNK on these pain-related molecules and mechanical allodynia were substantially occluded by TRPA1 antagonist menthol.ConclusionsIn the newly designed CPP model, our findings highlighted the potential utility of intrathecal 2R, 6R-HNK for preventing and therapeutic modality of CPP. TRPA1-mediated uprgulation of CGRP and neuronal hyperexcitability in nociceptive pathways may undertake both unique characteristics and solving process of CPP.

A biopsychosocial approach as a part of an osteopathic intervention in the management of chronic prostatitis/chronic pelvic pain: A case report

IntroductionThe aetiology behind chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) remains unknown, which makes treatment challenging, while the diagnostic uncertainty related to CP/CPPS creates confusion and frustration for both patients and clinicians. As CP/CPSS may be persuaded by nociplastic pain mechanism and is associated with psychosocial and lifestyle factors, interventions should address biopsychosocial factors in combination with the treatment of the biomechanical impairments. Case descriptionThis is a case study of a 71-year-old man diagnosed with CP/CPPS who was referred to the osteopathic clinic by his urologist. His main complaint was a constant dull aching pain in the urethra and right groin that had started almost 10 years previously. The patient was treated six times over a time period of 5 months using a multimodal osteopathic approach. OutcomesThe osteopathic intervention significantly decreased the numeric pain rating scale score, improved quality of life and reduced pain and dysfunction as measured with the National Institutes of Health chronic prostatitis symptom index. DiscussionAs CP/CPPS may be a nociplastic pain syndrome, and a multimodal osteopathic approach may therefore be needed that includes treatment of the biomechanical impairments with osteopathic manipulative treatment while also addressing various biopsychosocial factors via education, dietary modifications, advice about physical activity, breathing exercises, sleep and stress management. ConclusionsApplication of the biopsychosocial model in addition to a biomedical osteopathic model seems to be a beneficial intervention strategy to improve quality of life, pain and dysfunction in a patient with CP/CPPS.

ЦЕНТРAЛЬНAЯ СЕНСИТИЗAЦИЯ ПРИ ПСOРИAТИЧЕСКOМ AРТРИТЕ

Introduction. Chronic pain consists of nociceptive, neuropathic and nociplastic components. Nociplastic pain based on central sensitization. Patients with central sensitization may experience severe pain even with no any signs of clinical and laboratory inflammation, and describe it in descriptors of neuropathic pain. The prevalence and influence of central sensitization in clinical and laboratory activity, the development of mood disorders in patients with psoriatic arthritis are not explored well. Aim. To assess the prevalence of central sensitization in patients with psoriatic arthritis, to compare the parameters of patients with and without central sensitization. Materials and methods. We examined 107 patients with psoriatic arthritis: number of tender and swollen joints, severity of pain, patient global assessment, and C-reactive protein were determined. Activity of disease was assessed with Disease activity in psoriatic arthritis, Ankylosing Spondylitis Disease Activity Score. Central sensitization was determined with Central Sensitization Inventory, presence of anxiety and depression - with Hospital Anxiety and Depression Scale. Descriptors of neuropathic pain were determined with Pain Detect Questionnaire. Statistical processing was carried out with Statistics 26.0. Differences were considered significant at p-value &lt; 0.05. Results and discussion. Central sensitization was found in 46 (43%) patients – they had patient global assessment (p=0.004) and severity of pain (p=0.002) in higher values. The C-reactive protein (p=0.423), Disease activity in psoriatic arthritis (p=0.083) did not differ between groups, but the Ankylosing Spondylitis Disease Activity Score (p=0.002) was higher in patients with central sensitization. High prevalence of anxiety (25.2%) and depression (40.2%) was found; more often in patients with central sensitization (p=0.001 and p=0.004). Most of patients described the tactile allodynia, «electric shocks», and burning. Conclusion. Significant contribution of central sensitization to the persistence of pain in patients with psoriatic arthritis was found. The frequency of clinically significant anxiety and depression in patients with psoriatic arthritis was shown, as well as their higher prevalence among patients with central sensitization. Patients with psoriatic arthritis often described pain like neuropathic pain, which can indicate both local damage to the nervous system and the formation of pain sensitization without direct damage to peripheral nerve structures.

Application of a Clinical Approach to Diagnosing Primary Pain: Prevalence and Correlates of Primary Back and Neck Pain in a Community Physiatry Clinic

Chronic back or neck pain (CBNP) can be primary (nociplastic or neuroplastic; without clear peripheral etiology) or secondary (to nociceptive or neuropathic causes). Expanding on available models of nociplastic pain, we developed a clinic-ready approach to diagnose primary/nociplastic pain: first, a standard physical exam and review of imaging to rule out secondary pain; and second, a detailed history of symptom presentation to rule in primary pain. We trained a physician who evaluated 222 patients (73.9% female, age M = 59.6) with CBNP; patients separately completed pain and psychosocial questionnaires. We estimated the prevalence of primary CBNP and explored biomedical, imaging, and psychological correlates of primary CBNP. Although almost all patients (97.7%) had at least 1 spinal anomaly on imaging, the diagnostic approach estimated that 88.3% of patients had primary pain, 5.0% had secondary pain, and 6.8% had mixed pain. Patients with primary pain were more likely than the other 2 groups of patients (combined as “non-primary pain”) to report certain functional conditions, central sensitization, and features such as sensitivity to light touch, spreading pain, and pain worsening with stress; however, no difference was detected in depression, anxiety, and pain catastrophizing between those with primary and nonprimary pain. These findings are consistent with prior estimates that 85 to 90% of CBNP is “nonspecific.” Further research is needed to validate and perhaps refine this diagnostic approach, which holds the potential for better outcomes if patients are offered treatments targeted to primary pain, such as pain neuroscience education and several emerging psychological therapies. PerspectiveWe developed an approach to diagnose chronic primary pain, which was applied in a physiatry clinic to 222 patients with CBNP. Most patients (88.3%) had primary pain, despite almost universal anomalies on spinal imaging. This diagnostic approach can guide educational and psychological treatments tailored for primary pain.