Nociceptive, neuropathic, or nociplastic low back pain? The low back pain phenotyping (BACPAP) consortium's international and multidisciplinary consensus recommendations

The potential to classify low back pain as being characterised by dominant nociceptive, neuropathic, or nociplastic mechanisms is a clinically relevant issue. Preliminary evidence suggests that these low back pain phenotypes might respond differently to treatments; however, more research must be done before making specific recommendations. Accordingly, the low back pain phenotyping (BACPAP) consortium was established as a group of 36 clinicians and researchers from 13 countries (five continents) and 29 institutions, to apply a modified Nominal Group Technique methodology to develop international and multidisciplinary consensus recommendations to provide guidance for identifying the dominant pain phenotype in patients with low back pain, and potentially adapt pain management strategies. The BACPAP consortium's recommendations are also intended to provide direction for future clinical research by building on the established clinical criteria for neuropathic and nociplastic pain. The BACPAP consortium's consensus recommendations are a necessary early step in the process to determine if personalised pain medicine based on pain phenotypes is feasible for low back pain management. Therefore, these recommendations are not ready to be implemented in clinical practice until additional evidence is generated that is specific to these low back pain phenotypes.

Cross-cultural adaptation and validation of Injustice Experience Questionnaire in Greek

PURPOSE

The Injustice Experience Questionnaire (IEQ) gauges the extent to which individuals with chronic pain perceive feelings of injustice concerning their pain. The study's objective was to assess the feasibility, absolute and relative reliability, as well as the convergent and construct validity of the Greek version of the IEQ.

METHODS

A cross-cultural adaptation of the IEQ in Greek was carried out according to the published guidelines. Ninety patients with chronic pain and 44 healthy participants completed the IEQ-GR, the Pain Catastrophizing Scale (PCS), and the Hospital Anxiety and Depression Scale (HADS). A subset of 36 volunteers completed the IEQ-GR twice over 1 week.

RESULTS

The ICC was calculated at 0.98 for IEQ-total and 0.83-0.96 for all items. The Cronbach's a was estimated at 0.98 for IEQ-total and 0.91-0.98 for all items. The SEM ranged from 0.20 to 1.63 and the SDC was 0.36-2.62 for all items. Positive and significant correlations between IEQ-GR and PCS (r = 0.59, p < 0.01), HADS (r = 0.58, p < 0.01), HADS depression (r = 0.50, p < 0.01), and HADS anxiety (r = 0.55, p < 0.01), were found. There was a statistically significant difference in IEQ between the patient and control groups.

CONCLUSIONS

The IEQ-GR demonstrated excellent reliability, internal consistency, convergent and discriminant validity in a Greek population.

Virtual Reality-Based Exercise Therapy for Patients with Chronic Musculoskeletal Pain: A Scoping Review

This scoping review aimed to identify interventions utilizing virtual-reality-based exercise therapy in patients with chronic musculoskeletal pain. Searches were conducted in four databases using descriptors related to virtual reality, exercise, and chronic musculoskeletal pain. Two reviewers screened the titles and abstracts of the studies to assess eligibility, with a third author resolving any discrepancies. Data were extracted and summarized in a narrative format by three independent raters. Clinical trials were evaluated using the PEDro scale to assess the effectiveness of virtual-reality-based exercise therapy in chronic musculoskeletal pain patients. A total of 162 articles were identified from the databases. After applying the inclusion criteria, nine articles were considered suitable for analysis, including six randomized clinical trials. The selected articles were categorized based on study characteristics, virtual-reality-based exercise therapy interventions (including technologies and equipment used), exercise interventions, outcome measures, and effectiveness. The findings indicate that virtual-reality-based exercise therapy shows promising results in reducing pain, improving disability, enhancing range of motion, and increasing treatment satisfaction in patients with chronic musculoskeletal pain. However, it is not possible to conclude that virtual-reality-based exercise therapy is superior to other treatments due to the limited number of available studies, heterogeneity in application protocols, and varying methodological quality. Further research is needed to draw more definitive conclusions.

Psychometric properties of quantitative sensory testing in healthy and patients with shoulder pain: A systematic review

Quantitative Sensory Testing (QST) is a psychophysical battery of various tests developed to quantify the subjects' self-reported sensory experience. Although the use of QST is valuable for the clinical assessment of pain, standard evaluation protocols have not yet been established. This systematic review aimed to investigate the level of evidence for the psychometric properties of QST in healthy and patients with shoulder pain. Eight databases were searched for peer-reviewed studies published until August 2021. The methodological quality of studies was evaluated using the COSMIN checklist. Twelve studies were included for qualitative synthesis, which included three different tests (Pressure Pain Threshold (PPT), Conditioned Pain Modulation (CPM) and Temporal Summation (TS)). As the body of evidence consisted of studies of low methodological quality, the psychometric properties of PPT, CPM, and TS in healthy and patients with shoulder pain were classified as unknown. Although there is a risk that the conclusions may be 'superficial' in nature, the reliability seems to be nearly excellent for the PPT, however, the protocols' variation and the low methodological quality of the studies do not allow for clear conclusions. Further studies are required for the CPM and TS in patients with shoulder pain.

Towards precision pain medicine for pain after cancer: the Cancer Pain Phenotyping Network multidisciplinary international guidelines for pain phenotyping using nociplastic pain criteria

Pain after cancer remains underestimated and undertreated. Precision medicine is a recent concept that refers to the ability to classify patients into subgroups that differ in their susceptibility to, biology, or prognosis of a particular disease, or in their response to a specific treatment, and thus to tailor treatment to the individual patient characteristics. Applying this to pain after cancer, the ability to classify post-cancer pain into the three major pain phenotypes (i.e. nociceptive, neuropathic, and nociplastic pain) and tailor pain treatment accordingly, is an emerging issue. This is especially relevant because available evidence suggests that nociplastic pain is present in an important subgroup of those patients experiencing post-cancer pain. The 2021 International Association for the Study of Pain (IASP) clinical criteria and grading system for nociplastic pain account for the need to identify and correctly classify patients according to the pain phenotype early in their treatment. These criteria are an important step towards precision pain medicine with great potential for the field of clinical oncology. Within this framework, the Cancer Pain Phenotyping (CANPPHE) Network, an international and interdisciplinary group of oncology clinicians and researchers from seven countries, applied the 2021 IASP clinical criteria for nociplastic pain to the growing population of those experiencing post-cancer pain. A manual is provided to allow clinicians to differentiate between predominant nociceptive, neuropathic, or nociplastic pain after cancer. A seven-step diagnostic approach is presented and illustrated using cases to enhance understanding and encourage effective implementation of this approach in clinical practice.

Nociplastic Pain Criteria or Recognition of Central Sensitization? Pain Phenotyping in the Past, Present and Future

Recently, the International Association for the Study of Pain (IASP) released clinical criteria and a grading system for nociplastic pain affecting the musculoskeletal system. These criteria replaced the 2014 clinical criteria for predominant central sensitization (CS) pain and accounted for clinicians' need to identify (early) and correctly classify patients having chronic pain according to the pain phenotype. Still, clinicians and researchers can become confused by the multitude of terms and the variety of clinical criteria available. Therefore, this paper aims at (1) providing an overview of what preceded the IASP criteria for nociplastic pain ('the past'); (2) explaining the new IASP criteria for nociplastic pain in comparison with the 2014 clinical criteria for predominant CS pain ('the present'); and (3) highlighting key areas for future implementation and research work in this area ('the future'). It is explained that the 2021 IASP clinical criteria for nociplastic pain are in line with the 2014 clinical criteria for predominant CS pain but are more robust, comprehensive, better developed and hold more potential. Therefore, the 2021 IASP clinical criteria for nociplastic pain are important steps towards precision pain medicine, yet studies examining the clinimetric and psychometric properties of the criteria are urgently needed.

Cross-cultural Adaptation and Psychometric Properties of the Greek Version of the Central Sensitization Inventory

OBJECTIVES

Recent studies support the opinion that central sensitization (CS) plays an important role in the pathophysiology of many chronic pain conditions. CS refers to hyperexcitability of the central nervous system, which can result in pain hypersensitivity and other somatosensory symptoms. Recognition of CS-related symptomology is crucial in chronic pain evaluation and rehabilitation. The Central Sensitization Inventory (CSI) was created to evaluate symptoms that have been found to be associated with CS. The aim of the current study was the cross-cultural adaptation of the CSI into Greek (CSI-Gr).

METHODS

To evaluate discriminate validity, 200 patients with chronic pain and 50 healthy control subjects participated. The sample was divided into 4 diagnostic groups (fibromyalgia, single pain complaints, multiple pain complaints, and a control group) and into 5 CSI severity subgroups, from subclinical to extreme. Convergent validity was determined by evaluation of the relationship between the CSI-Gr and the Pain Catastrophizing Scale (PCS). Additionally, 30 patients completed the CSI a second time for the purpose of a test/retest analysis.

RESULTS

The results showed high internal consistency (Cronbach's alpha = 0.994) and test-retest reliability (intraclass correlation coefficient = 0.993). The standard error of measurement was 2.1. The CSI-Gr correlated moderately with the PCS (r = 0.68). Statistically significant differences were found among the 3 comparison groups, with patients who had fibromyalgia reporting the highest CSI severity and healthy control subjects reporting the lowest severity.

CONCLUSIONS

As determined in the present study, the CSI-Gr was found to be a reliable and valid tool for recognition of CS-related symptomology.