Psychometric Evaluation of the Pain Anxiety Symptoms Scale (PASS) in Chronic Pain Patients

Gray Matter Adaptations to Chronic Pain in People with Whiplash-Associated Disorders are Partially Reversed After Treatment: A Voxel-based Morphometry Study

Gray matter (GM) changes are often observed in people with chronic spinal pain, including those with chronic whiplash-associated disorders (CWAD). These GM adaptations may be reversed with treatment, at least partially. Pain neuroscience education combined with exercise (PNE+Exercise) is an effective treatment, but its neural underlying mechanisms still remain unexplored in CWAD. Here, we performed both cross-sectional and longitudinal voxel-based morphometry to 1) identify potential GM alterations in people with CWAD (n = 63) compared to age- and sex-matched pain-free controls (n = 32), and 2) determine whether these GM alterations might be reversed following PNE+Exercise (compared to conventional physiotherapy). The cross-sectional whole-brain analysis revealed that individuals with CWAD had less GM volume in the right and left dorsolateral prefrontal cortex and left inferior temporal gyrus which was, in turn, associated with higher pain vigilance. Fifty individuals with CWAD and 29 pain-free controls were retained in the longitudinal analysis. GM in the right dorsolateral prefrontal cortex increased after treatment in people with CWAD. Moreover, the longitudinal whole-brain analysis revealed that individuals with CWAD had decreases in GM volumes of the left and right central operculum and supramarginal after treatment. These changes were not specific to treatment modality and some were not observed in pain-free controls over time. Herewith, we provide the first evidence on how GM adaptations to CWAD respond to treatment. PERSPECTIVE: This article presents which gray matter adaptations are present in people with chronic pain after whiplash injuries. Then, we examine the treatment effect on these alterations as well as whether other neuroplastic effects on GM following treatment occur.

Sustainability of cognitive behavioural interventions for chronic back pain: A long-term follow-up

BACKGROUND

There is a significant research gap with respect to the long-term sustainability of psychological treatment effects in chronic pain patients. This study aimed to investigate long-term treatment effects of two psychological treatments: cognitive behavioural therapy (CBT) as a broad-spectrum approach and exposure as a specific intervention for fear-avoidant pain patients.

METHODS

Patients with chronic low back pain were randomized to CBT or exposure in vivo. Long-term follow-up (LTFU) data were available for 64 patients up to 8 years after treatment, with a response rate of 73%. The primary outcomes were pain-related disability and pain intensity and secondary outcomes were emotional distress, psychological flexibility, catastrophizing and pain-related fear. The data analysis was performed with longitudinal multilevel modelling.

RESULTS

Multilevel analyses showed improvements in all primary outcomes as well as all secondary outcomes from pre-treatment to LTFU for both treatments. The mean proportion of cases meeting reliable and clinical improved criteria in all primary outcome was 36% (range: 22%-46%) in the exposure group and 50% (range: 33%-60%) in the CBT group. Dropout analyses revealed significantly higher deterioration rates over time. Pre-treatment to LTFU effect sizes of the primary outcomes ranged from 0.54 to 1.59.

CONCLUSIONS

Our results indicate that the effects of psychological treatments might be stable over several years. Treatment gains for exposure as a stand-alone treatment seem to be of shorter duration than a general CBT intervention. Thus, psychological treatments might offer a promising and sustainable long-term perspective for patients with chronic back pain.

SIGNIFICANCE

The long-term stability of treatment effects is a highly neglected issue despite its inherent importance in the context of chronic pain. This study is the first to investigate treatment effects of cognitive behavioural therapy and in vivo exposure in chronic back pain sufferers up to 8 years after treatment. The findings contribute to an understanding of the sustainability of psychological cognitive behavioural therapy-based intervention effects.

The Pain Anxiety Symptom Scale: Initial Development and Evaluation of 4 and 8 Item Short Forms

Elevated levels of anxiety in relation to chronic pain have been consistently associated with greater distress and disability. Thus, accurate measurement of pain-related anxiety is an important requirement in modern pain services. The Pain Anxiety Symptom Scale (PASS) was introduced over 30 years ago, with a shortened 20-item version introduced 10 years later. Both versions of the PASS were derived using Principal Components Analysis, an established method of measure development with roots in classical test theory. Item Response Theory (IRT) is a complementary approach to measure development that can reduce the number of items needed and maximize item utility with minimal loss of statistical and clinical information. The present study used IRT to shorten the 20-item PASS (PASS-20) in a large sample of people with chronic pain (N = 2,669). Two shortened versions were evaluated, 1 composed of the single best-performing item from each of its 4 subscales (PASS-4) and the other with the 2 best-performing items from each subscale (PASS-8). Several supplementary analyses were performed, including comparative item convergence evaluations based on sample characteristics (ie, female or male sex; clinical or online sample), factor invariance testing, and criterion validity evaluation of the 4, 8, and 20-item versions of the PASS in hierarchical regression models predicting pain-related distress and interference. Overall, both shortened PASS versions performed adequately across these supplemental tests, although the PASS-4 had more consistent item convergence between samples, stronger evidence for factor invariance, and accounted for 83% of the variance accounted for by the PASS-20% and 92% of the variance accounted for by the PASS-8 in criterion variables. Consequently, the PASS-4 is recommended for use in situations where a briefer evaluation of pain-related anxiety is appropriate. PERSPECTIVE: The Pain Anxiety Symptom Scale (PASS) is an established measure of pain-related fear. This study derived 4 and 8-item versions of the PASS using IRT. Both versions showed strong psychometric properties, stability of factor structure, and relation to important aspects of pain-related functioning.

Neural processing of pain-related distress to neck-specific movements in people with chronic whiplash-associated disorders

ABSTRACT

Pain-related distress contributes to long-term disability in chronic whiplash-associated disorders. Recently, neuroimaging studies have revealed altered neural responses to viewing pictures of movements associated with back pain in key regions for threat and affective processing. In this study, we examined neural correlates of imagining neck-specific movements designed to elicit pain-related distress in individuals with whiplash-associated disorders (n = 63) when compared with that in sex-matched pain-free controls (n = 32). In the scanner, participants were presented with neck-specific movement-related pictures divided into 3 categories (high fear, moderate-fear, and neutral control pictures) and asked to imagine how they would feel if they were performing the movement. Whole-brain analyses revealed greater differential activation (high-fear vs neutral) in individuals with whiplash-associated disorders when compared with that in pain-free controls in 6 clusters including right and left postcentral gyri, left parietal operculum, dorsal precuneus, left superior frontal gyrus/anterior cingulate cortex, and posterior cingulate cortex/ventral precuneus. For the contrast moderate-fear vs neutral, patients showed greater differential activation than controls in the right and left posterolateral cerebellum. Activation patterns in the precuneus and posterior cingulate cortex were negatively associated with pain-related fear, but no other correlations were observed. Together, the findings suggest that when conceptualizing neck-specific movements associated with pain, people with chronic whiplash-associated disorders may predict-and potentially amplify-their sensory and affective consequences and therewith trigger dysfunctional affective and/or behavioral responses. Herewith, we provide new insights into the neural mechanisms underlying chronic pain in people with whiplash-associated disorders, pointing towards a complex interplay between cognitive/affective and sensorimotor circuitry.

Pain-Related Anxiety in Spanish-Speaking Mexican Americans Who Report Chronic Pain: Psychometric Evaluation of a New Spanish Adaptation of the 20-Item Pain Anxiety Symptom Scale (PASS-20)

The 20-item Pain Anxiety Symptom Scale (PASS-20) was adapted for Spanish-speaking Mexican Americans who report chronic pain (SSMACP). The instrument measures pain-related anxiety with fear, physiological, avoidance/escape, and cognitive anxiety as subtypes. In SSMACP, the Spanish PASS-20's psychometric properties were evaluated while exploring relationships between pain-related anxiety with other variables. Using convenience sampling, 188 SSMACP (women = 108, men = 77; mean age = 37.20 years, standard deviation = 9.87) were recruited across the United States. Confirmatory factor analyses examined the structural validity of the hierarchical factor structure. Hierarchical multiple regression examined incremental validity. Correlational analyses examined convergent validity. Cronbach's coefficient alphas and McDonald's omegas examined internal consistency. Pearson's r, t-tests, and analysis of variance tests examined relationships between demographic variables and PASS-20 scores. Confirmatory factor analyses supported the hierarchical factor structure (root mean square error of approximation = .061, standardized root mean residual = .038, comparative fit index = .940). Total and subscale PASS-20 scores had acceptable convergent validity and internal consistency (range = .75-.93). Hierarchical multiple regression found that total and subscale PASS-20 scores have adequate incremental validity, considering that they contributed uniquely to the prediction of generalized anxiety scores above and beyond other pain-related scores. Demographic variables were significantly related to total and subscale PASS-20 scores. Evidence supports the use of Spanish total and subscale PASS-20 scores in SSMACP. Exploratory evidence also informed on the possible consequences and predictors of their pain-related anxiety. The results also encourage pain research in specific populations from Latin America (eg, Mexican Americans). PERSPECTIVE: The Spanish PASS-20 has adequate psychometric properties in SSMACP. This instrument can help catalyze pain research in SSMACP by informing on their pain-related anxiety and by helping evaluate other pain-related instruments. Evidence also informed on pain-related anxiety in SSMACP.

Psychometric properties of the Persian version of the pain anxiety symptom scale (PASS-20) in chronic non-specific neck pain patients

OBJECTIVES

Pain-related anxiety has been linked to avoidance behaviour, maintenance of pain and disability. A valid and reliable tool is required to evaluate pain-related anxiety among Persian speaking adults with chronic non-specific neck pain (CNSNP). This study aimed to evaluate psychometric properties of the Persian pain anxiety symptom scale-20 (PASS-20) according to the consensus-based standards for the selection of health measurement instruments (COSMIN) checklist in Iranian adults with CNSNP.

METHODS

198 individuals with CNSNP completed the PASS-20. The factorial structure (confirmatory factor analysis (CFA), exploratory factor analysis (EFA)), test-retest reliability (intraclass correlation coefficient (ICC), standard error of measurement (SEM) and minimal detectable change (MDC)), internal consistency (Cronbach's alpha), and construct validity (convergent and known-group validity) were assessed. The correlation between PASS-20 with pain catastrophizing scale (PCS), Tampa Scale for Kinesiophobia (TSK), neck disability index (NDI), Beck Depression Inventory (BDI), visual analog scale (VAS) (Spearman's rank correlation) were examined. Known-group validity of PASS-20 was evaluated by comparing the difference between the PASS-20 scores of the known groups based on level of disability, pain intensity and gender using non-parametric tests.

RESULTS

The CFA showed almost the best fit with the original version. The subscales and total score demonstrated good internal consistency (Cronbach's α: 0.70-0.92) and high test-retest reliability (ICC: 0.94-0.97). PASS-20 had significant moderate correlations with PCS, TSK, NDI, VAS and a significant low correlation with BDI. Regarding known-group validity, the total score of Persian PASS-20 was higher in CNSNP with higher levels of pain and disability and in the female gender.

CONCLUSIONS

The Persian PASS-20 has acceptable psychometric properties in adults with CNSNP. The results of the factor analysis supported the four-factor structure comparable to the original version.

ETHICAL COMMITTEE NUMBER

921672004.

A Randomized, Sham-Controlled Trial of Repetitive Transcranial Magnetic Stimulation Targeting M1 and S2 in Central Poststroke Pain: A Pilot Trial

OBJECTIVES

Central poststroke pain (CPSP), a neuropathic pain condition, is difficult to treat. Repetitive transcranial magnetic stimulation (rTMS) targeted to the primary motor cortex (M1) can alleviate the condition, but not all patients respond. We aimed to assess a promising alternative rTMS target, the secondary somatosensory cortex (S2), for CPSP treatment.

MATERIALS AND METHODS

This prospective, randomized, double-blind, sham-controlled three-arm crossover trial assessed navigated rTMS (nrTMS) targeted to M1 and S2 (10 sessions, 5050 pulses per session at 10 Hz). Participants were evaluated for pain, depression, anxiety, health-related quality of life, upper limb function, and three plasticity-related gene polymorphisms including Dopamine D2 Receptor (DRD2). We monitored pain intensity and interference before and during stimulations and at one month. A conditioned pain modulation test was performed using the cold pressor test. This assessed the efficacy of the descending inhibitory system, which may transmit TMS effects in pain control.

RESULTS

We prescreened 73 patients, screened 29, and included 21, of whom 17 completed the trial. NrTMS targeted to S2 resulted in long-term (from baseline to one-month follow-up) pain intensity reduction of ≥30% in 18% (3/17) of participants. All stimulations showed a short-term effect on pain (17-20% pain relief), with no difference between M1, S2, or sham stimulations, indicating a strong placebo effect. Only nrTMS targeted to S2 resulted in a significant long-term pain intensity reduction (15% pain relief). The cold pressor test reduced CPSP pain intensity significantly (p = 0.001), indicating functioning descending inhibitory controls. The homozygous DRD2 T/T genotype is associated with the M1 stimulation response.

CONCLUSIONS

S2 is a promising nrTMS target in the treatment of CPSP. The DRD2 T/T genotype might be a biomarker for M1 nrTMS response, but this needs confirmation from a larger study.

An Exploration of the Psychometric Properties of the PASS-20 in Older Adults with Chronic Pain: Preliminary Development and Validity

OBJECTIVES

The Pain Anxiety Symptoms Scale (PASS-20) is well validated in adults and younger populations, but not in older adults. This study aimed to analyze the psychometric properties of the PASS-20 in Spanish older adults who experience chronic pain.

METHODS

Participants were 111 older adults with chronic pain living in nursing homes (mean age = 83.36; SD = 6.53; 78.6% female). Face-to-face interviews were conducted which included assessment of pain anxiety (PASS-20), chronic pain acceptance (CPAQ), depression symptoms (GDS), catastrophizing beliefs (PCS), pain severity, and sociodemographic information. An Exploratory Structural Equation Modeling (ESEM) approach was used to refine the scale.

RESULTS

The final scale was composed of seven items, measuring two factors that could be labeled "Internal experiences" and "Escape/Avoidance behaviors". The two factors explained 60.98% of the total variance. PASS-7 version fit properly: χ²/df = 14.57/13, CMIN/df = 1.121, CFI = 0.99, RMSEA = 0.033, TLI = 0.98, GFI = 0.96, AGFI = 0.92. Good validity indices were found and acceptable reliability results in the scale and its subscales (Chronbach´s α; Internal Experiences = 0.70; Escape/Avoidance Behaviors= 0.73; Total Scale = 0.77).

CONCLUSIONS

The short version of the PASS-7 has good psychometric properties.

CLINICAL IMPLICATIONS

The brevity of the PASS-7 increases the feasibility of this instrument which could potentially be utilized in a variety of clinical settings and research studies with older people with chronic pain samples, specially institutionalized older adults.

Moderators of the Relationship Between Pain and Pain-Related Sexual Disability in Women with Provoked Vestibulodynia Symptoms

BACKGROUND

Previous studies have demonstrated the deleterious effects of pain anxiety (ie, the degree to which one fears pain), stress, and solicitous partner responses (ie, expressions of sympathy and attention to one's partner's pain) on pain and pain-related disability, but little is known about whether these variables moderate the robust pain-pain-related disability relationship in individuals with provoked vestibulodynia (PVD).

AIM

We investigated whether pain anxiety, stress, and solicitous partner responses moderated the relationship between penetrative pain and pain-related sexual disability in women with PVD symptoms.

METHODS

Participants with PVD symptoms (N = 65, age range = 18-73 years) completed an online survey assessing pain anxiety (Pain Anxiety Symptoms Scale-20), perceived stress (Perceived Stress Scale), solicitous partner responses (WHYMPI Solicitous Responses Scale), penetrative pain (Female Sexual Function Index), and pain-related sexual disability (Pain Disability Index). Moderated regression analyses were performed using pain anxiety, stress, and solicitous partner responses as moderators of the relationship between penetrative pain, and pain-related sexual disability.

OUTCOMES

Outcomes in the current study included the moderating effect of pain anxiety, perceived stress, and solicitous partner responses on the relationship between penetrative genital pain and pain-related disability in sexual behavior.

RESULTS

Higher genital pain from penetrative intercourse and higher pain anxiety significantly predicted higher pain-related sexual disability, but perceived stress was not significantly related to sexual disability. Solicitous partner responses were significantly positively correlated with pain-related sexual disability. None of the moderators significantly moderated the pain-pain-related sexual disability relationship.

CLINICAL IMPLICATIONS

For women with PVD, pain anxiety and solicitous partner responses to their pain may exacerbate their pain-related sexual disability, signifying that pain anxiety and solicitous partner responses represent important targets of therapeutic intervention for women with PVD.

STRENGTHS AND LIMITATIONS

The present study extended past research on the relationships between psychological and behavioral factors and pain in women with PVD symptoms by demonstrating the deleterious relationship between pain anxiety, solicitous responses, and pain-related sexual disability. However, the study was correlational in nature, which precludes conclusions about the effect of pain anxiety, and solicitous partner responses on pain-related sexual disability.

CONCLUSION

High pain anxiety and frequent solicitous partner responses to an individual's pain predicted higher pain-related sexual disability, suggesting that it may be possible to improve the quality of life of PVD sufferers through interventions that aim to decrease pain anxiety, and solicitous partner responses, in addition to interventions that aim to decrease pain per se. Maunder L, Dargie E, Pukall C. Moderators of the Relationship Between Pain and Pain-Related Sexual Disability in Women with Provoked Vestibulodynia Symptoms. J Sex Med 2022;19:809-822.

Generalization of fear of movement-related pain and avoidance behavior as predictors of work resumption after back surgery: a study protocol for a prospective study (WABS)

Background

Previous studies indicated that about 20% of the individuals undergoing back surgery are unable to return to work 3 months to 1 year after surgery. The specific factors that predict individual trajectories in postoperative pain, recovery, and work resumption are largely unknown. The aim of this study is to identify modifiable predictors of work resumption after back surgery.

Methods

In this multisite, prospective, longitudinal study, 300 individuals with radicular pain undergoing a lumbar decompression will be followed until 1-year post-surgery. Prior to surgery, participants will perform a computer task to assess fear of movement-related pain, avoidance behavior, and their generalization to novel situations. Before and immediately after surgery, participants will additionally complete questionnaires to assess fear of movement-related pain, avoidance behavior, optimism, expectancies towards recovery and work resumption, and the duration and severity of the pain. Six weeks, 3 months, 6 months, and 12 months after surgery, they will again complete questionnaires to assess sustainable work resumption, pain severity, disability, and quality of life. The primary hypothesis is that (generalization of) fear of movement-related pain and avoidance behavior will negatively affect sustainable work resumption after back surgery. Second, we hypothesize that (generalization of) fear of movement-related pain and avoidance behavior, negative expectancies towards recovery and work resumption, longer pain duration, and more severe pain before the surgery will negatively affect work resumption, pain severity, disability, and quality of life after back surgery. In contrast, optimism and positive expectancies towards recovery and work resumption are expected to predict more favorable work resumption, better quality of life, and lower levels of pain severity and disability after back surgery.

Discussion

With the results of this research, we hope to contribute to the development of strategies for early identification of risk factors and appropriate guidance and interventions before and after back surgery.

Trial registration The study was preregistered on ClinicalTrials.gov: NCT04747860 on February 9, 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40359-022-00736-5.

Pain-Related Anxiety among Adults with Obesity and Chronic Pain: Relations with Pain, Opioid Misuse, and Mental Health

Obesity affect a significant proportion of the population in the United States, and is associated with numerous health consequences including anxiety, depression, and chronic pain. Additionally, pain among adults with obesity has been associated with greater mental health problems and substance use problems. Yet little work has examined psychological vulnerability factors associated with these relations, and pain-related anxiety may be one candidate psychological correlate of these relations. Therefore, the current study examined the association of pain-related anxiety with pain intensity, disability, opioid misuse, anxiety, and depression among 164 adults (81.7% female, M_age = 40.13 years, SD = 10.85) with obesity (M_BMI= 37.21, SD = 6.70) and chronic pain. Results suggested that pain-related anxiety was significantly associated with all outcomes, and these results suggest that pain-related anxiety may play an important role in physical health, mental health, and substance use outcomes among adults with obesity and chronic pain.

Are Reports of Pain, Disability, Quality of Life, Psychological Factors, and Central Sensitization Related to Outcomes of Quantitative Sensory Testing in Patients Suffering From Chronic Whiplash Associated Disorders?

BACKGROUND

Chronic whiplash associated disorders (CWAD) are characterized by long-lasting symptoms of neck pain occurring after an acceleration-deceleration injury. Central sensitization (CS) has been suggested as the possible underlying mechanism for these symptoms, and is characterized by changes in the central nervous system. Besides CS, psychological factors are believed to play an important role in the experience of (chronic) pain.

OBJECTIVE

Investigating the relationships between self-reported pain, disability, quality of life, psychological factors, and symptoms of CS; and electrical-based quantitative sensory testing (QST) outcomes in CWAD patients. Secondly, to investigate the differences in QST between CWAD patients and pain-free controls.

METHODS

Seventy-two individuals with CWAD and 55 pain-free controls underwent electrical stimuli-based QST. Detection and pain thresholds (EPT), temporal summation (TS), and conditioned pain modulation were examined. Spearman correlation and linear mixed models analyses were performed to assess, respectively, the hypothesized associations and group differences in QST.

RESULTS

The Pain Catastrophizing magnification subscale correlated with the left wrist EPT (r=-0.332; P=0.004), and the Pain Anxiety Symptom Scale-20 with the left wrist (r=-0.325; P=0.005) and ankle (r=-0.330; P=0.005) EPT. TS at the ankle correlated with the CS inventory (r=0.303; P=0.010), Short Form 36 pain subscale (r=-0.325; P=0.005), and Illness Perception Questionnaire revised consequences subscale (r=0.325; P=0.005). EPTs left (P=0.011) and right wrist (P=0.023) were lower in the CWAD group, but conditioned pain modulation and TS did not differ between groups.

CONCLUSION

QST outcomes relate to psychological constructs, rather than to self-reported pain intensity and distribution. Local hyperalgesia was found in individuals with CWAD, but no differences in endogenous pain facilitation nor inhibition.

Outcomes of a 6-week Cognitive-Behavioral Therapy for Chronic Pain Group for veterans seen in primary care

Primary Care Mental Health Integration (PC-MHI) visits are mandated to be brief, limited in number, and delivered in the primary care practice area. Current evidence-based protocols for Cognitive-Behavioral Therapy for Chronic Pain (CBT-CP) do not meet these PC-MHI requirements, however, and thus PC-MHI providers are often left with the daunting task of modifying these protocols for the primary care setting. The aims of the current study were to examine effectiveness for a brief CBT-CP Group (6, 50-min sessions) for patients seen in primary care with various chronic pain conditions and to assess whether opioid medication use was associated with treatment outcomes. The current study represents a single-arm treatment study in which outcomes were evaluated by comparing self-reported symptom levels at the beginning of treatment (Session 1) to the end of treatment (Session 6). Dependent variables included pain symptoms, physical function lower/upper body, family disability, emotional functioning, sleep problems, satisfactions with outcomes/care, pain-related anxiety, generalized anxiety, pain catastrophizing, and depressed mood. Seventy-seven participants were enrolled and completed the treatment group. They were 56.81 ± 13.11 years old, 61% male, 51.9% taking opioids, with 39% reporting multiple pain diagnoses. Results showed that participation in the Brief CBT-CP Group resulted in statistically significantly improvement across all dependent variables (except emotional functioning). Results also showed that there were no significant treatment-related differences between patients taking opioids compared with patients who were not on opioids. The current protocol for Brief CBT-CP is effective in a real-world setting and aligns with the PC-MHI model of care.

A contemporary neuroscience approach compared to biomedically focused education combined with symptom-contingent exercise therapy in people with chronic whiplash associated disorders: a randomized controlled trial protocol

BACKGROUND

To address the need for a better treatment of chronic whiplash associated disorders (WAD), a contemporary neuroscience approach can be proposed.

OBJECTIVE

To examine the effectiveness of a contemporary neuroscience approach, comprising pain neuroscience education, stress management, and cognition-targeted exercise therapy versus conventional physical therapy for reducing disability (primary outcome measure) and improving quality of life and reducing pain, central sensitization, and psychological problems (secondary outcome measures) in people with chronic WAD.

METHODS

The study is a multi-center, two-arm randomized, controlled trial with 1-year follow-up and will be performed in two university-based and one regional hospital. People with chronic WAD (n=120) will be recruited. The experimental group will receive pain neuroscience education followed by cognition-targeted exercise therapy, and stress management. The control group will receive biomedically focused education followed by graded and active exercise therapy focusing on muscle endurance, strength, and flexibility, and ergonomic principles. The treatment will have a duration of 16 weeks. Functional status (Neck Disability Index) is the primary outcome measure. Secondary outcome measures include quality of life, pain, central sensitization, and psychological and socio-economic factors. In addition, electroencephalography will measure brain activity at rest and during a conditioned pain modulation paradigm. Assessments will take place at baseline, immediately post-treatment and at 6 and 12 months follow-up.

CONCLUSIONS

This study will examine whether a contemporary neuroscience approach is superior over conventional physical therapy for improving functioning, quality of life, and reducing pain, central sensitization, and psychological problems in people with chronic WAD.

Pain Anxiety as a Mechanism Linking Pain Severity and Opioid Misuse and Disability Among Individuals With Chronic Pain

OBJECTIVE

Chronic pain affects a significant number of individuals in the United States and is associated with several negative health-related outcomes, including possibility of opioid misuse and disability. The identification of factors associated with both opioid misuse and disability is of critical public health importance, and significant research suggests that pain severity has been shown to be associated with both. Pain-related anxiety has been uniquely associated with both opioid misuse and disability, yet little research has examined pain-related anxiety as a potential mechanism linking pain severity with opioid misuse and disability.

METHOD

Therefore, the current study examined whether pain-related anxiety explains, in part, the relationship between pain severity, opioid misuse, and disability among 396 adults with chronic pain (55.8% female, Mage 36.61, SD 11.40).

RESULTS

Cross-sectional analyses indicated that pain-related anxiety significantly mediated the relationship between pain severity, opioid misuse outcomes, and psychosocial disability, but not physical disability.

CONCLUSIONS

These results build upon the literature indicating the importance of pain-related anxiety in those with chronic pain by suggesting this construct may account, in part, for the relation of pain intensity to opioid misuse and psychosocial disability. Future research should longitudinally examine these associations.

How Much Is Needed? Comparison of the Effectiveness of Different Pain Education Dosages in Patients with Fibromyalgia

OBJECTIVE

To assess the effect of different dosages of pain neuroscience education (PNE) programs on central nociceptive processing in patients with fibromyalgia. Second, to compare the effects of different dosages of PNE programs on numerical pain rating scale (NPRS), disability, and psychological variables.

DESIGN

Single-blind randomized controlled trial.

SETTING

Three fibromyalgia centers in Spain (Valencia, Alcorcón, Alcalá de Henares).

SUBJECTS

Seventy-seven patients with fibromyalgia.

METHODS

Participants were randomized to four groups of PNE: 1) high-dose PNE (N = 20), 2) low-concentrated dose PNE (N = 20), 3) diluted low-dose PNE (N = 20), and (4) control treatment (N = 17), conducted in two 30-50-minute sessions in groups of four to six participants. Conditioned pain modulation (CPM), temporal summation (TS), and pressure pain thresholds (PPTs) were assessed at baseline and at three-month follow-up. Secondary outcome measures were the Fibromyalgia Impact Questionnaire, Pain Catastrophizing Scale, and Pain Anxiety Symptoms Scale.

RESULTS

There were significant between-group differences for NPRS in favor of the groups receiving high-dose PNE, with a large effect size at three-month follow-up (P < 0.01, η2p = 0.170), but there were no significant differences between groups for the remaining variables (P > 0.05). All groups improved for central nociceptive processing, psychological variables, disability, and pain intensity (NPRS).

CONCLUSIONS

In patients with fibromyalgia, higher dosages of PNE produced a larger improvement in pain severity at three-month follow-up than other dosages of PNE and biomedical education. However, PNE was not superior to biomedical education in the central nociceptive processing, disability, or psychological variables in patients with fibromyalgia.

Machine learning suggests sleep as a core factor in chronic pain

Patients with chronic pain have complex pain profiles and associated problems. Subgroup analysis can help identify key problems. We used a data-based approach to define pain phenotypes and their most relevant associated problems in 320 patients undergoing tertiary pain management. Unsupervised machine learning analysis of parameters "pain intensity," "number of pain areas," "pain duration," "activity pain interference," and "affective pain interference," implemented as emergent self-organizing maps, identified 3 patient phenotype clusters. Supervised analyses, implemented as different types of decision rules, identified "affective pain interference" and the "number of pain areas" as most relevant for cluster assignment. These appeared 698 and 637 times, respectively, in 1000 cross-validation runs among the most relevant characteristics in an item categorization approach in a computed ABC analysis. Cluster assignment was achieved with a median balanced accuracy of 79.9%, a sensitivity of 74.1%, and a specificity of 87.7%. In addition, among 59 demographic, pain etiology, comorbidity, lifestyle, psychological, and treatment-related variables, sleep problems appeared 638 and 439 times among the most important characteristics in 1000 cross-validation runs where patients were assigned to the 2 extreme pain phenotype clusters. Also important were the parameters "fear of pain," "self-rated poor health," and "systolic blood pressure." Decision trees trained with this information assigned patients to the extreme pain phenotype with an accuracy of 67%. Machine learning suggested sleep problems as key factors in the most difficult pain presentations, therefore deserving priority in the treatment of chronic pain.

Progressive vasoconstriction with sequential thermal stimulation indicates vascular dysautonomia in sickle cell disease

Persons with sickle cell disease (SCD) exhibit subjective hypersensitivity to cold and heat perception in experimental settings, and triggers such as cold exposure are known to precipitate vaso-occlusive crises by still unclear mechanisms. Decreased microvascular blood flow (MBF) increases the likelihood of vaso-occlusion by increasing entrapment of sickled red blood cells in the microvasculature. Because those with SCD have dysautonomia, we anticipated that thermal exposure would induce autonomic hypersensitivity of their microvasculature with an increased propensity toward vasoconstriction. We exposed 17 patients with SCD and 16 control participants to a sequence of predetermined threshold temperatures for cold and heat detection and cold and heat pain via a thermode placed on the right hand. MBF was measured on the contralateral hand by photoplethysmography, and cardiac autonomic balance was assessed by determining heart rate variability. Thermal stimuli at both detection and pain thresholds caused a significant decrease in MBF in the contralateral hand within seconds of stimulus application, with patients with SCD showing significantly stronger vasoconstriction (P = .019). Furthermore, patients with SCD showed a greater progressive decrease in blood flow than did the controls, with poor recovery between episodes of thermal stimulation (P = .042). They had faster vasoconstriction than the controls (P = .033), especially with cold detection stimulus. Individuals with higher anxiety also experienced more rapid vasoconstriction (P = .007). Augmented vasoconstriction responses and progressive decreases in perfusion with repeated thermal stimulation in SCD are indicative of autonomic hypersensitivity in the microvasculature. These effects are likely to increase red cell entrapment in response to clinical triggers such as cold or stress, which have been associated with vaso-occlusive crises in SCD.

Initial evaluation of the Chronic Pain Acceptance Questionnaire - 2

Greater acceptance of chronic pain is associated with lesser levels of pain-related distress and disability and better overall functioning. Pain acceptance is most often assessed using the Chronic Pain Acceptance Questionnaire (CPAQ), which includes both an eight-item short form (CPAQ-8) and a twenty item parent measure (CPAQ-20). This study derived a two-item CPAQ for use in busy clinical settings and for repeated measurement during treatment, the CPAQ-2. An Item Response Theory (IRT) approach was used to identify the strongest items from the CPAQ-20, one from each of its two subscales. Next, regression analyses were conducted to evaluate the utility of the CPAQ-2 by examining variance accounted for in the CPAQ-8, CPAQ-20, and in measures of depression, pain-related fear, physical disability, and psychosocial disability. Four clinical databases were combined (N = 1,776) for the analyses. Items 9 and 14 were identified as the strongest CPAQ-20 items in the IRT analyses. The sum score of these two items accounted for over 60% of the variance in the CPAQ-8 and CPAQ-20. Furthermore, this score accounted for significant variance in measures of depression, pain-related fear, physical disability, and psychosocial disability after controlling for data collection method (i.e. in clinic or online), participant age, education, pain duration and usual pain. Finally, the amount of variance accounted for by the CPAQ-2 was comparable to that accounted for by both the CPAQ-8 and CPAQ-20. These results provide initial support for the CPAQ-2 and suggest that it is well-suited as a brief assessment of chronic pain acceptance. SIGNIFICANCE: The most frequently used measure of pain acceptance is the CPAQ, which includes both an eight-item short form, the CPAQ-8, and a longer twenty item parent measure, the CPAQ-20. The present study sought to derive a two-item measure of the CPAQ for use in busy clinical settings and for repeated measurement during treatment, the CPAQ-2. An IRT approach was used to identify the strongest items from the CPAQ-20, one from each of its two subscales in a large sample of 1,776 individuals with chronic pain. The two item measure accounted for significant variance in measures of depression, pain-related fear, physical disability, and psychosocial disability. The brief measure will be useful in assessing pain acceptance in busy clinical setting and longitudinal designs.

Effects of Virtual Reality versus Exercise on Pain, Functional, Somatosensory and Psychosocial Outcomes in Patients with Non-specific Chronic Neck Pain: A Randomized Clinical Trial

Background: Virtual reality (VR) applied to patients with neck pain is a promising intervention to produce positive effects when used alone or combined with exercise. Therefore, the objective of this manuscript is to compare the effects of VR versus exercise treatment on pain intensity, conditioned pain modulation (CPM), temporal summation (TS) and functional and somatosensory outcomes in patients with non-specific chronic neck pain (NS-CNP). Methods: A single-blinded, randomized clinical trial was carried out. A total sample of 44 patients with NS-CNP was randomized into a VR treatment group or neck exercises group. The intervention consisted of two treatment sessions per week, for four weeks and eight sessions. Four measurement moments (at baseline, immediately, 1 month, and 3 months after intervention) were considered. Pain intensity, CPM, TS, functional and somatosensory outcomes were measured. Results: Statistically significant differences were revealed for time factor (F = 16.40, p < 0.01, η_p² = 0.28) and group*time interaction for kinesiophobia (F = 3.89, p = 0.01, η_p² = 0.08) showing post-hoc differences in favor of the VR group at 3 months (p < 0.05, d = 0.65). Significant effects were shown for time factor (p < 0.05) but not for the group*time interaction (p > 0.05) for pain intensity, rotation range of motion (ROM), Neck Disability Index, pain catastrophizing, fear-avoidance beliefs, left side pressure pain threshold (PPT) and anxiety. Statistically significant differences were not found for time factor (p > 0.05) and neither in group*time interaction (p > 0.05) for CPM, TS, right side PPT, flexo-extension and lateral-flexion ROM. Conclusions: Kinesiophobia was the only outcome that showed differences between VR and exercise at 3 months. Nevertheless, pain intensity, CPM, TS, ROM, neck disability, pain catastrophizing, fear-avoidance beliefs, PPT and anxiety did not show differences between both interventions.

Differences in adaptive and maladaptive psychosocial responses to chronic pain among adults with varying physical activity levels

Aim

Chronic pain is a global public health problem that detrimentally impacts people's health and well-being. Physical activity is beneficial and a recommended self-management strategy for adults living with chronic pain. Yet, many of them struggle to meet the public health recommendation of 150+ minutes/week of moderate-vigorous physical activity. Identifying modifiable factors related to physical activity participation is needed. Adaptive (i.e., self-regulatory efficacy to overcome pain and related barriers [SRE-pain], psychological flexibility) and maladaptive (i.e. pain anxiety) responses were the modifiable factors examined in the present study. The purpose was to investigate whether adults living with chronic pain who were sufficiently active, insufficiently active or inactive significantly differed in their adaptive and maladaptive responses to chronic pain.

Methods

Adults with self-reported chronic pain for 6+ months (N = 318) completed an online survey that measured physical activity, psychological flexibility, SRE-pain and pain anxiety. Sufficiently active (n = 139), insufficiently active (n = 91) and inactive (n = 88) groups were identified.

Results

A significant multivariate analysis of covariance (MANCOVA) (p < .001) with univariate follow-up tests illustrated that the sufficiently active individuals reported the highest psychological flexibility and SRE-pain compared to insufficiently active and inactive individuals (p's < .001). Overall, sufficiently active participants responded the most adaptively and least maladaptively to their pain, followed by the insufficiently active. Inactive participants responded the most maladaptively.

Conclusion

Identifying differences in adaptive and maladaptive responses to pain highlights possible modifiable factors to target in future physical activity intervention research that focuses on improving chronic pain self-management.

Exploring Pain-Related Anxiety and Depression in Female Patients With Provoked Vulvodynia With Associated Overactive Pelvic Floor Muscle Dysfunction

Introduction

Vulvodynia is a chronic pain condition with potential associated factors, including musculoskeletal and psychosocial components.

Aim

This study explores the prevalence of pain-related anxiety and depression in women with provoked vestibulodynia with associated overactive pelvic floor muscle dysfunction (PVD-PFD).

Methods

A retrospective chart review of 352 women presenting to 2 urban vulvovaginal specialty clinics over the course of a year was conducted. Women presenting for initial evaluation completed validated questionnaires for pain-related anxiety and depression. Women who completed these questionnaires with a diagnosis of PVD-PFD independently confirmed by a women's health physical therapist were included in analysis. Information on previously attempted treatments was gathered.

Main Outcome Measures

Pain-related anxiety was measured with the Pain Anxiety Symptoms Scale-20 and depression with the Patient Health Questionnaire 8.

Results

Of 79 women with confirmed PVD-PFD, 22% met criteria for pain-related anxiety alone, 4% for depression alone, and 27% for both pain-related anxiety and depression, with a significant association between anxiety and depression (χ² (1) = 21.44, P < .0005, phi = 0.521). There was also a significant association between anxiety and/or depression and whether prior treatment was attempted (χ² (2) = 6.81, P = .03, phi = 0.294).

Conclusion

The study found that 49% of women with PVD-PFD experienced pain-related anxiety, with or without depression. In addition, there was a statistically significant association between attempts at prior treatment and greater pain-related anxiety and depression. This is the first study to report a rate of pain-related anxiety specifically in women with PVD-PFD. These findings are consistent with studies showing elevated pain-related anxiety in other chronic musculoskeletal conditions, including lower back pain and fibromyalgia.

Govind V, Krapf JM, Mitchell L, et al. Exploring Pain-Related Anxiety and Depression in Female Patients With Provoked Vulvodynia With Associated Overactive Pelvic Floor Muscle Dysfunction. J Sex Med 2020;8:517–524.

Effects of pain neuroscience education and dry needling for the management of patients with chronic myofascial neck pain: a randomized clinical trial

OBJECTIVES

The aim of this study was to observe the medium-term effects on pain, disability, and psychological factors of a combination of myofascial trigger point (MTrP) dry needling (DN) with pain neuroscience education (PNE) versus DN alone versus control care as usual (CUC) in patients with chronic neck pain.

METHODS

A total of 60 patients were randomly selected in a Spanish National Health Service Public Hospital and divided into three groups: 6 sessions of DN with 3 sessions of PNE (TrPDN + PNE group, n = 21), 6 sessions of DN alone (TrPDN group, n = 20), or 10 sessions of usual care (CUC group, n = 19). The primary outcome was neck pain intensity, while neck disability, medication intake, and psychological factors were secondary outcomes. These variables were measured at baseline, post-treatment, and at 1 month and 3 months after treatment.

RESULTS

TrPDN + PNE and DN alone were associated with greater reductions in pain intensity and disability compared to CUC (p < 0.01). TrPDN + PNE resulted in greater improvements in kinesiophobia, pain anxiety, and pain-related beliefs than DN alone and CUC (p < 0.01). No differences between groups were observed in medication intake, quality of life, catastrophizing, depression, or fear of pain (p > 0.05).

DISCUSSION

Provision of PNE and DN in the management of chronic neck pain in a Spanish National Health Service Public Hospital was associated with greater improvements in psychological factors than DN therapy only.

CONCLUSION

DN alone was more effective at reducing chronic non-specific neck pain and disability than CUC at 3-month follow-up. However, the inclusion of PNE combined with DN resulted in greater improvements in kinesiophobia, pain anxiety, and pain-related beliefs.

TRIAL REGISTRATION NUMBER

NCT03095365 (ClinicalTrials.gov).

Importance of Outcome Domain for Patients With Musculoskeletal Pain: Characterizing Subgroups and Their Response to Treatment

BACKGROUND

Patient-centered care models allow for the ability to tailor treatment to outcomes of importance to patients.

OBJECTIVE

The purposes of this study were to (1) define patient subgroups based on outcomes of importance; (2) determine whether patient subgroups based on outcomes of importance differed in demographic, clinical, and psychological measures; and (3) determine whether outcome domain subgroups differed in treatment responses.

DESIGN

This was a prospective, longitudinal observational study.

METHODS

This was a secondary analysis of the Optimal Screening for Prediction of Referral and Outcome study. Patients in the development phase completed the Patient Centered Outcome Questionnaire (PCOQ) and questionnaires related to negative mood, fear avoidance, and positive coping, as well as region-specific questionnaires. Patients in the validation cohort completed the PCOQ, measures of treatment satisfaction and region-specific questionnaires at 4 weeks, 6 months, and 1 year. A hierarchical agglomerative cluster analysis identified profiles based on importance outcomes as determined by the PCOQ. Analysis of variance and chi-squared assessed baseline subgroup differences in demographics, psychological factors, and clinical outcomes. Repeated-measure analysis of variance considered subgroup differences in outcomes longitudinally.

RESULTS

Cluster analysis identified 3 subgroups: (1) "Multiple Outcome Domains Important" subgroup characterized by high importance attached to improvement in all domains, (2) "Pain and Function Outcomes Important" subgroup characterized by high importance attached to improvement in pain and interference, and (3) "Pain Important" subgroup characterized by greatest importance attached to improvement in pain.

LIMITATIONS

Our sample included patients from outpatient physical therapy and may not be representative of patients in other settings.

CONCLUSION

Patients can be characterized by the importance attached to improvement in outcome domains. The identified subgroups differed in baseline measures as well as response to treatment.

Pain interference type and level guide the assessment process in chronic pain: Categorizing pain patients entering tertiary pain treatment with the Brief Pain Inventory

Chronic pain patients enter treatment with different problem profiles making careful assessment a necessity for more individualized treatment plans. In this cross-sectional study we assigned 320 patients entering tertiary multidisciplinary pain treatment into four categories based on whether they scored low or high on the activity and the affective pain interference dimensions of the Brief Pain Inventory (BPI). To determine whether this categorization system delineates issues that should be assessed further, the categories were compared with ANOVA and MANOVA analyses on three domains: variables affecting physical well-being (body mass index, exercise, substance use), psychological resources (mood), and pain-specific psychological factors (pain anxiety, pain acceptance). The results indicated that subjects who scored low on both interference dimensions compared similarly in weight: mean Body Mass Index (BMI) 27.0 (SD 6.0) kg/m², and exercise: mean of 2.4 (SD 1.7) exercising sessions over 20 minutes per week, to the general population, had no depressive symptoms on average: mean Beck Depression Index II (BDI-II) score 11.7 (SD 7.5), and had the most favorable psychological reactions to pain relative to the other categories: mean total Pain Anxiety Symptoms Scale-20 (PASS-20) score 36.4 (SD 17.9). In contrast, when interference was high on activity, more physical well-being problems were evident e.g. weight: mean BMI 31.0 (SD 7.3) kg/m², diminished exercise: mean of 1.5 (SD 1.6) exercising sessions per week, and avoidance behavior: mean PASS-20 Escape/Avoidance subscale 3.7 (95% CI: 1.7 to 5.8) scores higher in comparison to activity interference remaining low. With high affective interference, more depressive symptoms: mean BDI-II score 17.7 (SD 7.3), and more cognitive pain anxiety: mean PASS-20 Cognitive Anxiety subscale 2.8 (95% CI 0.7 to 4.8) scores higher in comparison to affective interference remaining low, emerged. Having high interference on both dimensions indicated accumulated risks for reduced physical well-being: mean BMI 29.9 (SD 6.1) kg/m², mean of 1.2 (SD 1.7) exercising sessions per week, mood problems: mean BDI-II 20.3 (SD 10.6), and negative psychological reactions to pain: mean total PASS-20 score 53.2 (18.4). The results suggest that low interference on both dimensions may allow assessment with only physician consultations, while high interference on either dimension may call attention to distinct issues to be addressed with the help of a physiotherapist or a psychologist, whereas high interference on both dimensions highlights the need for a full multidisciplinary assessment.

Education and exercise supplemented by a pain-guided hopping intervention for male recreational runners with midportion Achilles tendinopathy: A single cohort feasibility study

OBJECTIVES

To examine the feasibility of recommended education and exercise supplemented by a hopping intervention implemented based on self-reported pain over 12 weeks for recreational runners with Achilles tendinopathy.

DESIGN

Single cohort feasibility study.

SETTING

One private physiotherapy clinic in Melbourne, Australia.

PARTICIPANTS

Fifteen male recreational runners with midportion Achilles tendinopathy.

MAIN OUTCOME MEASURES

Recruitment and adherence measures, adverse events, intervention acceptability and treatment effect trends were measured at baseline, 4 and 12 weeks.

RESULTS

Recruitment (100%), retention (87%) and follow-up (93%) rates were high. Exercise adherence was 70% (SD = 12.7) but fidelity was 50% (SD = 13.9). Three participants suffered adverse events (undertaking activities contrary to advice). Participants reported the education package, perceived benefit, and feedback frequency as intervention enablers; while the onerous time commitment was regarded a barrier. At 12 weeks, five participants were satisfied and eight very satisfied, while VISA-A had improved 24 ± 20.65 points (μ2 = 0.740).

CONCLUSIONS

A randomised control trial including recommended education and exercise with a pain-guided hopping intervention as treatment for recreational runners with midportion Achilles tendinopathy may be warranted, once strategies to improve adherence and reduce adverse events are addressed.

Pain-Related Fear-Dissociable Neural Sources of Different Fear Constructs

Fear of pain demonstrates significant prognostic value regarding the development of persistent musculoskeletal pain and disability. Its assessment often relies on self-report measures of pain-related fear by a variety of questionnaires. However, based either on “fear of movement/(re)injury/kinesiophobia,” “fear avoidance beliefs,” or “pain anxiety,” pain-related fear constructs plausibly differ while it is unclear how specific the questionnaires are in assessing these different constructs. Furthermore, the relationship of pain-related fear to other anxiety measures such as state or trait anxiety remains ambiguous. Advances in neuroimaging such as machine learning on brain activity patterns recorded by functional magnetic resonance imaging might help to dissect commonalities or differences across pain-related fear constructs. We applied a pattern regression approach in 20 human patients with nonspecific chronic low back pain to reveal predictive relationships between fear-related neural pattern information and different pain-related fear questionnaires. More specifically, the applied multiple kernel learning approach allowed the generation of models to predict the questionnaire scores based on a hierarchical ranking of fear-related neural patterns induced by viewing videos of activities potentially harmful for the back. We sought to find evidence for or against overlapping pain-related fear constructs by comparing the questionnaire prediction models according to their predictive abilities and associated neural contributors. By demonstrating evidence of nonoverlapping neural predictors within fear-processing regions, the results underpin the diversity of pain-related fear constructs. This neuroscientific approach might ultimately help to further understand and dissect psychological pain-related fear constructs.

Acceptance and Commitment Therapy for Chronic Pain: Does Post-traumatic Stress Disorder Influence Treatment Outcomes?

Objective

The aim of this study was to determine whether post-traumatic stress disorder (PTSD) moderates treatment outcomes in Acceptance and Commitment Therapy for chronic pain.

Design

Longitudinal.

Setting

Veterans Affairs San Diego Healthcare System.

Subjects

A total of 126 veterans with chronic pain participating in an Acceptance and Commitment Therapy intervention for chronic pain. A structured clinical interview was used at baseline to designate PTSD-positive (N = 43) and -negative groups (N = 83).

Methods

Linear mixed-effects models to determine whether PTSD moderated change in pain interference, pain severity, pain acceptance, depressive symptoms, or pain-related anxiety at post-treatment and six-month follow-up.

Results

Participants with co-occurring PTSD reported greater pain interference, pain severity, depressive symptoms, and pain-related anxiety at baseline. PTSD status did not moderate treatment effects post-treatment. Rather, there were significant improvements on all study measures across groups (P &lt; 0.001). PTSD status moderated change in depressive symptoms at six-month follow-up (P &lt; 0.05). Specifically, participants with chronic pain alone demonstrated improvement in depressive symptoms compared with pretreatment levels, whereas participants with PTSD regressed to pretreatment levels.

Conclusions

PTSD status did not significantly affect treatment outcomes, with the exception of depressive symptoms at six-month follow-up. Overall, Acceptance and Commitment Therapy for chronic pain appears helpful for improving outcomes among veterans with co-occurring PTSD; however, veterans with co-occurring PTSD may experience fewer long-term gains compared with those with chronic pain alone.

An analysis of within-treatment change trajectories in valued activity in relation to treatment outcomes following interdisciplinary Acceptance and Commitment Therapy for adults with chronic pain

A key issue in chronic pain treatment concerns changes necessary for reduced pain-related distress and disability. Acceptance and Commitment Therapy (ACT), a behavior change approach, theorizes several important treatment processes. Increased engagement in valued activities appears highly relevant as previous work has indicated it is related to current and future functioning and to treatment outcomes. This study sought to examine change trajectory in valued activity over the course of an interdisciplinary program of ACT and its relation to outcomes at treatment conclusion and three-month follow-up (N = 242). Latent change trajectories of valued activity were assessed weekly over four weeks of treatment and analyzed via latent growth curve and growth mixture modeling. A single latent trajectory with an increasing linear slope was indicated. Overall, slope of change in valued activity was predictive of improvement in psychosocial outcomes at post-treatment, including psychosocial disability, depression, pain anxiety, and discrepancy between values importance and success. Slope was not related to change in pain intensity or physical disability at post-treatment, nor was it related to change in any variable at follow-up. Findings are discussed in relation to the ACT model, in that support was provided in relation to post-treatment improvements for psychosocial variables.

Goal conflict in chronic pain: day reconstruction method

Background

When suffering from chronic pain, attempts to control or avoid pain often compete with other daily activities. Engaging in one activity excludes engaging in another, equally valued activity, which is referred to as "goal conflict." As yet, the presence and effects of goal conflicts in patients with chronic pain remain poorly understood.

Methods

This study systematically mapped the presence and experience of goal conflicts in patients with fibromyalgia compared to healthy controls. A total of 40 patients and 37 controls completed a semi-structured interview in which they first reconstructed the previous day, identified conflicts experienced during that day, and classified each of the conflicting goals in one of nine goal categories. Additionally, they assessed how they experienced the previous day and the reported conflicts.

Results

Results showed that patients did not experience more goal conflicts than healthy controls, but that they did differ in the type of conflicts experienced. Compared to controls, patients reported more conflicts related to pain, and fewer conflicts involving work-related, social or pleasure-related goals. Moreover, patients experienced conflicts as more aversive and more difficult to resolve than control participants.

Discussion

This study provides more insight in the dynamics of goal conflict in daily life, and indicates that patients experience conflict as more aversive than controls, and that conflict between pain control (and avoidance) and other valued activities is part of the life of patients.

The Relationship Between Heart Rate Variability, Psychological Flexibility, and Pain in Neurofibromatosis Type 1

Individuals with neurofibromatosis type 1 (NF1) and plexiform neurofibromas (PNs) can experience chronic pain. Previous research has examined the relationship between heart rate variability (HRV) and persistent pain. HRV is an index of autonomic nervous system functioning, and reflects the variability in time elapsed between heartbeats. Patients with chronic pain tend to exhibit lower HRV, which has been associated with poor adaptability, or psychological flexibility, to stress. The aim of the current study was to examine relationships between HRV, psychological flexibility, and pain in a sample of adolescents and young adults (AYAs) with NF1 and PNs. AYA participants (n = 40) 16 to 34 years of age with NF1 completed baseline measures of pain and psychological functioning, and underwent a 5-minute electrocardiogram (ECG). A subset of 20 participants completed follow-up questionnaires and a second ECG 8 weeks later. Spectral analyses of ECGs yielded a measure of high-frequency heart rate variability (HF-HRV). Baseline correlations revealed that lower HF-HRV is related to greater inflexibility and more pain interference, but not pain intensity. Moreover, psychological inflexibility significantly mediated the relationship between HF-HRV and pain interference. Finally, regression models indicated that baseline psychological inflexibility is a significant predictor of HF-HRV at follow-up and, separately, that baseline HF-HRV significantly predicted pain intensity at follow-up. These findings suggest complex mind-body processes in the experience of pain in NF1, which have not been studied previously. Implications for pain-related interventions and future research are discussed.

Chronic Pain and Selective Attention to Pain Arousing Daily Activity Pictures: Evidence From an Eye Tracking Study

Introduction

According to the pain research literature, attentional bias for pain is the mechanism responsible for the development and maintenance of fear of pain in patients with chronic pain. However, there is still some debate about the exact mechanism and the role of faster engagement versus difficulty in disengagement in the development of attentional bias.

Methods

To investigate attentional bias in patients with chronic pain, we used an eye-tracker with the pictures of pain-provoking activities and compared the results with an age- and gender-matched group of pain-free participants. In addition, other measures of pain-related cognition and pain severity ratings were included to assess their contribution to the attentional bias toward pain-related information.

Results

Calculating the frequency of the first fixations showed that both groups fixated initially on pain-provoking pictures compared to neutral one. Calculating the speed of fixations showed that control participants were faster in fixating on neutral stimuli, but patients with pain were faster in fixating on pain-provoking pictures, indicating a relative vigilance for the pain-related stimuli among them. These patients reported that the intensity of pain in the previous week was positively correlated with the speed of their fixation on the painful stimuli.

Conclusion

Although these results did not provide unequivocal support for the vigilance-avoidance hypothesis, they are generally consistent with the results of studies using eye tracking technology. Furthermore, our findings put a question over characterization of attentional biases in patients with chronic pain by simply relating that to difficulty in disengaging from pain-related stimuli.

Reliability and Validity of the Pain Anxiety Symptom Scale in Persian Speaking Chronic Low Back Pain Patients

STUDY DESIGN

Psychometric testing of the Persian version of Pain Anxiety Symptom Scale 20.

OBJECTIVE

The aim of this study was to assess the reliability and construct validity of the PASS-20 in nonspecific chronic low back pain (LBP) patients.

SUMMARY OF BACKGROUND DATA

The PASS-20 is a self-report questionnaire that assesses pain-related anxiety. The Psychometric properties of this instrument have not been assessed in Persian-speaking chronic LBP patients.

METHODS

One hundred and sixty participants with chronic LBP completed the Persian version of PASS-20, Tampa Scale of Kinesiophobia (TSK), Fear-Avoidance Beliefs Questionnaire (FABQ), Pain Catastrophizing Scale (PCS), trait form of the State-Trait Anxiety (STAI-T), Oswestry Low Back Pain Disability Index (ODI), Beck Depression Inventory (BDI-II), and Visual Analogue Scale (VAS). To evaluate test-retest reliability, 60 patients filled out the PASS-20, 6 to 8 days after the first visit. Test-retest reliability (intraclass correlation coefficient [ICC], standard error of measurement [SEM], and minimal detectable change [MDC]), internal consistency, dimensionality, and construct validity were examined.

RESULTS

The ICCs of the PASS-20 subscales and total score ranged from 0.71 to 0.8. The SEMs for PASS-20 total score was 7.29 and for the subscales ranged from 2.43 to 2.98. The MDC for the total score was 20.14 and for the subscales ranged from 6.71 to 8.23. The Cronbach alpha values for the subscales and total score ranged from 0.70 to 0.91. Significant positive correlations were found between the PASS-20 total score and PCS, TSK, FABQ, ODI, BDI, STAI-T, and pain intensity.

CONCLUSION

The Persian version of the PASS-20 showed acceptable psychometric properties for the assessment of pain-related anxiety in Persian-speaking patients with chronic LBP.

LEVEL OF EVIDENCE

3.

Individuals with sickle cell disease have a significantly greater vasoconstriction response to thermal pain than controls and have significant vasoconstriction in response to anticipation of pain

The painful vaso-occlusive crises (VOC) that characterize sickle cell disease (SCD) progress over hours from the asymptomatic steady-state. SCD patients report that VOC can be triggered by stress, cold exposure, and, pain itself. We anticipated that pain could cause neural-mediated vasoconstriction, decreasing regional blood flow and promoting entrapment of sickle cells in the microvasculature. Therefore, we measured microvascular blood flow in the fingers of both hands using plethysmography and laser-Doppler flowmetry while applying a series of painful thermal stimuli on the right forearm in 23 SCD patients and 25 controls. Heat pain applied to one arm caused bilateral decrease in microvascular perfusion. The vasoconstriction response started before administration of the thermal pain stimulus in all subjects, suggesting that pain anticipation also causes significant vasoconstriction. The time delay between thermal pain application and global vasoconstriction ranged from 5 to 15.5 seconds and increased with age (P < .01). Although subjective measures, pain threshold and pain tolerance were not different between SCD subjects and controls, but the vaso-reactivity index characterizing the microvascular blood flow response to painful stimuli was significantly higher in SCD patients (P = .0028). This global vasoconstriction increases microvascular transit time, and may promote entrapment of sickle cells in the microvasculature, making vaso-occlusion more likely. The rapidity of the global vasoconstriction response indicates a neural origin that may play a part in the transition from steady-state to VOC, and may also contribute to the variability in VOC frequency observed in SCD patients.

Prediction of persistent post-operative pain: Pain-specific psychological variables compared with acute post-operative pain and general psychological variables

BACKGROUND

Psychological variables and acute post-operative pain are of proven relevance for the prediction of persistent post-operative pain. We aimed at investigating whether pain-specific psychological variables like pain catastrophizing add to the predictive power of acute pain and more general psychological variables like depression.

METHODS

In all, 104 young male patients undergoing thoracic surgery for pectus excavatum correction were studied on the pre-operative day (T0) and 1 week (T1) and 3 months (T2) after surgery. They provided self-report ratings (pain-related: Pain Catastrophizing Scale, Pain Anxiety Symptoms Scale = PASS, Pain Vigilance and Awareness Questionnaire = PVAQ; general psychological: Screening for Somatoform Symptoms, State-Anxiety Inventory-X1, Center for Epidemiologic Studies Depression Scale = CES-D). Additional predictors (T1) as well as criterion variables (T2) were pain intensity (Numerical Rating Scale) and pain disability (Pain Disability Index).

RESULTS

Three months after surgery, 25% of the patients still reported clinically relevant pain (pain intensity ≥3) and over 50% still reported pain-related disability. Acute post-operative pain as well as general psychological variables did not allow for a significant prediction of persistent post-operative pain; in contrast, pain-related psychological variables did. The best single predictors were PASS for pain intensity and PVAQ for pain disability.

CONCLUSIONS

Pain-related psychological variables derived from the fear-avoidance model contributed significantly to the prediction of persistent post-operative pain. The best possible compilation of these measures requires further research. More general psychological variables may become relevant predictors later in the medical history.

SIGNIFICANCE

Our results suggest that pain-specific psychological variables such as pain anxiety and pain hypervigilance add significantly to the prediction of persistent post-operative pain and might even outperform established predictors such as acute pain and general psychological variables. Clinicians might benefit from the development of time-economic screening tools based on these variables.

Treatment response and central pain processing in Anterior Cutaneous Nerve Entrapment Syndrome: An explorative study

BACKGROUND

10-30% of chronic abdominal pain originates in the abdominal wall. A common cause for chronic abdominal wall pain is the Anterior Cutaneous Nerve Entrapment Syndrome (ACNES), in which an intercostal nerve branch is entrapped in the abdominal rectus sheath. Treatment consists of local anaesthetics and neurectomy, and is ineffective in 25% of cases for yet unknown reasons. In some conditions, chronic pain is the result of altered pain processing. This so-called sensitization can manifest as segmental or even generalized hyperalgesia, and is generally difficult to treat.

OBJECTIVE

The aim of this study was to assess pain processing in ACNES patients responsive and refractory to treatment by using Quantitative Sensory Testing, in order to explore whether signs of altered central pain processing are present in ACNES and are a possible explanation for poor treatment outcomes.

METHODS

50 patients treated for ACNES with locally orientated treatment were included. They were allocated to a responsive or refractory group based on their response to treatment. Patients showing an improvement of the Visual Analogue Scale (VAS) pain score combined with a current absolute VAS of <40mm were scored as responsive. Sensation and pain thresholds to pressure and electric skin stimulation were determined in the paravertebral bilateral ACNES dermatomes and at four control areas on the non-dominant side of the body, i.e. the musculus trapezius pars medialis, musculus rectus femoris, musculus abductor hallucis and the thenar. The ACNES dermatomes were chosen to signal segmental hyperalgesia and the sum of the control areas together as a reflection of generalized hyperalgesia. Lower thresholds were interpreted as signs of sensitized pain processing. To test for alterations in endogenous pain inhibition, a conditioned pain modulation (CPM) response to a cold pressor task was determined. Also, patients filled in three pain-related questionnaires, to evaluate possible influence of psychological characteristics on the experienced pain.

RESULTS

Patients refractory to treatment showed significantly lower pressure pain thresholds in the ACNES dermatomes and for the sum of as well as in two individual control areas. No differences were found between groups for electric thresholds or CPM response. Duration of complaints before diagnosis and treatment was significantly longer in the refractory compared to the responsive group, and refractory patients scored higher on the pain-related psychological surveys.

CONCLUSION AND IMPLICATIONS

In this hypothesis-generating exploratory study, ACNES patients refractory to treatment showed more signs of sensitized segmental and central pain processing. A longer duration of complaints before diagnosis and treatment may be related to these alterations in pain processing, and both findings could be associated with less effective locally orientated treatment. In order to validate these hypotheses further research is needed.

REGISTRATION NUMBER

NCT01920880 (Clinical Trials Register; http://www.clinicaltrials.gov).

Differences in psychosocial responses to pain between sufficiently and insufficiently active adults with arthritis

OBJECTIVE

Adults with arthritis struggle to meet the physical activity recommendation for disease self-management. Identifying psychosocial factors that differentiate adults who meet (sufficiently active) or do not meet (insufficiently active) the recommendation is needed. This study sought to examine differences in psychosocial responses to arthritis pain among adults who were sufficiently or insufficiently active.

DESIGN

This prospective study included adults with medically diagnosed arthritis (N = 136, M_age = 49.75 ± 13.88 years) who completed two online surveys: (1) baseline: pain and psychosocial responses to pain and (2) two weeks later: physical activity.

MAIN OUTCOME MEASURES

Psychosocial responses examined in this study were psychological flexibility in response to pain, pain anxiety and maladaptive responses to pain anxiety.

RESULTS

A between-groups MANCOVA comparing sufficiently active (n = 87) to insufficiently active (n = 49) participants on psychosocial responses, after controlling for pain intensity, was significant (p = .005). Follow-up ANOVA's revealed that sufficiently active participants reported significantly higher psychological flexibility and used maladaptive responses less often compared to insufficiently active participants (p's < .05).

CONCLUSIONS

These findings provide preliminary insight into the psychosocial profile of adults at risk for nonadherence due to their responses to arthritis pain.