Impact of controllability on pain and suffering

The effect of unpredictability on the perception of pain: a systematic review and meta-analysis

ABSTRACT

Despite being widely assumed, the worsening impact of unpredictability on pain perception remains unclear because of conflicting empirical evidence, and a lack of systematic integration of past research findings. To fill this gap, we conducted a systematic review and meta-analysis focusing on the effect of unpredictability on pain perception. We also conducted meta-regression analyses to examine the moderating effect of several moderators associated with pain and unpredictability: stimulus duration, calibrated stimulus pain intensity, pain intensity expectation, controllability, anticipation delay, state and trait negative affectivity, sex/gender and age of the participants, type of unpredictability (intensity, onset, duration, location), and method of pain induction (thermal, electrical, mechanical pressure, mechanical distention). We included 73 experimental studies with adult volunteers manipulating the (un)predictability of painful stimuli and measuring perceived pain intensity and pain unpleasantness in predictable and unpredictable contexts. Because there are insufficient studies with patients, we focused on healthy volunteers. Our results did not reveal any effect of unpredictability on pain perception. However, several significant moderators were found, ie, targeted stimulus pain intensity, expected pain intensity, and state negative affectivity. Trait negative affectivity and uncontrollability showed no significant effect, presumably because of the low number of included studies. Thus, further investigation is necessary to clearly determine their role in unpredictable pain perception.

Multi-disciplinary community-based group intervention for fibromyalgia: a pilot randomized controlled trial

Fibromyalgia is characterized by widespread pain, fatigue, sleep disturbances, mood disturbances, and cognitive impairment. Most individuals with fibromyalgia experience poorly managed symptoms and increased healthcare service use. Multicomponent therapies, with a focus on nonpharmacological modalities, are increasingly supported in the literature. However, given the limited resources available, implementation in smaller communities remains a challenge. This research tested a community-based multidisciplinary group intervention for individuals diagnosed with FM living in a small urban centre. The primary outcome was perceptions of quality of care and secondary outcomes included disease-related functioning, anxious and depressive symptoms, pain beliefs, and health service utilization. A pilot randomized control trial was conducted in which 60 patients diagnosed with fibromyalgia were randomized into a 10-week community-based multidisciplinary group intervention program or usual care. Treatment components included twice-weekly exercise sessions and weekly education sessions (e.g., pain education, cognitive behavioral strategies for stress, nutrition, peer support). The trial (NCT03270449) was registered September 1 2017. Statistically significant post-intervention improvements were found in the primary outcome, perceived quality of care (Cohen's d = 0.61, 0.66 for follow up care and goal setting, respectively). Secondary outcomes showing statistically significant improvements were disease-related daily functioning (Cohen's d = 0.70), depressive symptoms (Cohen's d = 0.87), and pain beliefs (Cohen's d = 0.61, 0.67, 0.82 for harm, disability and control, respectively). No adverse events were reported. Community-based multidisciplinary group interventions for fibromyalgia show promise for improving satisfaction with quality of care, disease-related functioning, and depression, and fostering more adaptive pain beliefs.

Pain and related suffering reduce attention toward others

BACKGROUND

It has been proposed that the expression of pain-related suffering may lead to an enhanced focus on oneself and reduced attention toward the external world. This study aimed at investigating whether experimentally induced painrelated suffering may lead persons to withdraw into themselves, causing a reduced focus on external stimuli as reflected by impaired performance in a facial recognition task and heightened perception of internal stimuli measured by interoceptive awareness.

METHODS

Thirty-two participants had to recognize different emotional facial expressions (neutral, sad, angry, happy), or neutral geometrical figures under conditions of no pain, low, and high prolonged pain intensities. Interoceptive accuracy was measured using a heartbeat-detection task prior to and following the pain protocol.

RESULTS

Males but not females were slower to recognize facial expressions under the condition of high painful stimulation compared to the condition of no pain. In both, male and female participants, the difficulty in recognizing another person's emotions from a facial expression was directly related to the level of suffering and unpleasantness experienced during pain. Interoceptive accuracy was higher after the pain experiment. However, neither the initial interoceptive accuracy nor the change were significantly related to the pain ratings.

CONCLUSIONS

Our results suggest that long-lasting and intense painful stimuli, which induce suffering, lead to attentional shifts leading to withdrawal from others. These findings contribute to a better understanding of the social dynamics of pain and pain-related suffering.

The role of expectations, control and reward in the development of pain persistence based on a unified model

Chronic, or persistent pain affects more than 10% of adults in the general population. This makes it one of the major physical and mental health care problems. Although pain is an important acute warning signal that allows the organism to take action before tissue damage occurs, it can become persistent and its role as a warning signal thereby inadequate. Although per definition, pain can only be labeled as persistent after 3 months, the trajectory from acute to persistent pain is likely to be determined very early and might even start at the time of injury. The biopsychosocial model has revolutionized our understanding of chronic pain and paved the way for psychological treatments for persistent pain, which routinely outperform other forms of treatment. This suggests that psychological processes could also be important in shaping the very early trajectory from acute to persistent pain and that targeting these processes could prevent the development of persistent pain. In this review, we develop an integrative model and suggest novel interventions during early pain trajectories, based on predictions from this model.

Measuring pain and nociception: Through the glasses of a computational scientist. Transdisciplinary overview of methods

In a healthy state, pain plays an important role in natural biofeedback loops and helps to detect and prevent potentially harmful stimuli and situations. However, pain can become chronic and as such a pathological condition, losing its informative and adaptive function. Efficient pain treatment remains a largely unmet clinical need. One promising route to improve the characterization of pain, and with that the potential for more effective pain therapies, is the integration of different data modalities through cutting edge computational methods. Using these methods, multiscale, complex, and network models of pain signaling can be created and utilized for the benefit of patients. Such models require collaborative work of experts from different research domains such as medicine, biology, physiology, psychology as well as mathematics and data science. Efficient work of collaborative teams requires developing of a common language and common level of understanding as a prerequisite. One of ways to meet this need is to provide easy to comprehend overviews of certain topics within the pain research domain. Here, we propose such an overview on the topic of pain assessment in humans for computational researchers. Quantifications related to pain are necessary for building computational models. However, as defined by the International Association of the Study of Pain (IASP), pain is a sensory and emotional experience and thus, it cannot be measured and quantified objectively. This results in a need for clear distinctions between nociception, pain and correlates of pain. Therefore, here we review methods to assess pain as a percept and nociception as a biological basis for this percept in humans, with the goal of creating a roadmap of modelling options.

A psychometric evaluation of the Italian short version of the Fear of Pain Questionnaire-III: Psychometric properties, measurement invariance across gender, convergent, and discriminant validity

Introduction

The Fear of Pain Questionnaire-III (FPQ-III) is a self-assessment instrument developed specifically to measure fear based on various pain stimuli converging on three factors: severe pain, medical pain, and minor pain. It actually remains the most studied and internationally used tool even in its short versions. The aim of this work was to propose a new validation study oriented to confirm the good psychometric properties of a short model of the FPQ-III for the Italian context.

Methods

A large sample of participants was recruited (n  = 1,064) and Exploratory Factor Analysis (EFA) as well as Confirmatory Factor Analysis (CFA) were performed. Measurement invariance of the FPQ-III across gender was also evaluated. In order to examine convergent validity, a further convenient sample (n  = 292) was used and variables related to the individual's pain experience, locus of control and coping orientations were assessed. A final discriminant assessment using experimental manipulation through fear eliciting videos was performed.

Results

The three factors structure of the 13-item version of the questionnaire was confirmed (χ² = 148.092, CFI = 0.971, TLI = 0.962, RMSEA = 0.046, RMSEA 90% CI = 0.037-0.056) as well as the measurement invariance across gender. Item internal reliability was satisfactory. The results provided evidence of the good predictive validity of the FPQ-III and the discriminant assessment demonstrated that the instrument is suitable in detecting changes in fear of pain induced by specific situational conditions.

Discussion

The scale in this short version is suitable for quickly and efficiently gathering information about the perceived intensity of such anticipatory fears that might affect even the healthy person dysfunctionally.

What is Pain-Related Suffering? Conceptual Critiques, Key Attributes, and Outstanding Questions

Suffering holds a central place within pain research, theory, and practice. However, the construct of pain-related suffering has yet to be operationalized by the International Association for the Study of Pain and is largely underdeveloped. Eric Cassell's seminal work on suffering serves as a conceptual anchor for the limited pain research that specifically addresses this construct. Yet, important critiques of Cassell's work have not been integrated within the pain literature. This Focus Article aims to take a preliminary step towards an updated operationalization of pain-related suffering by 1) presenting key attributes of pain-related suffering derived from a synthesis of the literature and 2) highlighting key challenges associated with Cassell's conceptualization of suffering. We present 4 key attributes: 1) pain and suffering are inter-related, but distinct experiences, 2) suffering is a subjective experience, 3) the experience of suffering is characterized by a negative affective valence, and 4) disruption to one's sense of self is an integral part of suffering. A key outstanding challenge is that suffering is commonly viewed as a self-reflective and future-oriented process, which fails to validate many forms of suffering and marginalizes certain populations. Future research addressing different modes of suffering - with and without self-reflection - are discussed. PERSPECTIVE: This article offers a preliminary step toward operationalizing the construct of pain-related suffering and proposes priorities for future research. A robust operationalization of this construct is essential to developing clinical strategies that aim to better recognize and alleviate suffering among people living with pain.

Increased functional connectivity between limbic brain areas in healthy individuals with high versus low sensitivity to cold pain: A resting state fMRI study

Background

The representation of variability in sensitivity to pain by differences in neural connectivity patterns and its association with psychological factors needs further investigation. This study assessed differences in resting-state functional connectivity (rsFC) and its association to cognitive-affective aspects of pain in two groups of healthy subjects with low versus high sensitivity to pain (LSP vs. HSP). We hypothesized that HSP will show stronger connectivity in brain regions involved in the affective-motivational processing of pain and that this higher connectivity would be related to negative affective and cognitive evaluations of pain.

Methods

Forty-eight healthy subjects were allocated to two groups according to their tolerability to cold stimulation (cold pressor test, CPT, 1°C). Group LSP (N = 24) reached the cut-off time of 180±0 sec and group HSP tolerated the CPT for an average of 13±4.8 sec. Heat, cold and mechanical evoked pain were measured, as well as pain-catastrophizing (PCS), depression, anxiety and stress (DASS-21). All subjects underwent resting state fMRI. ROI-to-ROI analysis was performed.

Results

In comparison to the LSP, the HSP had stronger interhemispheric connectivity of the amygdala (p = 0.01) and between the amygdala and nucleus accumbens (NAc) (p = 0.01). Amygdala connectivity was associated with higher pain catastrophizing in the HSP only (p<0.01).

Conclusions

These findings suggest that high sensitivity to pain may be reflected by neural circuits involved in affective and motivational aspects of pain. To what extent this connectivity within limbic brain structures relates to higher alertness and more profound withdrawal behavior to aversive events needs to be further investigated.

Evaluation of the Glymphatic System With Diffusion Tensor Imaging-Along the Perivascular Space in Cancer Pain

Cancer pain (CP) is one of the most common symptoms affecting life quality, and there is considerable variation in pain experience among patients with malignant tumors. Previously, it has been found that the fluid drainage function in the brain can be regulated by peripheral pain stimulation. However, the relationship between cancer pain and functional changes of the glymphatic system (an important pathway for fluid drainage in the brain) remains unclear. In this study, 97 participants were enrolled, which included 40 participants in the cancer pain (CP) group, 27 participants in the painless cancer (PLC) group and 30 participants in the control (NC) group. Differences in glymphatic system function among the three groups and between before and after pain pharmacological intervention were analyzed by measuring diffusivity and the index along the perivascular space (ALPS index) using diffusion tensor imaging. We found that diffusivity and the ALPS index were significantly lower in the CP group than in the PLC and NC group and increased following intervention with pain relief. Moreover, the ALPS index was negatively correlated with the degree of pain in the CP group. The present study verified that alterations in glymphatic function are closely related to cancer pain, and the quantification of functional changes reflects pain severity. Our findings support the use of neuroimaging biomarkers for cancer pain assessment and indicate that pain can be alleviated by regulating brain function status.

The skin conductance response indicating pain relief is independent of self or social influence on pain

Pain relief is defined as the ease of pain and is thus highly relevant for clinical applications and everyday life. Given that pain relief is based on the cessation of an aversive pain experience, it is reasonable to assume that pain relief learning would also be shaped by factors that alter subjective and physiological pain responses, such as social presence or a feeling of control. To date, it remains unclear whether and how factors that shape autonomic pain responses might affect pain relief learning. Here, we investigated how pain relief learning is shaped by two important factors known to modulate pain responses, i.e. social influence and controllability of pain. Skin conductance responses (SCRs) were recorded while participants learned to associate a formerly neutral stimulus with pain relief under three different pain conditions. In the social‐influence condition (N = 34), the pain stimulation could be influenced by another person’s decisions. In the self‐influence condition (N = 31), the participants themselves could influence the pain stimulation. Finally, in the no‐influence condition (N = 32), pain stimulation was simply delivered without any influence. According to our results, the SCRs elicited by the stimulus that was associated with pain relief were significantly smaller compared to the SCRs elicited by a neutral control stimulus, indicating pain relief learning. However, there was no significant difference in the pain relief learning effect across the groups. These results suggest that physiological pain relief learning in humans is not significantly influenced by social influence and pain controllability.

The contents of this page will be shown on the eTOC on the online version only. It will not be published as part of the article PDF. Subjective and physiological pain responses can be altered by social support or pain controllability. Pain relief strongly depends on the perceived pain, but we found that it is less influenceable. Neither social nor self‐influence changed the magnitude of physiological pain‐relief responses. We conclude that pain relief is a basic mechanism not easily influenced by circumstantial manipulations.

The Stressful Characteristics of Pain That Drive You NUTS: A Qualitative Exploration of a Stress Model to Understand the Chronic Pain Experience

OBJECTIVE

Despite decades of research on the identification of specific characteristics of situations that trigger a physiological stress response (novelty, unpredictability, threat to the ego, and sense of low control [NUTS]), no integrative research has examined the validity of this framework applied to pain experiences. This study aimed to 1) explore the stressful characteristics of pain among individuals living with chronic pain and 2) examine whether the NUTS framework comprehensively captures the stressful nature of pain.

SUBJECTS

Participants were 41 adult participants living with chronic pain.

METHODS

Interviews in six focus groups were conducted in French using a semistructured interview guide. Participants first discussed how pain is stressful. Then, they were introduced to the NUTS framework and commented on the extent to which it captured their experience. The verbatim transcriptions of interviews were reviewed using reflexive thematic analysis. Analyses were conducted in French; quotes and themes were translated into English by a professional translator.

RESULTS

The pain-NUTS framework adequately captured participants' experiences. Multiple aspects of pain (pain intensity fluctuations, pain flare-up duration, pain quality and location, functional limitations, diagnosis and treatment) were associated with one or more stress-inducing characteristics. In addition, a second layer of meaning emerged in the context of chronic pain that provided contextual information regarding when, how, and why pain became more or less stressful.

CONCLUSIONS

The NUTS characteristics seem to offer a comprehensive framework to understand how pain and its context of chronicity can be a source of stress. This study provides preliminary support for the pain-NUTS framework to allow the formal integration of pain and stress research.

Patients´ experiences of pain in the intensive care - The delicate balance of control

AIM

To explore the patients´ experiences of pain when being cared for in the intensive care.

DESIGN

An exploratory, qualitative design was chosen.

METHOD

Interviews were performed with patients (October 2015-March 2017) within a week of post-intensive care (N = 16). Thematic analysis was used as method for analysis.

RESULTS

The findings generated two themes - a lack of control and to struggle for control. Pain was described as overwhelming, both in body and mind and generating the experience of a lack of control, with feelings of incapacitation, isolation, and having their needs unmet. Feeling in control of the pain and thus in control of the situation was experienced as a constant struggle. Well-planned care, finding ways to handle the pain and good communication were all helpful in this struggle.

CONCLUSION

The participants recalled their experience of pain in the ICU and control seems to be crucial for how pain is experienced. They experienced a lack of control due to not only the pain but also the treatment, which can be avoided by the nurse continuously evaluating and individualising the care. Balanced care, meeting the patients' needs and good communication helps the patient feel more in control when experiencing pain.

IMPACT

The experience of pain is dependent on control for the intensive care patient. The nurse may help them gain control and thereby handle the experience of pain through including the patient, striving for better communication and implementing individualised care that continuously assesses and treats pain.