No pain, no social gains: A social-signaling perspective of human pain behaviors

In this review article, we describe a social-signaling perspective of human pain and pain empathizing behaviors which is based on the premise that pain percepts evolved to serve both intrapersonal as well as interpersonal, communicative functions. This perspective offers a generative framework for understanding the natural origin and proximate expression of felt pain and pain empathizing behaviors. The basic thesis is that humans evolved sensory-behavioral heuristics for perceiving and inhibiting exogenous and endogenous pain sensations as part of more general expressive styles characterized by the demonstration of vulnerability gestures (i.e., trustworthiness cues) versus empowerment gestures (i.e., capacity cues), and these styles ultimately facilitate broader self-protection and social novelty-seeking life-history behavior strategies, respectively. We review the extant literature on how social contextual factors (e.g., audience characteristics) and how structural and functional components of individual’s social network appear to influence the expression of pain behaviors in ways that support basic predictions from the social-signaling perspective. We also show how the perspective can be used to interpret conventional findings of sex differences in pain percepts and pain empathizing behaviors and for predicting how the situational context and individual’s peer networks modulate these differences in vitro and in vitro. We conclude the article by describing how pain researchers may better understand how varying levels and divergent directions of changes in affect tend to co-occur with systematic changes in internal vs external pain sensitivities, and thus why, from an evolutionary perspective, pain may occur in the presence and absence of physical tissue damage.

MiR-34a affects dexmedetomidine-inhibited chronic inflammatory visceral pain by targeting to HDAC2

Background

Dexmedetomidine (DEX) has been used as an anesthetic for decades. The present investigation aimed to elucidate the analgesic impact of DEX on 2,4,6-Trinitrobenzenesulfonic acid (TNBS)-induced chronic inflammatory visceral pain (CIVP) in rats.

Methods

TNBS with or without DEX to Male Sprague-Dawley SD rats were randomly divided into four groups: normal, CIVP, DEX, and vehicle. Pain behaviors were assessed and the abdominal withdrawal reflex, mechanical withdrawal threshold, and thermal withdrawal latency were recorded. Quantitative polymerase chain reaction data showed increased expressions of pro-inflammatory cytokines (IL-6, IL-1β and TNF-α) in the spinal cord tissues of rats.

Results

RNA microarray and quantitative polymerase chain reaction results indicated that miR-34a was downregulated by TNBS induction, but it was upregulated by DEX administration. Further studies showed that transfection of adenovirus-miR-34a inhibitor reversed the effect of DEX on the pain behaviors and spinal-cord pro-inflammatory-cytokine generation in CIVP rats. Additionally, we found that miR-34a targeted the 3′-UTR of the HDAC2 gene, as evinced by the increased HDAC2 expression in the CIVP and DEX + miR-34a inhibitor groups, and decreased HDAC2 signaling in the DEX group. Moreover, knock-down of HDAC2 restored DEX-attenuated pain behaviors and reduced pro-inflammatory cytokine production.

Conclusions

DEX thus exhibited an analgesic effect on CIVP rats through the miR-34a-mediated HDAC2 pathway and suppressed visceral hypersensitivity.

Does pain behavior influence assessment of pain severity?

CONTEXT

Nurses are involved in assessment of pain in most clinical settings. Pain continues to be underestimated and undertreated.

MATERIALS AND METHODS

This study assessed the rating of pain severity by nurses who observed the two case scenarios using role plays. The data were computed and frequency distribution was derived.

RESULTS

Majority of the nurses underrated the pain and based their ratings on various factors.

CONCLUSIONS

It is important to increase the awareness among nurses about comprehensive assessment of pain for better management.

A model of pain behaviors in freely moving rats generated by controllable electrical stimulation of the peripheral nerve

BACKGROUND

Neuropathic pain patients have described experiencing unprovoked, intermittent pain attacks with shooting, stabbing, and burning qualities. Rodent models used in previous literature usually only involve acute exposure, and/or are unable to manipulate the stimulation intensity in vivo by the experimenter during an experiment.

NEW METHOD

This paper describes a method to induce controllable pain behaviors in rodents using a wireless portable electronic device that can be manipulated within the course of an experiment. A stimulating electrode was implanted at the L5 spinal nerve location in Sprague-Dawley rats and our custom-built wireless stimulating device was attached to deliver variable stimulation in freely moving animals (50 Hz, 0.5 V; 100 Hz, 1 V).

RESULTS

Implantation itself did not induce hypersensitivity as measured by the mechanical paw withdrawal threshold test. Observation of pain behaviors (paw elevation and licking) indicated that high stimulation intensity yielded a significant increase in pain behaviors. Even further, high intensity stimulation resulted in a behavioral "wind-up" of pain behaviors that persisted into the resting period when no stimulation was applied.

COMPARISON WITH EXISTING METHODS AND CONCLUSIONS

This method can be used to study pain behaviors in a controllable way in freely moving rodents in comparison to existing models that are acute and/or are unable to manipulate the stimulation intensity in vivo.

Racial Differences in Movement-Related Appraisals and Pain Behaviors Among Adults With Chronic Low Back Pain

Research documents racial disparities in chronic low back pain (CLBP). Few studies have examined racial disparities in movement-related appraisals and no studies have examined anticipatory appraisals prior to or pain behaviors during functional activities among individuals with CLBP. This cross-sectional study examined racial differences in anticipatory appraisals of pain, concerns about harm, and anxiety, appraisals of pain and anxiety during movement, and observed pain behaviors during 3 activities of daily living (supine-to-standing bed task, sitting-to-standing chair task, floor-to-waist lifting task) in a sample (N = 126) of non-Hispanic Black (31.0%), Hispanic (30.2%), and non-Hispanic White (38.9%) individuals with CLBP. Hispanic participants reported more expected pain, concerns about harm, and pre-movement anxiety prior to the bed and chair tasks compared to non-Hispanic White participants. Hispanic participants reported more pain during the bed task and more anxiety during the bed and chair tasks compared to non-Hispanic White participants. Non-Hispanic Black participants reported more expected pain, concerns about harm, and pre-movement anxiety prior to the bed task and more pre-movement anxiety prior to the chair task compared to non-Hispanic White participants. Non-Hispanic Black participants reported more anxiety during the bed and chair tasks compared to non-Hispanic White participants. Non-Hispanic Black participants were observed to have significantly more verbalizations of pain during the bed task compared to non-Hispanic White participants. Current findings identify racial disparities in important cognitive-behavioral and fear-avoidance mechanisms of pain. Results indicate a need to revisit traditional theoretical and treatment models in CLBP, ensuring racial disparities in pain cognitions are considered. PERSPECTIVE: This study examined racial disparities in anticipatory and movement-related appraisals, and pain behaviors during activities of daily living among Non-Hispanic Black, Non-Hispanic White, and Hispanic individuals with CLBP. Racial disparities identified in the current study have potentially important theoretical implications surrounding cognitive-behavioral and fear-avoidance mechanisms of pain.

Examining Resilient Pain Behaviors for Chronic Low Back Pain: A Scoping Review

OBJECTIVES

The objective of this scoping review was to examine resilience and resilient pain behaviors for those with CLBP in relation to resilience definitions, operationalization (e.g. trait or behavior), and application of theoretical frameworks.

DESIGN

This scoping review examined resilience and resilient pain behaviors for those with CLBP in relation to resilience definitions, operationalization (e.g. trait or behavior), and application of theoretical frameworks.

DATA SOURCES

To gather data, we used five databases: Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Ovid MEDLINE, PsycInfo, and Scopus.

REVIEW/ANALYSIS METHODS

Authors used a systematic data charting spreadsheet (Microsoft Excel) to review and analyze the extracted data.

RESULTS

A total of 26 articles, from 2011-2021, were included in the final analysis. A majority of articles were conducted in the United States (11) and cross-sectional secondary data analysis design (13). Resilience definitions varied across the studies. Three studies operationalized resilience as a trait and only one as a behavior. Most studies (20) did not include a theoretical framework.

CONCLUSION

The majority cross-sectional design and heterogeneity of a resilience definition indicates resilience research is still emerging. The lack of operationalized resilience, specifically as a behavior, and the limited use of theoretical frameworks suggest advancements in resilience pain research are needed.

NURSING PRACTICE IMPLICATIONS

This research has implications for nursing practice to support nurse's holistic perspective and the ability to incorporate resilience within nursing care. This research provides the initial steps to developing standard resilience definitions and frameworks to guide nursing practice.