Investigating the relationship between pain indicators and observers' judgements of pain.

BACKGROUND: Due to the inherent subjectivity of pain, it is difficult to make accurate judgements of pain in others. Research has found discrepancies between the ways in which perceived "objective" (e.g., medical evidence of injury) and "subjective" information (e.g., self-report) influence judgements of pain. This study aims to explore which potential cues (depictions of sensory input, brain activation, self-reported pain and facial expressions) participants are most influenced by when evaluating pain in others. METHODS: First, 60 participants (23 women, 36 ± 10 years old) judged who was in more pain between two different pain indicators representing two different patients. These trials revealed which congruent indicator (i.e., two high pain indicators) would most influence participant decisions. Second, participants prescribed quantities of analgesia for one patient's pain based on two different pain indicators. These trials revealed which incongruent indicators (i.e., one high and one low indicator) would most influence participant decisions. RESULTS: As predicted, facial expressions were perceived as subjective and were the least likely, among all pain indicators, to influence observer's judgements of pain. Participants relied upon indicators they perceived as objective. Self-report pain ratings had the greatest influence on participants judgements about how much analgesic cream to prescribe and was perceived as objective by half of the participants. CONCLUSIONS: We found that in situations where incongruent information was presented about an individual's pain, participants relied on pain indicators that they perceived to be objective. The current study provides important insights about biases that people hold when making judgements of pain in others. SIGNIFICANCE: Interpretation and assessment of pain remains one of the largest barriers to pain management and involves complex, idiosyncratic processing. This study provides insights into what information participants view as critical in making attributions of pain when presented with multiple, seemingly incongruent sources of information.

Investigation of the Relationships among Self-Efficacy, Stress, and Dyspareunia during the COVID-19 Pandemic.

This study examined whether low self-efficacy and heightened perceived stress were associated with dyspareunia at two timepoints during COVID-19. Sixty-two participants (31 with and 31 without dyspareunia) completed a longitudinal online survey. Self-efficacy declined during the pandemic, and individuals with dyspareunia reported lower self-efficacy compared to those without dyspareunia. Although stress was greater for those with dyspareunia, both groups reported stress reductions over time. Lower stress was associated with increases in self-efficacy. This study is the first to examine longitudinal trends of dyspareunia during the COVID-19 pandemic and illuminates psychological factors that may influence the experience of dyspareunia.

The chronic disease helplessness survey: developing and validating a better measure of helplessness for chronic conditions.

Introduction: Learned helplessness develops with prolonged exposure to uncontrollable stressors and is therefore germane to individuals living with pain or other poorly controlled chronic diseases. This study has developed a helplessness scale for chronic conditions distinct from previous scales that blur the conceptualization of control constructs. Extant measures commonly examine controllability, not the three pillars of helplessness identified by Maier and Seligman (1976): cognitive, emotional, and motivational/motor deficits. Methods: Individuals who self-report a chronic pain condition (N = 350) responded to a Chronic Disease Helplessness Survey (CDHS) constructed to capture cognitive, motivational/motor, and emotion deficits. Exploratory factor analysis (EFA; N = 200) and confirmatory factor analysis (CFA; N = 150) were performed. The CDHS was assessed for convergent and discriminant validity. Results: A three-factor solution corresponding to cognitive, emotional, and motivational/motor factors was identified by EFA. The solution exhibited sufficient model fit and each factor had a high degree of internal consistency. The CDHS was significantly associated with greater pain intensity and interference, PCS helplessness, lower perceived pain control, and lower general self-efficacy. Individuals with diabetes generally experience greater control strategies over daily symptoms (e.g., diet, oral medications, and insulin) than patients with chronic pain and in this study displayed significantly lower CDHS scores compared to individuals with chronic pain, demonstrating discriminant validity. Conclusions: This study provides preliminary evidence that the three-factor CDHS is a psychometrically sound measure of helplessness in individuals with chronic pain.

An Investigation of Descending Pain Modulation in Women With Provoked Vestibulodynia: Alterations of Brain Connectivity.

Provoked Vestibulodynia (PVD) is the most common vulvodynia subtype (idiopathic chronic vulvar pain). Functional magnetic resonance imaging (fMRI) studies indicate that women with PVD exhibit altered function in a number of pain modulatory regions in response to noxious stimulation, such as in the secondary somatosensory cortex, insula, dorsal midcingulate, posterior cingulate, and thalamus. However, previous neuroimaging studies of PVD have not examined periods of time before and after noxious stimulation or investigated functional connectivity among pain modulatory regions. Fourteen women with PVD and 14 matched Control participants underwent five fMRI runs with no painful stimuli interleaved randomly with five runs with calibrated, moderately painful heat stimuli applied to the thenar eminence. As recent findings indicate that pain processing begins before and continues after painful stimulation, 2-min periods were included in each run before and after the stimulus. Functional brain connectivity was assessed during both trials of Pain and No Pain stimulation for each group using structural equation modeling (SEM). Analyses of variance (ANOVAs) on connectivity values demonstrated significant main effects of study condition, and group, for connectivity among pain modulatory regions. Most of the differences between the Pain and No Pain conditions found only in the PVD group take place before (i.e., thalamus to INS, ACC to S1, thalamus to S1, and thalamus to S2) and after pain stimulation (i.e., INS to amygdala, PPC to S1, and thalamus to S2). Such differences were not observed in the Control group. These findings further support previous results indicating that women with PVD have altered pain processing compared to pain-free women.

An Investigation of Descending Pain Modulation in Women With Provoked Vestibulodynia (PVD): Alterations of Spinal Cord and Brainstem Connectivity.

The most common subtype of vulvodynia (idiopathic chronic vulvar pain) is provoked vestibulodynia (PVD). Previous imaging studies have shown that women with vulvodynia exhibit increased neural activity in pain-related brain regions (e.g., the secondary somatosensory cortex, insula, dorsal midcingulate, posterior cingulate, and thalamus). However, despite the recognized role of the spinal cord/brainstem in pain modulation, no previous neuroimaging studies of vulvodynia have examined the spinal cord/brainstem. Sixteen women with PVD and sixteen matched Control women underwent a spinal cord/brainstem functional magnetic resonance imaging (fMRI) session consisting of five runs with no painful thermal stimuli (No Pain), interleaved randomly with five runs with calibrated, moderately painful heat stimulation (Pain). Functional connectivity was also assessed in periods before, during, and after, pain stimulation to investigate dynamic variations in pain processing throughout the stimulation paradigm. Functional connectivity in the brainstem and spinal cord for each group was examined using structural equation modeling (SEM) for both Pain and No Pain conditions. Significant connectivity differences during stimulation were identified between PVD and Control groups within pain modulatory regions. Comparisons of Pain and No Pain conditions identified a larger number of connections in the Control group than in the PVD group, both before and during stimulation. The results suggest that women with PVD exhibit altered pain processing and indicate an insufficient response of the pain modulation system. This study is the first to examine the spinal cord/brainstem functional connectivity in women with PVD, and it demonstrates altered connectivity related to pain modulation in the spinal cord/brainstem.

Exploring the neural correlates of touch and pain in women with provoked vestibulodynia.

Group differences in touch and pain thresholds-and their neural correlates-were studied in women with provoked vestibulodynia (PVD; N = 15), a common subtype of vulvodynia (chronic vulvar pain), and pain-free control women (N = 15). Results from quantitative sensory testing and self-report measures indicated that, as compared with control participants, women with PVD exhibited allodynia (ie, pain in response to a normally nonpainful stimulus) and hyperalgesia (ie, an increased response to a normally painful stimulus) at vulvar and nonvulvar sites. In addition, brain imaging analyses demonstrated reduced difference scores between touch and pain in the S2 area in women with PVD compared with control participants, supporting previous findings of allodynia in women with PVD. There were no significant reductions in difference scores between touch and pain for regions related to cognitive and affective processing of painful stimuli. The results of this study contribute important information to the general pain and vulvodynia literatures in elucidating the specific sensorimotor neural mechanisms that underlie hyperalgesia in a chronic pain population. These results have implications for differentiating neural processing of touch and pain for women with and without PVD. Future research should attempt to examine alterations related to hyperalgesia in commonly comorbid conditions of PVD.

Detectable Viral Load May Be Associated with Increased Pain Sensitivity in Persons Living with HIV: Preliminary Findings.

OBJECTIVE: Animal models have previously shown that HIV is associated with hyperalgesia, or heightened sensitivity to painful stimuli. Efforts to determine whether this finding translates to humans are presently lacking. Among persons living with HIV (PLWH), those with detectable viral loads may be at greatest risk for heightened pain sensitivity. It was hypothesized that PLWH with detectable viral loads would be more sensitive to painful stimuli compared with PLWH without detectable viral loads and healthy controls without HIV. DESIGN: A total of 47 PLWH and 50 community-dwelling, healthy adults without HIV (controls) were recruited. Participants completed a quantitative sensory testing protocol to assess threshold, tolerance, and temporal summation in response to painful mechanical and heat stimuli. Most recent viral load was collected from medical records, and viral load was considered detectable if the count was greater than 50 copies/mL of blood. Of the 47 PLWH, 11 (23.4%) had detectable viral loads, the median viral load count was 10,200 copies/mL. RESULTS: PLWH with detectable viral loads demonstrated significantly lower pain thresholds for mechanical stimuli (F2,89 = 3.15, P = 0.049), significantly lower heat pain tolerances (F2,89 = 3.38, P = 0.039), and significantly greater temporal summation of heat pain at 48 °C (F2,89 = 10.66, P < 0.001) and 50 °C (F2,89 = 3.82, P = 0.026), compared with PLWH without detectable viral loads and healthy controls. CONCLUSIONS: These preliminary results tentatively suggest that the detectable presence of the virus may sensitize PLWH to painful mechanical and heat stimuli.

A novel zebrafish-based model of nociception.

Chronic pain affects the lives of millions yearly, but few new treatments are available. Due to decreasing budgets and increasing costs of preclinical research, alternatives are sought with high translatability and low cost. Here we demonstrate the utility of a zebrafish-based model of nociception to serve as a novel screening tool for analgesic drugs. Zebrafish swimming behavior was measured following administration of various algogens including histamine, cinnamaldehyde, mustard oil, acetic acid and complete Freund's adjuvant. All compounds reduce distance traveled, thought to be an expression of nociception. Additionally, the suppression of swimming was attenuated by administration of the common analgesic, morphine. Together these data provide support for the use of zebrafish as a cost-effective and translatable model of nociception.