Conditioned Pain Modulation in Children: The Effects of Painful and Nonpainful Conditioning Stimuli.

Conditioned pain modulation (CPM), a psychophysical measure in which 1 pain stimulus (conditioning stimulus) is used to inhibit another pain stimulus (test stimulus), is an important indicator of endogenous pain inhibition in adults, but is understudied in children. Preliminary evidence suggests that CPM effects are present in healthy children and are more robust in adolescents. However, developmental differences in younger children are not well documented and few studies control for potential distraction effects of the conditioning stimulus (CS). Participants were 54 healthy children aged 6 to 12 years. After a baseline pressure pain threshold (PPT) test, participants underwent 2 conditioning trials in which PPT was assessed while they placed their left hand in a water bath maintained at either 12 °C (painful CS) or 22 °C (nonpainful sham CS) in counterbalanced order. Results revealed a significant CPM effect. PPT values were significantly higher relative to baseline during the painful CS trial; PPT during the nonpainful CS trial did not differ from baseline. There were no significant age differences in magnitude of CPM effect. The results indicate that children as young as 6 years of age demonstrate CPM, suggesting that descending inhibitory pathways may be better developed in young children than previously thought. PERSPECTIVE: This study was successful in producing inhibitory CPM effects in physically healthy children while controlling for sensory distraction. The findings provide strong evidence that the obtained CPM responses cannot be attributed to sensory distraction or other nonspecific effects. Future studies could utilize CPM paradigms to study various aspects of pediatric endogenous pain inhibition, in order to better predict pain responses and improve interventions.

Working memory and visual discrimination distraction tasks improve cold pressor pain tolerance in children.

OBJECTIVE: Distraction is a well-established pain management technique for children experiencing acute pain, although the mechanisms underlying the effectiveness of distraction are not well understood. It has been postulated that engagement of executive functions, such as working memory, may be a critical factor in attenuating pain via distraction. To test this hypothesis, we compared a 1-back task requiring engagement of working memory with a simple visual discrimination task demanding focused attention, but lower cognitive load (0-back). METHOD: Seventy-nine children (6-12 years old) underwent a baseline cold pressor trial followed by cold pressor trials in which they completed the visual discrimination and 1-back tasks in counterbalanced order. Executive functioning ability was assessed via the Wechsler Intelligence Scale for Children (5th Edition) working memory subscales and by parent report on the Behavior Rating Inventory of Executive Function, Second Edition (BRIEF®2). RESULTS: Children's pain tolerance improved in both the visual discrimination and 1-back conditions though a differential response to the 2 tasks was not observed. Age moderated the relation between executive functioning and response to distraction; older children with better executive functioning skills demonstrated greater improvements in both distraction interventions. CONCLUSIONS: Findings demonstrate the benefits of both visual discrimination and working memory distraction tasks for elementary-aged children experiencing acute pain. Further research is required in order to elucidate the role of executive functioning skills and cognitive load in enhancing distraction analgesia in children, with particular focus on determining optimal load and task difficulty in light of emerging executive functioning abilities in this age group. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The effects of auditory background noise and virtual reality technology on video game distraction analgesia.

Background and aims The present study was designed to evaluate the relative efficacy of two video game display modalities - virtual reality (VR) assisted video game distraction, in which the game is presented via a VR head-mounted display (HMD) helmet, versus standard video game distraction, in which the game is projected on a television - and to determine whether environmental context (quiet versus noisy) moderates the relative efficacy of the two display modalities in reducing cold pressor pain in healthy college students. Methods Undergraduate students (n=164) were stratified by sex and self-reported video game skill and were randomly assigned to a quiet or a noisy environment. Participants then underwent three cold pressor trials consisting of one baseline followed by two distraction trials differing in display modality (i.e. VR-assisted or standard distraction) in counter-balanced order. Results Participants experienced improvement in pain tolerance from baseline to distraction in both display modality conditions (p<0.001, partial η2=0.41), and there was a trend toward greater improvement in pain tolerance from baseline to distraction when using the VR HMD helmet than during standard video game distraction (p=0.057, partial η2=0.02). Participants rated pain as more intense when experienced with concurrent experimental background noise (p=0.047, partial η2=0.02). Pain tolerance was not influenced by the presence or absence of background noise, and there was not a significant interaction between display modality and noise condition. Though exploratory sex analyses demonstrated a significant three-way interaction between noise condition, sex, and display modality on pain intensity (p=0.040, partial η2=0.040), follow-up post-hoc analyses conducted for males and females separately did not reveal significant differences in pain intensity based on the interaction between noise condition and display modality. Conclusions As expected, video game distraction both with and without an HMD helmet increased pain tolerance; however, the two display modalities only marginally differed in efficacy within the population under study. The effect of auditory background noise on pain was mixed; while pain tolerance did not vary as a function of the presence or absence of background noise, the addition of noise increased pain intensity ratings. The interaction between participant sex, noise condition, and distraction modality on pain intensity trended toward significance but would require replication in future research. Implications Results suggest that video game distraction via HMD helmet may be superior to standard video game distraction for increasing pain tolerance, though further research is required to replicate the trending findings observed in this study. Though it does not appear that background noise significantly impacted the relative efficacy of the two different video game display modalities, the presence of noise does appear to alter the pain response through amplified pain intensity ratings. Further research utilizing more sophisticated VR technology and clinically relevant background auditory stimuli is necessary in order to better understand the impact of these findings in real-world settings and to test the clinical utility of VR technology for pain management relative to standard video game distraction.