Overview of neurodevelopment and pain research, possible treatment targets

Growing up with chronic pain: a systematic review of the evidence in transitional care for young people with chronic pain

Objective

Paediatric chronic pain presents a significant individual and societal burden, with an estimated prevalence of 11–38%. A large proportion of adolescents with chronic pain will have unresolved pain that continues into adulthood and thus requires transitional care. The aim of this review was to investigate the current evidence for the core components of effective transitional care interventions designed for young people with chronic pain.

Methods

Studies were identified by searching the Embase, MEDLINE, CINAHL and PsycINFO databases. A search strategy using terms such as ‘Adolescent’, ‘Persistent long-term pain’ and ‘Transition’ (or variations of such words) was implemented. Inclusion criteria were sample population age 10–24 years, a confirmed diagnosis of a condition characterized by chronic pain, any healthcare setting, any service provider, published peer reviewed and English language.

Results

Ninety-eight articles were identified by the search and 14 were selected after abstract screening. Two independent reviewers screened the articles, followed by a senior reviewer. Of the 14 articles, full-text review found that none of the articles looked specifically at evidence with respect to core components of effective transitional care designed for young people with chronic pain.

Conclusion

Chronic pain is a feature of many long-term health conditions. It remains unknown as to whether there are any pain-specific aspects of transitional care. How pain management is addressed in existing transitional care provision and the relationship of pain to outcomes needs further research. If effective interventions can be provided during these crucial years, the trajectory of these young people can potentially be improved into adulthood.

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.

Transitional Pain Care in Quebec: Did We Forget Our Youths? A Brief Research Report

Adolescents and young adults (AYAs) represent a unique population with distinct psycho-social risks and care needs. About 10% of AYAs live with chronic pain (CP) and transition to adult pain care between 16 and 25 years of age. These transitions in care happen simultaneously with other bio-psycho-social changes and require flexible multi-disciplinary support models. As it stands, transitional pain care appears suboptimal, fragmented, and opportunistic in Quebec (Canada). The objective of this Brief Report is, therefore, to present our study findings and propose a multi-disciplinary transitional framework vision applicable to AYAs living with CP. Data were collected using a sequential-consensual qualitative design with a longitudinal participatory component. The consecutive stages of this work included an exploratory stage, semi-structured interviews with primary care providers, and inter-disciplinary deliberative stakeholder consultation groups. The deductive inductive thematic approach and the three-level Health Care Transition Research Consortium's theoretical framework were used to analyze the data. A representative group of stakeholders discussed findings from the first two steps, made fifteen actionable recommendations and formulated their vision of a transitional pain care model that can be further adapted in other settings. The study results present important insights into various psycho-social factors associated with transitional pain care for AYAs.

Effectiveness of eHealth and mHealth Interventions Supporting Children and Young People Living With Juvenile Idiopathic Arthritis: Systematic Review and Meta-analysis

BACKGROUND

Juvenile idiopathic arthritis (JIA) management aims to promote remission through timely, individualized, well-coordinated interdisciplinary care using a range of pharmacological, physical, psychological, and educational interventions. However, achieving this goal is workforce-intensive. Harnessing the burgeoning eHealth and mobile health (mHealth) interventions could be a resource-efficient way of supplementing JIA management.

OBJECTIVE

This systematic review aims to identify the eHealth and mHealth interventions that have been proven to be effective in supporting health outcomes for children and young people (aged 1-18 years) living with JIA.

METHODS

We systematically searched 15 databases (2018-2021). Studies were eligible if they considered children and young people (aged 1-18 years) diagnosed with JIA, an eHealth or mHealth intervention, any comparator, and health outcomes related to the used interventions. Independently, 2 reviewers screened the studies for inclusion and appraised the study quality using the Downs and Black (modified) checklist. Study outcomes were summarized using a narrative, descriptive method and, where possible, combined for a meta-analysis using a random-effects model.

RESULTS

Of the 301 studies identified in the search strategy, 15 (5%) fair-to-good-quality studies met the inclusion criteria, which identified 10 interventions for JIA (age 4-18.6 years). Of these 10 interventions, 5 (50%) supported symptom monitoring by capturing real-time data using health applications, electronic diaries, or web-based portals to monitor pain or health-related quality of life (HRQoL). Within individual studies, a preference was demonstrated for real-time pain monitoring over recall pain assessments because of a peak-end effect, improved time efficiency (P=.002), and meeting children's and young people's HRQoL needs (P<.001) during pediatric rheumatology consultations. Furthermore, 20% (2/10) of interventions supported physical activity promotion using a web-based program or a wearable activity tracker. The web-based program exhibited a moderate effect, which increased endurance time, physical activity levels, and moderate to vigorous physical activity (standardized mean difference [SMD] 0.60, SD 0.02-1.18; I²=79%; P=.04). The final 30% (3/10) of interventions supported self-management development through web-based programs, or apps, facilitating a small effect, reducing pain intensity (SMD -0.14, 95% CI -0.43 to 0.15; I²=53%; P=.33), and increasing disease knowledge and self-efficacy (SMD 0.30, 95% CI 0.03-0.56; I²=74%; P=.03). These results were not statistically significant. No effect was seen regarding pain interference, HRQoL, anxiety, depression, pain coping, disease activity, functional ability, or treatment adherence.

CONCLUSIONS

Evidence that supports the inclusion of eHealth and mHealth interventions in JIA management is increasing. However, this evidence needs to be considered cautiously because of the small sample size, wide CIs, and moderate to high statistical heterogeneity. More rigorous research is needed on the longitudinal effects of real-time monitoring, web-based pediatric rheumatologist-children and young people interactions, the comparison among different self-management programs, and the use of wearable technologies as an objective measurement for monitoring physical activity before any recommendations that inform current practice can be given.

Trajectories of pain severity in juvenile idiopathic arthritis: results from the Research in Arthritis in Canadian Children Emphasizing Outcomes cohort

We studied children enrolled within 90 days of juvenile idiopathic arthritis diagnosis in the Research in Arthritis in Canadian Children Emphasizing Outcomes (ReACCh-Out) prospective inception cohort to identify longitudinal trajectories of pain severity and features that may predict pain trajectory at diagnosis. A total of 1062 participants were followed a median of 24.3 months (interquartile range = 16.0-37.1 months). Latent trajectory analysis of pain severity, measured in a 100-mm visual analogue scale, identified 5 distinct trajectories: (1) mild-decreasing pain (56.2% of the cohort); (2) moderate-decreasing pain (28.6%); (3) chronically moderate pain (7.4%); (4) minimal pain (4.0%); and (5) mild-increasing pain (3.7%). Mean disability and quality of life scores roughly paralleled the pain severity trajectories. At baseline, children with chronically moderate pain, compared to those with moderate-decreasing pain, were older (mean 10.0 vs 8.5 years, P = 0.01) and had higher active joint counts (mean 10.0 vs 7.2 joints, P = 0.06). Children with mild-increasing pain had lower joint counts than children with mild-decreasing pain (2.3 vs 5.2 joints, P < 0.001). Although most children with juvenile idiopathic arthritis in this cohort had mild or moderate initial levels of pain that decreased quickly, about 1 in 10 children had concerning pain trajectories (chronically moderate pain and mild-increasing pain). Systematic periodic assessment of pain severity in the months after diagnosis may help identify these concerning pain trajectories early and lay out appropriate pain management plans. Focused research into the factors leading to these concerning trajectories may help prevent them.

Down-Regulation of Cough during Exercise Is Less Frequent in Healthy Children than Adults. Role of the Development and/or Atopy?

Cough is typically associated with physical activity in children with asthma, but the characteristics of the relationship between cough and exercise has not been established under physiological conditions. The aim of the study was to describe the effect of exercise on the reflex cough response elicited by a single breath of capsaicin in non-asthmatic children. A group of non-asthmatic adults was studied as reference. Thirty children and 29 adults were recruited. The cough reflex sensitivity to capsaicin was first determined to establish the dose that provokes 5 cough efforts (C5). The number of coughs elicited by C5 (NC5) was then compared at baseline and during a standardized submaximal treadmill exercise. Data are expressed as median (interquartile range). Children and adults showed a significant decrease in NC5 (respectively from 5.0 (4.0–6.0) to 2.5 (2.0–4.0), p < 0.0005 and from 6.0 (5.0–7.0) to 2.0 (0.0–3.0, p < 0.0005). During exercise, NC5 was observed to decrease in all adult subjects, but in only 24/30 children (80%, p = 0.02). A trend for a higher incidence of personal and familial atopy was observed in children that lacked cough down-regulation during exercise compared with other children. It is concluded that the cough reflex response to capsaicin is down regulated by exercise in both children and adults. The effect however is less consistently observed in the former. The difference may reflect maturation of descending inhibitory pathways of the cough reflex, but may also be associated to atopy. The data stress the importance of assessing the time relationship of cough and exercise in questionnaire studies of asthma.

Impact of Air Pollution on Age and Gender Related Increase in Cough Reflex Sensitivity of Healthy Children in Slovakia

BACKGROUND

Numerous studies show higher cough reflex sensitivity (CRS) and cough outcomes in children compared to adults and in females compared to males. Despite close link that exists between cough and environment the potential influence of environmental air pollution on age- and gender -related differences in cough has not been studied yet.

PURPOSE

The purpose of our study was to analyse whether the effects of exposure to environmental tobacco smoke (ETS) from parental smoking and PM10 from living in urban area are implied in age- and gender-related differences in cough outcomes of healthy, non-asthmatic children. Assessment of CRS using capsaicin and incidence of dry and wet cough was performed in 290 children (mean age 13.3 ± 2.6 years (138 females/152 males).

RESULTS

CRS was significantly higher in girls exposed to ETS [22.3 μmol/l (9.8-50.2 μmol/l)] compared to not exposed girls [79.9 μmol/l (56.4-112.2 μmol/l), p = 0.02] as well as compared to exposed boys [121.4 μmol/l (58.2-253.1 μmol/l), p = 0.01]. Incidence of dry cough lasting more than 3 weeks was significantly higher in exposed compared to not exposed girls. CRS was significantly higher in school-aged girls living in urban area [22.0 μmol/l (10.6-45.6 μmol/l)] compared to school-aged girls living in rural area [215.9 μmol/l (87.3-533.4 μmol/l); p = 0.003], as well as compared to teenage girls living in urban area [108.8 μmol/l (68.7-172.9 μmol/l); p = 0.007]. No CRS differences were found between urban and rural boys when controlled for age group. No CRS differences were found between school-aged and teenage boys when controlled for living area.

CONCLUSIONS

Our results have shown that the effect of ETS on CRS was gender specific, linked to female gender and the effect of PM10 on CRS was both gender and age specific, related to female gender and school-age. We suggest that age and gender related differences in incidence of cough and CRS might be, at least partially, ascribed to the effect of environmental pollutants. The role of age and gender in the effect of air pollution on cough strongly suggest some interplay of development with biological and behavioral factors.

An examination of sex differences in the effects of early-life opiate and alcohol exposure

Early-life exposure to drugs and alcohol is one of the most preventable causes of developmental, behavioural and learning disorders in children. Thus a significant amount of basic, animal and human research has focused on understanding the behavioural consequences and the associated neural effects of exposure to drugs and alcohol during early brain development. Despite this, much of the previous research that has been done on this topic has used predominantly male subjects or rodents. While many of the findings from these male-specific studies may ultimately apply to females, the purpose of this review is to highlight the research that has also examined sex as a factor and found striking differences between the sexes in their response to early-life opiate and alcohol exposure. Finally, we will also provide a framework for scientists interested in examining sex as a factor in future experiments that specifically examine the consequences of early-life drug and alcohol exposure.