Characterizing Fatigue Subtypes in Adolescents with Chronic Musculoskeletal Pain and Pain-Free Controls.

Context: General fatigue, sleep-related fatigue, and cognitive fatigue are prevalent and disruptive in adults with chronic musculoskeletal (MSK) pain, but little is known about these fatigue subtypes in pediatric musculoskeletal pain. Objective: To compare fatigue and its subtypes between adolescents with chronic MSK pain and pain-free controls and to test if fatigue subtypes were associated with concurrent pain and its impact (pain intensity, number of pain sites, pain interference, and functional disability) or experimental pain (intensity and tolerance) in adolescents with chronic MSK pain. Finally, we sought to explore adolescents' qualitative characterizations of their fatigue. Methods: Adolescents with chronic MSK pain (12-17 y.o., n = 26) and pain-free controls (n = 26) completed validated self-report measures of fatigue, pain, and functional disability, underwent an experimental pain tolerance task (cold water immersion of the hand), and provided qualitative descriptions of their fatigue (pain group only). Results: Adolescents with chronic MSK pain reported significantly greater general, sleep-related, and cognitive fatigue than pain-free controls (all p's < 0.001). In adolescents with chronic MSK pain, fatigue subtypes were associated with clinical pain and pain impact (r's = 0.43-0.84) but not experimental pain measures (p's > 0.05). Adolescents with chronic MSK pain qualitatively described the negative implications of the different fatigue subtypes, particularly when perceived as long-lasting. Conclusion: This preliminary study suggests that fatigue subtypes are prevalent and impactful in pediatric patients with chronic MSK pain. When planning multi-disciplinary treatment for pediatric MSK pain, providers should recognize fatigue as another disabling symptom.

Pediatric sickle cell pain-sleep relationships: The roles of positive and negative affect.

OBJECTIVE: The current study investigated the role of affect in the daily sleep quality-pain severity relationship in youth with sickle cell disease (SCD). Previous investigations have not allowed researchers to examine whether positive and negative affect work differentially in their relations with pediatric SCD pain, sleep, and the sleep-pain relationship. The current study focused on examining the possible mediating and moderating roles positive and negative affect have in the sleep-pain relationship for youth with SCD. METHOD: Eighty-eight youth with SCD (aged 8-17 years), and their guardians were recruited from three regional pediatric SCD clinics. Youth completed a twice daily ecological momentary assessment, where they reported on their daily pain severity, sleep quality, positive affect and negative affect. Multilevel models were calculated to examine the relationship between negative affect, positive affect, and the sleep-pain relationship. RESULTS: Multilevel mediation analyses indicated that low positive affect mediated the daily cyclic relationships between poor sleep and high pain. Moderation analyses indicated that high negative affect strengthened the relationship between high pain severity and poor sleep quality that night. CONCLUSION: Further research is needed to examine the differential roles of positive and negative affect in other pain and adult SCD populations. Research examining the mechanisms by which positive and negative affect may influence the sleep-pain relationship is needed to inform future interventions to improve sleep and pain in the pediatric SCD population. (PsycInfo Database Record (c) 2021 APA, all rights reserved).