Applications of laboratory pain methodologies in research with children and adolescents: emerging research trends.

Historically, laboratory pain research with children and adolescents has largely been conducted with healthy samples using the cold pressor task (CPT). Additional laboratory methodologies, commonly referred to as quantitative sensory testing (QST), include a variety of psychophysical tests assessing sensory perception (eg, pressure and heat tolerance) and sensory abnormalities. There is significant variation in QST protocols in terms of methodology (eg, number and type of measurement modalities) and data gleaned (eg, pain threshold vs central sensitization). Generally speaking, QST laboratory assessment methodologies yield measures of pain tolerance, pain threshold, or self-report of pain intensity. Studies utilizing these methods have greatly expanded knowledge of individual and social factors contributing to acute pain responses, including parental behavior [8], child sex differences, coping, distraction, catastrophizing, and anxiety [26]. CPT guidelines and reviews of use in pediatric pain research are available [4,34]. Additionally, researchers have begun to identify reference values and validate other QST protocols in healthy children and adolescents [5,23,30]. Despite the plethora of laboratory research examining pain responses in healthy children, much less is known about pain responses in pediatric clinical samples. In adult populations, laboratory pain research has proven useful for characterizing the neurobiology of chronic pain disorders [15,27]. The underlying biological, psychological, and motoric domains that contribute to the pain experience [31] change and becomemore complex as children move through childhood into adolescence and adulthood. Because youth are at risk for pain to persist into adulthood [6], a more complete understanding of factors that influence the onset and development of alterations in pain processing systems is critical. This information can be used to both inform lifespan models of pain conditions and to help identify potential targets for preventative interventions. This topical review aims to: (1) outline current knowledge of laboratory pain responses in clinical pediatric pain populations, (2) review emerging research methodologies, and (3) provide recommendations for future research that addresses gaps in the current literature. 2. Previous research with clinical pediatric pain populations