Enhancing Analgesia in Chronic Pain Through Exercise

This investigation is aimed at understanding how an exercise program currently performed at the Pediatric Pain Rehabilitation Center (PPRC) at Boston Children's Hospital, designed for individuals with chronic widespread pain is associated with pain relief and how this pain relief relates to changes in the brain. The specific aims/objectives are to explore the following: Aim 1 - Pain and sensorimotor behavior: To understand how thermal pain sensitivity, pain symptoms and motor performance are impacted in children with chronic pain after an exercise-based intervention. Sensory testing (for Hot \& Cold) will be collected using Quantitative Sensory Testing (QST) to establish pain thresholds. To address motor performance, we will perform the Bruininks-Oseretsky Test (BOT) 1 of motor proficiency (examining muscle power, strength, endurance). Pain symptom levels will be evaluated using self-report questionnaires that address fear of pain, pain catastrophizing, and pain symptom load. Aim 2 - Defining hierarchies during motor performance: To evaluate the brain regions involved in a simple motor task as well as how motor activity influences activity in pain regions. Participants will perform a tapping task within the MRI scanner to evaluate the brain regions that are active during motor control. 2 Functional magnetic resonance images will be processed using dynamic causal modeling (DCM) to evaluate effective connectivity (Figure 2) during task performance. Brain regions evaluated in DCM will be defined by the healthy control cohort. Aim 3 - Network structure: To evaluate the network structure of the brain, with emphasis on motor and pain regions, in persons with a pain disorder who have undergone an exercise intervention. Graph theory analyses implemented using resting-state functional magnetic resonance imaging will be performed to extract metrics reflecting network efficiency, nodal degree, and nodal centrality. Structural metrics (e.g., cortical thickness and white matter connectivity) will be collected as nuisance variables. Correlation analyses will be performed between network metrics and behavior (fear of pain, pain catastrophizing, motor performance) to evaluate their influence over network reorganization observed from the exercise intervention. Brain regions that define canonical pain and motor networks will be indexed from the healthy control group.