Brain Tissue Integrity and Autonomic Function Alterations in Childhood OSA and ADHD, and After Adenotonsillectomy.

Obstructive sleep apnea (OSA) and attention-deficit/hyperactivity disorder (ADHD) are two common, severe disorders in children. Unfortunately, pediatric OSA is closely associated with ADHD, and both diseases can cause cognitive impairment, behavior problems, and low academic performance. OSA can damage the brain and induce autonomic dysfunction, and then cause cognitive, behavioral, and quality-of-life problems. The presence of ADHD can further exacerbate these adverse effects of OSA. Therefore, the identification of robust biomarkers of OSA and ADHD is a key imperative to facilitate early identification of the pathological features and mechanisms and to optimize the treatment of OSA and ADHD for the pediatric population. Diffusion MRI of the brain is one of the most widely used technology for assessment of brain tissue integrity and heart rate variability is one of the most widely used measurements of autonomic function. However, the effects of ADHD and adenotonsillectomy on MRI and HRV biomarkers in children with OSA have not been reported. We hypothesize that comorbid ADHD can deteriorate brain damage and autonomic dysfunction, and adenotonsillectomy can reverse these alternations in children with OSA. The aims of this study are (1) to investigate the differences in pediatric brain tissue integrity, autonomic function, attention, behavior, quality-of-life, and sleep factors between the 'OSA with ADHD', 'OSA without ADHD', and 'healthy control' group; (2) to evaluate the efficacy of adenotonsillectomy versus watchful waiting with supportive care, with respect to the same variables of interest; (3) to evaluate whether the relative efficacy of the treatment differs according to baseline ADHD, weight, or OSA severity; and (4) to develop a predictive model for surgical success rate using both conventional well-known factors and MRI/HRV biomarkers. This is a 3-year prospective study that includes two parts. The Part I study is a cross-sectional study recruiting 100 chi