Objective-Sleep-disordered breathing describes a spectrum of upper airway obstruction in sleep from simple primary snoring, estimated to affect 10% of preschool children, to the syndrome of obstructive sleep apnea. Emerging evidence has challenged previous assumptions that primary snoring is benign. A recent report identified reduced attention and higher levels of social problems and anxiety/depressive symptoms in snoring children compared with controls. Uncertainty persists regarding clinical thresholds for medical or surgical intervention in sleep-disordered breathing, underlining the need to better understand the pathophysiology of this condition. Adults with sleepdisordered breathing have an increased risk of cerebrovascular disease independent of atherosclerotic risk factors. There has been little focus on cerebrovascular function in children with sleep-disordered breathing, although this would seem an important line of investigation, because studies have identified abnormalities of the systemic vasculature. Raised cerebral blood flow velocities on transcranial Doppler, compatible with raised blood flow and/or vascular narrowing, are associated with neuropsychological deficits in children with sickle cell disease, a condition in which sleepdisordered breathing is common. We hypothesized that there would be cerebral blood flow velocity differences in sleep-disordered breathing children without sickle cell disease that might contribute to the association with neuropsychological deficits.Design-Thirty-one snoring children aged 3 to 7 years were recruited from adenotonsillectomy waiting lists, and 17 control children were identified through a local Sunday school or as siblings of cases. Children with craniofacial abnormalities, neuromuscular disorders, moderate or severe learning disabilities, chronic respiratory/cardiac conditions, or allergic rhinitis were excluded. Severity of sleep-disordered breathing in snoring children was categorized by attended polysomnography. Weight, height, and head circumference were measured in all of the children. BMI and occipitofrontal circumference z scores were computed. Resting systolic and diastolic blood Address correspondence to Catherine M. Hill, BM, MSc, MRCP, FRCPCH, University of Southampton-Child Health, Mail Point 803, Southampton General Hospital, Southampton, Hampshire SO16 6YD, United Kingdom. Email: cmh2@soton.ac.uk The authors have indicated they have no financial relationships relevant to this article to disclose.Drs Hill and Hogan contributed equally to this work and share first authorship. NIH Public Access Author ManuscriptPediatrics. Author manuscript; available in PMC 2007 October 1. Published in final edited form as:Pediatrics. 2006 October ; 118(4): e1100-e1108. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript pressure were obtained. Both sleep-disordered breathing children and the age-and BMI-similar controls were assessed using the Behavior Rating Inventory of Executive Function (BRIEF), Neuropsychological Test Battery...