The impact of sleep-disordered breathing on cognition and behavior in children: A review and meta-synthesis of the literature CHARLES S. EBERT, JR, MD, MPH, and AMELIA F. DRAKE, MD, Chapel Hill, North Carolina OBJECTIVES: The goal of this review is to provide a synthesis of the current literature addressing the ef- fects of sleep-disordered breathing on cognition and behavior in children aged 2-18. STUDY DESIGN AND SETTING: A computerized search was performed to include studies between 1966 and 2001. Studies were assessed based on research question, sampling, intervention, out- comes, confounding, and statistical methods. Sen- sitivity analyses were performed for quantitative as- sessments of selection bias, misclassification, and confounding. RESULTS: Seventeen reports with 5312 patients were reviewed. The majority of these studies demon- strated poor sampling, insufficient consideration of confounders, and imprecise use of statistical tools. However, there was little evidence of bias in two studies when scrutinized using a sensitivity analysis. CONCLUSIONS: Despite suggested links between daytime behavior problems and neurocognitive deficits, there is little certainty for causality based on the quality of the evidence. SIGNIFICANCE: By discussing the quality of the cur- rent evidence, we hope to improve study design and contribute to the development of an under- standing of this complex topic. (Otolaryngol Head Neck Surg 2004;131:814-26.) S leep-disordered breathing (SDB) is a common prob- lem and in some form may affect up to 25% of men and 9% of women. 1 Since Guilleminault first recognized a pediatric form of obstructive sleep apnea (OSA) in 1976, SDB has become an increasingly recognized entity in children. 2,3 SDB represents a continuum of sleep-related breathing disturbances. At the severe end of the spec- trum is obstructive sleep apnea syndrome (OSAS), characterized by prolonged periods of complete or par- tial alveolar hypoventilation associated with sporadic arousals/sleep fragmentation, paradoxical chest wall movements, intermittent hypoxia, and hypercapnia. 4-7 The reported prevalence of pediatric OSAS ranges from 0.7% to 3.0%, which corresponds to roughly 500,000 children in the United States alone. 4,8-12 The peak in- cidence of OSAS is described to be from 2 to 5 years, which are the ages when tonsils and adenoids are the largest in relation to the underlying airway size. 7,13-16 Upper-airway resistance syndrome (UARS) falls in the mid portion of the spectrum and is not characterized by significant airflow obstruction or hypoxemia, but rather by periods of negative intrathoracic pressure during inspira- tion that result in sleep fragmentation and brief electroen- cephalogram arousals. 4 Most likely due to the difficulty in identifying UARS, its incidence and prevalence in chil- dren are not known. Some propose that UARS in children may be even more common than OSAS. 17 At the milder end of the spectrum lies primary snoring (PS), habitual snoring without disturbances in sleep architecture or problems of oxygenation. 18 The reported prevalence of PS in children ranges from 7% to 22%. 4,11,19-24 Milder forms of SDB may progress to more severe manifestations, and potential complications of unrecog- nized SDB could be dangerous. Studies have suggested that OSAS may cause systemic hypertension and asso- ciated right ventricular hypertrophy (RVH). 13,25-26 Hunt and colleagues claimed that as many as half of patients with OSAS have radiological and/or electro- cardiographic support of RVH. 27 Also, there have been reports of cardiac arrhythmias, cor pulmonale, and even deaths resulting from OSAS. 13,26-28 Complicating this issue further is that children tend to have a more subtle clinical presentation than adults, making the evaluation of the severity of the airway obstruction even more difficult. Rosen and others have suggested that children who snore are difficult to dif- ferentiate from those with OSAS. 14,28 In fact, children may have a higher degree of airway obstruction, sleep disturbance, and oxygenation problems than simply revealed by history and physical exam alone. 7 Leach et From the Department of Otolaryngology–Head and Neck Surgery, University of North Carolina School of Medicine, Chapel Hill, NC. Presented at the Annual Meeting of the American Academy of Otolaryngolo- gy–Head and Neck Surgery, Orlando, FL, September 21-24, 2003. Reprint requests: Charles S. Ebert, Jr, Department of Otolaryngology–Head and Neck Surgery, CB# 7070, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7070; e-mail, cebert@med.unc.edu 0194-5998/$30.00 Copyright © 2004 by the American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. doi:10.1016/j.otohns.2004.09.017 814