title: [Common causes of sleep disturbances in Icelandic children who undergo sleep studies.].
abstract: BACKGROUND
  Sleep disturbances are common problems in children. Frequently, these problems are attributed to learned behavioral patterns, but little is known about organic causes of sleep disturbances in children. Obstructive sleep apnea (OSA) is a common cause of sleep disordered breathing in adults. Gastroesophageal reflux (GER) is also common in this population. Less is known about OSA and GER as potential causative agents of sleep disturbances in children, and these medical problems have not been addressed in Icelandic children. This study was designed to investigate the organic causes of sleep disordered breathing in Icelandic children, evaluate their severity and possible therapies.
  
  
  METHODS
  One hundred and ninty children who were referred to the Pediatric Department at Reykjavik Hospital due to sleep disturbances were hospitalized over night and a sleep study was recorded, using the sleep equipment, EMBLA. The latter machine has 16 channels that record informations about sleep patterns and breathing. The children were 0-18 years of age. Informations were collected from EEGs, EMGs, and eye movements to determine sleep stages, and with respiratory belts with sensors on the chest and abdomen as well as an air-flow sensor that measures airflow through the nose and mouth. When GER was suspected, a pH meter was inserted and the pH values were measured in the upper and lower parts of the esophagus.
  
  
  RESULTS
  The results demonstrate that a large number of children who suffer from sleep disturbances have an underlying disease. Of 61 children who underwent a sleep study and were suspected to have OSA, 46 had a positive study that resulted in a change in therapy. In addition, 69 of 89 children who underwent pH measurements in the esophagus were diagnosed with GER which prompted changes in therapy.
  
  
  CONCLUSIONS
  The study demonstrates that both OSA and GER are common problems in children with sleep disturbances. We conclude that sleep studies are important in the overall workup of children with sleep disturbances, and can provide valuable informations regarding the causes, prevalence and severity of these medical problems. Sleep studies also facilitate the selection of children who require specific treatments such as operation of the oropharynx or CPAP/BiPAP treatment for OSA, or drug therapy for GER.
authors.affiliation: Department of Childrens Medicine, Landspitali University Hospital, Fossvogi, 108 Reykjavík, Iceland. hakonh@landspitali.is.
authors.forename: H
authors.initials: H
authors.lastname: Hákonarson
authors.forename: A
authors.initials: A
authors.lastname: Thornórsson