FRIDAY, April 21, 2006 (HealthDay News) -- Abnormal sleep patterns and obstructive sleep apnea affect more than half of children with Down syndrome, but parents may not know whether their children have these problems, U.S. researchers report.
Based on the findings, they also advise that all parents of youngsters with Down syndrome get their child's sleep patterns tested by polysomnography by age 3 or 4.
Researchers at the Cincinnati Children's Hospital Medical Center conducted sleep studies on 56 children with Down syndrome, ages 4 months to 63 months. The children completed overnight polysomnography, which monitors brain waves, breathing, stages of sleep, and blood oxygen levels.
The results showed that that 32 (57 percent) of the children had abnormal polysomnography results and evidence of obstructive sleep apnea. When the researchers included an elevated "arousal index" (10 or more disturbances in sleep per hour), they found that 80 percent of the children had abnormal results.
Reporting in the April Archives of Otolaryngology - Head & Neck Surgery, they also noted that rapid eye movement (REM) sleep should make up 25 percent to 30 percent of sleep time in children younger than age five. Only nine of the children in this study spent more than 25 percent of their sleep time in REM sleep, however.
As part of the study, the children's parents were asked to complete surveys about their youngsters' sleep habits. Of the 35 parents who completed surveys, 69 percent reported that their children had no sleep problems -- even though 54 percent of those parents' children had abnormal polysomnography results.
Abnormal polysomnography results were found in 36 percent of children whose parents did report sleep problems in their children.
The findings lead the Cincinnati team to recommend polysomnography testing, "in all children with Down syndrome at age three to four years."
The National Down Syndrome Society has more about Down syndrome and health.