Aug. 21, 2006 -- Sleep apneain children can lead to brain cell damage and lowered intelligence, new research suggests.
These children also had lower IQ scores and they scored lower on standardized learning tests than children without the sleep disorder.
It is not clear if the injury is permanent or reversible with treatment for sleep apnea, but one of the study's researchers tells WebMD that there is an urgent need for additional research to find out.
"Sleep apnea is very treatable in children," pediatric lung specialist Ann C. Halbower, MD, says. "If it does cause permanent impairment in [brain] function that makes early treatment all the more important."
Sleep apnea is less common in children than in adults, but it is estimated that 2% of kids in the U.S. have some form of obstructed breathing during sleep. Enlarged tonsils and adenoids is the most common cause of sleep apnea in children, but obesityand chronic allergiescan also be a cause.
Functional brain imaging studies in adults with sleep apnea have identified abnormalities in three key regions of the brain associated with learning and memory -- the frontal cortex, the cerebellum, and the hippocampus. Although studies have also linked sleep apnea in children with memory problems, lowered intelligence, and other behavioral issues, it has not been clear if they experience the same brain changes as adults do.
In an effort to answer this question, Halbower and colleagues from Johns Hopkins University School of Medicine in Baltimore conducted specialized brain imaging studies on children with severe sleep apnea and on children without the disorder. They also conducted IQ tests and performed other standardized tests designed to measure verbal performance, memory, and learning skills.
The average IQ score among the children with sleep apnea was in the low-normal range and was 16 points lower than children without the sleep breathing disorder (85 vs. 101). Children with sleep apnea also scored consistently lower on the other performance tests.
The brain imaging studies in the children with sleep apnea showed decreased activity in regions similar to those shown in adult studies.
Wake-up Call for Parents, Pediatricians
Halbower tells WebMD that the findings should serve as a wake-up call for both parents and pediatricians about the importance of treating sleep-breathing problems in children.
She adds that the importance of determining if the brain changes are permanent or can be reversed with effective treatment for sleep apneacannot be overemphasized.
Surgery is the treatment of choice for kids with enlarged tonsils and adenoids, and other treatments are available for those with restricted nighttime breathing due to other causes.
"These findings highlight the importance of recognizing and treating sleep-disordered breathing in children as soon as possible," Halbower says. "Sleep is critical for learning and brain function, so parents should not hesitate to discuss sleep disturbance with their child's pediatrician."
A child who snores regularly and also exhibits signs of abnormal daytime sleepiness, irritability, or hyperactivity may have sleep apnea. Sleep apnea-related behavioral problems are often misdiagnosed as attention deficit hyperactivity disorder (ADHD).
Atlanta mom Susan Williams is a believer. Her now 4-year-old daughter Zelda's severe sleep apnea led to speech delays and constant daytime sleepiness. Surgery six months ago to remove enlarged tonsils and adenoids has made all the difference, Williams says.
"She is a different kid," she says. "Almost immediately after the surgery her speech began to improve and she is much more alert during the day. It just makes sense that if a kid is not getting the oxygen they need then they aren't going to develop as well mentally or physically."