P>"This should be a wake-up call to both parents and doctors that undiagnosed or untreated sleep apnea might hurt children's brains," lead author Dr. Ann C. Halbower, from Johns Hopkins University School of Medicine in Baltimore, said in a statement. "This is truly concerning because we saw changes that suggest injury in areas of the brain that house critical cognitive functions, such as attention, learning, and working memory."
Previous reports have tied childhood sleep apnea to deficits in memory, learning, and executive function, but until now, no studies have demonstrated neuronal injury.
As reported in the August 22nd online issue of the Public Library of Science Medicine, Dr. Halbower's team performed polysomnography and neuropsychologic assessments in 19 children with moderate to severe obstructive sleep apnea (apnea hypopnea index of at least 8) and in 12 healthy controls. Six of the sleep apnea patients and six matched controls underwent proton magnetic resonance spectroscopic imaging to assess neuronal physiology.
Consistent with earlier research, verbal working memory and verbal fluency were impaired in children with sleep apnea. In addition, the average IQ of the sleep apnea group was just 85.8 compared with 101.1 in the control group.
Spectroscopic imaging in sleep apnea patients revealed metabolic changes suggesting neuronal injury in the hippocampus and frontal cortex, the authors note.
"We cannot say with absolute certainty that sleep apnea caused the injury, but what we found is a very strong association between changes in the neurons of the hippocampus and the right frontal cortex and IQ and other cognitive functions in which children with OSA score poorly," Dr. Halbower noted.
Further research is needed to determine if early diagnosis and treatment of obstructive sleep apnea can reverse the deficits identified in the present study, the authors conclude.
PLoS Medicine 2006.
Last Updated: 2006-08-23 13:45:04 -0400 (Reuters Health)
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