Sleep apnea in children tied to changes in gray matter

By Andrew M. Seaman

(Reuters Health) - In children with obstructive sleep apnea (OSA), areas of the brain involved with thinking and problem-solving appear to be smaller than in children who sleep normally, a study finds.

While the study can't show that the brain changes actually cause problems for children at home or school, researchers point out that OSA has been tied to behavior and cognitive problems.

"It really does seem that there is a change in the brain or that the brain is affected," said study author Paul Macey of the University of California, Los Angeles School of Nursing.

According to Macey and colleagues, up to 5% of all children are affected by OSA.

The researchers used magnetic resonance imaging to analyze gray matter volume in 16 children with OSA and 200 children without the condition, all between ages 7 and 11.

As reported online March 17 in Scientific Reports, children with OSA had decreases in gray matter volume throughout areas of the superior frontal and prefrontal, and superior and lateral parietal cortices. Other affected sites included the brainstem, ventral medial prefrontal cortex, and superior temporal lobe, mostly on the left side.

"Thus," the researchers write, "pediatric OSA subjects show extensive regionally-demarcated grey matter volume reductions in areas that control cognition and mood functions, even if such losses are apparently independent of cognitive deficits."

"Since OSA disease duration in our subjects is unknown, these findings may result from either delayed neuronal development, neuronal damaging processes, or a combination thereof, and could either reflect neuronal atrophy or reductions in cellular volume (neurons and glia)," they add.

Macey, who is also affiliated with the UCLA Brain Research Institute, said it's unclear how closely changes in the brain are connected to behavior, cognition and other issues.

"We know these two things are happening, but we’re not sure how much the reduced gray matter tracks with poor scores," he told Reuters Health.

Dr. Eliot Katz, of Harvard Medical School and Boston Children’s Hospital, said previous research shows treating OSA by removing tonsils and adenoids improves children's school performance, behavior and sleep-related issues. Evidence is mixed on whether it improves cognition.

Katz, who wasn't involved with the new study, said the previous research on problems faced by children with OSA - like behavior and cognition - is fitting nicely with the brain imaging studies.

"This is really the first large, really well controlled study that has found decrements in gray matter in children with obstructive sleep apnea," he told Reuters Health.

SOURCE: http://bit.ly/2mY9IFX

Scientific Reports 2017.

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