islamabad - Sleep apnea, a common condition in which breathing briefly stops during the night, may reduce the amount of gray matter in a child’s brain, finds a recent study.

The study team was headed up by Dr. Leila Kheirandish-Gozal, director of pediatric clinical sleep research at the University of Chicago. The team worked in conjunction with researchers from the University of California at Los Angeles, who analyzed the images.

The test results and brain scans were compared with a further nine children without sleep apnea, matched for gender, age, weight, and ethnicity. They also compared the children with sleep apnea with a database of 191 MRI scans in a pre-existing National Institutes of Health (NIH) database.

Once the analysis was complete, the results were striking. The children with obstructive sleep apnea had substantial reductions in the volume of gray matter - the information processing part of the brain. These gray matter losses appeared in a range of brain regions, including:

Although reduction in gray matter was measured, the impact of these deficits cannot yet be assessed. Also, because the children’s brains were not scanned before the obstructive sleep apnea began, it is impossible to know when and how the damage occurred.

As co-author Dr. David Gozal says, “MRI scans give us a bird’s eye view of the apnea-related difference in volume of various parts of the brain, but they don’t tell us, at the cellular level, what happened to the affected neurons or when.” He continues: “The scans don’t have the resolution to determine whether brain cells have shrunk or been lost completely.”

Although the study was only conducted on a small number of children with sleep apnea, the findings are concerning. Substantial loss of gray matter is likely to have an impact on cognitive performance. As Dr. Gozal says:

“If you’re born with a high IQ - say 180 - and you lose 8-10 points, which is about the extent of IQ loss that sleep apnea will induce on average, that may never become apparent. But if your IQ as a child was average, somewhere around 90-100, and you had sleep apnea that went untreated and lost 8-10 points, that could potentially place you one standard deviation below normal. No one wants that.”

Future research will be needed to back up and expand on the current results, published this week in the journal Scientific Reports. There are now many more questions that are begging an answer, such as, importantly, can these changes be reversed?

Because sleep apnea is a treatable disorder, parents who are concerned that their child may have the condition should not delay in having it checked out by an expert.