Untreated sleep apnea in children can harm brain cells tied to cognition and mood

March 17, 2017
Cortical regions of significantly reduced regional grey matter volume in OSA over control subjects (P < 0.01) displayed in yellow on the cortical surface on a single subject in MNI space. Credit: Mona Philby, Paul Macey, Richard Ma, Rajesh Kumar, David Gozal and Leila Kheirandish-Gozal

A study comparing children between 7 and 11 years of age who have moderate or severe obstructive sleep apnea to children the same age who slept normally, found significant reductions of gray matter - brain cells involved in movement, memory, emotions, speech, perception, decision making and self-control - in several regions of the brains of children with sleep apnea.

The finding points to a strong connection between this common disturbance, which affects up to five percent of all children, and the loss of neurons or delayed neuronal growth in the developing brain. This extensive reduction of in children with a treatable disorder provides one more reason for parents of children with symptoms of sleep apnea to consider early detection and therapy.

"The images of gray matter changes are striking," said one of the study's senior authors, Leila Kheirandish-Gozal, MD, director of pediatric clinical sleep research at the University of Chicago. "We do not yet have a precise guide to correlate loss of gray matter with specific cognitive deficits, but there is clear evidence of widespread neuronal damage or loss compared to the general population."

For this study, published March 17, 2017, in the journal Scientific Reports, the researchers recruited 16 children with (OSA). The children's sleep patterns were evaluated overnight in the University of Chicago's pediatric sleep laboratory. Each child also went through neuro-cognitive testing and had his or her brain scanned with non-invasive magnetic resonance imaging (MRI). Colleagues from the University of California at Los Angeles performed the image analysis.

The researchers compared those scans, plus neuro-cognitive test results, with MRI images from nine healthy children of the same age, gender, ethnicity and weight, who did not have apnea. They also compared the 16 children with OSA to 191 MRI scans of children who were part of an existing pediatric-MRI database assembled by the National Institutes of Health.

They found reductions in the volume of gray matter in multiple regions of the brains of children with OSA. These included the frontal cortices (which handle movement, problem solving, memory, language, judgement and impulse control), the prefrontal cortices (complex behaviors, planning, personality), parietal cortices (integrating sensory input), temporal lobe (hearing and selective listening) and the brainstem (controlling cardiovascular and respiratory functions).

Although these gray matter reductions were rather extensive, the direct consequences can be difficult to measure.

"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," said co-author David Gozal, MD, professor of pediatrics, University of Chicago. "The scans don't have the resolution to determine whether have shrunk or been lost completely," he added. "We can't tell exactly when the damage occurred. But previous studies from our group showed that we can connect the severity of the disease with the extent of the cognitive deficits, when such deficits are detectable."

In addition, "we are planning future collaborative studies between the University of Chicago and UCLA that will use state-of-the-art imaging approaches to answer the many questions raised by the current study," said Paul Macey, PhD, who, along with colleague Rajesh Kumar, PhD, led the image analyses at UCLA.

Without extensive tests of cognitive function prior to the onset of sleep apnea, "we can't measure the effect of the loss of neurons," Gozal said.

"If you're born with a high IQ - say 180 - and you lose 8 to 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 to 100, and you had that went untreated and lost 8-10 points, that could potentially place you one standard deviation below normal," Gozal said. "No one wants that."

Or, it may just be too soon to measure. The children in this study were between 7 to 11 years old. The connections between greater and intelligence have been documented only in with an average age of 15.4 years.

"The exact nature of the gray matter reductions and their potential reversibility remain virtually unexplored," the authors conclude, but "altered regional gray matter is likely impacting brain functions, and hence cognitive developmental potential may be at risk." This, they suggest, should prompt "intensive future research efforts in this direction."

Explore further: Young children with sleep apnea may face learning difficulties: study

More information: Scientific Reports, DOI: 10.1038/srep44566

Related Stories

Young children with sleep apnea may face learning difficulties: study

May 17, 2016
(HealthDay)—Sleep apnea in young children may affect youngsters' attention, memory and language development, a new study suggests.

Tonsillectomy for sleep apnea carries risks for some kids: study

September 21, 2015
(HealthDay)—Children who have their tonsils removed to treat sleep apnea are more likely to suffer breathing complications than kids who have the procedure for other reasons, a new review shows.

Study finds no link between sleep apnea and joint pain

August 1, 2016
Consistent with previous reports, poor sleep quality was linked with joint pain in a recent Arthritis Care & Research study of the general population, but the study found no association between obstructive sleep apnea and ...

Women with sleep apnea have higher degree of brain damage than men, study shows

December 3, 2012
Women suffering from sleep apnea have, on the whole, a higher degree of brain damage than men with the disorder, according to a first-of-its-kind study conducted by researchers at the UCLA School of Nursing. The findings ...

Brain damage caused by severe sleep apnea is reversible

September 8, 2014
A neuroimaging study is the first to show that white matter damage caused by severe obstructive sleep apnea can be reversed by continuous positive airway pressure therapy. The results underscore the importance of the "Stop ...

Recommended for you

Remede system approved for sleep apnea

October 9, 2017
(HealthDay)—The Remede sleep system, an implanted device that treats central sleep apnea by activating a nerve that sends signals to the diaphragm to stimulate breathing, has been approved by the U.S. Food and Drug Administration.

Inflammation may precede sleep apnea, could be treatment target

September 1, 2017
Inflammation is traditionally thought of as a symptom of sleep apnea, but it might actually precede the disorder, potentially opening the door for new ways to treat and predict sleep apnea, according to researchers.

More evidence: Untreated sleep apnea shown to raise metabolic and cardiovascular stress

August 31, 2017
Sleep apnea, left untreated for even a few days, can increase blood sugar and fat levels, stress hormones and blood pressure, according to a new study of sleeping subjects. A report of the study's findings, published in the ...

Sleep patterns contribute to racial differences in disease risk

August 18, 2017
Poor sleep patterns could explain, in part, the differences in the risk of cardiometabolic disease between African-Americans and European-Americans, according to a new study published in Proceedings of the National Academy ...

Concerns that sleep apnea could impact healthspan

July 27, 2017
The number of people with obstructive sleep apnea has steadily increased over the past two decades. The disorder, which causes a person to briefly stop breathing when asleep, affects over 100 million people globally and is ...

Anti-nausea drug could help treat sleep apnea

June 6, 2017
An old pharmaceutical product may be a new treatment for obstructive sleep apnea, according to new research presented today by University of Illinois at Chicago and Northwestern University scientists at the SLEEP 2017 annual ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

LaPortaMA
not rated yet Mar 17, 2017
Cause, effect, or epiphenomenon?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.