Nav: Home

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

March 17, 2017

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 sleep 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 gray matter 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 obstructive sleep apnea (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 brain cells 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 sleep apnea 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 gray matter volume and intelligence have been documented only in children 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."
-end-
This study was funded by the Herbert T. Abelson Chair in Pediatrics at the University of Chicago. Additional authors were Mona Philby of the University of Chicago and Richard Ma of the University of California, Los Angeles.

University of Chicago Medical Center

Related Neurons Articles:

How do we get so many different types of neurons in our brain?
SMU (Southern Methodist University) researchers have discovered another layer of complexity in gene expression, which could help explain how we're able to have so many billions of neurons in our brain.
These neurons affect how much you do, or don't, want to eat
University of Arizona researchers have identified a network of neurons that coordinate with other brain regions to influence eating behaviors.
Mood neurons mature during adolescence
Researchers have discovered a mysterious group of neurons in the amygdala -- a key center for emotional processing in the brain -- that stay in an immature, prenatal developmental state throughout childhood.
Astrocytes protect neurons from toxic buildup
Neurons off-load toxic by-products to astrocytes, which process and recycle them.
Connecting neurons in the brain
Leuven researchers uncover new mechanisms of brain development that determine when, where and how strongly distinct brain cells interconnect.
The salt-craving neurons
Pass the potato chips, please! New research discovers neural circuits that regulate craving and satiation for salty tastes.
When neurons are out of shape, antidepressants may not work
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed medication for major depressive disorder (MDD), yet scientists still do not understand why the treatment does not work in nearly thirty percent of patients with MDD.
Losing neurons can sometimes not be that bad
Current thinking about Alzheimer's disease is that neuronal cell death in the brain is to blame for the cognitive havoc caused by the disease.
Neurons that fire together, don't always wire together
As the adage goes 'neurons that fire together, wire together,' but a new paper published today in Neuron demonstrates that, in addition to response similarity, projection target also constrains local connectivity.
Scientists accidentally reprogram mature mouse GABA neurons into dopaminergic-like neurons
Attempting to make dopamine-producing neurons out of glial cells in mouse brains, a group of researchers instead converted mature inhibitory neurons into dopaminergic cells.
More Neurons News and Neurons Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#540 Specialize? Or Generalize?
Ever been called a "jack of all trades, master of none"? The world loves to elevate specialists, people who drill deep into a single topic. Those people are great. But there's a place for generalists too, argues David Epstein. Jacks of all trades are often more successful than specialists. And he's got science to back it up. We talk with Epstein about his latest book, "Range: Why Generalists Triumph in a Specialized World".
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.