How sleep apnea may affect the way kids think
Sleep offers a chance for your body to heal and rejuvenate. Accordingly, a disrupted sleep cycle can have a negative effect on your health, mood and wellbeing. A chronic form of sleep disruption is sleep apnea.
Sleep apnea is a condition where you stop breathing briefly during the night. This condition is caused by muscles in the throat that relax during the night which causes an obstruction of the airways. This causes breathing to pause periodically during the night and is known as obstructive sleep apnea (OSA).
As the throat closes, the air is prevented from entering the body, which sends a signal to the brain alerting it about the danger. This wakes the person up, making the muscles contract and so clearing up the obstruction. These breaks in the breathing and the subsequent arousal are very brief, so much so that most often people don’t even realise what has happened.
Sleep apnea affects an estimate of 5 per cent of all children and new research shows that, in a child’s brain, these brief episodes of not breathing cause the brain to lose some of its grey matter.
The analysis revealed significant reductions in the volume of grey matter in many regions of the brain.
For this study, the researcher recruited 16 children between the ages of 7 and 11 who had moderate to severe sleep obstructive apnea. The children were evaluated overnight during their sleep at the University of Chicago’s paediatric sleep laboratory. The children went through neuro-cognitive testing and their brains were scanned with non-invasive MRI.
The results of the 16 children with apnea were compared to those of nine healthy children of the same age, gender, ethnicity and weight who did not have apnea. They were also compared with 191 MRI scans of children who were part of another existing paediatric study by the National institutes of Health.
The analysis revealed significant reductions in the volume of grey matter in many regions of the brain. Grey matter is responsible for processing information relating to movement, problem solving, memory, language, judgement, impulse control, behaviours, planning, personality, hearing, selective listening, sensory inputs and controlling cardiovascular and respiratory functions.
The regions of the brain where the researchers found a reduction of grey matter were: frontal cortices, prefrontal cortices, parietal cortices, temporal lobe and brainstem.
The current analysis did not show significant associations between the MRI findings and cognitive performance. Higher grey matter volume has been associated with higher intelligence quotients (IQ); however, those findings were in older-aged children and not in children in the age range of the current study. Brainstem volume reductions have been linked with autism but volume in this region is not associated with IQ.
Although grey matter was measured, the direct impact of the reduction in grey matter cannot be ascertained. The MRI scans can only give an overview of apnea-related difference in volume of grey matter in the brain and can’t show what happens to the affected neurons at a cellular level. This makes it impossible to determine whether the affected brain cells shrunk or were lost completely. As the children were not scanned before the OSA began, it’s hard to know when the damage occurred.
Previous studies, however, have shown that scientists can connect the severity of OSA with the extent of cognitive defects when such defects can be detected.
This study provides one more reason for parents of children who may have the symptoms of sleep apnea to get it diagnosed and treated early.
Source: Scientific Reports
