Untreated sleep apnea in children shrinks brain & may slow development
Brain scans of children who have moderate or severe obstructive sleep apnea have found significant reductions of gray matter across the brain.
The study compared brain scans from 16 children (aged 7-11) with obstructive sleep apnea to those from nine healthy children of the same age, gender, ethnicity and weight, who did not have apnea. The scans were also compared to 191 MRI scans of children who were part of an existing database.
Sleep apnea is known to affect cognition in adults, but it may be that it is even more damaging in brains that are still developing. However, adult studies have also shown that treating sleep apnea reverses gray matter loss and improves cognition. This finding therefore emphasizes the importance of treating children's sleep apnea.
Sleep apnea affects up to 5% of all children (and we can only assume that this will get more common, if childhood obesity continues to rise).
Developing brain regions in children are hardest hit by sleep deprivation
Another study of sleep deprivation in children gives weight to the idea that it is particularly important for proper brain development that children get good sleep.
The study measured the brain activity in 13 healthy five to 12-year-olds as they slept. On the first occasion, the children went to bed at their normal bedtime; the second time, they stayed awake until late and thus received exactly half the normal amount of sleep.
The results indicate that children's brains respond to sleep deprivation differently than adults’ brains do. In adults, being deprived of sleep creates a greater need for deep sleep, which is manifested in greater slow-wave activation in the prefrontal cortex. In the children's brains, this slow-wave increase occurred in the back regions of the brain, in the parietal and occipital lobes. This suggests that these areas might be especially vulnerable to sleep deprivation.
Moreover, this difference was linked to levels of myelin in part of the visual system. Myelin increases as the brain matures. Those with higher levels of myelin in certain nerve fibers in the visual system displayed slow-wave activation that was more similar to that of adults.
The researchers conclude that adequate sleep is important for neuronal connections to develop properly.
Poor sleep in early childhood may lead to cognitive, behavioral problems in later years
A study involving 1,046 children whose sleep was assessed at various points in their first seven years has found that children who didn’t get enough sleep in their preschool and early school years were more likely to have problems with attention, emotional control and peer relationships at age seven.
Sleep was assessed through interviews with the mothers when their children were around 6 months, 3 years and 7 years old, and from questionnaires completed when the children were ages 1, 2, 4, 5 and 6. Mothers and teachers filled out questionnaires evaluating each child's executive function and behavioral issues at around 7.
Children living in homes with lower household incomes and whose mothers had lower education levels were more likely to sleep less than nine hours at ages 5 to 7. Other factors associated with insufficient sleep include more television viewing, a higher body mass index, and being African American.
Insufficient sleep was defined as being less than the recommended amount of sleep at specific age categories:
- 12 hours or longer at ages 6 months to 2 years
- 11 hours or longer at ages 3 to 4 years
- 10 hours or longer at 5 to 7 years.
 . Reduced Regional Grey Matter Volumes in Pediatric Obstructive Sleep Apnea. Scientific Reports [Internet]. 2017 ;7:44566. Available from: http://www.nature.com/srep/2017/170317/srep44566/full/srep44566.html
 . Increased Sleep Depth in Developing Neural Networks: New Insights from Sleep Restriction in Children. Frontiers in Human Neuroscience [Internet]. 2016 ;10. Available from: http://journal.frontiersin.org/article/10.3389/fnhum.2016.00456/abstract
 . Prospective Study of Insufficient Sleep and Neurobehavioral Functioning among School-Age Children. Academic Pediatrics [Internet]. 2017 . Available from: http://www.academicpedsjnl.net/article/S1876-2859(17)30047-5/abstract