A recent study found that obstructive sleep apnea causes brain damage in memory-related regions, most likely as a result of low oxygen levels during REM sleep. Scientists discovered that brain scans showed greater white matter hyperintensities, which are indicators of tiny vessel injury, in those who had reduced oxygen saturation during REM.
Reduced size in the entorhinal cortex and hippocampal regions, which are both important for memory, was also connected to this damage, as was worse memory test scores. The study provides insight into how sleep apnea may contribute to cognitive decline and memory loss in aging and Alzheimer’s disease, even though it does not establish causation.
What Is Sleep Apnea?
Sleep apnea is a common condition that occurs when your breathing stops and restarts many times while you sleep. This can prevent your body from getting enough oxygen. If someone tells you that you snore or gasp for air during sleep, you may want to talk to your healthcare provider. You may also want to ask your provider about sleep apnea if you experience other symptoms of poor sleep quality, such as excessive daytime sleepiness.
Key Findings on REM Sleep, Oxygen Levels, and Brain Health
Oxygen and Brain Damage: Small vessel brain damage has been associated with low oxygen levels during REM sleep.
Memory Regions Affected: Damage was associated with decreased entorhinal cortex and hippocampal volume.
Potential Cognitive Impact: Poorer sleep-dependent memory was linked to these brain alterations.
The study discovered a high correlation between the degree of oxygen level drops during rapid eye movement (REM) sleep and the alterations in the brain.
People with obstructive sleep apnea wake up frequently to breathe because their throat muscles relax while they sleep, obstructing their airway. The brain’s tiny blood vessels may sustain damage as a result of the oxygen levels being lowered by this disturbed sleep pattern.
The majority of dreams happen during REM sleep, which is also linked to other important sleep processes, such as processing emotional experiences and consolidating memories.
Throughout the night, during all phases of sleep, including REM sleep, the researchers took measurements of their oxygen levels.
To measure brain structure, participants underwent brain scans.
Researchers discovered that higher levels of white matter hyperintensities in the brain were linked to decreased oxygen levels during REM sleep. Bright areas on brain scans known as “white matter hyperintensities” are believed to represent damaged white matter tissue. Damage to the brain’s tiny blood arteries may be the cause of this harm.
The quantity of total white matter hyperintensities in the brain was predicted by the minimum blood oxygen saturation levels during sleep and the total amount of time spent asleep below a blood oxygen level of 90%. If your blood oxygen level is 90% or less, you should be concerned.
Additionally, researchers evaluated the thickness of the entorhinal cortex and the volume of the hippocampus, two regions linked to memory. They discovered that both decreased volume and decreased thickness in these regions were associated with higher white matter hyperintensities.
To assess sleep-dependent memory, participants completed a memory test both before and after bed. Researchers discovered that decreased entorhinal cortex thickness was associated with deficiencies in sleep-dependent memory.
