What are the Effects of Sleep Apnea on the Brain?

Normal sleep is defined by two phases: REM sleep and non-REM sleep. Both are controlled by the brain. We cycle through these phases about every 100 minutes. Sleep apnea disrupts these normal cycles. The brain cannot adapt to the erratic patterns of sleep apnea and normal brain functioning is affected both during sleep and while awake.

These disruptions not only affect neural function but also breathing patterns and oxygen levels. When breathing becomes erratic due to frequent apneas, less oxygen reaches the brain. Long-term, fragmented sleep causes cognitive impairment, problems with memory and mood swings.

With reduced oxygen flow to the brain comes chronic inflammation. This inflammation can eventually cause breakdowns in the brain known as neurodegeneration. Most neurodegenerative diseases like Alzheimer’s, Parkinson’s, and dementia have a link to the sleep deprivation due to sleep apnea.

The Journal of the American Medical Association¹ studies have discovered that those who did not have obstructive sleep apnea were less likely to develop cognitive problems related to neurodegenerative diseases.

The study concluded that disruptive sleep patterns long-term can cause neural dysfunction that can impact cognitive ability and eventually may lead to some neurogenerative problems.

With reduced oxygen flow to the brain, due to sleep deprivation, brain function and brain tissue health are compromised. Oxygen is essential to the brain for managing energy metabolism and neuronal activity.

Long-term reduced oxygen leads to a condition known as hypoxia. This occurs when insufficient oxygen supply leads to tissue damage. For the brain the results can be alarming. When sleep apnea is left untreated for an extended period, patients risk white brain matter abnormalities, brain lesions, and cerebral atrophy.

Disturbed sleep is not the only result of sleep apnea. Daytime symptoms can reveal a brain that has not been properly restored with a good night’s sleep. Daytime drowsiness and chronic fatigue are signs of sleep deprivation due to sleep apnea. When the brain has not been restored with healthy sleep, concentration becomes impaired.  The highest functions of the brain including decision-making are reduced.

Attention becomes short. Your ability to think quickly is dramatically slowed and the ability to solve even the most basic problems is impaired.  Often simple cognitive assessments can become difficult for someone who is sleep deprived. Only with restorative sleep can you regain brain health and robust cognitive performance.

Simply put, you need sleep to perform well in daily life. When put to more complex tasks involving work or creativity, a tired brain can hold you back. While a well-rested brain can think innovatively.

Often a good night’s sleep can produce the solution to a problem you have tried to solve while awake. “Sleeping on a problem” is a common technique for those who know the importance sleep plays in creative thinking and problem-solving.

Sleep health does more than help you perform during the day; it can also help you live longer. Poor sleep can escalate brain age, leading to early cognitive decline as you get older. One key aspect of brain health is the glymphatic system, which helps remove waste to keep brain tissue healthy and to distribute biochemicals important to brain health including glucose, lipids and amino acids.

When the performance of the glymphatic system is impaired by poor sleep, the brain begins to lose its self-restorative properties.

Along with the proper treatment of sleep disorders, sleep health can be promoted with a consistent sleep schedule, avoiding alcohol close to bedtime and avoiding blue light stimulants like the TV, phone or computer before going to bed. Add to this a healthy diet and exercise and you can help keep your brain functioning better, longer.

Sleep apnea occurs when the airway temporarily closes while you sleep, causing you to gasp for air in the middle of the night and disrupting normal REM sleep. Over time, these apneas reduce oxygen flow to the brain, leading to brain dysfunction on the most fundamental level, including memory loss.

In a study with patients with Alzheimer’s disease, it was found that those with breathing problems were diagnosed with mild cognitive impairment an average of 10 years earlier than people without sleep breathing problems.

Learn about the relationship between sleep apnea and Alzheimer’s in this article. 

That continual oxygen depletion during sleep starts to cause significant and measurable brain damage. Studies show that the brains of troubled sleepers were nearly 20% smaller than those without sleep issues.² In addition, the effects of sleep apnea on the brain are worsened by daytime fatigue that results from poor sleep.

Along with shape, brain function begins to change as well as lower oxygen levels compel the brain to adapt chemically. Gamma-aminobutyric acid or GABA is a critical brain chemical for healthy brain function and communication between nerve cells. Sleep apnea reduces GABA, which can lead to anxiety mood disorders, and difficulty concentrating.

The good news is that the effects of sleep apnea on the brain are not permanent. The use of CPAP therapy provides continuous airway pressure while sleeping, keeping the airway open and preventing apneas. This treatment for sleep apnea when strictly followed can improve sleep, increase oxygen flow to the brain, and reduce many of the harmful side effects of sleep apnea on brain function.