Obstructive sleep apnea (OSA) not only has a large effect on the heart but can also alter and cause severe effects to the brain. These changes in brain matter can damage to neurons that can lead to memory loss, Alzheimer’s disease and other complications. In recent studies, it is shown that those with sleep apnea have changes of neurotransmitters in the brain.
People with sleep apnea tend to experience symptoms that include excessive daytime fatigue, shortened attention span, moodiness, shortened response time and reduced short-term recall. These are just a small range of daytime symptoms caused by lack of sleep and waking up multiple times throughout the entire night. Studies have shown that people with sleep apnea have trouble converting short-term memories into long-term ones. This memory-creating process occurs during sleep, and if you don’t sleep it leads to impaired memory formation and forgetfulness.
Sleep apnea may hasten memory and cognitive thinking declines, leading to earlier diagnoses of mild cognitive impairment and Alzheimer’s disease. On an average people with OSA were diagnosed with mild cognitive impairment (MCI) nearly 10 years earlier than those who are healthy according to New York University researchers.
Patients with Alzheimers Disease have a five times higher chance of presenting with OSA than cognitively non-impaired individuals of similar age. In addition, data also suggests that around half of patients with Alzheimers Disease have experienced OSA at some point after their initial diagnosis. The changes in cerebral blood flow and the cellular redox status in OSA patients contribute to cognitive decline and may further aggravate Alzheimer’s progression.
“This study is adding to the emerging story that sleep apnea may be contributing in some way to the acceleration of cognitive decline as you age,” said study coauthor. Dr. Andrew Varga, an instructor in medicine at the New York University Sleep Disorders Center. “And that is potentially another good reason to get evaluated and treated.”
Sleep Apnea can actually change the size of the brain. Duress caused during an apnea ( which starves the brain of oxygen) paired with chronic fatigue, can cause physical, & measurable brain damage. Researchers at UCLA compared the mammillary bodies, structures in the brain that are responsible for memory storage of several adults suffering from sleep apnea with those of healthy people. It was concluded that the mamillary bodies in the people with the sleep disorder were nearly 20% smaller.
Doctor Seung Bong Hong of the Sungkyunkwan University School of Medicine in Seoul to concluded that “Poor sleep quality and progressive brain damage induced by OSA could be responsible for poor memory, emotional problems, decreased cognitive functioning and increased cardiovascular disturbances.” In 2008, a UCLA study found significant damage in the brain’s fiber pathways and structural changes in its white matter. These are areas that regulate mood, memory, and blood pressure.
A February 2016 study published in the Journal of Sleep Research by the UCLA School of Nursing investigated the injury caused to the insular cortex of the brain by sleep apnea. It focused on the levels of two important brain chemicals, called neurotransmitters: glutamate and gamma-aminobutyric acid, known as GABA. “We actually found substantial differences in these two chemicals that influence how the brain is working,” said Paul Macey, the lead researcher on the study and an associate professor at the UCLA School of Nursing. “It is rare to have this size of the difference in biological measures,” Macey said. “We expected an increase in the glutamate because it is a chemical that causes damage in high doses and we have already seen brain damage from sleep apnea. What we were surprised to see was the drop in GABA. That made us realize that there must be a reorganization of how the brain is working.” Macey results were encouraging. “In contrast with damage, if something is working differently, we can potentially fix it.” “Stress, concentration, memory loss — these are the things people want fixed.”
There is evidence that treating sleep apnea, (with an Oral Appliance or in this particular study with CPAP therapy) can possibly return a patients’ brain chemicals back to its normal levels. According to the American Academy of Sleep Medicine, studies evaluated the effects of therapy on several subjects who had significant damage of their brain matter. However, after a year of treatment, the patients’ white matter was almost completely restored, while their gray matter had a faster recovery time of only three months. The results of several studies suggest that the early treatment of OSA, particularly in the early stages of Azlhermiers and dementia, may decelerate dementia progression (Ancoli-Israel et al., 2008; Cooke et al., 2009b; Troussière et al., 2014).
If you have symptoms of Sleep Apnea, talk to your us and find out more about testing for sleep apnea. Raphaelson Dental Sleep Center offers a home sleep study that can help diagnose your symptoms. If you’re ready to schedule a sleep study contact us now.
Ancoli-Israel S., Coy T. (1994). Are breathing disturbances in elderly equivalent to sleep apnea syndrome? Sleep 17, 77–83. [PubMed]
Ancoli-Israel S., Klauber M. R., Butters N., Parker L., Kripke D. F. (1991). Dementia in institutionalized elderly: relation to sleep apnea. J. Am. Geriatr. Soc. 39, 258–263. 10.1111/j.1532-5415.1991.tb01647.x [PubMed] [Cross Ref]
Ancoli-Israel S., Palmer B. W., Cooke J. R., Corey-Bloom J., Fiorentino L., Natarajan L., et al. . (2008). Cognitive effects of treating obstructive sleep apnea in Alzheimer’s disease: a randomized controlled study. J. Am. Geriatr. Soc. 56, 2076–2081. 10.1111/j.1532-5415.2008.01934.x [PMC free article] [PubMed] [Cross Ref]
Cooke J. R., Ancoli-Israel S., Liu L., Loredo J. S., Natarajan L., Palmer B. S., et al. . (2009a). Continuous positive airway pressure deepens sleep in patients with Alzheimer’s disease and obstructive sleep apnea. Sleep Med. 10, 1101–1106. 10.1016/j.sleep.2008.12.016
Troussière A. C., Charley C. M., Salleron J., Richard F., Delbeuck X., Derambure P., et al. . (2014). Treatment of sleep apnoea syndrome decreases cognitive decline in patients with Alzheimer’s disease. J. Neurol. Neurosurg. Psychiatr. 85, 1405–1408. 10.1136/jnnp-2013-307544 [PubMed] [Cross Ref]
American Academy of Sleep Medicine
Macey, P. M., Sarma, M. K., Nagarajan, R., Aysola, R., Siegel, J. M., Harper, R. M. and Thomas, M. A. (2016),
Obstructive sleep apnea is associated with low GABA and high glutamate in the insular cortex.
Sleep Research. doi: 10.1111/jsr.12392
University of California – Los Angeles. “Memory Loss Linked To Common Sleep Disorder.” ScienceDaily. ScienceDaily, 13 June 2008.