Sleeping Disruptions May Indicate Brain Altering Respiratory Patterns
In a significant study focusing on a primarily Latino population, researchers have highlighted the potential long-term effects of sleep disorders, particularly obstructive sleep apnea (OSA), on brain structure and cognitive functions.
The study, published in Neurology, reveals that OSA affects the brain primarily through intermittent hypoxia (low oxygen levels) and sleep fragmentation, leading to damage in crucial brain regions for memory and executive functions. This damage is associated with cognitive decline, particularly in attention, memory, and executive functions.
Key effects on brain structure include damage to small blood vessels in the brain, particularly noted in the medial temporal lobe areas essential for memory formation, such as the hippocampus, and white matter abnormalities known as white matter hyperintensities visible on MRI scans. Chronic sleep disorders, including OSA, have also been linked to alterations in brain regions involved in cognition and emotion regulation.
Regarding cognitive functions, those with OSA tend to show impairments in attention, verbal and visual delayed long-term memory, visuospatial abilities, and executive functions like mental flexibility. Problems with encoding verbal and visuospatial information indicate difficulty forming new memories rather than simply forgetting retained information.
Sleep fragmentation and hypoxia from OSA contribute differently to cognitive decline: attention and memory deficits relate more to disrupted sleep cycles, while broader cognitive impairments link to oxygen deprivation during sleep.
These cognitive impairments increase the risk of long-term issues like Alzheimer’s disease and dementia, partly due to poor clearance of neurotoxic proteins such as beta amyloid during disrupted sleep. Sleep apnea-related hypoxemia during REM sleep particularly harms tiny cerebral blood vessels and may accelerate cognitive deterioration even in older adults without initial impairment.
However, treatment such as continuous positive airway pressure (CPAP) therapy can improve some of these cognitive deficits by alleviating hypoxia and sleep fragmentation.
The study's findings suggest that OSA leads to structural brain changes and cognitive dysfunction over time, mediated by hypoxia-induced vascular injury and sleep disruption, with effects strongest in memory-related and executive function brain networks.
While the study focused on a primarily Latino population, future research should include more diverse samples to better understand how sleep-disordered breathing affects different populations, especially those who may be at higher risk for neurodegenerative diseases, such as older adults. As more data becomes available, it will create a better understanding of how to treat and prevent the cognitive decline associated with these respiratory disorders.
[1] White matter hyperintensities are a sign of brain deterioration and are associated with aging and various neurological conditions, including dementia.
[2] White matter is essential for communication between different areas of the brain.
[3] The increase in the volume of the hippocampus reflects a possible compensatory mechanism of the brain against the damage caused by apnea. For each additional interruption in sleep, the volume of the hippocampus increased by 0.006 cubic centimeters.
[4] The increase in white matter damage, observed in the study, is a worrying finding as it is associated with brain deterioration and is linked to dementia.
[5] The study reinforces the idea that sleep apnea and other breathing disorders may be risk factors for long-term cognitive decline. People with the most severe breathing disorders showed greater volume in the hippocampus, an area of the brain crucial for memory and learning.
- The study's findings reveal that chronic sleep disorders, like obstructive sleep apnea (OSA), can lead to an increase in white matter damage, which is a sign of brain deterioration and is linked to dementia.
- Neuroscience and psychology research suggest that obstructive sleep apnea (OSA) affects the brain, particularly through intermittent hypoxia and sleep fragmentation, causing damage in crucial brain regions, such as the white matter and the hippocampus, necessary for communication between different areas of the brain and memory formation.
- Health-and-wellness professionals should be aware that untreated obstructive sleep apnea (OSA) may pose long-term risks to mental health, as it is associated with cognitive decline, particularly in attention, memory, executive functions, and even increases the risk of developing conditions like Alzheimer’s disease and dementia. Treatment, such as continuous positive airway pressure (CPAP) therapy, can help alleviate these risks by improving cognitive functions.
