Could sleep apnea contribute to memory loss in patients with early signs of Alzheimer’s?
It’s possible, according to a new study out of France, published Wednesday in the medical journal Neurology. Researchers followed 122 adults around 69 years old from 2016 through 2020. None of them had memory problems to begin with. Twenty-six participants, however, had amyloid plaques, clumps of misfolded proteins that clog up the brain—a key feature of patients with Alzhemier’s disease, and an early sign of the disease.
By the end of the study, brain volumes were generally lower in the medial temporal lobe area of the brain—key to memory—among people with the plaques who also had severe sleep apnea. The finding suggests a potential loss of brain cells in such participants, according to the study.
Such loss wasn’t seen in people who didn’t have the plaques, even if they experienced sleep apnea.
“People who are in the very early stages of the Alzheimer’s continuum showed a specific vulnerability to sleep apneas,” said Geraldine Rauchs, a cognitive neuropsychology researcher from France and one of the study’s authors.
Further studies should examine whether treating sleep apnea could improve cognition and delay or even prevent decline in cognitive functioning, she added.
The study doesn’t prove that sleep apnea causes lower brain volume—and, thus, memory loss—in predisposed patients; it merely shows a connection, the authors cautioned.
Previous studies have shown a correlation between sleep apnea and an increased risk of dementia. A study published last fall in the Journal of Sleep Research found that patients with sleep apnea had a “significantly increased” risk of developing multiple neurocognitive disorders, including Alzheimer’s, Parkinson’s, and Lewy body dementia, with vascular dementia being the exception.
Signs of sleep apnea
People with sleep apnea stop breathing during the night. If they do this because of an airway blockage, sleep apnea is considered to be “obstructive.” If they do this because their brain isn’t controlling their breathing well, their sleep apnea is considered to be “central.” Some people experience both.
Regardless, the symptoms are the same, according to the Cleveland Clinic. If you’re experiencing any of the following, you’ll want to have a discussion with your primary care doctor. They may refer you to a sleep specialist or simply for a sleep study, which may be able to be performed at home with a kit you’ll receive.
- Feeling exhausted from the moment you wake up
- Daytime sleepiness
- Snoring
- Mood changes
- Repeatedly waking up at night, perhaps feeling like you’re choking
- Pauses in breathing that others, like your spouse or partner, witness
- Unusual breathing patterns
- Insomnia
- Night sweats
- Feeling restless at night
- Headaches when waking up
For feedback on whether you might have a sleep disorder, take Harvard University’s screening survey.
