When Sleep Apnea Masquerades as Dementia - A New York Times article

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October 6, 2010, 3:44 pm

By PAULA SPAN

The woman who came to see Dr. Ronald Petersen, an Alzheimer’s specialist at the Mayo Clinic, was only in her 60s but complained that she was having trouble concentrating. “Her attention was waning,” Dr. Petersen recalled. “She couldn’t follow a television program or stay focused during a conversation.”

Ryan Collerd for The New York Times A C.P.A.P. machine at the home of a sleep apnea patient in Pottstown, Pa.

She was probably developing dementia, Dr. Petersen thought as he took her history. But along the way he asked, as he usually does, how she was sleeping. The woman, who lived alone, hadn’t noticed any problems.
Her son, however, had stayed with her the previous night to drive her to the appointment. “She was snoring like a freight train,” he reported.
Aha. Overnight sleep testing determined that the woman had obstructive sleep apnea — nightlong interruptions in breathing that reduce oxygen flow to the brain and prevent deep sleep. The interruptions can happen 10 or more times an hour and are quite common in older adults, exacerbating — or sometimes mimicking — dementia symptoms.
Treated with a C.P.A.P. machine — the acronym stands for continuous positive airway pressure, a therapy that involves wearing a mask over the nose and/or mouth during sleep — the woman rapidly improved. Her scores on neuropsychological tests eventually climbed back into the normal range. A year later, Dr. Petersen said, “I can’t find any abnormalities.”
Most of the time, cognitive problems won’t evaporate when seniors are treated for sleep apnea. But researchers find that with C.P.A.P., many older patients see marked improvement. “They’re not dozing off during the day, they’re not dragging,” said Dr. Bradley Boeve, a neurologist at the Mayo Clinic. “Quality of life improves.”
Life gets easier for their caregivers, too, a key concern in trying to keep people out of nursing homes.
But apnea frequently goes undetected, especially in the elderly, although they are more likely to have it. Estimates of the percentage of older adults with sleep apnea are all over the map, in part because of varying definitions of the condition — but they’re always startlingly high. Sonia Ancoli-Israel, professor of psychiatry at the University of California, San Diego, has studied the disorder for 30 years and reports that almost half of older adults experience apnea to some degree, with even higher rates among those with dementia.
“It’s under-recognized in all age groups,” she told me in an interview. “But in older people, physicians are even less likely to recognize it.”
Why? Apnea in younger people frequently coincides with obesity; in elderly patients, that’s less often true. Loud snoring, often a tip-off, may go unnoticed when seniors live alone. And, as Dr. Ancoli-Israel pointed out, “there’s a belief that old people are supposed to be sleepy during the day.”
They’re not, and one reason she wants them and their caregivers to recognize the problem is the now-established connection between apnea and cognitive decline. “If you’re waking up hundreds of times a night and you’re not getting enough oxygen to the brain, of course you’ll see the effect,” Dr. Ancoli-Israel said.
She and her team, in a study published in 2008 in The Journal of the American Geriatrics Society, randomly assigned patients with Alzheimer’s disease to use real C.P.A.P. machines or fake ones for several weeks. The treatment produced “modest but statistically significant improvements,” particularly in vigilance (the ability to pay attention) and executive function (judgment and decision-making).
“We didn’t cure the dementia,” Dr. Ancoli-Israel cautioned. “But it wasn’t as severe as before.” As the researchers followed up months later, they also found that while all the patients continued to decline cognitively, in those using C.P.A.P. the decline was more gradual.
For years, physicians doubted that dementia patients could or would use these machines. Even younger people with apnea frequently find the C.P.A.P. mask uncomfortable, pulling it off during sleep or just not bothering to use it. But in recent studies, seniors diagnosed with Alzheimer’s disease did use the devices — not for as many hours each night as their doctors might wish, but long enough.
Now Dr. Ancoli-Israel is investigating whether C.P.A.P. therapy might help reduce the cognitive damage from Parkinson’s disease. “This isn’t just Alzheimer’s,” she said. “Any time there are symptoms of dementia, you should think about sleep apnea and discuss it with your doctor.”
Be forewarned: diagnosing sleep apnea can be complicated, requiring an overnight stay in a sleep center. If apnea proves to be the problem, technicians have to calibrate each C.P.A.P. machine’s settings and individually fit the mask. All those processes become harder with someone who’s cognitively impaired. (To find treatment centers, consult the American Academy of Sleep Medicine or the National Sleep Foundation.)
But when someone with apnea does stick with the treatment, “you’ll see the effects within a month or so,” Dr. Boeve said. “Sometimes even within a week.”

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Paula Span is the author of “When the Time Comes: Families With Aging Parents Share Their Struggles and Solutions.”