I Can't Remember How I Slept…

Obstructive sleep apnea patients have poorer long term memory than healthy sleepers

(RxWiki News) If you snore loudly, there is a possibility you have obstructive sleep apnea. The condition can affect much more than just the quality of your sleep though. It could affect your memory.

A recent study looked at all the research related to obstructive sleep apnea and long-term memory.

The analysis involved over 40 studies and found that people with untreated sleep apnea appeared to suffer certain memory problems when compared to individuals with no sleeping disorder.

The long-term memory issues could be significant enough to interfere with people's everyday lives, the researchers said.

"Treat sleep apnea."

The study, led by Anna Wallace, MPsych, of the School of Psychology at the University of Western Australia in Perth, looked at the "episodic memory" in patients who had obstructive sleep apnea.

Episodic memory refers to the long-term memory that stores your biographical information and the events and experiences you've lived through.

The researchers pulled together 42 studies that looked at memory and sleep apnea. All together, these studies included 2,294 adults with untreated obstructive sleep apnea and 1,364 healthy adults without a sleeping disorder.  

The researchers only included studies that involved a measure of the participants' memory at the start of the study as well as at the end - a before and after.

The participants' episodic memory was assessed using tests of immediate recall, delayed recall, learning and/or memory of recognition.

The researchers found that the patients with obstructive sleep apnea across the studies had a poorer performance on all those memory tests than the healthy comparison individuals.

The patients with obstructive sleep apnea also had poorer spatial-related short-term and long-term memory than the comparison individuals, but they performed just as well as the others on the short-term visual-only memory and overall visual-spatial learning.

The researchers then compared the performance of the patients with obstructive sleep apnea to the averages of individuals their age in general - not just the comparison adults in the studies.

In this analysis, the only memory type that was poorer in the obstructive sleep apnea patients was verbal short-term and long-term memory.

The researchers concluded that those with untreated obstructive sleep apnea are therefore at a higher risk for having certain memory problems. These difficulties with episodic memory "are likely to affect the daily functioning of individuals with obstructive sleep apnea," the researchers wrote.

According to William Kohler, MD, the director of the Florida Sleep Institute in Spring Hill, Florida, and a dailyRx expert, sleep apnea can cause memory problems for a number of different reasons.

"For one, the disruption of sleep that the apnea causes can cause difficulty with concentration or focusing so that the input for the memory can be decreased," Dr. Kohler said. He added that the hypoxemia - or lower oxygen levels the person is getting - can also contribute to memory loss.

The standard treatment for obstructive sleep apnea is continuous positive airway pressure, or CPAP, which is typically delivered to a person's airways through a face mask worn while the patient is asleep.

CPAP requires a prescription and can cost anywhere from $500 to over $5,500. Most insurance plans will cover some or all of the expense of a CPAP machine and the mask, which ranges from $30 to $200.

The study was published in the February issue of the journal Sleep. The research did not receive external funding, and the researchers declared no conflicts of interest.

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Review Date: 
February 13, 2013