Common Sleep Disorder Damages Memory

By Kirsten Houmann, Ivanhoe Health Correspondent

ORLANDO, Fla. (Ivanhoe Newswire) -- A common sleep disorder called sleep apnea disturbs the sleep of an estimated 20 million Americans. Could it also be draining their memory?

A new study links sleep apnea with memory loss similar to that of alcoholics and Alzheimer’s patients. Sleep apnea takes place when the muscles in the throat, soft palate and tongue relax during sleep. The tongue then slides to the back of the mouth, blocking the airway and interrupting sleep.

“It’s as if you’re being smothered, and then allowed to breathe, and then smothered, and then allowed to breathe, repeatedly,” Ronald Harper, Ph.D., distinguished professor of neurobiology at the David Geffen School of Medicine at UCLA and lead researcher of the study, told Ivanhoe.

Researchers at the University of California, Los Angeles found mammillary bodies, small structures on the underside of the brain, were 20 percent smaller in sleep apnea patients than in control participants. These structures are responsible for transferring recent memory into long-term memory, and for operating spatial memory, which keeps track of where you are in space, Dr. Harper explained. Patients suffering memory loss from other syndromes like alcoholism and Alzheimer’s disease also show shrunken mammillary bodies.

Dr. Harper hypothesizes that the brain injury is caused by apnea episodes, which starve the brain tissue of oxygen and cause damaging inflammation.

“It’s this constant lowering of oxygen and then re-flushing of any new oxygen that seems to be damaging,” Dr. Harper said.

Dr. Harper advises those who suffer from sleep apnea to take vitamin B1, or thiamine, supplements and to seek treatment. In a future study, he plans to explore whether taking supplemental thiamine helps restore sleep apnea patient’s memory, since it has been shown to do so in alcoholic patients.

If this story or any other Ivanhoe story has impacted your life or prompted you or someone you know to seek or change treatments, please let us know by contacting Lindsay Braun at lbraun@ivanhoe.com.

SOURCE: Ivanhoe interview with Ronald Harper, Ph.D.; Neuroscience Letters, 2008;438:330-334