Sleep apnea, which affects close to 20 million Americans, occurs when the muscles of the throat relax so much during sleep that the flow of air is blocked. When air flow is blocked, so is the flow of oxygen to the brain. Sleepers often snore excessively, wake violently, gasping for air, before falling back to sleep. This cycle of sleeping-gasping-waking can happen hundreds of times every night.
It’s little wonder then that, after a night of such fitful sleeping, a person is left feeling tired and groggy the next day. The ability to focus can become troublesome and memory loss is common. Prior studies have shown a close association between sleep apnea and an increased risk for developing diabetes, heart disease, and stroke.
A team of researchers from UCLA’s David Geffen School of Medicine recently examined brain scans taken of 43 people who suffer from sleep apnea. They were particularly interested in documenting any effect the sleep apnea might have on two structures in the brain known as the mammillary bodies.
Alcoholism and Alzheimer’s disease are both known to cause memory loss, as are a number of other medical conditions. When the mammillary bodies in the brains of patients suffering from these conditions is examined, they are generally smaller than normal and appear shrunken.
The UCLA research team found the mammillary bodies in the sleep apnea patients to be almost 20% smaller than those in a control group of 66 subjects matched for gender and age. In many cases, the left mammillary body was the most damaged. The shrinkage is thought to be a result of the repeated interruptions of the oxygen supply to the brain, especially when these waking episodes happen many times every night and over an extended period of time.
A common treatment for alcohol-related memory loss is thiamine (vitamin B1) in very large doses. The vitamin is thought to help damaged brain cells recover and become functional again.
Further research is being planned to explore the mechanisms in sleep apnea which cause the damage to brain cells.
A spokesperson for the National Heart, Lung and Blood Institute says the findings of this study underscore the value of early treatment of sleep apnea for prolonged quality of life.