Sleep apnea device may not cure daytime sleepiness

Many people who suffer from sleep apnea continue to suffer excessive daytime sleepiness despite standard treatment with continuous positive airway pressure, or CPAP.

Sleep apnea occurs when the soft tissues at the back of the throat temporarily collapse during sleep, causing repeated breathing interruptions. Major symptoms include loud snoring and daytime sleepiness -- the latter of which, studies show, may cause irritability, cloud thinking and concentration, or increase the risk of traffic accidents.

CPAP treatment involves wearing a special face mask that delivers pressurized air to keep the airways open overnight.

In a study of 502 patients from 37 sleep centers who were using CPAP, researchers found that 6 percent continued to experience excessive daytime sleepiness.