For Norman Siegel, a stocky, 40-year-old English teacher from Bridgeport, Conn., drowsiness had been a curse since high school days. He could fall asleep and indeed often did, at almost any timeāin front of his class, at the wheel of his car and even while giving driver-training instruction. For years, despite spending thousands of dollars looking for a cure and being twitted by his friends about his intermittent stupors, he was unable to do anything about his affliction.
Siegel was one of the 50,000 or more Americans who suffer from a little-known, and often misdiagnosed disorder called sleep apnea (literally, want of...