Some people give credence to the adage that rousing a sleepwalker can give him a heart attack. But experts say it's highly unlikely.

Dr. Ana C. Krieger, the director of the Sleep Disorders Center at New York University, said the myth probably started because of sleepwalkers' response when they're awakened. Many are confused and terrified, having no idea how they ended up in a dark closet or gliding down a hallway.