In the game, children use dog leashes, bungee cords wrapped around their necks or other means to temporarily cut blood flow to their head. The goal is a dreamlike, floating-in-space feeling when blood rushes back into the brain.
As many as 20 percent of teens and preteens play the game, sometimes in groups, according to some estimates based on a few local studies. But nearly all the deaths were youths who played alone, according to the count complied by the U.S. Centers for Disease Control and Prevention.
The CDC started the research after receiving a letter last year from a Tacoma, Wash., physician who said her 13-year-old son died from playing the game in 2005.
"At the time I had never heard of this," said Dr. Patricia Russell, whose son was found hanging in his closet, but later learned he had talked to a friend about it.
The CDC counted reports from media and advocacy organizations in the years 1995 through 2007, totaling 82 fatalities of children ages 6 to 19. They did not include deaths in which it was unclear if the death was from the choking game or if it was a suicide. They also did not include deaths that involved autoerotic asphyxiation, which is self-strangulation during masturbation and is said to be mainly done by adult males.
The 82 deaths were spread across the country. Nearly 90 percent were boys, at an average age of about 13, the CDC found.
The report is being published this week in a CDC publication, Morbidity and Mortality Weekly Report.
CDC officials urged parents to be aware the fad exists, and to watch for possible warning signs like bloodshot eyes, marks on the neck, frequent and severe headaches, disorientation after spending time alone, and ropes, scarves or belts tied to bedroom furniture or doorknobs or found knotted on the floor.
The authors acknowledged that 82 is probably an undercount. They could not rely on death certificates, which do not differentiate choking-game deaths from other unintentional strangulation deaths. Instead, they relied mainly on a news database that is large but doesn't include all media outlets.
It's likely that there are about 100 U.S. choking game deaths each year, said Dr. Tom Andrew, New Hampshire's chief medical examiner, who has been studying the phenomenon for several years.
Andrew said many coroners and medical examiners likely label the deaths as suicides because they don't have the time or resources to interview a victim's friends and look for alternate explanations.
Many of the children who died form the choking game were described as bright, athletic students who apparently were intrigued by a method of getting high that doesn't involve drugs or alcohol, he said.