Sept. 15, 2008 -- Sex triggered a life-threatening stroke in a healthy 35-year-old Illinois woman, her doctors report.

Sex- and orgasm-triggered strokes in relatively young women and men are rare, but not unheard of. They require a combination of factors and events not unusual in themselves, but which are highly unlikely to occur at the same time.

The 35-year-old woman's symptoms were typical of this unusual kind of "cryptogenic" stroke, says Jose Biller, MD, professor and chair of the neurology department at Loyola University, Chicago.

"This young woman ... while having intercourse had numbness on the left side of her face, slurred speech, and weakness in her left arm," Biller tells WebMD. "When she was transferred to our care six hours after onset, she was completely unable to move her left arm, her face was paralyzed, her speech was garbled, and she was in a state of panic."

It was too late to inject the woman with the clot-busting drug tPA, which must be given within three hours of a stroke. So Biller's team quickly ran a catheter from an artery in the woman's groin up into her brain to find the blood clot by angiography. Once it was found, they had only one option: to apply tPA directly to the clot.

It was a risky decision. "We did this with a lot of sweat," Biller says.

The woman's symptoms began to improve almost immediately; within an hour she was out of the woods and within 12 hours the symptoms were almost gone. Today she is well, with only an almost imperceptible fold in the skin under her nose and slight loss of dexterity in her left hand.