Dr. Jose Biller treats hundreds of stroke patients each year. But few cases were as baffling as the one he received late one afternoon on Dec. 3, 2007.
What puzzled Biller, chairman of the department of neurology at the Loyola University Medical Center in Chicago, was that this patient didn't fit the profile of a typical stroke sufferer. The patient was a 35-year-old woman with no known cardiovascular risk factors. In short, she was a young, healthy, nonsmoking woman.
But for some reason, on this day, she suffered from a stroke under very unusual circumstances; only minutes after having sexual intercourse with her boyfriend, the woman began complaining of numbness on the left side of her face, her speech became slurred, and her left arm became weak.
"She was in a real state of panic," Biller recalled. "The family, the boyfriend, everyone was very disturbed."
In this case, which was released Monday in the Journal of Stroke and Cerebrovascular Disease, it's likely that the patient's sexual activity triggered her stroke. What made the case Biller faced even more puzzling was the lack of typical risk factors that usually accompany the onset of stroke. Typically, men face a higher risk than women, and it is usually a condition that affects those in their later years.
But it turns out that a defect in the patient's heart predisposed her to the condition. And oddly enough, cases like these are not as rare as one might think.
"I have seen this sort of thing on several occasions and treated many patients -- male and female -- sometimes with success and sometimes without," said Dr. Pat Lyden, medical director of the UCSD Stroke Center.
Fortunately, according to stroke experts, sexual intercourse, in of itself, is not likely to trigger a stroke without accompanying risk factors.
"There is nothing about sex that should be reported to increase stroke risk," Lyden explained. "Stroke can occur any time: in the shower, on the toilet, working out in the gym or during a class. I have seen patients [who suffered a stroke] with each of these scenarios."
According to the National Institute of Neurological Disorders and Stroke, more than 700,000 Americans suffer a stroke each year and about 160,000 of them die. Survivors often face serious disability as a result of the stroke.
Though hopeful about the recovery of his young stroke patient, Biller still faced a much larger dilemma to solve: What was the cause of this patient's stroke, and what could be done to prevent her from having another one?
The only potential risk factor this patient had for developing a blood clot was the fact that she was on birth control pills -- a medication known for increasing one's risk for developing blood clots. But were birth control pills alone to blame for the stroke? In order to find the answer, Biller and a team of neurologists began investigating the patient's medical history and testing the patient's heart function.
Shortly after, they found the source of the problem: This patient had a hole in her heart that had not been previously detected.
Biller and his team immediately pursued the possibility of a blood clot elsewhere in the patient's body that, when teamed up with a hole in the heart, might be the culprit for the cause of her stroke. Soon after, they found that the patient had a blood clot in one of the main veins in her right leg.
"Most likely what happened was that the clot that was in the venous system traveled to the heart, and because she had that hole, due to the pressure changes that occurred during intercourse, most likely the clot migrated from the right to the left chambers of her heart, and then from the left chamber of the heart and into the brain," Biller explained.
Biller prescribed the patient aspirin and a blood thinner, advised her to stop taking birth control pills on account of her present risk factors, and scheduled her for a surgery to repair the hole in her heart.
Within four days of being treated, the patient was released from the hospital with only one lingering symptom of her stroke: The facial muscles on her left side were slightly weakened.
Although stroke is highly uncommon in young and otherwise healthy individuals, stroke experts stress that unidentified cardiovascular abnormalities such as this patient's hole in her heart are not as rare as many might think.
A study published in the journal Archives of Neurology in 2004 found that about one out of every four people has a hole in the heart without knowing it.
According to stroke experts, it is not too uncommon for young people with this defect -- properly known as patent foramen ovale -- to suffer a stroke during sexual intercourse, or any other activity that could introduce pressure changes in the heart.
"In some respects, to a stroke specialist there is nothing surprising about this case," said Dr. Eric Aldrich, medical director of the Stroke Service at Johns Hopkins Hospital. "Although most strokes occur in older people, and are typically due to atherosclerosis, approximately 25 percent of strokes occur in people less than 60 years old."
Although the risk of stroke in a young person is still extremely low, Aldrich added that a "classic cause of a 'young stroke' is a PFO."
"Patients with the same heart condition as this lady are at risk for stroke, and that stroke can occur any time," Lyden said.
According to Lyden, other risk factors for stroke in young people include migraine, drug use, diseases of coagulation and athletic injuries that cause a tear in the neck arteries.
Still, some stroke experts stress that even with such risk factors present in an individual the chances of a young person suffering from stroke are extremely small.
"I cannot stress enough that even with these major risk factors present, the risk of stroke in a 30-year-old woman is still very, very small," said Dr. Robert Wityk, associate professor of neurology at Johns Hopkins Hospital.