Minutes after having sexual intercourse with her boyfriend, a 35-year-old woman felt her left arm go weak. She also lost feeling on the left side of her face and began slurring her speech.

She was having a stroke, according to a study authored by doctors from Loyola University Medical Center and published Monday in the Journal of Stroke and Cerebrovascular Disease.

Doctors believe it was the combination of many factors that caused the woman’s stroke including sexual intercourse, birth control pills, a venous blood clot and a heart defect.

While, it's extremely rare to experience a stroke after sexual intercourse, it does happen, according to background offered by the Loyola doctors.

A 2004 study in the Archives of Neurology reported on four patients who had strokes during intercourse: a 38-year-old man and three women in their 20s. Like the Loyola patient, they all had a condition that caused a hole in the walls of their hearts called patent foramen ovale or PFO defect.

PFO occurs in about 1 in 4 adults, but in many people it will never cause problems. In some, however, the defect may increase the risk of a stroke.

In the Loyola case, doctors believe birth control pills caused a small clot to form in one of the veins of the woman’s thigh. The clot then broke loose and traveled to the right atrium (the heart's upper right pumping chamber). Normally, the clot would be pumped out of the right atrium and travel to the lungs, where it may dissolve.

In this case, however, the hole in the woman’s heart separated the right atrium from the left atrium. Pressure changes in the heart, triggered by sexual intercourse, enabled the clot to travel through the hole from the right atrium to the left atrium.

From there, it traveled to her brain, lodged in a narrow blood vessel and blocked blood flow to an area of the brain that controls movements on the left side of the body, said Dr. Jose Biller, co-author of the report and chairman of the Department of Neurology at Loyola University Chicago Stritch School of Medicine, in a news release.

The woman arrived at Loyola six hours after her stroke. It was too late for doctors to give her tPA — a drug used to dissolve clots and restore blood flow to brain cells before they are irreversibly damaged — intravenously. Instead, they delivered it directly into the affected blood vessel in the brain.

To do so, a catheter was inserted into a groin artery and guided up to the spot in the brain where the clot was lodged.

The improvement was immediate and dramatic, according to the study. After two months, her only lingering symptoms were a slight weakening of her facial muscle and minimal impairment of her left hand, said Dr. Simona Velicu, who assisted Biller and is the lead author of the case report.

Doctors prescribed aspirin and a blood thinner, advised the woman to stop taking birth control pills and scheduled a follow-up procedure to repair the hole in her heart.

Click here to read more on this study published in the Journal of Stroke and Cerebrovascular Diseases.