Doctors attribute several factors to the stroke suffered by an unidentified 35-year-old woman who began feeling weakness in her left arm just minutes after engaging in sexual intercourse. The very act of sex itself causes changes in blood pressure but the woman also had a clot in her brain, thought to be caused by birth control pills, a side effect of which can be an increased risk of blood clots and stroke. Further examination revealed a common heart defect, too.

While it is not entirely unheard of that young people experience stroke during or shortly after intercourse, the event is still quite rare and most people suffering from post-coital strokes are found to have similar heart defects, called patent foramen ovale (PFO). It is estimated that around one out of every four adults has a PFO, although most of them will never experience any adverse effects associated with the defect. It is unknown whether having a PFO increases the risk of stroke and controversy surrounds the way these defects are managed by the medical community.

Weakness in her left arm just moments after intercourse was the first sign of trouble for the Loyola patient, with slurred speech and loss of feeling on the left side of her face quickly following. A trip to a community hospital was followed by a transfer to Chicago’s Loyola University Medical Center, where doctors administered tPA, an intravenous drug that can dissolve a clot and reduce or reverse damage caused by the stroke.

When administered within three hours from the onset of stroke symptoms, tPA is safe and effective but the woman didn’t reach the Loyola medical center until six hours after first symptoms appeared. In an unusual attempt to speed delivery of the drug to the clot in the woman’s brain, an interventional neuroradiologist inserted a catheter into the woman’s groin. The catheter was threaded through her circulatory system to the spot in her brain where the clot was lodged. Once the catheter was in place, the medical team administered tPA directly to the clot, where results were said to be both dramatic and immediate.

Stroke damage is measured on a scale of 1 to 43, with 43 being the worst possible outcome. When admitted to the medical center, the patient scored 13 on the stroke assessment scale. Just one hour after treatment, her score had dropped to 5 and then to 3 after about 12 hours. Two months after the stroke, the woman’s stroke assessment score was just a 1 and her only remaining symptoms of stroke were a slightly weakened facial muscle and minimally impaired left hand.

Doctors think the patient developed a small clot in the vein of a thigh. After dislodging itself from the thigh vein, the clot is thought to have traveled to the right pumping chamber (right atrium) of the woman’s heart, a situation that often resolves itself as the clot gets pumped out of the heart and into the lungs, where it most often dissolves uneventfully.

In this patient’s case, however, her heart had a small hole (PFO) in the wall that separates the heart’s right pumping chamber from the left. Doctors think changes in blood pressure as the result of sexual activities made it possible for the clot to travel from the right atrium, through the left atrium, and into a blood vessel in the brain, where it became lodged and caused the stroke.

No statitical data exists as to how frequently young adults experience stroke during sexual intercourse but a 2004 report described only four patients having done so. These patients, three women in their 20s and a man aged 38, all had similar PFO heart defects.

The Loyola medical team has reported this highly unusual case in the medical publication, Journal of Stroke and Cerebrovascular Disease.