Jan. 31, 2012 at 8:56 AM ET
For one young man, the most terrifying part of being on a roller coaster happened two weeks after his ride. That's when the 22-year-old African American started having some weird symptoms.
He had headaches, dizziness, nausea, vomiting, and trouble walking, according to a case report in the American Journal of Emergency Medicine. After two days of feeling miserable, he headed to the emergency room.
The doctors who saw this previously healthy guy noticed that he was walking like he was drunk and his eyes had an up-and-down movement. It was clear his problems weren't alcohol-related and a scan showed swelling on the right side of his brain.
An MRI found that his vertebral artery, one of the main arteries in the neck, had a flap-like tear in its inner wall, says Dr. Davi Sa Leitao, the case study's lead author. This injury to his neck artery caused a clot to form, and the clot dislodged and clogged a smaller blood vessel feeding the cerebellum.
In other words, he had suffered a stroke in a region of the brain responsible for balance, equilibrium, and coordination.
The most likely culprits for a stroke in a young adult are high blood pressure, which the guy didn't have; a genetic abnormality that weakens the blood vessels, or some type of trauma, meaning a physical injury.
Upon questioning, the man mentioned riding a roller coaster two weeks before his symptoms began.
"We believe the roller coaster ride triggered the tear in the blood vessel in his neck and the subsequent stroke," says Sa Leitao, an internal medicine physician at Albert Einstein Medical Center in Philadelphia. "When you ride a roller coaster, your full body is restrained but your neck is still free to move in all directions," he points out.
Although rare, a roller coaster's speeding up and slowing down, and abrupt changes in direction may apply force to the neck and injure one of its blood vessels.
"It's the same rationale when you have a rear-end motor vehicle accident. Your neck goes forward and backwards, what we call the whiplash mechanism," explains Sa Leitao
As for the two-week lag between the ride and the start of symptoms, Sa Leitao suspects the tear in the man's neck artery was small, so it took more time for the clot to develop. This clot eventually clogged the artery causing a stroke.
The guy made a full recovery, but his roller-coaster riding days are behind him.
It's hard to know who may be at risk for developing complications from riding a roller coaster, and they're generally considered safe. But if you have symptoms -- dizziness, nausea, vomiting, trouble walking, neck pain, or vision problems -- after riding one that don't go away, seek immediate medical attention, recommends Sa Leitao.
Readers: Share your roller coaster horror story or tell us why you love them.