This type of stroke often happens in young, healthy people, but most people have never heard of it.
On a Friday last September, Shawn Crawford was enjoying the amusement park rides. Then he had a headache all weekend, and by Monday was seeing flashing lights.
"Very suddenly I lost 90% of my vision and everything went a very milky white," Crawford said.
36 years old and he was having a stroke. Shawn had a dissection of his left carotid artery. It's a tear of the inner lining of the blood vessel.
That injury causes a blood clot and blood flow to the brain stops. Dr. Carolyn Brockington is director of the stroke center at St. Luke's Roosevelt Hospital. She says the roller coaster may be to blame.
"It's really just that you moved your head or neck in the wrong way. It's usually young healthy people," Dr. Brockington said.
It happened to 31-year old Lauren Teo last month. She was blow drying her hair.
"When I flipped my head up I felt this snap but I didn't think anything of it," Teo said.
An hour later, she was dizzy and slurring her words.
There are 4 major arteries to the brain - the 2 carotids in front, 2 vertebral arteries in the back. If any one of them is injured, you can end up with a stroke.
Dr. Brockington says she sees 4 or 5 patients a month.
"One person was running in the park and she had a dissection because she turned her head in the wrong way. Another person was doing yoga and had a dissection," Brockington said.
Lauren has almost fully recovered but still has trouble finding words. Shawn has no peripheral vision on the right and still struggles with reading. The message is not to stop riding roller coasters or drying your hair. It is about knowing the warning signs
"If someone develops with neck pain, but in association with sudden weakness or the face is dropping or speaking that maybe those things are linked and it's time to go the emergency room right away," she said.
If you catch it early, blood thinners and medication can stabilize the problem and prevent permanent damage to the brain.