There's a ride at Denver theme park Elitch Gardens called Mind Eraser. One of the first suspended roller coasters in the world, the Mind Eraser uses a series of tight corkscrews and disorienting turns to jostle the rider's brain. Every once in a while, it jostles a little too hard.
Deborah Lee Benagh rode Mind Eraser with her sons back in 1997. Instead of a thrilling rush, she suffered repeated knocks to the head that left her temporarily unconscious. Over the following weeks, her vision blurred, she blacked out repeatedly, and her short-term memory vanished. Mind Eraser, indeed. Benagh was diagnosed with traumatic brain injury, though she eventually recovered and sued the park, settling out of court for an undisclosed amount [source: Gilbert].
More than 10,000 people visited the emergency room in 2000 for injuries sustained on thrill rides. Most were accidents, but some resulted from rides operating exactly as designed, like Mind Eraser. A 2002 report by the National Institute of Neurological Disease and Stroke showed that 58 people had suffered brain trauma after being on amusement park rides that operated normally. Eight of them died [source: Gilbert].
If you get off a ride and have a terrible headache, get to a hospital quickly. It's possible to rupture a blood vessel in the brain and die if it's not treated in a timely fashion. Again, not a likely scenario, but better to be safe than sorry.