I had what they suspect was a TIA last March. Going to Disneyland and want to know if it is safe to ride Thunder Mountain. It would be classified as a "milk rollercoaster" in comparison to regular rollercoasters. The TIA was not attributed to anything with the heart (do not take high blood pressure meds but do take a diuretic. They think I had a blood clot that passed through the brain. No symptoms other than with vision for about 10 min.