My co-resident Ji Won had a memorable appointment a few years back by a patient with a history of seizures. The patient had a seizure during the dental procedure which certainly came as a surprise to Ji and the dental assistant. Ji handled it very professionally, and as our residency was based out of a hospital, the patient was given medical attention immediately.
I ran across this video that gives instructions for First Aid for Seizures on an epilepsy website based in the UK. This video is for the general audience, is approximately two minutes long, and well worth every second.