People who suffer from major epilepsy, also known as grand mal, often experience an aura prior to a tonic-clonic siezure.
The aura can take any one of a wide range of forms. Some epileptics might experience an unusual taste in their mouth, while others might experience a tingling in their elbow. Sometimes it is not the epileptic who has the aura. I met a woman once who said she always knew when her mother was about to have a siezure (she did not explain how), and I once read in a newspaper about a man who could tell he was about to have a siezure from the behaviour of his girlfriend's dog.
Can anyone explain the aura? I am aware that there is not yet a proven explanation, but has anyone ventured a possible explanation?