Convulsions, seizures in cats

This forum is for cat lovers seeking everyday advice and suggestions on health-related issues. Remember, however, that advice on a public forum simply can't be a substitute for proper medical attention. Only your vet can say assuredly what is best for your cat.

In Loving- Memory of- Bubbles --

Purred: Fri May 6, '05 8:29am PST 
Re another cat of mine (not Bubbles or Cuca); My cat Missy (two years old) had a seizure a couple of weeks ago. My mother found her convulsing on the floor, appearing as if she was having a very violent fight with an imaginary foe; she said that after about a minute Missy stopped convulsing, stiffened and appeared dead. Missy eventually came to but was very disoriented, and her eyes were dilated for another few minutes. The whole episode lasted less than five minutes but appeared very violent. She's never had any major health problems, has had checkups and was spayed and has her shots. She was a rescue at two weeks of age (she nearly froze to death when we found her) but we kept her warm and bottle fed her KMR until she was eating on her own. She's always eaten the best food, first Iams and then Max Kat and now Wellness. She eats well and is very smart, playful and attentive. What could have caused this seizure in what appears to be a healthy and normal cat? Thank you in advance for any advice!