I think my cat is having seizures

We took our cat Sonny to the vet today because he keeps having these 'episodes' where he opens his mouth and his face/head will kind of twitch and he looks like he's going to throw up but all he does is produce a lot of saliva which just hangs from his mouth. It will only last about 10-15 seconds and then he'll just shake it off and he's fine.

The vet thinks they might be seizures, very small ones. He started having them on Saturday afternoon (Feb 3rd) and continues to have them. They are very frequent. Anywhere from every 30 min to every 2 hours. The vet took blood for tests and gave us Phenobarbitol.

Has anyone every experienced this before? Particularily the same type of 'episodes/seizures'? I am very interested in hearing from you if you have.

Thank you!