HELP Strange Symptoms Cat IS in the Hospital Vet stumped

[Jendra]

Hello,
My cat who has to date (other than being blind) has always been very healthy. She is an indoor cat. All hardwood floors. Nothing to get into.
I do believe she had a urinary infection (would only urinate in a bowl, darker than normal urine and odd odor to it, that we were going to be seeing the Vet for) Before I could do that.
2 days ago she was walking funny (not really eating, but our other two cats were not really interested either, I suspected something wrong with the food? New bag and none of them really wanted it)
Then she started throwing up, just yellowish mucous. No fever, is alert, did not look like she "felt" "ill".. Then she would try and walk and fall over. We went to the Vet, they thought middle ear infection. Antibiotic, ear meds. Said she wasn't eating because the infection gave her nausea. She was not dehydrated. I stayed up all night with her giving her real mussy almost liquid food by syringe, she started twitching and what looked like muscle contractions. Called the Vet 2am, no call back, took her in first thing in the morning, she is still in the Hospital. He thought maybe Incephlmalitious, but I don't think that really fits either. No fever, not swelling, she does not look like her head hurts, no real signs of "pain".. her eyes, and voice healthy sounding. Shes alert. Just twitching almost in time with her heart, contractions, her body feels cold at times. She is on antibiotic IV, Vet said that she is not shaking as bad, but he does not know if that is a good or bad thing. We have done full blood and it came back fine, so did x-rays. I don't know what to do, as he does not seem to really know what to do. This is a good office with 6 Vets. They said it seemed like a disease Toxin Cats can get from flea medicine, but she has not been in contact with any, of any kind. Any help, idea's .. I have a video of her I took while visiting her in the hospital.. I don't know how or where to post it.