Senior cat experiencing vertigo

Question
Magic is a 14 yr old cat, in late Oct he began having brief dizzy spells every few days. First there were 3 incidents of his eyes going back and forth for 5-10 seconds. Later he began stumbling here and there but recovering quickly. My vet suggested a neurologist and last Wed took him there, during a blood draw he had the worst and longest dizzy episode.

I was alarmed and had an immediate MRI and spinal tap done under gen anesthesia of course. Complete blood work. Everything came back clean including his ears, but he's been acting dizzy and lethargic since he got home.  He was able to use the litter box by himself and eating regularly though not as much as normal until today. He stopped eating this AM and vomited twice. I called my on call emergency vet and he suggested 12.5 mg Bonine daily to help the vertigo.

If this doesn't work what can I try next? Antibiotics? Steroids? Cerenia? What if he still won't eat? If there is no known cause does vertigo usually go away by itself?

Answer
This is called vestibular disease and it is from either the inner ear or from something in the brain.  Usually, if the eyes wiggle side to side (horizontal nystagmus) then it is from the inner ear.  If these eye movements are vertical, then it is most likely in the brain.  Bonine (meclizine) usually helps relieve some of the dizziness, but high dose steroids are often used to decrease any inflammation around the nerves.  I have even done myringotomy (putting a hole in the eardrum) in some of these cases because the vestibular problem can arise from a change in the air pressure within the middle ear cavity.