Good! Remember that idiopathic means unknown cause, though.
I would recommend you read the following:
http://www.winnfelinehealth.org/Health/Feline_Vestibular_Disease_Thayer.pdf
http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=564
http://www.fabcats.org/owners/wobbly_kittens/info.html
http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/31000.htm
they are all very helpful. Has Juba ever been treated with Streptomycin? The reason I´m asking is taht this drug is neurotoxic specifically to the nerves that control balance, while the "brother" Dihydrostreptomycin (DHS), is toxic to the nerves that regulate hearing.
Good luck with continued testing and perhaps some treatment will result?
Per
The vet at the specialty clinic called it congenital vestibular disease. She asked if he had bengal, siamese or burmese anywhere in his lineage claiming it is a known condition in some lines of these cats, especially siamese and burmese. I'll ask his breeder about that as well as about exposure of the queen to drugs during and after pregnancy as well as the litter. I'll ask her about the drugs you mentioned. I know he didn't get any of those while he's been with me.
I'm not doing any further testing. The MRI showed no structural abnormalities, no lesions, no tumors, or infection. He's had blood, urinalysis, spinal tap, and radiograph. At this point, I think we'll call it quits unless something happens to degrade his condition but I think, from all the literature I've read, that we can expect a long life for him and we'll deal with any recurrent dizziness episodes as they happen.