If its a stroke an MRI scan of the brain would show it along with any blood clots or any other problems. They actually see so much on MRI scans that somethings they dont know what they are yet.
Usually when you have had a stroke it shows as patches in the brain, sometimes very small. What they cant tell is when it happened unless there ghas been a previous MRI.
My ear problem was originally thought to be a stroke and my doctor would not believe that it was an ear problem and also I apparently had high blood pressure but I now have a white coat effect. The MRI scan did not show any proper signs of a stroke although there was some minor damage. However when I eventually saw an ear specialist he knew staright away I had an ear problem and its something that you cant see.
I would think that the next step would be an MRI but they are expensive and Tom would have to be sedated heavily, I think.
As he doesnt have high blood pressure and all other tests are normal, I would still think its an ear problem but maybe one that they cannot do anything about in a cat.
Even GPs dont recognoze the symptoms of many ear problems and the symptoms it seems are the same as a minor stroke ie one that does not cause loss of movement caused by damage to the brain.
I also had heart checks and all sorts but at end of day its my ears and sadly I learned that although the brain learns very quickly that you are unbalanced, after a couple of weeks without corrective treatment , it does not learn that you are balanced again for a very long time. Its now over 3 years since I had treatment but although I am much more balanced I am still not fully balanced and may never be so again.
I am assuming that a cats ear works the same as a humans and that within the ear it has crystals that are on tiny hairs. If a virus damages the hairs the crystals can end up in the wrong part of the ear and this causes the imbalance. Until it settles this is made worse by movement cos one gets dizzy , pulled to one side or falls over. Ironically once an Epley manoevre is performed on a human its movement that helps to re-educate the brain that the person is balanced again. The critical time is two weeks from onset and if the Epley manoevre is performed in this time, one can be better immediately. In my case it took over a year to diagnose.
I suspect you cannot do this prodcedure with a cat cos I had to remain at no worse than a 45 degree angle for 24 hrs after the treatment to allow the crystals to settle back into the right part of the ear.
I am obviously no expert but would have thought that a stroke would have indicators of high blood pressure and the problem is ear/brain oriented. It could of course be brain oriented and not an ear problem. One can also have an ear virus which can not be treated or seen that gives this effect too but the virus just has to burn itself out.
I really hope that Tom starts to improve without any backward steps