I know someone who had to go through vestibular therapy after a cerebral hemorrhage followed by stroke. It was not pretty, and the therapy can only do so much. On the other hand, without therapy he was utterly unable to function.
They had me walking balancing beams {very close to the floor for obvious reasons} and other task some may not understand. This was to improve my eye to muscle coordination. It's still bad I would likely flunk a field sobriety test. But they helped me adapt which is what Occupational Therapy does. Four years later I got in the Navy. Had they checked me for two eye vision I would have flunked. They check my left eye fine then the right also fine but not both at once which will not happen.
When my wife went quad I learned a lot more about the Inner Ear as this is one of the first things Paraplegics and Quads loose. Thus the reason for the Tilt Table seen in rehab centers.
My damage was due to severe Sinus allergies they think. Ever hear the saying Snotty Nose brat? LOL..
I retired at the ripe old age of 34 about 16 years ago. My concentration was shot as well as my ability to tolorate a lot of audio or visual stimulation. For disability I am diagnosed as having General Anxiety Disorder. I also have Myoclonic seizures with it which produces severe upper torso spasms. Some would call me spass I reckon LOL.
Looking at me a person would say I'm healthy though except now my feet and legs are giving out from too many years walking off balance.