Re: Can 26 year old have brain degeneration?
My son has a cerebellar atrophy disorder, and his symptoms are quite different. There are many forms of this, I know, but the one thing they all seem to have quite early in the onset is ataxia - lurching walk and loss of reliable balance without dizziness. Nothing has shown up on MRI or PET except for very minor shrinkage of the cerebellar cells. It started when he was 37.
If you do have this then it can really only be diagnosed after symptoms develop further. My son, despite being significantly disabled, has not been conclusively diagnosed. Maybe we never will know for sure. It make his planning for any future needs very difficult.
Ask to be referred to a neurologist. If any new progression of symptoms develops, then you will have more to go on. Good luck, Sera