Unfortunately, without more information and an in-person interview, I have no way of knowing what might be wrong with your brother.
Your family might try having a second or a third evaluation. It’s not uncommon to receive multiple opinions. These evaluations could provide insight into what might be wrong. Otherwise, you might have to wait and see if anything changes. I’m sorry that I cannot provide you with a more specific answer. Good luck and thanks for writing.
Dr. Kristina Randle