Subdural Hematoma Complications

My 49 year old brother with down’s syndrome had evacuation of a subdural hematoma 8 weeks ago. He continues to have periods of extreme weakness and screaming episodes. His follow-up CT is negative for changes. I have heard so many different stories about how long his recovery will take.

When he first came home he was functioning better than he is now. Currently, he is unable to take care of any hygiene needs, dress himself or even feed himself. He was able to do all these things before. What expectations should I have regarding his recovery knowing his course will be different from the average man his age?