Very sad to hear!
I had a very bad accident just over a year ago. Broken neck, broken back, two places, broken hip, broken femur, broken knee (tibial crown), both feet broken in multiple places. The other stuff I don't even count.
All that happened to my helmet was a small silver dollar sized scratch on the back, that being said, I won't ride without a helmet!
I'll never be the same, will never work in the job field I was in again. Gotta move on.
I had a friend that had a head injury and when I would come by and talk to him he would do the same as your uncle, he knows you're there.
He is going to need your whole family to stay strong for the duration, it will take patients on everyones part. Hang in there. Sending good vibes and strength to your uncle and family.