Martin,
A year ago last June while ATGATT I too suffered multiple skull fractures, bleeding on the brain, swelling of the brain and 4 days in an ICU "step down unit". I walked out of the hospital on day 5 and for 2 weeks prayed for the headache to just go away.
I was back to work again in 2 weeks and riding again in 8 weeks. While I do see some long term (and probably permanent) affects of the brain injury I received, they are very minimal and simply are not serious. I am now in the 3rd year of a PhD program, this accident did not terminate my rather lofty educational goals.
My point is 2 fold....1.) people do recover form this type of serious brain injury and, 2.) I was ATGATT when I crashed the bike. I cracked my skull in several locations while wearing a 2 month old Nolan N103 full faced helmet. The ATGATT saved me from any missing skin and any other significant injuries, but it didn't save me the head injury!