Change brings controversy. You have a brain injury and you're doing CrossFit? Hold the presses, isn't that the one that people are dying from? I hate to be the bearer of bad news, but people die from everything: football injuries, driving a car, going to work, you get the idea.
When I was first introduced to CrossFit, I found it to be the hardest workout that I'd ever done. The results that I have seen in my strength and physicality have been unparalleled to any other things I have ever done in my more than 20 years in the fitness business.