Acquired Savant Syndrome abbreviated is ASS. We know what a savant is. It's a brilliantly smart person, smart in usually one area and usually disabled. Acquired savants then, get the savantism due to a head injury.
This greatly interested me. I had a head injury and seem to be getting only smarter.
Savantism is already rare. To get it from a head injury is even more rare. http://www.theatlantic.com/health/archive/2012/05/eureka-when-a-blow-to-the-head-creates-a-sudden-genius/257282/
I talk about mine before I heard about acquiring it, http://thoughtfulveg.blogspot.com/2012/03/neuroplasticity-created-rainman.html
It is possible to have a head injury and then be smart.
[If you know of something else, please leave it in the comments. I did write this, and many other things AFTER a brain injury. Also, that piece above on neuroplasticity requires quite a bit of knowledge about the brain. I did not write before the brain injury.]