I just read an article that reminded me of a speaker that Andrea and I once attended who was studying people who were in a vegetative state. They used a functional MRI which can basically show which parts of the brain are working. They asked these people (who were in a vegetative state) to imagine themselves playing tennis OR walking through their home. These 2 different "thoughts" would activate completely different areas of the brain (one would light up a motor area and the other a memory area). Anyway, it was a very low percentage (around 10% I think) but some of these vegetative patients consistently could follow the commands to use these parts of their brain. It can be distressing to think that these people were so completely "locked in" that no one knew they were aware of their surroundings. However, the hope from the research was that knowing this, researchers could find a way to communicate with these severely brain injured people again.
The following article is actually just about one individual who was thought to be in a vegetative state, but thanks to some researchers they realized that she was NOT and found a way to communicate with her almost 2 years following her severe brain injury. And after this, they were able to improve her ability to communicate because the brain showed some remapping/recovery.
"This is a unique demonstration of plastic change in the brain of an adult starting years after a severe brain injury."
And this is the basis of all neurological rehabilitation. The brain can remap and recover some functions. Sometimes even small functional improvements can significantly improve someone's quality of life. Our brains are so cool!