Traumatic Brain Injury and types

So! Yeah. Very nice forum here, hope to milk it out quite a bit before I get bored and leave. 

In my initial looking around at the concept of CT, though, I noticed that brain scans are a key way of deciding upon a person's type--certain brain regions get lit up to a larger degree for certain people, etc. 

But of course, all this leads me to ask about just what happens when you take certain parts of the brain out. 

In the event of a TBI, the brain is literally going to rewire itself. Whole sections, such as the ones involved in certain functions, might not be there anymore. In such an event, therefore, one might reasonably be able to assume that type could change. On the other hand, however, it's equally likely that, rather than type being the thing that changes, what actually ends up changing is simply which brain region is responsible for a function. Like how some TBI-sufferers are reported to be able to regain certain abilities that were lost as a result of the brain damage, those sufferers might also be able to rewire their brains so that certain functions start to originate in different brain regions. 

So...thoughts?