The biggest strides are coming in treating brain injuries as soon as they occur, since much of the damage done happens after the acute injury. Tissue swells, blood flow may be reduced or eliminated to parts of the brain, inflammation sets in, connections stretch or break, and the chemistry of the brain goes haywire. All of these things add to the original insult of injury. So research is trying to step in early in the process and prevent this cascade of damage.

The problem with an older injury is that the brain is extraordinarily complex. You can lose a large chunk of your liver and it will regenerate, because it doesn't matter which cell goes where in your liver. It makes all the difference in the brain. The fine structures, the links, the organization of the brain itself create the person, their memories, and all their abilities. When the brain is damaged, its like dropping a crystal vase onto concrete. How do you gather all the pieces and put them together again?