Complex sentence: The brain, up to about the age of 8, is not set and has the ability to reroute many signal paths that may have been affected by the initial trauma; the earlier it has help in doing this the more successful it will be.
Split into simpler sentences: The brain, up to about the age of 8, is not concrete in its development. It has the ability to reorganise and reroute many signal paths that may have been affected by the initial trauma; the earlier it has help in doing this the more successful it will be.