Until recently scientists thought that when a region of the brain was damaged, its function was lost forever. Stroke patients who couldn’t use an injured arm were taught to dress and bathe with their good arm.
But sophisticated imaging tests of the brain at work have since revealed that it can reorganize itself after injury so that when nerve cells die, their functions are taken over by other cells… read in full at… http://www.consumerreports.org/health/conditions-and-treatments/stroke-prevention/stroke-therapy/index.htm