Doctors yesterday reported the first evidence that targeted electrical brain stimulation may help head-trauma victims stuck in a state of semiconsciousness, after an experiment apparently restored some of one patient's abilities to function and communicate.
Although the technique has been tried on only one patient, the experiment marks an unprecedented step that could lead to a new way to try to coax thousands of patients mired in similar states back toward more awareness, enabling them to function more and interact better with their families and others.

http://www.washingtonpost.com/wp-dyn/content/article/2006/10/15/AR2006101500403.html