patient jennifer gleeson. can you describe how you feel as you are about to head in and undergo a change? >> i'm looking forward to it. like a kid on christmas morning. you want to get there right now. >> reporter: it's finally time for jennifer to get into the operating room. >> we are going to introduce you to the team. hundreds of these deep-brain stimulations have been performed usually for patient with parkinson's and tremors. recently they've been performed on people with psychological disorders. jennifer is one of the first to undergo the procedure for . >> the first part is the most painful. jennifer is fitted with a head brace. her skull must remain still during the procedure. dr lee prepares for surgery as jennifer undergoes a series of high resolution m.r.i.s, crucial to avoid haemorrhage. later on, dr lee passes electrodes deep in her brain. >> it's like gaining x-ray vasion, we can look through the vessels. >> reporter: inside the operating room the procedure gets under way. >> you will hear a lit