Doctors talking with their patients ... during brain surgery. The one way to know if sensitive surgery is impacting a patient's function ... ask them while you're operating.

Dr. Prabhu: "Have her move her right leg and right arm."

She has function.

Nurse: "Terri, what is this a picture of? A flower. Good."

She comprehends and she speaks. All good signs since Terri Shepherd had a brain tumor within millimeters of critical areas.

Dr. Vikram Prabhu, Loyola Neurosurgeon: "Hers was in close proximity to her speech and her motor cortex."

Just one month before surgery Terri felt fine. Then one night a terrible headache.

Terri Shepherd, Brain tumor patient: "I was nauseated, I had a stiff neck, eyes sensitive to light."

Her doctor suggested a trip to the ER.

Terri Shepherd: "They did a CT scan and within an hour of being there that's when they told me I had a brain tumor."

Then her neurosurgeon told her something equally shocking. He was going to operate and wake her up during surgery.

Terri: "I was anxious about waking up. What would I be thinking when I woke up would I be scared."

But it turns out Terri, like many of Loyola University Hospital's Dr. Vikram Prabhu's patients was calm.

Terri Shepherd: "I remember having to count backwards from 20. I remember Dr. Prabhu telling me 'Terry I need you to talk.'"

Dr. Vikram Prabhu, neurosurgeon, Loyola University Health System: "They will banter with us and talk to us and sometimes even select the kind of music they want to listen to."

With very carefully controlled anesthesia, patients are asleep for the pain of surgery but awake for the most crucial test.

Dr. Prabhu: "This gives us immediate feedback that their neurological functions are intact and that we are not injuring or getting close to these critical areas."

Before going into surgery doctors map the brain knowing where they want to avoid and where they need to delve in to remove tumor.

Dr. Prabhu: "We use lasers and we use small coagulation tips to do that but in essence we gently debunk it without hurting anything around it."

Terri told them during the operation and now after.

Terri Shepherd: "I feel as good or better than before surgery."

Surgeons say they have been using brain mapping and waking patients for years but now better pre-operative imaging and better anesthesia techniques make for even better outcomes.