A new device is helping doctors at the Mayo Clinic better map the brain during surgery on patients with epilepsy uncontrolled by medication.
The device, known as the QT Grid, was developed by neurologist Dr. William Tatum and neurosurgeon Dr. Alfredo Quinones-Hinojosa.
During certain surgeries on people with epilepsy, doctors remove the portion of the brain triggering seizures. However, the brain controls many critical functions like speech, movement and facial expression, all in areas just millimeters apart.
“There are different areas of the brain that have such delicate functions that removing them would create as much or more of a disability than somebody that has ongoing seizures uncontrolled by medication,” Tatum said.
The QT Grid helps pinpoint locations causing the seizures along with those that are critical to avoid.
“Use this little circular device, put it right on the brain and begin to stimulate several parts of the brain,” Quinones said. “The two of us communicate with each other as we’re stimulating this brain right here, and then the patient in turn is talking to the two of us.”
Yes – the patient is often awake during the surgery. In fact, they play a vital role by performing tasks to help the doctors see what function corresponds with the area being stimulated.
“[For example] the patient is talking to you and suddenly you stimulate a part of the brain and then they stop talking,” Quinones said.
“If there’s an area right down there that contains a function that we know needs to be avoided, we’ll place a type of marker in that area,” Tatum said. “And that way, when you actually look at the site that’s being operated, you get a little splay of a map.”
Tatum used a comparison of cameras to illustrate the map they get with the new device compared to previous technology.
“If you compare a Kodak Instamatic camera with a 35mm, they’re both cameras but the ability to look with a 35mm is so much better you can pick out the detail to a much greater degree,” he said.
Tatum said so far they’ve used the QT Grid on around 60 patients; many of them have become seizure-free.