What is an awake craniotomy?
A craniotomy is a procedure in which the skull is opened to access the brain or the space around the brain. Most of the time, craniotomies are performed with the patient under general anesthesia (asleep). In some cases, however, there is value in mapping the surface of the brain to determine the safest way to perform a surgery. Certain forms of brain mapping, particularly the mapping of speech, require the patient to be awake and interactive. In these cases, I use a technique called an awake craniotomy.
Why map a brain function like speech?
The parts of our brain used for speaking are similar in location but vary slightly from one person to the next. If a tumor or other lesion is located near a speech region, keeping the patient awake and testing their speech during the operation allows me to reduce the risk that speech will be affected by the procedure. In other words, mapping allows me to avoid damaging important brain functions that I am trying to preserve.
What is an awake craniotomy like?
The patient’s scalp is numbed and they are sometimes sedated slightly until it is time to map the brain. There is some discomfort, but it is usually manageable, since the scalp is anesthetized, and the skull and the brain do not have many pain fibers. A probe is used to apply painless electric current to the surface of the brain while a patient is speaking, and I identify the areas where speech gets interrupted by the electric current. This allows me to determine which areas are essential for speech and which are not. Based on what I find, I can plan the safest way to perform the operation.
What does speech mapping look like?
Below are two photos of an awake craniotomy I performed for removing a tumor in the left temporal lobe. The first shows the surface of the brain during speech mapping, and the second shows the sites that were important to the patient’s speech (yellow stars). I used this mapping to remove the tumor without violating the speech center.
Do you use other kinds of mapping?
I use mapping commonly when removing brain tumors - both speech mapping as well as another technique called motor mapping, which allows me to identify and avoid the motor (movement) center and fibers in the brain. Motor mapping is different than speech mapping in that it can be performed with the patient asleep.
Should I meet with you?
If you live near Denver and have a brain tumor near an area important for speech or movement, please consider meeting me in consultation to learn about your treatment options.