COLUMBUS, Ohio – Global positioning system technology has added precision to brain surgery that already carries a significant “wow” factor because it is performed while patients are awake.
Though the procedure, called awake craniotomy, is not new, the combination of mapping and imaging technologies adds benefits for doctors and patients. Surgeons know the location of a tumor in the brain down to the millimeter before making a single incision, and patients’ risk for neurologic deficits are lower while they’re awake.
“Patient comfort is an important issue in performing these types of surgeries,” says Dr. E. Antonio Chiocca, director of neurological surgery at Ohio State University Medical Center. “Patients often want to move while they’re awake, but they can’t move while we’re operating on their brain. So speed is important in these procedures.”
Discomfort does not equate to pain, Chiocca notes, because the skull and brain have no pain receptors – the incision of the skin on the scalp is what usually leads to pain during the procedure, and this can be alleviated with local anesthesia.
The use of a global positioning system (GPS) in the operating room and magnetic resonance imaging (MRI) technologies allows surgeons to make smaller scalp incisions and also remove smaller segments of the skull. It also allows for reduced disruption of normal brain tissue to find the tumor. With GPS technology, surgeons use a wand that triangulates to other fixed objects in the room and provides an image of the tumor’s position on an MRI scan, guiding physicians directly to the incision site “so we don’t have to expose a large area to find the tumor.”
The awake craniotomy technique is used primarily to preserve patients’ speech during surgeries in which doctors are removing tumors, and is particularly helpful in guiding surgeons during removal of oddly shaped tumors that infiltrate into normal brain tissue.
“It’s a very effective way of monitoring the function of the patient and achieving maximum resection of a tumor,” says Chiocca, who also co-directs the Esther Dardinger Neuro-Oncology Center and holds the Dardinger Family Endowed Chair in Oncological Neurosurgery.
The awake procedure can also be applied to surgery on epilepsy patients in which segments of the brain that cause seizures are removed from areas near speech, movement and short-term memory centers of the brain.
The primary sections of the brain related to speech are Broca’s area, which is responsible for speech production and articulation, and Wernicke’s area, the home for language comprehension. Both are usually located in the left hemisphere of the brain. In these specific areas of the brain, Chiocca explains, any damage caused during surgery can lead to temporary or permanent impairment.
Patients undergoing awake brain surgery are anesthetized just enough so they will doze during the incision in their skin and removal of a section of the skull. Anesthesia is then withdrawn and patients are coaxed into consciousness so they can speak during procedures on the brain itself.
“You need a very good team to do this. Neuroanesthesiologists give patients just enough medicine so they will sleep during the first phase, and then they will wake them up when we get to the brain,” Chiocca says. “We have a speech pathologist talk to the patient as we remove the tumor. If we notice any trouble speaking, or if the patient develops a halting pattern of speech, we know we’ve gone too far and we stop.”
Though these brain centers are universal among patients, the mapping and imaging allow physicians to adapt to the “uniqueness of each brain,” Chiocca says. “And having the patient awake allows us to take care of individual differences.”
Patients who undergo awake brain surgery often are able to leave the hospital and return to normal activities within 48 to 72 hours.
Sleeping patients whose surgeries occur near these speech, memory and motion centers of the brain are at higher risk for suffering temporary or permanent deficits, but some patients will opt not to be awake, Chiocca says.
In addition to specializing in the latest neurosurgical techniques, Chiocca is a leading investigator in the use of biologic therapies and gene delivery methods to treat brain tumors and other central nervous system disorders. He joined the Ohio State medical faculty in 2004.
# # #Emily Caldwell
Medical Center Communications
614.293.3737
emily.caldwell@osumc.edu