Scientists Report Refinements to Brain Surgery
WEDNESDAY Jan. 2, 2008 -- New so-called mapping technology will enable surgeons to perform brain surgery with less damage to parts of the brain that govern language, researchers report.
As a bonus, brain researchers may also get a more detailed "map" of the language centers of the brain.
The new technique, described in the Jan. 3 issue of the New England Journal of Medicine, is called "negative brain mapping." After a neurosurgeon has removed part of the skull, the surgeon stimulates small sections -- approximately 1 centimeter square -- using a bipolar electrode. This method relies on knowledge of brain areas that contain no language function, compared to the traditional method that requires identification -- with the patient's participation -- of areas that control speech, naming or articulation, the researchers said.
According to the researchers, the benefits of this new approach include reducing the amount of skull that has to be removed and reducing the amount of time a patient has to be awake.
The neurosurgeons developed and tested this technique over the course of eight years. They used the method on 250 patients (146 men and 104 women) who had gliomas, a common and deadly form of brain tumor. All tumors were in the dominant hemisphere of their brain.
Surgery to remove brain tumors, such as gliomas, can often result in indirect damage to parts of the brain that control language ability, the researchers said.
When the researchers followed up after a week after surgery, they found that three out of four (77.6 percent) of the patients had the same degree of language function they had prior to surgery. After six months, only 1.6 percent of patients had worse language skills.
The researchers also found that the anatomy of language varied significantly between patients. This information could be useful to people suffering from brain disorders, including seizures and stroke-related damage, that affect language, according to the research team.
"This study represents a paradigm shift in language mapping during brain tumor resection," senior author Dr. Mitchel Berger, chairman of the University of California, San Francisco Department of Neurological Surgery and director of the UCSF Brain Tumor Research Center, said in a prepared statement. "Not only have we proven this technique can be safely relied upon for brain tumor resection, we have shown functional language organization to be much more diverse and individualized than previously thought."
Posted: January 2008