Professor’s findings on electrical properties of the skull may hold key to brain research

New findings about the electrical properties of the human skull by Bin He, a professor in the Institute of Technology’s Department of Biomedical Engineering, may hold the key to more accurately diagnosing and monitoring epilepsy, comas and other brain activity. Knowing the conductivity levels of the brain and skull are key to techniques commonly used to scan brain activity.

Professor He and his colleagues, including Yingchun Zhang, a post doctoral associate in the University of Minnesota's Department of Biomedical Engineering, and Wim van Drongelen, an assistant professor in the Department of Pediatrics at the University of Chicago, studied the human brain-to-skull conductivity of two children undergoing treatment for epilepsy.

In the past, doctors have tried to identify the specific areas of the brain responsible for seizures with electrodes implanted inside the brain. During this study, doctors also measured the brain activity of the children using electrodes on their scalps in conjuction with the implanted electrodes.

With the help of sophisticated computer models consisting of more than 160,000 small elements, use of the supercomputing facility in the University of Minnesota’s Supercomputing Institute, and nearly 50 sets of electrical measurements, researchers found that the brain is surprisingly only about 18.7 times more conductive than the skull. Old data used for 30 years estimated that the brain was 80 times more conductive than the skull, while other more recent experiments suggested that the brain is 25 times more conductive.

"While the electrical conductivity of the brain is relatively well known, there has been a big disparity of findings on the electrical conductivity of the skull,” He said. “Our group is the first in the world to develop a sophisticated computer model which can accurately compute the electrical field in the setting of simultaneous intra- and extra-cranial electrical recordings.”

The new findings offer more hope for future work in using non-invasive techniques to pinpoint areas of the brain responsible for seizures or other brain abnormalities. This would mean more “accurate surgical outcomes” in future brain surgeries, He said.

The research findings by He and his colleagues were detailed recently in the journal Applied Physics Letters and covered by Live Science and Fox News.