Pinpointing Problems In The Brain - Neurologists Use New Brain Scanning Device To Better Control Seizures

March 1, 2007 — Doctors are now using a new kind of brain scan called magnetoencephalography (MEG), which measures brain activity in real time. In some cases, MEG can pinpoint the source of an epileptic seizure much more accurately than the traditional method of electroencephalography (EEG). Using a combination of MEG and MRI, neurosurgeons have a detailed brain map that allows them to remove just the damaged tissue while preserving healthy cells.

Dawn Helton has tried just about everything available to stop her seizures so she can get back to living her life. "I mostly, um, just lose my hearing and my speech ... confusion. Then, of course, I'm really tired and stuff," she says.

Epilepsy is a frustrating and often debilitating condition. Medication may control seizures in about 75 percent of cases, but neurologists say surgery is the only potential cure.

A Geodesic Sensor Net was supposed to help doctors pinpoint where Helton's seizures happen, but it didn't work. Now there's new hope when all else fails. A powerful new brain scanning tool could make all the difference. Magnetoencephalography, or MEG, works by measuring the magnetic field created by brain activity ... And it does that in real time.

"Unlike other, other imaging tools that sample it several or tens or hundreds times, this imaging technology can take thousands of samples every second," Anto Bagic, M.D., a neurologist at the Center for Advanced Brain Magnetic Source Imaging at UPMC in Pittsburgh, tells DBIS.

That means in some cases MEG can pinpoint the source of an epileptic seizure much more accurately than the traditional method of electroencephalography (EEG). Using a combination of MEG and MRI, neurosurgeons have a detailed brain map guiding them during surgery to remove just the damaged tissue, while preserving healthy cells.

Researchers say in the future, the MEG brain scanner may aid in the diagnosis and study of other disorders like dementia, migraines, Parkinson's disease, depression and traumatic brain injuries, in addition to epilepsy -- a breakthrough that could lead to helping patients like Helton.

"I think it's fabulous," Helton says. "I think if anybody can come up with even anything more, more advanced, it's even greater! Stop these seizures. Or slow 'em down, or something."

 

BACKGROUND: At the university of Pittsburgh Medical Center, a scanning device which measures the brain's magnetic field in real time is allowing clinicians to more accurately pinpoint those areas of the brain causing epileptic seizures.

The scanner also can aid in the diagnosis and study of disorders such as Parkinson's disease, multiple sclerosis, dementia, and schizophrenia. Currently, researchers are using the device to determine the location of seizures in epileptic patients and identify the functional centers of the brain responsible for language, vision, motor and sensory information.

HOW IT WORKS: Real-time brain mapping and monitoring is considered to be one of the most exciting areas of neuroscience today. Magnetoencephalography (MEG) measures the magnetic fields produced by electrical activity in the brain via extremely sensitive superconducting sensors. Any electrical current will produce a magnetic field, and MEG measures the field generated by the brain's electrical currents. Traditionally, brain activity has been measured using electroencephalography (EEG), in which the electrical signals are recorded from electrodes placed on the scalp.

BENEFITS: With MEG, clinicians can now map nerve cell activity in the brain non-invasivelyto see the brain in action, rather than analyzing a series of still images. The system simultaneously produces 306 separate recordings of magnetic activity and determines where it originates and which parts of the brain undertake various tasks. An MEG scan can also determine how the brain functions both normally and in cases of illness. The graphical representations produced by the system can be sent directly into a navigational system used by neurosurgeons in the operating room to help guide them to the area of the brain that should be taken out, while at the same time marking vital centers and abnormalities -- thereby improving surgical outcomes.

ABOUT EPILEPSY: Epilepsy is a disorder of the central nervous system, specifically affecting the brain. A network of nerve cells (called neurons) runs through the body like telephone wires, delivering "messages," via chemical messengers known as neurotransmitters, from the brain. Epilepsy disrupts this vast communications network. The brain's electrical rhythms tend to become imbalanced by sudden surges, leading to seizures. Around 2.7 million Americans have been treated for epilepsy in the past five years: 8 out of every 1,000 people. And up to 5 percent of the world's population may have a single seizure at some point in their lives.

The American Association of Physicists in Medicine contributed to the information contained in the video portion of this report.

Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.

Note: This story and accompanying video were originally produced for the American Institute of Physics series Discoveries and Breakthroughs in Science by Ivanhoe Broadcast News and are protected by copyright law. All rights reserved.