A new functional MRI technique, pioneered at Wayne State, could be used to rehabilitate brain-damaged patients, or it can be used on cases like the controversially prolonged 2005 death of Terri Schiavo, to determine if people can come out of vegetative states or comas.
The New England Journal of Medicine published an article Feb. 3 that outlines a technique using functional MRI to communicate with brain injury patients through simple questions
According to Randall Benson, assistant professor in the department of neurology at the Wayne State School of Medicine, the researchers were able to know if the patients were answering ‘yes’ versus ‘no’ by establishing a known for their pattern of brain activity.
“So they had to start by making statements that they knew the patients knew the answers to,” Benson said. “So, in a sense, they were letting the patient tell them what the networks look like.”
Benson has worked on MRI studies since 1992 when at Massachusetts General Hospital he studied the beginnings of a technique to look at language activity in the brain. The research team found it was able to predict language dominance, in either hemisphere, by using functional MRI.
According to the WebMD Web site, MRI is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body.
A more common technique at the beginning of the 20th century was the invasive Wada test when doctors or nurses injected anesthetic into the corroded artery. The anesthetic would “shut down” a hemisphere of the brain for a couple of minutes for testing before surgery.
Two years ago, the Food and Drug Administration approved functional MRI as a clinical test for preoperative mapping, Benson said.
“I feel good about the fact that we sort of pioneered the whole thing,” he said.
In 2004, Benson implemented his language paradigm techniques with an 11-year-old comatose boy admitted at the Children’s Hospital of Michigan to determine his brain activity. The yet-to-be published findings revealed that the patient showed activity in the appropriate regions based on previous studies of healthy patients. He came of out of the coma after a few weeks, and his MRI scans showed more of the same activity previously measured.
“I firmly believe that the initial scan we did on him was very informative,” Benson said. “It’s one thing to look at somebody and just have a gut feeling. It’s another thing to actually know what’s going on inside the brain.”
MRI results could help to determine treatment and rehabilitation pathways for patients, according to Benson.
“There’s pretty good evidence that a large part of the benefit from rehab comes not from actual performance of the movement, but comes by the conception of the movement,” he said.
A scientist named Alvin Liberman studied what he called mirror neurons in the 1990s. In his studies with monkeys, these neurons activated not only when the monkeys moved but also when they observed other monkeys moving, according to the Asian EFL Journal. Other studies show mirror neurons are also in humans.
If a patient can’t move it doesn’t mean damage to the brain’s motor neurons at the highest level. According to Benson, they may be stimulated and the motor system activated as a part of rehabilitation.
In addition to that, Benson said doctors can predict who is likely to emerge from a coma or vegetative state by help of the cognitive activity seen from brain scans rather than just relying on outward physical movements.
“So I think there’s a lot of room for exploration,” he said.
Benson is currently collaborating with a magnetic resonance physicist and professor of the department of radiology at the SOM, Dr. E. Mark Haacke, and others at Harper University Hospital and WSU.
They are working on using less conventional MRI techniques to diagnose brain injury in those who show minimal to no signs of brain injury on the standard imaging.
Their brain injury studies include using Diffusion Tensor Imaging. It looks at water flow in the brain, indicating damage to white matter.
There’s another technique called Susceptibility Weighted Imaging, which is sensitive to iron compounds such as hemoglobin in blood and can detect the smallest of hemorrhages.
Another technique is MR Spectroscopic Imaging that measures concentrations of metabolites altered in brain injuries. There are more techniques in development.
“Our philosophy on this is, ‘Why do one technique when TBI (traumatic brain injury) causes many different problems and we have different MRI techniques that are able to detect these various consequences of trauma?’” Benson said.
The MRI is not one thing, he said, but a platform for imaging studies. Research and collaboration is ongoing.
“This is not your grandfather’s MRI,” Benson said.
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