23rd January 2006
After several conventional MRI scans that have been made a misery by panic-inducing claustrophobia, I've finally discovered the answer.
Advanced MRI helped pain patients learn to control their sensations by watching activity in their brains. By Carey Goldberg, Globe Staff.
The back pain has been with 32-year-old Laura Tibbitts ever since she was thrown from a horse eight years ago -- sometimes a dull ache, sometimes a sharp stab, yet always there.
But recently, she found some relief using what may be the highest-tech pain treatment there is: Strapped into an MRI scanner, she was able to watch the activity levels in a part of her brain that helps control the perception of pain.
By watching that direct feedback from her brain, she trained herself to moderate the pain.
Tibbitts, a conference coordinator at Stanford University, was participating in a new study that found that when people could see their own brains at work, they gained new control over their pain.
Though still highly experimental and not likely to become available for several years, the method offers hope of a new option for the estimated 50 million Americans who suffer chronic pain.
The brain-watching method, now being explored in the Boston area and elsewhere, could also offer a variety of other benefits for stroke patients, dyslexics, and others, said imaging scientists.
Instead of going to a gym to work out a specific muscle, a patient could go to a brain scanner to work out a specific region of the brain, suggested Dr. Sean Mackey, a Stanford University pain expert and the study's senior author. Or, perhaps, someone could conquer depression or a phobia by taking direct control of the brain circuits causing the problem, he said.
"That is still in the realm of science fiction, but now, for the first time, we see the possibilities of bringing that science fiction to reality," said Mackey, chief of Stanford's neuroimaging and pain lab.
Only a dozen pain patients took part in the study, which was published last month in the Proceedings of the National Academy of Sciences, but the effects of its single session of training were promising enough that researchers are now pursuing bigger, longer-term trials.
''The next step is to ask the question whether we can produce sustained decreases in pain long-term, and therefore clinical benefit," said Christopher deCharms, the study's lead author and president of Omneuron, a California start-up that aims to commercialize the brain-watching technology, called real-time functional MRI.
DeCharms acknowledges that the treatment will be hard to bring to widespread use because of the need for a multiton, multimillion-dollar scanner.
But deCharms argues that patients with severe, intractable pain can easily accrue hundreds of thousands of dollars in healthcare costs over a lifetime, not to mention the horrific cost to their quality of life. ''If we're able to produce a long-term benefit for these patients, I think the procedure will be justified," he said.
In the study, the researchers focused on an area of the brain called the rostral anterior cingulate cortex, which is involved in translating nerve signals from the body into feelings of pain.
Subjects in the study were alternately instructed to increase their perception of pain by focusing on it more, for example, or thinking anxiously about it, and to reduce their pain by, for example, calming themselves or focusing on pain-free parts of their bodies.
As they did, they could watch the activity level of their anterior cingulate rise and fall on a screen inside the magnet. They could watch it as a simple graph and as an image of a flame that could flare up or flicker.
With the real-time MRI, the patients reduced their pain by an average of about 40 percent for a time, Mackey said, which is about as much as many pain drugs on the market. Healthy subjects who practiced reducing the pain from an uncomfortably hot stimulus also found that through training, they could dim the pain by 20 to 40 percent, Mackey said.
It may seem strange that such direct brain feedback would make a difference; after all, the intensity of pain itself is quite a powerful form of feedback.
But the study included several control groups, and none saw anywhere near the effects that the brain-watching subjects did. Two groups received extensive instruction on heightening and reducing pain but no MRI time; a third watched a part of the brain that apparently has nothing to do with pain processing, and a fourth watched someone else's brain when they thought it was their own. An additional group got feedback from body functions such as their heart rate but not from the brain.
It does seem, Mackey said, that the subjects ''really learned to control their brain and, through that, their pain."
The idea of training people by using feedback from brain activity is not all new. For years, pain clinics have offered biofeedback to help patients try to stem their suffering by learning to control physical functions like heart rate and breathing. Even ''neurofeedback" has been around for years: Some use the term to refer to a method of monitoring brain activity using electrodes pasted on a person's head to pick up brain waves.
But MRIs allow a far more specific, under-the-hood view of the level of activity in specific regions of the brain, and the latest technology includes software so powerful that those signals can be read out in real time, allowing people to watch their own brains at work.
John Gabrieli, an imaging scientist at MIT and a contributing author to the Stanford study, plans to explore whether real-time functional MRI can help stroke patients recover, he said. Brain scans indicate that when stroke damage is in the brain's left hemisphere, patients recover speech best if their right hemisphere takes over that function. Real-time MRIs might help them make that shift.
Also, he said, there is a fair amount of evidence about which parts of the brain are important for maintaining attention, so perhaps MRI training could help people with attention deficit disorder; similarly, some brain areas have been implicated in dyslexia, so perhaps MRI training could help those with trouble reading.
''We're super-excited because it's cool and potentially helpful, but we just don't know," Gabrieli said.
For Laura Tibbitts, the readout from her brain helped her realize when she wasn't concentrating well enough on pain-relief techniques, she said in a phone interview. Sometimes, she said, she would imagine snowflakes soothing the heat of her pain; other times, she imagined little men marching along her body and scooping the pain away, because being strapped down in the MRI made her feel like Gulliver among the Lilliputians.
At first, she would think she was turning down the pain well, but the graph would tell her otherwise, she said. But after a few rounds of bringing the pain up and down, she started to get better at it, and when she emerged from the scanner, she felt a kind of exhausted runner's high for hours.
The effect did not last, however, once she was out of the magnet, she said. For her, at this point, ''it's just one more tool, one more thing in my arsenal of tricks to try," like acupuncture, yoga, and exercise.Email Carey Goldberg.
It's your basic, cool science
New brain-watching techniques clearly have some medical potential, but they also offer the opportunity for some basic, cool science.
Seung-Schik Yoo, an imaging scientist at Brigham and Women's Hospital, plans to explore the idea of a ''virtual keyboard" for ''locked-in" people who cannot move enough even to communicate. His concept: Patients could be trained to maneuver a cursor around a 36-character keyboard by using six types of thought and two types of time intervals. If it worked, a patient would be able to type using only the power of mind.
He is also working on using a real-time MRI to allow brain control of a robotic arm and of a drawing device like an Etch-a-sketch.
It gets weirder. European researchers reported at a brain-mapping conference last year that they had created a new game called ''Brain Pong."
Subjects, who had been trained by the scanners' instant feedback from their own brains, managed to use only their mental muscles to play a match of Pong, the primitive, tennis-like computer game. With one subject in one scanner and another scanner in another, they could even play against each other, brain pitted directly against brain.