New technology turns thoughts into actions, offering hope to spinal-cord patients.
By Tom Avril
Inquirer Staff Writer
http://www.philly.com
Philadelphia Inquirer
With the aid of electrodes implanted in his brain, a man paralyzed from the neck down was able to perform certain everyday activities - move a computer cursor, open e-mail, turn on a TV set - merely by imagining them.
The patient, whose spinal cord was injured when an attacker stabbed him in the neck, was even able to open and close a prosthetic hand, his thoughts translated into action by a computer system developed at Brown University.
The results, reported in today's issue of the journal Nature, offer hope that thousands of people with injured spinal cords could someday regain significant function by simply bypassing the injury. Authors predicted a commercial version of the system would be available in just a few years and would also work for victims of stroke and amyotrophic lateral sclerosis, commonly called Lou Gehrig's disease.
For now, patients must be tethered to a cart loaded with electronics, connected by a cable that plugs into the skull. Eventually the Brown team wants to implant wireless devices and program them so a patient could activate not just computer cursors or prosthetic devices, but his own hands and arms.
Coincidentally yesterday, a team that includes Drexel University scientists reported progress toward a similar goal in lab rats, albeit by different means. The researchers removed a nerve from each animal's leg and transplanted it across the injured spinal cord, restoring some mobility to paralyzed forelimbs.
The efforts of the Brown team, which worked with researchers in Chicago and Massachusetts, seem like something out of science fiction.
After implanting electrodes in the brain of Matthew Nagle, the 26-year-old stabbing victim from Weymouth, Mass., scientists discovered that the neurons associated with moving his arms and hands could still generate electrical signals - a surprising find three years after the attack.
They ran wires through his skull to BrainGate, an electronic device that filtered out noise and learned to interpret the signals. When connected to a computer, Nagle was able to play the video game Pong and also drew a circle using a computer drawing program.
"I just imagined moving the cursor," he said in a telephone interview from his room in a Massachusetts rehab hospital.
University of Pittsburgh neurobiologist Andrew Schwartz, who was not part of this study but who has done similar work in monkeys, said the success in human patients was a good start.
It is "still far from being a useful device," he wrote in an e-mail from Europe, where he was traveling.
John Donoghue, senior author of the Nature article and chief scientific officer of Cyberkinetics Neurotechnology Systems Inc., the company that makes BrainGate, acknowledged there was room for improvement.
But the technology has gotten even better since his team wrote the article, he said.
Nagle sometimes moved the cursor in a wobbly fashion and overshot his target on the computer screen. Subsequent patients have performed much better because researchers have refined the computer algorithm, Donoghue said.
Other teams of researchers have experimented with an external system that reads brain signals through the scalp - an approach that has the advantage of not requiring surgery. But patients sometimes need weeks or months to learn to operate the scalp-based system, because the signals are not as precise.
Nagle and others with implants have been able to communicate their thoughts immediately, simply by thinking "left," "right," "up," "down."
Still, translating such signals is tricky because millions of neurons are associated with moving the arm, whereas BrainGate's hair-thin electrodes only pick up signals from dozens.
People with spinal-cord injuries are wary of getting their hopes up for every new discovery, but this field is getting some attention. Mark Chilutti, who was paralyzed from the chest down by a gunshot wound, had a one-word reaction to the latest developments: "Wow!"
"When they're ready and working, we're all going to be getting in line," said Chilutti, who now works at Magee Rehabilitation Hospital in Philadelphia, where he was once a patient.
Alisa Brownlee, a technology specialist with the ALS Association of Greater Philadelphia, said: "For years we've been waiting for this brain-wave technology... . It holds exciting potential."
One hitch is that the array of electrodes implanted in Nagle's brain seemed to have suffered a short-circuit toward the end of the 14-month experiment.
The breakdown was not caused by any adverse reaction in the brain itself, Donoghue said. "The barriers to this seem more technological, but surmountable, rather than anything biological," he said. "I'm very encouraged."
When the team develops a wireless device, it would function somewhat like today's cochlear implants, the implantable devices that bypass the inner ear so deaf people can perceive sound.
While the current system allows patients to move computer cursors and prosthetic devices, the researchers hope someday to transmit electrical signals from the brain to a patient's real hands and arms.
Nagle's parents were somewhat apprehensive about the brain implant, but he was determined to press forward.
The electrodes were removed after the experiment, so he no longer can bypass his crippling injury with the futuristic BrainGate. But Nagle's participation was not just about bettering his own condition, he said, his voice raspy because he breathes with a ventilator:
"I knew it would give a lot of people hope."