FRIDAY, Oct. 26, 2001 (HealthDayNews) -- Areas of the brain that control both movement and feeling continue to work normally years after severe spinal cord injuries, says a new study.
The discovery represents a possible first step toward a long-term goal of implanting electrodes that would bypass damaged nerves and allow paralyzed people to move their extremities at will, even restore a sense of touch -- recognizing hot and cold, for instance, says chief researcher Richard Normann, professor of bioengineering and ophthalmology at the University of Utah. His findings appear in the Oct. 25 issue of the journal Nature.
Normann says those possibilities are a long way off, but "eventually these signals could be used to directly control the muscles of a paraplegic person, ultimately allowing them to move their body just through the desire to do so."
Normann says his study strongly indicates that the brain retains the ability to send signals to muscles at least five years after spinal cord damage.
In his study, Normann asked five patients who had been paralyzed in auto accidents five years earlier and five uninjured volunteers to move the same body parts while undergoing magnetic resonance imaging (MRI). "They were asked to move their hands, purse their lips, move their ankles, rotate their elbows and extend their knees," Normann says.
In all 10 people, increased electrical activity registered in the same areas of the brain that control movements of various body parts.
Norman says researchers had feared that the brains of paralyzed people might not retain the ability to send signals to muscles. When portions of the brain are not used, they often undergo a reorganization in which other parts of the brain take over some functions. The new study showed the fears were unwarranted.
Normann says the next step will be lab experiments to show if an electrode can be safely implanted to read brain signals. The process will require more research because of the high risk of even more serious injury. "What we're talking about is highly invasive, and we have to be absolutely certain that the benefits outweigh the risks," he says.
Normann says he envisions implanting many electrodes. To restore movement to paralyzed people, bypassing the damaged spinal cord by sending brain signals to muscles through electrodes will not be enough. The brain also must be able to receive sensory feedback from the muscles. To enable two-way communication and control, he says electrodes would be needed in both the motor cortex and the sensory cortex as well as corresponding electrodes in the spinal cord.
The concept is not farfetched science fiction. Dr. William Heetderks, director of the neural prosthesis program at the National Institutes of Health in Washington, D.C., says Normann's research shows that the technology isn't all that far from actual use. Heetderks, who keeps track of similar biotechnical research all over the world, says within 10 years, "a paralyzed person not will only be able to move his limbs, but also will have some level of sensation in them."
"There are a lot of questions that will have to be answered before these enhancements could be part of clinical practice, but there appears to be absolutely no obvious showstoppers that would prevent it," he says.
What To Do
The National Spinal Cord Injury Association offers a variety of information and services and keeps up with new research.
The latest developments also are reported by the Spinal Cord Injury Resource Center and the Christopher Reeve Paralysis Foundation.
If you'd like to be part of this research, you can register at the University of Michigan Spinal Cord Care System.
