Brains of Paralyzed People Retain Ability to Control Movement
Oct. 26, 2001 -- Contrary to concerns that unused areas of the brain in paralyzed people with spinal cord injuries would wither, new research is showing that these nerve areas are still alive and well -- and might one day help them walk again.
The research is in its very early stages, but Richard Normann, professor of bioengineering and ophthalmology at the University of Utah, says that in the future this new technology will be used to get someone up and moving.
"This study suggests that many years from now, technologies being developed in the laboratory today might enable paralyzed individuals to stand up out of a wheelchair and walk," Normann says in a news release.
Researchers feared that areas of the brain that controlled movement and sensation might not retain this ability when unused for a long period of time, such as in paralyzed people. But Normann's research has shown that this does not happen.
They were able to show that these areas of the brain can still send signals, but the spinal cord and muscles just don't respond since the connection has been severed.
Norman and his colleagues used a test called a functional MRI to show that the area of the brain that controls movement was still working in five paralyzed people with spinal cord injuries due to motor vehicle accidents.
Four of the injured volunteers were quadriplegics and thus had no movement in their arms or legs. The fifth had some movement in his hands.
The MRI scans showed increased activity in the appropriate areas of the brain when each person was asked to move a hand, elbow, ankle, or knee.
In order to confirm that the test was actually picking up activity in the correct areas of the brain, the tests were compared to five noninjured volunteers. The results of the study appear in the Oct. 25 issue of Nature.
There are many steps to complete before this research could become useful in humans, Normann says.
This would start with performing lab experiments to show that an electrode can be implanted to read brain signals on a long-term basis without harming the brain, proceed to implanting electrodes just outside the spinal cord to receive messages from the brain, and followed by developing electrodes that could send messages from the arms and legs back to the brain. This last step is necessary so that the brain will be able to detect the location of the arms and legs. This would require electrodes in a separate part of the brain -- the sensation area.
Spinal cord research is moving at record pace with some researchers looking at possible biological solutions, such as gene therapy or the use of immature stem cells that could regenerate damaged spinal tissue, Normann says.
But Normann understands that this is not in the near future. "That's really a long way away. This is not a problem I'm going to solve, but maybe my students will solve it," he says.