A man who spent 3 1/2 years in a wheelchair after serious spinal injury is now able to walk to the shops after electrodes were implanted in his spinal cord. The US researchers who got the man back on his feet believe that the technique could help up to 35 per cent of those with spinal injuries.
The process involves a combination therapy which includes giving electric shocks to nerves in the spine. The research is described in the February issue of the journal Spinal Cord.
Dr Richard Herman and colleagues at Arizona Sate University chose a 43-year-old wheelchair-dependent quadriplegic who had some limited sensation but no usable strength in any of his leg muscles. He was also mildly spastic.
The research team decided to combine two methods currently under study. One technique involves suspending a subject in a harness over a moving treadmill in an attempt to help the person relearn how to walk. The second involves applying an electric current in pulses to the spine to assist walklike movements in the legs.
Neither technique on its own delivered worthwhile results, the researchers noted in their report. They decided to use both, hoping that this "would be more effective than either therapy alone in restoring functional walking".
They first technique trained the patient into a walking rhythm by suspending him over the treadmill. After a time, he was able to walk for 50 feet in about three minutes, but could not support his weight.
Next, electrodes were implanted in his lower back. Pulses of electricity were applied and these greatly assisted the man's walking gait. The subject quickly reduced the walking time over 50 feet to 60 seconds. After several months of training he can now walk 1,000 feet.
The researchers believe that the electrodes may activate a "stored" locomotion programme in lower-limb nerves. While they have only tried the therapy on a single patient, they hope that it may be able to help up to one-third of patients who have lost the ability to walk through spinal cord injury.
