After implantation with the device, however, the patient couldwhile receiving electrical stimulation, and after a few weeks of locomotor trainingpush himself into a standing position and bear weight on his own. He can now remain standing, and bearing weight, for 20 minutes at a time. With the aid of a harness support and some therapist assistance, he can make repeated stepping motions on a treadmill. With repeated daily training and electrical stimulation, the patient regained the ability to voluntarily move his toes, ankles, knees, and hips on command.
The patient has no voluntary control over his limbs when the stimulation is turned off.
In addition, over time he experienced improvements in several types of autonomic function, such as bladder and bowel control, as well as temperature regulationa "surprise" outcome, Burdick says, that, if replicated in further studies, could substantially improve the lives of patients with spinal-cord injuries.
These autonomic functions began to return before there was any sign of voluntary movement, which was first seen in the patient about seven months after he began receiving epidural stimulation.
Adds Burdick, "This may help bladder and bowel function even in patients who don't have the strength to undergo rigorous physical training like this patient"who was an athlete and was in comparatively excellent physical condition before his injury.
The scientists aren't yet fully sure how these functions were regainedor, indeed, how the control of voluntary function was returned through the procedure. "Somehow, stimulation by the electrodes may have reactivated connections that were dormant or stimulated the growth of new connections," Burdick says. Almost certainly, reorganization of the neural pathways occurred below and perhaps also above the site of injury.
Notably, the patient had some sensation in his lower extremities after his injury, which means that
|Contact: Deborah Williams-Hedges|
California Institute of Technology