A breakthrough spinal injury treatment may offer hope to thousands of paralyzed patients.  

It involves using a small implantable device to give electrical stimulation to the spinal cord, which mimics brain signals.  

The team that developed this treatment over three decades is reporting it has allowed four men paralyzed in car accidents to move their legs for the first time.  

They say the stimulation teaches the spinal cord to control limbs so a patient gains some movement control.  

The team's results are published in the medical journal "Brain."