A spinal stimulator from Medtronic designed for chronic pain management helped four patients with paralyzed lower limbs to regain some control over their legs. In four men who had been paralyzed from the waist down, the RestoreAdvanced implant, coupled with physical therapy sessions, permitted them to move their legs and feet at will, and stand for short period of time.

The breakthrough was reported in the Brain journal and could represent a paradigm shift for the field of neurology, which had assumed that, in cases of spinal injury, restoring motor function required either healing or replacing the injured neurons. Furthermore, the research indicates that patients who had been paralyzed below the waist for years could regain some leg function. As the researchers explain in their abstract, "[they] have uncovered a fundamentally new intervention strategy that can dramatically affect recovery of voluntary movement in individuals with complete paralysis even years after injury."

The researchers, who are based at the University of Louisville in Kentucky and UCLA, also helped make headlines in 2011, when another one of their research subjects made progress in reversing his paralysis. Rob Summers, who was also treated with a Medtronic implant, regained the ability to stand and take steps with the aid of a harness after becoming paralyzed from the chest down in a 2006 accident. Summers was the first paralyzed person to walk, albeit with assistance, thanks to a spinal implant. In total, Summers received seven months of epidural stimulation and physical therapy, which enabled him to stand.

The researchers state that they would need to repeat their work with the stimulation device with a larger patient pool before FDA would consider approving its use for treating paralyzed patients.

The study was supported by the NIH and the Christopher and Dana Reeve Foundation.

Future therapies for treating the paralyzed may benefit from the research, and explore using a hybrid of medical devices and cell-based therapies, says Barth Green, MD, a neurosurgeon based at the University of Miami who is exploring cell based approaches to treating patients with paralysis.

Future implants may be delivered through the skin rather than require a full surgical procedure to implant them.