Rob Summers, 25, became paralyzed from the chest down after being the victim of a hit-and-run vehicle accident in 2006. Today he can stand up from a seated position without help and remain standing unaided, bearing his own weight, for up to four minutes at a time thanks to continual direct epidural electrical stimulation of his lower spinal cord, which mimics the signals his brain would normally transmit to initiate movement. This breakthrough, achieved by scientists at UCLA, the California Institute of Technology and the University of Louisville has been reported in the British medical journal The Lancet.

As soon as the signal to initiate movement is given, the neural network in his spinal cord together with the sensory input originating from his legs to his spinal cord can direct the muscle and joint movements needed to stand and step with assistance on a walking machine (treadmill). The authors say this achievement is the result of three decades of research on potential therapies for paralysis.

Summers can remain standing for up to an hour with some therapist assistance. When on a harness he is able to carry out stepping motions on a treadmill. He can also make his toes, ankles, knees and hips move whenever he wishes.

Summers, has also regained come bladder and sexual function.

The researchers believe this breakthrough may pave the way for the eventual creation of portable stimulation units to help patients with complete spinal cord injuries stand independently, keep their balance and carry out some effective stepping (with the assistance of a walker). However, they add that a great deal of research still remains to be done before any device and/or technique can become standard practice.

Summers underwent two years of extensive Locomotor Training while the spinal cord was being stimulated and he was suspended over the treadmill. His spinal cord neural networks were progressively retrained to produce the muscle movements required to stand up, remain standing and take some (assisted) steps.

Professor Reggie Edgerton, UCLA, said:

“The spinal cord is smart. The neural networks in the lumbosacral spinal cord are capable of initiating full weight bearing and relatively coordinated stepping without any input from the brain. This is possible, in part, due to information that is sent back from the legs directly to the spinal cord.

While these results are obviously encouraging, we need to be cautious. There is much work to be done.”

Lead author, Professor Susan Harkema, Kentucky Spinal Cord Research Center, University of Louisville, KY, USA, said:

“This is a breakthrough. It opens up a huge opportunity to improve the daily functioning of these individuals. But we have a long road ahead.”

The authors stress that their study involved just one subject – an athlete with an extraordinary constitution before becoming injured. Even though Summers was completely paralyzed from the C7/T1 vertebra spinal section down (chest down), he did have some feeling below the injury level. He was rated “B” on the American Spinal Injury Association’s classification system.

The researchers do not know how an “A” rated patient might respond (with no feeling at all below the injury level).

There are some drug interventions which were found in animal studies to enhance sensitivity and functioning of the spinal cord’s neural network. Further research is required, including human studies, to see whether they could be added to this therapy.

Over five million people have some type of paralysis in the United States, of which over 1.275 million are spinal cord injuries.

Susan Howley, Executive Vice President for Research at the Christopher & Dana Reeve Foundation, said:

“Today’s announcement clearly demonstrates proof of concept. It’s an exciting development. Where it leads to from here is fundamentally a matter of time and money.”

Summers said:

“This procedure has completely changed my life. For someone who for four years was unable to even move a toe, to have the freedom and ability to stand on my own is the most amazing feeling. To be able to pick up my foot and step down again was unbelievable, but beyond all of that my sense of well-being has changed.

My physique and muscle tone has improved greatly, so much that most people don’t even believe I am paralyzed. I believe that epidural stimulation will get me out of this chair.”

“Effect of epidural stimulation of the lumbosacral spinal cord on voluntary movement, standing, and assisted stepping after motor complete paraplegia: a case study”
Prof Susan Harkema PhD, Yury Gerasimenko PhD, Jonathan Hodes MD, Prof Joel Burdick PhD, Claudia Angeli PhD, Yangsheng Chen PhD, Christie Ferreira BSc, Andrea Willhite BA, Enrico Rejc MSc, Prof Robert G Grossman MD, Prof V Reggie Edgerton PhD
The Lancet, Early Online Publication, 20 May 2011 doi:10.1016/S0140-6736(11)60547-3

Written by Christian Nordqvist