Paraplegic Moving Legs as Scientists Rewire Spine

Source: telegraph.co.uk

A paraplegic man who lost the use of his legs following a motorcycle accident is standing and moving again after doctors stimulated his spinal cord using electrical signals.

The 32-year-old was paralysed from the waist down after completely severing his spine in the crash, and had made no progress despite 80 sessions of regular physiotherapy.

However researchers at the University of Louisville, in Kentucky, US, have to re-awaken his nerves using spinal cord epidural stimulation (scES), where an electrical device is implanted in the lower back, below the injury.

Humans are able to move because electrical signals originating in the brain's motor cortex travel down to the lumbar region in the lower spinal cord, where they activate motor neurons that coordinate the movement of muscles responsible for extending and flexing the leg.

But injury to the upper spine can cut off communication between the brain and lower spinal cord.

In the new therapy,  a stimulator is placed inside the body and wired to the central pattern generator (CPG), a mini-brain within the spinal cord that is able to interpret sensory information and move muscles accordingly. 

When switched on it sends commands such as ‘move my right leg’ which awaken nerve cells in the spinal cord and eventually, over time, allow new neural pathways to form to the brain

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After 44 months of training the patient was able to stand independently, even when the device was not switched on and move his limbs.

Prof Susan Harkema, of the Department of Neurological Surgery atLouiseville of said: “The prognosis for recovery of lower limb motor function in individuals with chronic clinically motor complete spinal cord injury is poor.

“These findings show the remarkable recovery potential of the human nervous system after chronic clinically motor complete spinal cord injury and have clear implications for the rehabilitation community.

“These findings suggest that when there is no ability to voluntarily generate movement below the level of injury, residual descending input to the spinal circuitry may be accessed with intense activity-based interventions to result in plasticity that can promote movement recovery.”

Other scientists are working on devices which link up the brain directly to the spine, but this implant allows new neural pathways to develop on their own, effectively working around the injury.

The epidural stimulation also allows the recovery of critical functions, including improved bladder and bowel control, sexual function and temperature regulation.

The research was published in the journal Scientific Reports.