Today’s medical world considers spinal cord injury (SCI) in humans to be an incurable pathology.
How is SCI caused?
It is primarily caused by a severe trauma to the spinal cord where neurons and nerve roots in and around the spinal cord are damaged (i.e. disconnected completely or incompletely). Depending where the damage is located in the spinal cord, the patient will have lost any function below the injured area. This means that all motor and sensory control of the lower extremities is lost. For example, the ability to contract muscles voluntarily or feel a prick on your skin is non-existent because the nerve fibres connecting to the muscles and back to the spinal cord have been disconnected. This feedback loop, that includes nerve and muscle fibres, is impaired and the brain cannot send and receive any neuronal signals.
Rat with SCI able to walk again
It is fascinating to hear that neuroscientists in Switzerland have managed to bring back the ability to walk in rats with SCI. Part of the treatment involved the injection of chemicals to the rats‘ spinal cord. Additionally, the outer layer of the spinal cord was stimulated electrically with small currents.
What was the result of these injections and electric stimulations?
In a simplistic way, new nerve connections in the spinal cord were formed which allowed the transduction of signals to reach the lower extremities. The damaged connections were bypassed by the new nerve pathways. The feedback loop was partially re-created and it was sufficient for the rats to VOLUNATRILY walk again.
I find such medical news simply amazing!
Although these findings in rats are not directly applicable to humans with SCI (due to different physiological mechanisms), it is a quantum leap forward in the challenge to fix SCI in human patients.
At my own university, scientists are working on a microscopically small device that can be implanted to create new nerve connections and thus potentially reverse SCI in humans. If you are interested, read HERE.