Paralysis usually occurs because there’s damage to the spinal cord. The higher up the damage, the worse it is.
The reason why it’s not reversible is because the nervous system doesn’t have the same regeneration potential as other systems. For example, the liver has great regeneration potential.
Further research with stem cell technology (cells that can become anything) may help with repairing the damaged parts potentially reducing the paralysis or even curing it but it still has a long way to go
Latest Answers