These are often emergency situations. Assuming whatever caused the damage is resolved, the swelling can last from 1 day to a week. But chronic problems will have chronic swelling and may not go away. The main problem is that the cord is already pretty tight, and there is not enough room for the cord to swell, and this can cause compression of the cord. When compressed, the nerve
cells and fibers (axons) can be permanently damaged. The problem in the spinal cord is that such damage cannot be repaired. Where this becomes most important is when there is brief damage that can be fixed (like a neck fracture
), but if the cord swells it will cause permanent paralysis
. So when people have severe cord injuries there is an emergency treatment to stop the cord from swelling, hopefully preventing the delayed paralysis. The cord will swell somewhat, which may temporarily "stun" the cord, but if compression can be avoided people can recover. This is why some people are "paralyzed" with a neck injury
, get prompt treatment, and then get their movement back.