We just can't do as much as we did before. Not everyone who had polio will develop post-polio syndrome. It appears to strike an estimated 20 to 30 per cent of them. Repair Job Fails Scientists theorize that it happens when the body's repair job to the original nerve damage caused by polio begins to fail. The polio virus did its damage by attacking the motor neurons, the nerve cells that control the voluntary muscles such as those in the arms and legs.
Some neurons recover, but others die leaving muscles stranded.
Patients like Thompson regained the use of their affected limbs because the remaining neurons were able to sprout new tentacles to those muscles, reactivating them. The problem is, the theory goes, these muscles are served by far fewer neurons than normal. Over time they begin to break down, triggering the weakness of post-polio syndrome. Dr. Rubin Feldman, a rehabilitation medicine specialist who started Canada's first post-polio clinic at the University of Alberta Hospital, and other researchers showed that the right kind of exercise could preserve strength. The important thing is not to overdo it, to stop at the first hint of fatigue.