What was the Cause of Franklin Delano Roosevelt's Paralytic Illness?

Summary: In 1921, when he was 39 years of age, Franklin Delano Roosevelt contracted an illness characterized by: fever; protracted symmetric, ascending paralysis; facial paralysis; bladder and bowel dysfunction; numbness; and dysaesthesia. The symptoms gradually resolved except for paralysis of the lower extremities. The diagnosis at the onset of the illness and thereafter was paralytic poliomyelitis. Yet his age and many