Paralytic polio is a serious form of poliomyelitis, an infection caused by the poliovirus. Because it is so severe, it has historically occupied a large share of the media coverage of polio. Some very notable historical figures have suffered from this condition, such as American President Franklin Delano Roosevelt. This form is actually quite rare, however, and it is steadily decreasing.
The poliovirus, which is very infectious, prefers the environment of the intestinal tract. Someone infected with the disease usually suffers from a mild form that will often resolve on its own, with around 95% of cases being classified as mild. In a few instances, however, the virus will be more aggressive, and in around 2% of cases, it develops into paralytic polio.
In these cases, the virus attacks the central nervous system. When only the spinal cord is affected, as in the vast majority of serious cases, it is known as spinal polio. When the brain stem is attacked, it is known as bulbar polio, and when both brain and spinal cord are involved, it is classified as bulbospinal polio. As the virus attacks the central nervous system, it causes paralysis and a host of complications.
The symptoms of paralytic polio include difficulty swallowing, trouble breathing, muscle aches, fever, stiffness, muscle weakness, tremors, and spasms. In some cases, the muscles that regulate respiration become paralyzed, in which case the patient needs to be put on an artificial ventilator so that he or she can breathe. Historically, patients often wound up in iron lungs, specialized negative pressure ventilators.
In 5 to 10% of cases, this illness kills. The mortality rate is higher in adults, in whom polio infections appear to be more severe. Many people suffer complications from paralytic polio, such as paralysis, malformed limbs, muscle weakness, and difficulty breathing. Physical therapy can greatly assist with these complications of the disease, making life more comfortable and enjoyable for the patient.
The great tragedy of polio is that is preventable through vaccination. In most regions of the world, herd immunity has been achieved through extensive vaccine coverage, making cases very rare. Some developing nations still have instances of polio, however, much to the frustration of healthcare workers who would like to eradicate this disease.