Post-polio syndrome can affect polio survivors many years after recovering from an initial acute attack of the poliovirus. This syndrome is characterized by new muscle pain, worsening of existing weakness, and new weakness or paralysis. The cause is unknown, and there is currently no cure. Treatment is focused on relieving the symptoms. Researchers estimate that this syndrome affects 25 to 50 percent of polio survivors in the United States.
What Is Post-Polio Syndrome?
Post-polio syndrome is a condition that affects some polio survivors many years after recovery from an initial acute attack of the poliovirus. Decades later, 25 percent to 40 percent of people who contracted paralytic poliomyelitis in childhood will develop:
- New muscle pain
- Worsening of existing weakness
- New weakness or paralysis.
Post-polio syndrome is not an infectious disease, and people who are experiencing it do not shed poliovirus.
What Causes It?
The cause of this condition is not known. However, research scientists believe the new weakness seen in post-polio syndrome is related to the damage of individual nerve terminals in the motor units that remain after the initial poliovirus infection.
Risk Factors for Post-Polio Syndrome
While risk factors do not cause post-polio syndrome, certain factors can increase a person's risk for developing the condition. Risk factors include:
- Increasing length of time since acute poliovirus infection
- Presence of permanent disability after recovery from the original polio virus infection
- Being female.
The symptoms of post-polio syndrome can vary in number and severity between different people with the condition. Some patients experience only minor symptoms of post-polio syndrome, while others develop more severe symptoms.
Common post-polio syndrome symptoms can include:
- Slowly progressive muscle weakness
- Loss of muscle
- Unaccustomed fatigue
- Joint pain
- Increasing skeletal deformities such as scoliosis.