What is Post-Polio Syndrome?

Post-polio syndrome (PPS) is a condition that affects polio survivors years after recovery from an initial acute attack of the poliomyelitis virus. PPS is mainly characterized by new weakening in muscles that were previously affected by the polio infection and in muscles that seemingly were unaffected.  Symptoms include slowly progressive muscle weakness, unaccustomed fatigue (both generalized and muscular), and, at times, muscle atrophy.   Pain from joint degeneration and increasing skeletal deformities such as scoliosis are common. Some patients experience only minor symptoms. While less common, others may develop visible muscle atrophy, or wasting.

PPS is rarely life-threatening. However, untreated respiratory muscle weakness can result in underventilation, and weakness in swallowing muscles can result in aspiration pneumonia.

The severity of residual weakness and disability after acute poliomyelitis tends to predict the development of PPS. Patients who had minimal symptoms from the original illness will most likely experience only mild PPS symptoms. People originally hit hard by the poliovirus and who attained a greater recovery may develop a more severe case of PPS with a greater loss of muscle function and more severe fatigue.    It should be noted that many polio survivors were too young to remember the severity of their original illness and that accurate memory fades over time.

According to estimates by the National Center for Health Statistics, more than 440,000 polio survivors in the United States may be at risk for PPS. Researchers are unable to establish a firm prevalence rate, but they estimate that the condition affects 25 percent to 50 percent of these survivors, or possibly as many as 60 percent, depending on how the disorder is defined and which study is quoted.

Patients diagnosed with PPS sometimes are concerned that they are having polio again and are contagious to others.  Studies have shown that this does not happen.