Post-polio syndrome (PPS) is a condition that affects polio survivor’s years after recovery from an initial acute attack of the poliomyelitis virus. Post Polio Syndrome 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.
What Research is Being Conducted?
Scientists are working on a variety of investigations that may one day help individuals with PPS. Some basic researchers are studying the behavior of motor neurons many years after a polio attack. Others are looking at the mechanisms of fatigue and are trying to discover the role played by the brain, spinal cord, peripheral nerves, the neuromuscular junction (the site where a nerve cell meets the muscle cell it helps activate), and the muscles.
Determining if there is an immunological link in PPS is also an area of intense interest. Researchers who discovered inflammation around motor neurons or muscles are trying to find out if this is due to an immunological response.
Other investigators have discovered that fragments of the poliovirus, or mutated versions of it, are in the spinal fluid of some survivors. The significance of this finding is not known and more research is being done.