Affecting polio survivors, Post-Polio Syndrome (PPS) is a return of muscle weakness that affects a different set of muscles than those originally affected by polio (poliomyelitis). PPS may develop several years or decades after the initial infection. Often characterized by periods of improvement and decline, PPS isn’t contagious and isn’t a relapse of polio.
Who Gets PPS?
Post-polio syndrome is limited to polio survivors, of which there are more than 400,000 in the U.S. alone; all of whom are statistically at risk to develop PPS at some point. Progressive muscle weakness is the most common sign of PPS. The condition may reach a point where it affects supporting joints and increases the risk of experiencing skeletal deformities.
No one knows for sure what causes post-polio syndrome to occur. There are several theories as to what the cause could be, though. One theory is that it happens because of degeneration in individual nerve terminals after a person has been infected with polio. A second theory is that post-polio syndrome is just the polio virus reactivating. A third theory suggests the cause could be another virus infecting the neurons that survived polio. The fourth theory is that post-polio syndrome is caused by the normal stress of aging and weight gain on a polio survivor’s body.
There are a few risk factors for polio survivors. These factors include:
Post-polio syndrome is more likely to affect female polio survivors than male. It is most likely to occur somewhere between 30 and 35 years after the initial polio infection.
Possibly related to subsequent stress placed on motor units created by nerve cells or nerve terminals since the initial polio infection, PPS has no clear cause. Since symptoms vary, doctors look for signs of new muscle weakness and exclude other possible neurological and musculoskeletal issues to make a diagnosis. There is no definitive treatment for PPS, although exercise and dietary changes may help ease symptoms and reduce muscle weakness.
Management of symptoms may involve:
There is nothing that will absolutely guarantee a polio survivor will not get post-polio syndrome. Maintaining a healthy lifestyle, getting regular and productive sleep, and adopting a regular exercise routine tailored to specific muscle groups and level of comfort (cardiopulmonary endurance exercises tend to be more effective) may help manage some of the symptoms. It’s estimated that anywhere from 25 to 50 percent of polio survivors may experience PPS.
Because no one knows what causes post-polio syndrome to occur, there is no way to prevent it for the time being. Doctors are more focused on management strategies after the onset of polio as a means of minimizing the effects of post-polio syndrome when it does occur.
Polio survivors should discuss strategies for managing their condition with a doctor familiar with neuromuscular disorders. Recommended management strategies for post-polio syndrome include, but are not limited to: