Post-poliomyelitis syndrome as a possible viral disease

• The definition and diagnostic criteria for post-polio syndrome (PPS) are reported.
• Estimates of polio survivors and prevalence data on those who develop PPS show that millions of people are affected worldwide.
• Pathogenetic hypotheses are presented, with emphasis on possible chronic poliovirus infection.
• Current treatment is discussed. Novel therapeutic options against polioviruses are summarized.
• Ongoing clinical trials are reported with emphasis on the infusion of human immunoglobulins.

SummaryThis review summarizes current concepts on post-polio syndrome (PPS), a condition that may arise in polio survivors after partial or complete functional recovery followed by a prolonged interval of stable neurological function. PPS affects 15–20 million people worldwide. Epidemiological data are reported, together with the pathogenic pathways that possibly lead to the progressive degeneration and loss of neuromuscular motor units. As a consequence of PPS, polio survivors experience new weakness, generalized fatigue, atrophy of previously unaffected muscles, and a physical decline that may culminate in the loss of independent life. Emphasis is given to the possible pathogenic role of persistent poliovirus infection and chronic inflammation. These factors could contribute to the neurological and physical decline in polio survivors. A perspective is then given on novel anti-poliovirus compounds and monoclonal antibodies that have been developed to contribute to the final phases of polio eradication. These agents could also be useful for the treatment or prevention of PPS. Some of these compounds/antibodies are in early clinical development. Finally, current clinical trials for PPS are reported. In this area, the intravenous infusion of normal human immunoglobulins appears both feasible and promising.