Post-polio syndrome (PPS, poliomyelitis sequelae) is a group of latent symptoms of poliomyelitis (polio), occurring at about a 25 to 40% rate (latest data greater than 80%). It is a viral infection of the nervous system after the initial infection. Symptoms typically occur 15 to 30 years after an initial acute paralytic attack. Symptoms include decreasing muscular function or acute weakness with pain and fatigue. The same symptoms may also occur years after a nonparalytic polio (NPP) infection. Source: Wikipedia
The causes of PPS have been investigated for around 100 years, but as yet none of the theories regarding its mechanism has been generally accepted as an explanation. The most prevalent is the 'Neural Fatigue' theory - which suggests that neurons which have remained intact after a polio infection are under increased strain, and the natural ageing process cause them to gradually fail.
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