Post-poliomyelitis syndrome or Post-polio syndrome (PPS) is the commonly accepted term to describe the neuromuscular symptoms that may develop many years after acute paralytic poliomyelitis. The prevalence estimates of late onset neuromuscular symptoms in prior polio patients vary between 25 and 74%. PPS patients are diagnosed on the basis of a confirmed history of paralytic poliomyelitis, followed by partial to fairly complete neurological recovery and functional stability for at least 15 years. After this recovery period, new or increased muscle weakness or abnormal muscle fatigability (decreased endurance), with or without generalized fatigue, muscle atrophy, or muscle and joint pain, appear usually gradually. PPS diagnosis is made by exclusion. Laboratory tests are used to show evidence of prior polio and to exclude other diseases: electromyography (EMG) displays signs of reinnervation and denervation both in symptomatic and non-symptomatic muscles. Muscle biopsy findings include type-grouping of muscle fibres as the result of reinnervation, and hypertrophy of muscle fibres as a compensation for the loss of muscle fibres. No curative treatment is available for PPS. Management is preferably multidisciplinary and aims both at reducing muscle overuse and rebalancing muscular capacities and demands. It consists of exercise, assistive devices and life style changes. The etiology of PPS is still unclear. It is currently hypothesized that muscle fibres undergo denervation again due to distal degeneration of axons of enlarged motor units.
- Dr F. [Frans] NOLLET