The reason being for this lies in the continuous additional stress on the remnant nerve cell bodies (giant motor nerve cell units formed after the acute illness), triggered by the physical and metabolic stress (high accumulation of excitatory nerve transmitters) to support and re-model the additional fibres that have been supporting more muscle fibres.
This had already been suggested by Wiechers and Hubbell from the state university of Ohio in Columbus in the early 1980s. According to their research, they found out that during an advanced number of years after the convalescence period, the motor nerve cells of poliomyelitis survivors increasingly lost their functional abilities.
Other causes that have been proposed by medical experts, whereby the evidence supporting these theories is extremely limited:
– a persistent infection of some kind,
– environmental chemicals, etc.
During the phase of functional stability, a continuous dysfunction of alpha motor nerve cells can be determined. According to current knowledge – once a certain threshold (destruction of more than approx. 50% of the alpha motor nerve cells) is exceeded then this results in a decompensation of the de- and re-innervation process that was started after the acute phase of poliomyelitis.
The de-compensation is pre-programmed, because under normal everyday conditions, the damaged nerve structures are already working on, or over their upper load limit and it is only a question of time, depending on the initial damage and the height of the overload before de-compensation takes place.