Post-poliomyelitic motor neuron disease. Clinical aspects and its relation to typical motor neuron disease.

Eighteen cases of post-poliomyelitic motor neuron disease (PPMND) were found in a series of 869 subjects affected by motor neuron disease (MND). The mean age of onset of acute anterior poliomyelitis (AAP) was 43.6 months. The mean age of onset of MND was 45.9 years. No case had a bulbar onset and hyperreflexia was found in only 2 subjects, one of them having also bilateral extensor plantar response. The survival curve showed a better course of these cases, compared to typical MND (TMND). The present study seems to indicate that PPMND and TMND are different diseases.