Upper motor neurone signs

Upper motor neurone signs are the result of an interruption in the neural pathway above the anterior horn cell.

Characteristic of an upper motor neurone disease are:

• weakness - the extensors are weaker than the flexors in the arms, but the reverse is true in the legs
• muscle wasting is absent or slight - muscle wasting is prominent in a lower motor neurone lesion
• hyper-reflexia and clonus - reflexes are absent or reduced in a lower motor neurone lesion
• spasticity
• no fasciculations - fasciculations occur in a lower motor neurone lesion
• extensor plantar responses