upper motor neurone signs

Last reviewed 01/2018

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