upper motor neuron lesion
英[ˈʌpə ˈməutə ˈnʊərˌɔn ˈli:ʒən]美[ˈʌpɚ ˈmotɚ ˈnʊrˌɑn ˈliʒən]
An upper motor neuron lesion (also known as pyramidal insufficiency) is a lesion of the neural pathway above the anterior horn cell of the spinal cord or motor nuclei of the cranial nerves. This is in contrast to a lower motor neuron lesion, which affects nerve fibers traveling from the anterior horn of the spinal cord or the cranial motor nuclei to the relevant muscle(s).