Last reviewed 01/2018

The pathology of motor neurone disease involves changes that are:

  • macroscopic:
    • thinning of the anterior roots of the spinal cord
  • microscopic:
    • loss of neurons in anterior horns, cranial nerve nuclei, and the motor cortex
    • among the cranial nuclei, the hypoglossal nucleus, nucleus ambiguus and trigeminal motor nucleus are particularly affected with the third and the fourth nerve nuclei invariably spared
    • reduction of corticospinal and corticobulbar tract fibres - corticospinal degeneration is asymmetrical