Applied anatomy

  1. Upper motor neurons e.g cortico-spinal tract can be involved at various levels in vascular lesions of the brain (Cerebro-vascular accident/ stroke). They present with features of upper motor neuron lesions. The effect depends on the level.
    Capsular and mid brain lesions involve all cranial and spinal nerves
    Medullary lesions involve hypoglossal nerves and spinal cord
    (check brain stem lesions)

  2. Upper motor lesions are necessarily confined to the central nervous system

  3. Lower motor neurons involve the brain stem, brain stem and peripheral nerves and present with typical lower motor deficits.

  4. Extra-pyramidal lesions tend to be more degenerative in nature such as parkinsons disease and chorea (check basal ganglia disorders)