Question

Upper motor neuron lesions of the facial nerve result in contra-lateral paralysis of the lower muscles of facial expression. What is spared due to bilateral UMN innervation?

1) Forehead
2) Eyes
3) Mouth
4) Nose

Answer 1

Upper motor neuron lesions of the facial nerve result in contra-lateral paralysis of the lower muscles of facial expression, while the muscles responsible for forehead, eye, and nose movement are spared.

Step-by-step explanation:

Upper motor neuron lesions of the facial nerve result in contra-lateral paralysis of the lower muscles of facial expression.

However, due to bilateral upper motor neuron (UMN) innervation, the muscles responsible for forehead movement, eye movement, and nose movement are spared. Only the muscles of the lower face, including the mouth, are affected by the UMN lesions.