A patient who is able to smile while laughing but cannot smile on command likely has a:
A)unilateral lesion of the facial nerve
B)unilateral lesion of an upper motor neuron innervating the facial nerve
C)bilateral lesion of the facial nerve
D)bilateral lesion of the upper motor neurons innervating the facial nerve

Question

Quizplus · Accepted Answer

A unilateral lesion of an upper motor neuron would impair voluntary movement of facial muscles;thus the patient would not be able to smile when asked to do so.

A Patient Who Is Able to Smile While Laughing but Cannot