Facial Nerve

The facial nerve is the 7th cranial nerve which carries fibres that control expressions and facial movements. It is evaluated by checking for face twitching or facial paralysis. To evaluate the facial nerve, the doctor starts by asking the patient to furrow up their forehead or raise their eyebrows, close their eyes and hold them closed against resistance, blow out their cheeks, and display their teeth to test this nerve.

The result can help determine if and where the problem may arise. The issue occurs in the top motor neuron when the patient can lift their brow bilaterally, but their facial muscles are paralyzed unilaterally. When a patient's entire side (forehead, eyes, and smile) is paralyzed, the issue is in the lower motor neuron.