Advanced Facial Nerve Quiz

Q1. Which pattern most strongly suggests a lower motor neuron lesion of the facial nerve on the right?

• Loss of right facial sensation with normal facial movement
• Weakness of the left lateral rectus only
• Weakness of both the upper and lower right face
• Weakness limited mainly to the lower right face with forehead sparing

Q2. Why can a unilateral supranuclear corticobulbar lesion often spare forehead movement?

• The temporal branch of CN VII crosses to the opposite side
• Upper facial motor neurons receive substantial bilateral corticobulbar input
• Upper facial muscles have no cortical innervation
• The forehead is supplied by the trigeminal motor root

Q3. A facial nerve lesion proximal to the nerve to stapedius may cause which additional symptom?

• Loss of pupillary constriction
• Complete deafness from cochlear destruction
• Loss of corneal sensation
• Hyperacusis

Q4. A lesion of CN VII proximal to the chorda tympani but distal to the greater petrosal nerve can cause which combination?

• Facial weakness with impaired anterior tongue taste and reduced submandibular and sublingual secretion, with lacrimation relatively spared
• Ophthalmoplegia with a fixed dilated pupil
• Loss of posterior tongue taste and parotid secretion only
• Isolated loss of facial sensation with normal facial movement

Q5. Why can a lesion at the geniculate ganglion affect several different functional components of CN VII?

• All trigeminal divisions synapse there
• The geniculate ganglion contains lower motor neurons for all facial muscles
• The geniculate region is a key proximal convergence point for facial nerve sensory and autonomic pathways near the motor trunk
• It is the final parasympathetic ganglion for the parotid gland

Q6. Why does a lesion of the facial nerve within the parotid gland usually not reduce parotid secretion?

• Parotid secretion is controlled only by CN VII
• Parotid secretomotor innervation comes from CN IX through the otic ganglion and auriculotemporal nerve
• The parotid gland has no autonomic innervation
• The facial nerve provides sympathetic but not parasympathetic fibers to the parotid

Q7. Which corneal reflex pattern is expected with an isolated right facial nerve lesion?

• The right eye blinks normally but the left never blinks
• Neither eye blinks only when the right cornea is touched
• Both eyes fail to blink regardless of which cornea is touched
• The right eye fails to blink when either cornea is stimulated, while the left eye can blink

Q8. Which sequence correctly traces facial nerve parasympathetic fibers to the lacrimal gland?

• Nerve to stapedius to ciliary ganglion to lacrimal nerve
• Facial motor root to submandibular ganglion to optic nerve
• Chorda tympani to otic ganglion to auriculotemporal nerve to lacrimal gland
• Greater petrosal nerve to nerve of the pterygoid canal to pterygopalatine ganglion to V2 and V1 branches to lacrimal gland

Q9. Which sequence correctly traces taste fibers from the anterior two-thirds of the tongue to the brainstem?

• Lingual nerve to trigeminal ganglion to motor trigeminal nucleus
• Glossopharyngeal nerve to otic ganglion to nucleus ambiguus
• Hypoglossal nerve to ciliary ganglion to solitary nucleus
• Lingual nerve to chorda tympani to geniculate ganglion to solitary nucleus

Q10. Which statement best integrates facial nerve anatomy?

• CN VII is purely motor and has no intratemporal branches
• CN VII is a mixed nerve with an intratemporal facial canal course, sensory and parasympathetic branches, and an extracranial motor distribution to facial expression muscles
• CN VII is purely sensory and exits through the jugular foramen
• CN VII supplies facial sensation through three trigeminal divisions