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

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

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

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

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

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
• Isolated loss of facial sensation with normal facial movement
• Loss of posterior tongue taste and parotid secretion only

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

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

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

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

• Neither eye blinks only when the right cornea is touched
• The right eye blinks normally but the left never blinks
• 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?

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

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

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

Q10. Which statement best integrates facial nerve anatomy?

• 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 supplies facial sensation through three trigeminal divisions
• CN VII is purely sensory and exits through the jugular foramen
• CN VII is purely motor and has no intratemporal branches