A patient undergoing middle ear surgery develops facial palsy. Post-operatively, lacrimation is normal, stapedial reflex is present, but taste over the anterior two-thirds of the tongue is lost. Where is the facial nerve lesion located?

• A Proximal to the geniculate ganglion
• B Between the geniculate ganglion and the nerve to stapedius
• C Distal to the chorda tympani
• D Between the nerve to stapedius and the chorda tympani ✓

Explanation

The facial nerve gives off the nerve to stapedius and then the chorda tympani in the mastoid segment. A lesion between these two branches preserves the stapedial reflex but causes loss of taste. A lesion proximal to the geniculate ganglion affects all functions including lacrimation. A lesion between the ganglion and stapedius spares lacrimation but affects both stapedius and taste. A lesion distal to the chorda tympani spares all three functions.

Reference: Cummings Otolaryngology: Head and Neck Surgery, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.