A 42-year-old patient with a history of chronic otitis media develops sudden onset of unilateral facial palsy, hyperacusis, and loss of taste on the anterior tongue. The lesion is most likely at which segment of the facial nerve canal?

• A Internal acoustic meatus, before geniculate ganglion
• B Between geniculate ganglion and origin of nerve to stapedius
• C Between origin of chorda tympani and stylomastoid foramen
• D At or proximal to the geniculate ganglion ✓

Explanation

At or proximal to the geniculate ganglion, all branches are involved: the greater petrosal nerve (lacrimation — reduced), nerve to stapedius (hyperacusis if absent), chorda tympani (taste loss anterior 2/3 tongue), and the main motor trunk (facial palsy). Hyperacusis results from stapedius paralysis; stapedius nerve arises distal to the geniculate ganglion in the mastoid segment — so a lesion at the geniculate ganglion level or just proximal would involve all these branches. In chronic OM, the erosion typically reaches the second genu of the facial canal near the geniculate.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.