A patient with middle ear infection develops sudden onset of ipsilateral facial palsy and loss of taste on the anterior two-thirds of the tongue without any hearing loss. The chorda tympani nerve was most likely damaged at which anatomical point?

• A At its origin from the facial nerve in the petrous temporal bone just before the stylomastoid foramen
• B At the otic ganglion in the infratemporal fossa
• C At the geniculate ganglion within the facial canal
• D As it crosses the middle ear cavity (tympanic cavity) between the malleus and incus ✓

Explanation

The chorda tympani arises from the facial nerve within the facial canal, enters the middle ear cavity, and runs across the tympanic membrane between the neck of the malleus (lateral) and the long process of the incus (medial) without carrying taste fibres from the geniculate ganglion. Middle ear infections or otitis media with effusion can directly injure it as it crosses this exposed path, producing loss of taste from the ipsilateral anterior two-thirds of tongue and reduced salivary secretion (sublingual and submandibular glands) via the submandibular ganglion. Because hearing mechanisms (ossicular chain) may remain intact initially, conductive hearing loss is not an early feature of isolated chorda tympani damage.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.