A patient with right lower motor neuron facial palsy complains that sounds seem unpleasantly loud and distorted in the affected ear. This symptom indicates the lesion lies:
- A Distal to the origin of the chorda tympani
- B Proximal to the origin of the nerve to stapedius ✓
- C At the stylomastoid foramen only
- D Within the internal auditory canal only
Correct answer: B. Proximal to the origin of the nerve to stapedius
Explanation
Hyperacusis in facial palsy results from paralysis of the stapedius muscle, which normally dampens stapes movement. The nerve to stapedius arises from the facial nerve at the level of the pyramidal eminence in the mastoid segment, so hyperacusis appears only when the lesion is proximal to this branch, that is, in the labyrinthine or tympanic segment or at the geniculate ganglion. B lesion at or distal to the stylomastoid foramen spares the nerve to stapedius and does not cause hyperacusis.
Reference: Dhingra's Diseases of Ear, Nose and Throat, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.