In cochlear implant surgery, the facial nerve monitor electrode is typically placed in which muscles to detect mechanical stimulation of the facial nerve during mastoidectomy?
- A Orbicularis oculi and orbicularis oris ✓
- B Mentalis and frontalis
- C Masseter and temporalis
- D Platysma and buccinator
Correct answer: A. Orbicularis oculi and orbicularis oris
Explanation
Facial nerve monitoring electrodes are placed in the orbicularis oculi (for upper division) and orbicularis oris (for lower division) muscles. These represent the major branches at risk during mastoid and tympanic surgery. Continuous electromyographic monitoring alerts the surgeon to mechanical or thermal insult to the facial nerve during drilling and dissection.
Reference: Cummings Otolaryngology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.