A 55-year-old patient with nasopharyngeal carcinoma extending to the skull base develops loss of sensation over the hard palate and soft palate. Which branch of the trigeminal nerve is most likely compressed?

• A Greater and lesser palatine nerves from the pterygopalatine ganglion (CN V2) ✓
• B Inferior alveolar nerve (CN V3) entering the mandibular foramen
• C Lingual nerve (CN V3) in the floor of the mouth
• D Infraorbital nerve (CN V2) through the infraorbital foramen

Explanation

The hard palate receives sensory innervation from the greater palatine nerve (anterolateral hard palate) and the nasopalatine nerve (incisive canal), while the soft palate is supplied by the lesser palatine nerve. Both greater and lesser palatine nerves are branches of the pterygopalatine ganglion receiving sensory fibers from CN V2 (maxillary nerve). Nasopharyngeal carcinoma invading the pterygomaxillary fissure or pterygopalatine fossa compresses these nerves. The inferior alveolar and lingual nerves supply the mandibular region; infraorbital nerve supplies the cheek and upper lip.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.