A patient with a fracture of the occipital condyle develops ipsilateral tongue weakness with deviation of the protruded tongue toward the lesion. Which structure has been injured within its bony canal?

• A Hypoglossal nerve in the hypoglossal canal ✓
• B Lingual nerve in the pterygomandibular space
• C Glossopharyngeal nerve at the jugular foramen
• D Inferior alveolar nerve in the mandibular canal

Explanation

The hypoglossal nerve leaves the medulla as rootlets that unite and pass through the hypoglossal canal in the occipital bone, lying just above the occipital condyle. Lower motor neuron injury causes ipsilateral tongue weakness with deviation toward the affected side on protrusion. The lingual and inferior alveolar nerves are branches of V3 in the infratemporal fossa and are unrelated to skull base canals.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.