A patient with a fracture through the foramen magnum presents with weakness and atrophy of the tongue with deviation toward the side of the lesion. Which nerve is injured and through which foramen does it exit the skull?

• A Glossopharyngeal nerve via jugular foramen
• B Vagus nerve via jugular foramen
• C Hypoglossal nerve via hypoglossal canal ✓
• D Accessory nerve via jugular foramen

Explanation

The hypoglossal nerve (CN XII) exits the skull through the hypoglossal canal (anterior condylar canal) in the occipital bone. It supplies all intrinsic and extrinsic tongue muscles except palatoglossus. A unilateral lesion causes the tongue to deviate toward the paralyzed side on protrusion due to the unopposed action of the contralateral genioglossus muscle. The jugular foramen transmits CN IX, X, and XI, not the hypoglossal nerve.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.