The cavernous sinus is a dural venous sinus in the middle cranial fossa. A cavernous sinus thrombosis (from facial infection via the dangerous area of face) would affect multiple cranial nerves. Which nerve runs WITHIN the substance of the lateral wall of the cavernous sinus?

• A CN VI (abducens) within the lateral wall
• B CN III (oculomotor), CN IV (trochlear), and V1 (ophthalmic division) and V2 (maxillary division) of trigeminal ✓
• C CN VII (facial nerve) within the lateral wall
• D CN II (optic nerve) within the lateral wall

Explanation

The cavernous sinus is unique in having cranial nerves running within its lateral wall dura mater. From superior to inferior within the lateral wall: CN III (oculomotor), CN IV (trochlear), V1 (ophthalmic), V2 (maxillary). CN VI (abducens) runs through the sinus itself (medially, adjacent to the internal carotid artery), NOT in the lateral wall. This explains why CN VI is most susceptible to increased sinus pressure in cavernous sinus thrombosis (it is freely suspended in blood within the sinus), while CN III, IV, V1, V2 are protected by dural investments.

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

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Written and medically reviewed by the StethoPrep medical team.