Unusual presentations of cavernous carotid aneurysms: Further evidence for topographic organization of the oculomotor nerve

Two patients with carotid cavernous aneurysms presented with uncommon patterns of third nerve involvement, one with an isolated elevation deficit without ptosis and the other with a depression deficit with possible pupillary involvement. These patterns are best explained by topographic organization of third nerve fibers within the cavernous sinus (prior to its anatomic bifurcation) that subserve individual extraocular muscles.