Facial and trigeminal neuropathies in cavernous sinus fistulas.

Three patients with carotid-cavernous fistulas had prominent ipsilateral facial nerve neuropathy. One patient also had ipsilateral third division trigeminal neuropathy, manifesting as painful trismus and lower facial numbness. Rarely reported in carotid-cavernous fistula, these neuropathies may occur when there is substantial drainage of the fistula into a dilated inferior petrosal sinus. Closure of the fistula in two cases resulted in full recovery of the neuropathies within weeks to months. The neuropathies may be caused by ischemia from an unfavorable arteriovenous flow gradient, venous compression, or secondary inflammation.