Brainstem congestion caused by direct carotid-cavernous fistula--case report.

A 41-year-old woman presented with tinnitus in the left ear and headache, followed by diplopia and pain in the left cheek. Angiography showed a left high-flow direct carotid-cavernous fistula (CCF), causing steal of the blood flow from the internal carotid artery into the cavernous sinus. A few days later, she rapidly developed right hemiparesis, dysarthria, and ocular conjugate deviation to the right, and became somnolent. Angiography at that time revealed occlusion of the superior petrosal sinus, causing engorgement of the veins in the surrounding brainstem. The CCF was completely embolized with interlocking detachable coils. Her consciousness disturbance and ophthalmoparesis dramatically improved within a few days, and the right hemiparesis and dysarthria gradually resolved. Magnetic resonance (MR) imaging after the treatment showed small pontine hemorrhage and perifocal edema but no ischemic lesions in the cerebral hemisphere. Re-evaluation of the MR imaging with gadolinium taken on admission demonstrated engorged veins in the brainstem parenchyma, which corresponded to the hemorrhagic lesion in the brainstem. Brainstem congestion caused by direct CCF is very rare, but it can be life-threatening. Good outcome can be expected if the CCF is completely occluded before congestive hemorrhage occurs.