[A case of suspected vertebral artery stump syndrome assessed by CT angiography].

A 55-year-old man developed ischemic stroke in the bilateral cerebellar hemispheres and bilateral occipital lobes. He was admitted to our hospital 17 months later with recurrent ischemic stroke in the posterior circulation. The left vertebral artery (VA) was occluded on brain magnetic resonance angiography but was visualized with a delay on continuous three-phase CT angiography (CTA). Conventional angiography confirmed a to-and-fro blood flow pattern at the distal end of the left VA, therefore the patient was diagnosed with VA stump syndrome (VASS). VASS is a recurrent posterior circulation ischemic stroke caused by thrombi in an occluded unilateral VA. VASS should be suspected in patients with unilateral VA occlusion and repeated posterior-circulation ischemic stroke. The diagnostic criteria for VASS include confirmation of VA occlusion and the presence of an antegrade flow component at the distal end. In this case, the presence of collateral circulation in the VA was suspected based on CTA findings, leading to the diagnosis of VASS. It was thus suggested that devising the imaging method of CTA may help diagnose VASS.

Occurrence of De Novo Dural Arteriovenous Fistula after Transvenous Embolization of Dural Arteriovenous Fistula : Case Reports of Two Patients

Development of de novo dural arteriovenous fistula (DAVF) at a different site after resolution of an initial DAVF, is rare. Here we report two cases, which we encountered in our hospital. A 68-year-old woman presented with pulsatile tinnitus on the left side. Cerebral angiography demonstrated a left anterior condylar confluence (ACC) DVAF and she underwent transvenous embolization. Four years after this treatment, she presented with tinnitus on the left side, and cerebral angiography revealed a right DAVF around the sinus of the lesser sphenoid wing. Another 69-year-old woman presented with left-sided orbital bruits, chemosis, and conjunctival hyperemia. Cerebral angiography showed left cavernous sinus (CS) DAVF, for which she underwent transvenous embolization for CS DAVF. One year later, she developed a left ACC and transverse-sigmoid sinus (TSS) DAVF.

Cerebellar Hemorrhage due to a Direct Carotid–Cavernous Fistula after Surgery for Maxillary Cancer

Infratentorial cerebral hemorrhage due to a direct carotid–cavernous fistula (CCF) is very rare. To our knowledge, only four such cases have been reported. Cerebellar hemorrhage due to a direct CCF has not been reported. We describe a 63-year-old female who presented with reduced consciousness 3 days after undergoing a maxillectomy for maxillary cancer. Computed tomography showed a cerebellar hemorrhage. Magnetic resonance angiography showed a left-sided direct CCF draining into the left petrosal and cerebellar veins through the left superior petrosal sinus (SPS). Her previous surgery had sacrificed the pterygoid plexus and facial vein. Increased blood flow and reduced drainage could have led to increased venous pressure in infratentorial veins, including the petrosal and cerebellar veins. The cavernous sinus has several drainage routes, but the SPS is one of the most important routes for infratentorial venous drainage. Stenosis or absence of the posterior segment of the SPS can also result in increased pressure in the cerebellar and pontine veins. We emphasize that a direct CCF with cortical venous reflux should be precisely evaluated to determine the hemodynamic status and venous drainage from the cavernous sinus.