[Ruptured vertebral artery dissecting aneurysm presented with vertebral artery occlusion: a case report].

We report a rare case of a ruptured vertebral artery dissecting aneurysm (VADA) with affected vertebral artery (VA) occlusion. A 66-year-old hypertensive man presented with subarachnoid hemorrhage. No cerebeller sign or cranial nerve palsy was found on admission. Initial CT angiography and digital subtraction angiography (DSA) revealed the right VA occlusion. On the three days after onset, the right VA was recanalized and visualized as a posterior inferior cerebellar artery (PICA)-involved VADA. Endovascular internal trapping of the right VA including PICA origin was performed. In conclusion, it is essential that patients of VA occlusion associated with subarachnoid hemorrhage should be carefully diagnosed considering the possibility of VADA.

Magnetic resonance imaging of brain abscess with hemorrhage: implications for the mechanism of hemorrhage.

A 68-year-old woman presented with an extremely rare brain abscess associated with old and acute hemorrhages manifesting as gradual onset of symptoms of headache and fever. Magnetic resonance imaging clearly visualized the hemorrhage as heterogeneously hyperintense on diffusion-weighted imaging, concentric hypo-isointense on T(1)-weighted imaging, and homogeneously hyperintense with a hypointense rim on T(2)(*)-weighted imaging. T(1)-weighted imaging with contrast medium revealed a well-enhanced cyst wall. In spite of treatment with antibiotics, the neurological status of the patient deteriorated due to expansion of the abscess and perifocal edema. Needle aspiration of the cyst yielded bloody purulent fluid. The magnetic resonance imaging findings indicate that neovascularization of the cyst wall is involved in the mechanism of hemorrhage in brain abscess. Careful follow-up examinations are recommended in patients with brain abscess to detect warning signs of neurological deterioration.

[The posterior inferior cerebellar artery arising from the internal carotid artery directly: a variant of the persistent primitive hypoglossal artery].

We reported a rare case of the posterior inferior cerebellar artery arising from the internal carotid artery directly. A 33-year-old male was admitted to our hospital with the complaint of throbbing type headache. CT showed no abnormal findings. A saccular aneurysm at the bifurcation of the left middle cerebral artery was revealed by MR angiography and the left internal carotid angiography. The right internal carotid angiography demonstrated an anomalous branch originating at the level of the C1/2 in the cervical portion of the internal carotid artery. This branch terminated as the posterior inferior cerebellar artery without an interposed segment of the vertebro-basilar artery. The ipsilateral vertebral artery was aplasia. T2-weighted MR image showed a flow-void penetrating the right hypoglossal canal. This vessel was confirmed an artery passing through the hypoglossal canal with the source images of the three-dimensional time-of-flight MR angiography. We diagnosed it as a kind of variant of the persistent primitive hypoglossal artery. The persistent primitive hypoglossal artery is composed of the proximal segment derived from the primitive hypoglossal artery, and the distal segment consisting of portions of the lateral anastomotic channels (primitive lateral basillo-vertebral anastomosis) which give rise to the posterior inferior cerebellar artery. We speculated that this variant resulted from the persistence of the proximal segment, which communicated with the stem of the posterior inferior cerebellar artery via the distal segment, and next, the disconnection of the posterior inferior cerebellar artery origin with the vertebral artery due to the aplasia of right vertebral artery and the involution of the distal segment connected to the basilar artery.