A 39 year-old male without past notable medical history was admitted with a sudden headache and neck stiffness. Brain computed tomography (CT) demonstrated evidence of Fisher Grade III subarachnoid hemorrhage (SAH) predominance of the pre-pontine, left ambient and quadrigeminal cistern (), and a fusiform aneurysm of a left distal SCA was revealed on the CT angiography (). Subsequent digital subtraction angiography (DSA) revealed the fusiform dilatation (12 mm length; 4.5 mm width) involving the ambient segment of the left distal SCA. The left SCA was duplicated ahead of the aneurysm and there was sufficient collateral circulation from the ipsilateral anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA) (). The aneurysm was treated by endovascular occlusion of the aneurysm sac and the involved branch. Under general anesthesia an Excelsior SL-10 microcatheter was used to access the aneurysm. Seven detachable platinum coils were used to obliterate the lesion. Post-procedural angiography showed complete occlusion of the aneurysm sac and involved the SCA branch (). There was no immediate complication after embolization. Diffusion MRI was done 8 hours after embolization. MRI revealed scattered high signal change on the left posterior tegmentum, superior vermis, and superior part of the left cerebellum (). Left sixth nerve palsy occurred in the patient 1 day after EVT. The symptom completely recovered within 1 week of the post-procedural period. No neurological deficit was seen during the clinical 3-month follow-up.
A 54-year-old man with chronic hypertension visited ED of a local hospital following the sudden onset of posterior neck pain and left-sided homonymous hemianopsia. A brain CT revealed a subcortical hemorrhage in the right occipital lobe []. He was diagnosed with a hypertensive intracerebral hemorrhage and admitted for several days to receive conservative management before he was discharged home. However, 2 weeks later, he experienced dizziness and visited our ED. A brain MRI (diffusion-weighted images) revealed a high-intensity signal in the left cerebellar hemisphere which corresponded to the area perfused by the left PICA []. The left PICA was poorly depicted on the brain MRA [] and a presumptive diagnosis of atherosclerotic PICA occlusion was made. However, CTA of the extracranial vessels obtained the next day revealed a tapered occlusion of the left VA inside the transverse foramen []. In addition, a thin-slice contrast-enhanced axial image at the C5 level showed a double-lumen sign [], establishing the diagnosis of an extracranial VA dissection. In retrospect, the initial hemorrhage in the right occipital lobe was not an arterial bleeding but was a hemorrhagic infarction secondary to a temporary embolic occlusion of the left posterior cerebral artery. Anticoagulation with warfarin was initiated, and the patient has not experienced a recurrent infarction for over a year.