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 55-year-old woman visited our ED with a complaint of vertigo and sudden-onset headache. A diffusion-weighted MRI revealed a high-signal intensity lesion in the right cerebellar hemisphere [], leading to the diagnosis of CI. Although depiction of the right PICA was poor, a pathologic process involving the PICA remained unclear []. CTA performed the next day revealed a pearl-string lesion at the orifice of the right PICA [], establishing the diagnosis of a right PICA dissection. The patient recovered uneventfully with conservative management, including administration of aspirin. A repeated CTA obtained a month after admission showed improvement in the stenosis of the PICA distal to the dissection [].