Posterior inferior cerebellar artery with extracranial origin harboring an extracranial aneurysm

Abstract Background We report on a rare case of a saccular aneurysm on the TM segment of the right PICA. The aneurysm was located at the nonbifurcation region of the PICA. Case description The patient underwent a brain CT scan that revealed a diffuse SAH and an IVH in the fourth ventricle with obstructive hydrocephalus. After external ventricular drainage to relieve the hydrocephalus, the aneurysm was demonstrated by cerebral digital subtraction angiography. Conclusions The origin of the PICA aneurysm was extracranial and intradural, illustrating a rare location of such type of aneurysm.