Bilateral Internal Carotid Artery Occlusion as a Cause of Intraventricular Hemorrhage due to Pial Collateral Vessels.

In patients with high-grade atherosclerotic stenosis or occlusion of the extracranial cerebral arteries, subarachnoid hemorrhage (SAH) may occur, potentially due to rupture of fragile dilated pial collateral vessels. This association has been well described in Moyamoya disease. There are only few cases in the literature that reported SAH due to bilateral carotid artery stenosis but intraventricular hemorrhage caused by dilated pial collateral has not been reported yet. We present a case of bilateral carotid artery occlusion presented with intraventricular hemorrhage. Based on the findings in the present case, carotid artery stenosis or occlusion may present with intraventricular hemorrhage due to rupture of the dilated, fragile collateral vessels.