Ischaemia-induced vascular vulnerability resulting in intracerebral haemorrhage with ipsilateral internal carotid artery occlusion.

Intracerebral haemorrhage accompanied with cervical internal carotid artery (ICA) occlusion on the same side without moyamoya-like vessels is rare. A 73-year-old man with left ICA occlusion and no presence of moyamoya disease criteria underwent xenon-enhanced computed tomography with acetazolamide challenge test. The findings showed hypoperfusion and no vasoreactivity in the territory of the left middle cerebral artery. During follow-up he suffered bleeding in the left frontoparietal lobe. Cerebral angiography showed left ICA occlusion and cross flow via the anterior communicating artery without moyamoya vessels. Long-term ischaemia would make perforating or anastomotic arteries vulnerable. These arteries were easily ruptured by hypertension, resulting in intracerebral haemorrhage.