Severe vasospasm caused by repeated intraventricular haemorrhage from small arteriovenous malformation

A 26-year-old man was admitted due to intraventricular haemorrhage (IVH) in the right lateral ventricle, without apparent subarachnoid haemorrhage (SAH) in the basal cistern (Fig. 1a). He had no significant past history. He had severe headache, but was alert without any neurological deficit. Angiograms showed small abnormal vessels fed by the right anterior choroidal artery, without early venous drainage (Fig. 1b, c). The right posterior cerebral artery was hypoplastic and the posterior branch of the middle cerebral artery reached the occipital lobe. His headache improved within several days and angiograms at Day 20 showed no arterial narrowing. On Day 33, he developed a larger IVH again (Fig. 1d). At the onset he was alert, but fell into a confused state 17 days later. Angiograms revealed severe narrowing of middle and anterior cerebral arteries bilaterally (Fig. 1e, f). Despite endovascular intervention, he developed cerebral infarction in the right temporo-occipital region. CT cisternography demonstrated communicating hydrocephalus 28 days after rebleeding. Following a lumboperitoneal shunt procedure, the abnormal vessels were resected because of his repeated episodes and the same abnormal vessels demonstrated angiographically. The pathological diagnosis was that of an arteriovenous malformation (AVM). Postoperative angiograms demonstrated the arteries of normal caliber without abnormal vessels. The patient returned to his job 4 months later despite a left homonymous hemianopsia.