Vascular steal associated with vein of Galen aneurysm.

Seven patients presented with neonatal arteriovenous malformation and vein of Galen aneurysms. Six had a large degree of vascular steal demonstrated by cerebral angiography and all had significant parenchymal loss on initial CT. Angiographically, the steal affected the ophthalmic artery and branches of the middle and anterior cerebral arteries. Repeat CT in two patients, one of whom was untreated for 7 months, revealed pronounced atrophy. Patients with neonatal vein of Galen aneurysms present with parenchymal loss on CT which is related to vascular steal and may be progressive.