A newborn is admitted for high-output cardiac failure after presenting with seizures. CT shows dilated lateral ventricles suggestive of hydrocephalus. What is the most probable diagnosis?

Vein of Galen malformations are congenital vascular malformations characterized by extensive aerial feeders draining into an enlarged vein of Galen. It is a aeriovenous fistulae. Newborns can present with high-output cardiac failure due to the aeriovenous shunting. Hydrocephalus is common from compression of the cerebral aqueduct by the malformation. Seizures are also associated with these lesions. The extensive aeriovenous shunting can produce a steal effect and result in cerebral ischemia and infarction. The prognosis is often poor for patients diagnosed in early infancy with hea failure. The prognosis is better for those diagnosed later in life. Treatment is by endovascular embolization of feeding aeries. Ref: Cowan J.A., Thompson B. (2010). Chapter 36. Neurosurgery. In G.M. Dohey (Ed), CURRENT Diagnosis & Treatment: Surgery, 13e.