Vascular Lesions of the Brain

In this chapter, we describe the sonographic and Doppler features of the major arteriovenous malformations of the brain: vein of Galen aneurysmal malformation (VGAM) and dural sinus thrombosis (DST). VGAM represents a high cardiac output condition characterized by echocardiographic signs of cardiac overload/insufficiency and direct evidence of a primary cerebral arteriovenous malformation at the level of the vein of Galen. Neurosonography should investigate the possible presence of signs of secondary cerebral damage, such as hemorrhagic-ischemic necrosis of the white matter or obstructive hydrocephalus. Only 50–60% of liveborn are treated with embolization procedures with no sequelae, while the remaining develop major and/or minor motor and cognitive dysfunction and/or epilepsy. In the fetus, DST is mostly a benign, self-limiting condition. It is characterized by the formation of thrombus at the level of the torcular Herophili, which is often of aberrant morphology. In cases where extensive dilatation of this structure (lake) is present, the blood flows at low velocity favoring the development of a large thrombus which eventually completely obliterates the structure causing a block in venous brain circulation. Most cases resolve then spontaneously after birth.