Cerebral arteriovenous malformation locations may stop the circulation of the cerebrospinal fluid, causing accumulation of the fluid within the skull and giving rise to a clinical condition called hydrocephalus. A stiff neck can occur as the result of increased pressure within the skull and irritation of the meninges. AVMs are an abnormal connection between the arteries and veins in the human brain. Arteriovenous malformations are most commonly of prenatal origin. In a normal brain oxygen enriched blood from the heart travels in sequence through smaller blood vessels going from arteries, to arterioles and then capillaries. Oxygen is removed in the latter vessel to
Vascular remodelling in the embryo to the venous network, effectively changing their identity. This is thought to be due to the high luminal pressure in the arterial lines, which prevents reattachment of the branches back onto arterial vessels. This also prevents the formation of shunts between the two components of the network. Researchers have verified this identity-switching phenomenon by successfully grafting sections of quail endothelial tubing which had previously expressed arterial markers onto chick veins (or vice versa), showcasing the plasticity of the system. Reversing flow patterns in arteries and/or veins can also have the same effect, although it is unclear whether this is due