Arteriovenous malformations (AVMs) of the central nervous system are a set of vascular abnormalities. These congenital lesions are typified by the failure of development of the capillary network normally separating arteries and veins. Lack of a capillary bed allows exaggerated blood flow through the malformation, shunting and stealing blood from other areas of the vascular system, potentially hemorrhaging, and at times growing, so as to lead to obstructive hydrocephalus. The clinical features of the malformation depend on the site, size, and integrity of the malformation. The most common presentation is related to the hemorrhage of an AVM. Less than 15% of children with AVMs present with seizures, and the remainder are identified secondary to symptoms that include evidence of ischemia, congestive heart failure, developmental delay, or chronic headaches. AVMs may be divided into three subtypes: true AVMs, AVMs involving the vein of Galen (aneurysms of the vein of Galen), and cavernous hemangiomas.<\/p>\n
A tangled mass of small arteries intertwined with small veins that is present at birth; commonly abbreviated as AVM. Blood flows directly from the arteries into the veins, not through the bed of capillaries (very small blood vessels) that normally lie between them. An AVM is most serious when it occurs in the brain; this condition is called cerebral AVM. Since the vessels are fragile and lack normal support, they often bleed and cause hemorrhages.<\/p>\n
An anomalous intertwining of arteries and veins occurs, devoid of the customary intermediate capillary network, resulting in direct arterial-venous connections.<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Arteriovenous malformations (AVMs) of the central nervous system are a set of vascular abnormalities. These congenital lesions are typified by the failure of development of the capillary network normally separating arteries and veins. Lack of a capillary bed allows exaggerated blood flow through the malformation, shunting and stealing blood from other areas of the vascular […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-108346","post","type-post","status-publish","format-standard","hentry","category-a"],"yoast_head":"\n