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arteriovenous malformationNeurology A potentially fatal congenital intracranial anomaly with large arteries feeding in a mass of communicating vessels which empty into large draining veins filled with 'arterialized' blood; large AVMs produce a shunt large enough to ↑ cardiac output Location Brain, medulla, spinal cord Clinical Headaches, seizures, subarachnoid hemorrhage Imaging CT, MRI, endovascular angiography ASAP
malformation(mal?for-ma'shon) [ mal- + formation]
Abnormal shape or structure, esp. congenital; deformity.
arteriovenous malformationAbbreviation: AVM
cavernous malformation (of the brain)
A collection of tiny blood vessels surrounded by neural tissue, found in the brain on MR scans, but not easily seen with cerebral angiography. If these blood vessels rupture, they may cause headaches or seizures.
spinal cavernous malformation
A cavernous malformation in the spinal cord. If the abnormal veins in the malformation rupture, a patient may suffer stroke-like symptoms that correspond to the nerves at the level of the spinal cord where the hemorrhage occurs.
Abnormalities of size and shape that usually occur during the morphodifferentiation stage of tooth formation. Incomplete matrix formation or mineralization will also result in defective teeth that may or may not be abnormal in shape initially.
arteriovenous malformationAn abnormal, congenital network or clump of blood vessels linking an artery and a vein. These may occur anywhere in the body but are especially dangerous within the skull. The commonest presentation is a SUBARACHNOID HAEMORRHAGE. Blood flow though an arteriovenous malformation is often rapid and may be audible through the skull with a stethoscope.
An abnormal tangle of arteries and veins in which the arteries feed directly into the veins without a normal intervening capillary bed.