AVMs are diagnosed primarily by the following methods:
Computerized tomography (CT) scan is a noninvasive X-ray to view the anatomical structures within the brain to detect blood in or around the brain. A newer technology called CT angiography involves the injection of contrast into the blood stream to view the arteries of the brain. This type of test provides the best pictures of blood vessels through angiography and soft tissues through CT.&Magnetic resonance imaging (MRI) scan is a noninvasive test, which uses a magnetic field and radio-frequency waves to give a detailed view of the soft tissues of the brain.&Magnetic resonance angiography (MRA) – scans created using magnetic resonance imaging to specifically image the blood vessels and structures of the brain. A magnetic resonance angiogram can be an invasive procedure, involving the introduction of contrast dyes (e.g., gadolinium MR contrast agents) into the vasculature of a patient using a catheter inserted into an artery and passed through the blood vessels to the brain. Once the catheter is in place, the contrast dye is injected into the bloodstream and the MR images are taken. Additionally or alternatively, flow-dependent or other contrast-free magnetic resonance imaging techniques can be used to determine the location and other properties of the vasculature
AVMs can occur in various parts of the body:
brain (cerebral AV malformation)&spleen[6]&lung[7]&kidney[8]&spinal cord[9]&liver[10]&intercostal space[11]&iris[12]&spermatic cord[13]&extremities – arm, shoulder, etc
AVMs may occur in isolation or as a part of another disease (for example, Von Hippel-Lindau disease or hereditary hemorrhagic telangiectasia).
AVMs have been shown to be associated with aortic stenosis.[14]
Bleeding from an AVM can be relatively mild or devastating. It can cause severe and less often fatal strokes. If a cerebral AVM is detected before a stroke occurs, usually the arteries feeding blood into the nidus can be closed off to avert the danger. However, interventional therapy may also be relatively risky.
Symptoms of AVM vary according to the location of the malformation. Roughly 88%[1] of people with an AVM are asymptomatic; often the malformation is discovered as part of an autopsy or during treatment of an unrelated disorder (called in medicine an "incidental finding"); in rare cases, its expansion or a micro-bleed from an AVM in the brain can cause epilepsy, neurological deficit, or pain.
The most general symptoms of a cerebral AVM include headaches and epileptic seizures, with more specific symptoms occurring that normally depend on the location of the malformation and the individual. Such possible symptoms include:[2]
Difficulties with movement coordination, including muscle weakness and even paralysis;&Vertigo (dizziness);&Difficulties of speech (dysarthria) and communication, such as aphasia;&Difficulties with everyday activities, such as apraxia;&Abnormal sensations (numbness, tingling, or spontaneous pain);&Memory and thought-related problems, such as confusion, dementia or hallucinations
Cerebral AVMs may present themselves in a number of different ways:
Bleeding (45% of cases)&Acute onset of severe headache. May be described as the worst headache of the patient's life. Depending on the location of bleeding, may be associated with new fixed neurologic deficit. In unruptured brain AVMs, the risk of spontaneous bleeding may be as low as 1% per year. After a first rupture, the annual bleeding risk may increase to more than 5%.[3]&Seizure or brain seizure (46%) Depending on the place of the AVM, it can cause loss of vision in one place.&Headache (34%)&Progressive neurologic deficit (21%) May be caused by mass effect or venous dilatations. Presence and nature of the deficit depend on location of lesion and the draining veins.[4]&May be caused by mass effect or venous dilatations. Presence and nature of the deficit depend on location of lesion and the draining veins.[4]&Pediatric patients Heart failure Macrocephaly Prominent scalp veins&Heart failure&Macrocephaly&Prominent scalp vein
Pulmonary arteriovenous malformations[edit] => In the lungs, pulmonary arteriovenous malformations have no symptoms in up to 29% of all cases.[5]