Arteriovenous Malformation

Definition

Definition of Arteriovenous Malformation
Arteriovenous malformation or AVM is an abnormal connection between veins and arteries, usually congenital. This pathology is widely known because of its occurrence in the central nervous system, but can appear in any location. An arteriovenous malformation is a vascular anomaly. It is a RASopathy.

Symptoms

Symptoms of Arteriovenous Malformation
Symptoms of AVM vary according to the location of the malformation. Roughly 88% of people affected with 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, deficit or pain.

The most general symptoms of a cerebral AVM include headache and epilepsy, with more specific symptoms occurring that normally depend on the location of the malformation and the individual. Such possible symptoms include:

1. Difficulties with movement or coordination, including muscle weakness and even paralysis;
2. Vertigo (dizziness);
3. Difficulties of speech (dysarthria) and communication, such as aphasia;
4. Difficulties with everyday activities, such as apraxia;
5. Abnormal sensations (numbness, tingling, or spontaneous pain);
6. Memory and thought-related problems, such as confusion, dementia or hallucinations.

Causes

Causes of Arteriovenous Malformation
Can occur due to autosomal dominant diseases, such as Hereditary Hemorrhagic Telangiectasia.

Diagnosis

Diagnosis of Arteriovenous Malformation
AVMs can occur in various parts of the body:

1. brain, causing a cerebral arteriovenous malformation
2. spleen
3. lung
4. kidney
5. spinal cord
6. liver
7. intercostal space
8. iris
9. spermatic cord

Treatment

Treatment of Arteriovenous Malformation
Treatment for brain AVMs can be symptomatic, and patients should be followed by a neurologist for any seizures, headaches or focal deficits. AVM-specific treatment may also involve endovascular embolization, neurosurgery or radiation therapy. Embolization, that is, cutting off the blood supply to the AVM with coils or particles or glue introduced by a radiographically guided catheter, can be used in addition to either, but is rarely successful in isolation except for in smaller AVMs. The neurological risk of any such intervention is roughly 10%. For unruptured brain AVMs, the benefit for endovascular, neurosurgical or radiation therapy is as yet unknown. Therefore, the best way to follow an unruptured brain AVM is to join the NIH/NINDS funded international study designed for patients with an unruptured brain AVM.

Prognosis

Prognosis of Arteriovenous Malformation
The greatest potential danger posed by AVMs is hemorrhage. Researchers believe that each year between 2 and 4 percent of all AVMs hemorrhage. Most episodes of bleeding remain undetected at the time they occur because they are not severe enough to cause significant neurological damage. But massive, even fatal, bleeding episodes do occur. Whenever an AVM is detected, the individual should be carefully and consistently monitored for any signs of instability that may indicate an increased risk of hemorrhage.

Prevention

Prevention of Arteriovenous Malformation
Consult with your doctor.