Arteriovenous Malformation – Symptoms and Causes
Overview
Arteriovenous malformations (AVMs) are abnormal tangles of blood vessels that form inappropriate connections between arteries and veins. These tangled structures disrupt normal blood flow patterns and oxygen delivery to surrounding tissues.
AVMs can develop anywhere in the body. Brain AVMs are particularly concerning due to their potential complications.
In normal circulation, arteries carry oxygen-rich blood from the heart to the body’s tissues, while veins return oxygen-depleted blood back to the heart and lungs. AVMs create shortcuts that bypass the normal capillary network, preventing proper oxygen exchange.
The blood vessels within an AVM are structurally weak and prone to rupture. When a brain AVM bursts, it causes bleeding (hemorrhage) that can trigger a stroke or significant brain damage.
The exact cause of AVMs remains unclear. Most develop spontaneously, though a small percentage may have a genetic component and run in families.
Key Facts About AVMs:
- Can occur anywhere in the body
- Disrupt normal blood oxygen delivery
- May cause no symptoms until they rupture
- Can be effectively treated once diagnosed
- Treatment aims to prevent bleeding complications
Signs and Symptoms
An arteriovenous malformation (AVM) may not always cause noticeable problems. Sometimes doctors find AVMs by chance during imaging tests for other health issues.
When symptoms do appear, they often start after bleeding occurs.
Common symptoms include:
- Worsening cognitive function over time
- Headaches
- Nausea and vomiting
- Seizures
- Loss of consciousness
People with AVMs might also experience:
- Muscle weakness, especially in the legs
- Paralysis (loss of movement and feeling in one body area)
- Poor coordination affecting walking ability
- Difficulty with planning tasks
- Back pain
- Dizziness
- Vision problems (partial vision loss, eye movement difficulties)
- Speech problems or trouble understanding language
- Numbness, tingling, or sudden pain
- Memory problems or dementia
- Hallucinations (seeing or hearing things that aren’t real)
- Confusion
Children and teenagers with AVMs might show learning difficulties or behavioral problems.
A specific type called vein of Galen malformation appears at or shortly after birth. Signs include:
- Enlarged head due to fluid buildup
- Swollen veins on the scalp
- Seizures
- Failure to thrive
- Heart failure
When to Get Medical Help
If you experience headaches, dizziness, vision problems, seizures, or changes in thinking ability, see a doctor right away.
Many AVMs are discovered during CT scans or MRIs performed for other health concerns. Early detection can help manage the condition better and prevent serious complications.
Causes
Arteriovenous malformations occur when blood vessels connect abnormally. The exact cause remains unknown to medical experts. Some genetic mutations may contribute to their development, though most cases aren’t hereditary.
These abnormal connections form during fetal development, but doctors haven’t identified why certain people develop them while others don’t.
Risk Factors
Most arteriovenous malformations are not passed down in families. However, your risk may increase if:
- You have family members with this condition
- You have hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome)
These genetic factors are rare but important to consider if you have a family history of blood vessel abnormalities.
Complications
AVM (Arteriovenous Malformation) can lead to serious health problems. The two main complications are:
- Bleeding in the brain – This can damage brain tissue and may be fatal without treatment.
- Seizures – These can range from mild to severe.
Brain bleeding is particularly dangerous. It can cause permanent neurological damage or death if not treated promptly.
