Arteriovenous malformations (AVM) are abnormal connections between arteries and veins that form tangles of blood vessels. Although they can occur anywhere in the body, they are most commonly found in the brain and spinal cord. Some people with AVMs experience symptoms, while others only become aware of the condition after a brain bleed or other event.
Normally, oxygen-rich blood enters the spinal cord through arteries and flows into smaller blood vessels known as capillaries. The spinal cord uses the oxygen from the blood before it is drained away by veins to the heart and lungs. In spinal AVMs, however, blood flows directly from arteries to veins, bypassing the capillaries. This disrupts the delivery of oxygen to the surrounding cells, leading to tissue damage or cell death.
In addition to the lack of oxygen delivery, the tangled arteries and veins of spinal AVMs can also burst and cause bleeding in the spinal cord. Over time, the AVM may grow, causing increased blood flow and pressure on the spinal cord, leading to disability and other complications. Although some people may not experience symptoms, spinal AVM can be treated with surgery to prevent or reverse some of the damage caused by the condition.
Spinal AVM symptoms vary among individuals depending on the location and severity of the arteriovenous malformation, with some people remaining asymptomatic for many years or never experiencing symptoms. However, for others, the symptoms can be severe and even life-threatening. Most individuals tend to develop symptoms in their 20s, but approximately 20% of those diagnosed with spinal AVM are under 16 years of age.
Symptoms may appear gradually or sudden. Symptoms may include:
- Sudden, severe back pain
- Weakness or paralysis in the affected nerves of the body
- Difficulty in walking or climbing the stairs
- Numbness, tingling or sudden pain in the legs
- Difficulty urinating or bowel movements
- Stiff neck
- Sensitivity to light
It is recommended to seek medical attention if the patient is experiencing any symptoms of the spinal AVM.
Arteriovenous malformations (AVM) are believed to be congenital, developing during pregnancy, and their exact cause is unknown. Although rare cases have been linked to head trauma or certain infections, the majority of AVM are not associated with any particular risk factor. Additionally, hereditary factors are only believed to play a role in a small number of cases, with AVM typically not running in families.
While no specific risk factors for spinal arteriovenous malformation (AVM) have been identified, the condition typically affects younger individuals between the ages of 20 and 40, with those between the ages of 40 and 50 being particularly prone to experiencing symptoms.