About Spinal AVM
The spinal cord is composed of neurons, support cells and interwoven vascular structures that perfuse the spinal tissue. The spinal cord extends from the base of the brain, down the middle of the back, to level of the waist. The nerves that lie within the spinal cord function to carry messages back and forth from the brain to the spinal nerves located along the spinal cord.
Spinal cord vascular malformations are a group of blood vessel disorders that affect the spinal cord blood supply. These are collectively called spinal cord AVMs (arteriovenous malformations)
Spinal cord AVMs are categorized into four groups:
These are dural arteriovenous fistulas (AVF) arising at the dural nerve root sleeve. Symptoms aeries because the AVF causes venous congestion and hypertension, resulting in poor perfusion of the spinal cord. This is the most common type of spinal AVM. They usually occur in patients older than 40. Males are more common than females.
These are intradural glomus-type AVMs with a tightly compacted group of arterial and venous vessels inside a short segment of the spinal cord. These tend to occur in patients less than 30.
These are arteriovenous abnormalities of the spinal cord tissue and, often, surrounding soft tissue, fed by multiple vessels. They are called "juvenile" malformations and usually occur in patients less than 30
- These are intradural extramedullary arteriovenous fistulas on the surface of the cord.
The clinical presentation of spinal AVMs is specific to the type of AVM. The majority of these AVMs present with progressive neurological symptoms over several months to years. The symptoms are usually back pain associated with progressive sensory loss and lower extremity weakness. A small number of spinal cord AVMs present as a sudden onset of weakness, numbness, difficulty urinating, urinary incontinence, fecal incontinence, or paralysis due to acute hemorrhage.
MR (magnetic resonance) imaging of the spine will usually show dilated vascular vascular channels along the dorsal cord. Spinal angiography is performed to confirm the diagnosis and identify the specific vessels supplying the malformation.
Treatment of Spinal Cord AVM
The definitive treatment of spinal AVMs is either surgery or endovascular therapy. Surgery involves performing a laminectomy (removal of bone over the spinal cord) over the area of the AVM and removing the lesion. Endovascular therapy involves placing a catheter into the AVM from the groin (the femoral artery) and injecting glue or beads into the AVM to stop its blood flow.
Each spinal AVM is unique and require an individualized treatment strategy.