An arteriovenous malformation (AVM) is an abnormal tangle of arteries and veins within the brain that disrupts normal blood flow. Because the vessels are fragile and lack capillaries, AVMs can rupture, causing brain hemorrhage, seizures, or progressive neurological symptoms.
Modern AVM treatment combines microsurgery, endovascular embolization, and stereotactic radiosurgery to eliminate the lesion safely and prevent bleeding while preserving healthy brain tissue.
Symptoms
AVMs may remain silent for years or present suddenly with bleeding. The symptoms depend on the AVM’s size, location, and whether it has ruptured.
Common symptoms include:
- Sudden severe headache or vomiting (if rupture occurs)
- Seizures or convulsions
- Weakness, numbness, or difficulty speaking
- Vision loss or balance problems
- Progressive neurological deficits due to “steal phenomenon” (diversion of blood away from normal brain tissue)
In some cases, AVMs are found incidentally on MRI performed for other reasons.
Diagnosis
MRI and MRA are the first-line imaging tools to detect AVMs and any signs of bleeding.
For detailed evaluation, digital subtraction angiography (DSA) is essential — it precisely maps the feeding arteries, nidus (core of the AVM), and draining veins, allowing exact classification by the Spetzler–Martin grading system.
Functional MRI or perfusion imaging may be used to assess eloquent brain areas near the AVM.
Treatment Options
1. Microsurgical Resection
The definitive treatment for most surgically accessible AVMs.
Using microsurgical techniques, neuronavigation, and intraoperative angiography, the AVM is carefully disconnected and removed.
This provides immediate cure and eliminates the risk of future bleeding.
2. Endovascular Embolization
A minimally invasive procedure in which a microcatheter is guided through the arteries to inject materials (e.g., Onyx, glue, coils) to block abnormal vessels or reduce AVM size before surgery or radiosurgery.
Sometimes used as a stand-alone therapy in small, compact AVMs.
3. Stereotactic Radiosurgery (Gamma Knife / CyberKnife)
A precise, non-invasive option for deep or inoperable AVMs. Focused radiation gradually closes abnormal vessels over 1–3 years, preventing further bleeding. Best suited for small AVMs (<3 cm).
4. Combined / Multistage Treatment
Many AVMs require a tailored approach — combining embolization, surgery, and radiosurgery — to achieve the safest and most complete cure.
Recovery & Follow-Up
Hospital stay varies depending on the treatment method.
After microsurgery, most patients recover in 5–7 days, followed by gradual return to normal activity.
For radiosurgery or embolization, recovery is usually faster (1–2 days).
Regular MRI or DSA follow-ups are done to confirm complete AVM closure.
If the AVM ruptured, rehabilitation may be needed to recover neurological function.
When to See a Neurosurgeon
If you experience new-onset seizures, sudden headache, or weakness on one side, prompt evaluation is essential.c
Even an unruptured AVM can pose serious risk if located near critical brain structures or if showing signs of instability.