Grade IV or V lesions are only treated in circumstances of progressive neurological deterioration from hemorrhage, vascular steal, or seizure as seen in a case, which had a high risk of rebleeding because of presentation at young age with hemorrhagic episode, large size of the nidus, deep venous drainage pattern and associated aneurysm within the AVM 1).
Volume-Staged CyberKnife Stereotactic Radiosurgery for Treatment of Drug Resistant Epilepsy for a Spetzler-Martin AVM grading system V Arteriovenous Malformation: A Case Report and Review of the Literature 2).