Arteriovenous Malformations

Definition

• Fistulous connections b/w cerebral arteries & veins w/o a nml capillary bed.

Clinical Presentation

• Up to 40% present w/ unrelated Sx.
• The remainder w/ Sx related to the AVM (focal deficit, H/A, sz)
  • These Sx may be assoc. w/ hemorrhage, mechanical compression, irritation
• Medical attention in 50% due to ruptured AVM w/ hemorrhage (intraparenchymal MC, IVH, SDH, or SAH)

Subgroups of Presentation - Ruptured, Unruptured ( ± w/ microhemorrhages)

Hemorrhagic Presentation

• Risk factors: Small size, deep location, exclusive deep venous drainage, and association with aneurysms.
• Pts who initially presents w/ hemorrhage, have a high risk of rehemorrhage (20%–40%).
  • The highest risk is w/i the first yr.

Seizures as a Presentation

• 15%–35% of initial presentation.
• Common in supratentorial AVMs.
• Related to hemorrhage, mass effect, or flow characteristics.
• Risk factors: Superficial location, large nidus, cortical location.

Other Presentations

• Neurological deficits (<10%): Possibly due to steal phenomenon, microhemorrhages, mass effect.
• Headaches: May be due to meningeal artery involvement or venous outflow obstruction.

Management

Key articles

ARUBA trial

Medical management alone is superior to interventional therapy for preventing death or stroke in unruptured brain AVM. (Lancet 2014)