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)