- Evidence on MRI of: greater than 4 microhemorrhages (regardless of their anatomical location or diagnostic characterization as "possible" or "definite"), a single area of superficial siderosis, vasogenic edema, a macrohemorrhage, major stroke, prominent white matter disease with a rating score of 3 on the age-related white matter changes (ARWMC) scale from the European Task Force on ARWMC, or multiple lacunae (defined as more than 2 lacunae that are greater than 0.5 mm in size)