4. History of screening visit brain MRI scan indicative of any other significant abnormality, including but not limited to multiple microhemorrhages (2 or more), history or evidence of a single prior hemorrhage > 1 cm3, multiple lacunar infarcts (2 or more) or evidence of a single prior infarct > 1 cm3, evidence of a cerebral contusion, encephalomalacia, aneurysms, vascular malformations, subdural hematoma, or space occupying lesions of significance as determined by the PI (e.g., arachnoid cysts or brain tumors such as meningioma).