Teaching NeuroImages: Complex bilateral corpus callosum infarction after paradoxical embolism

A 47-year-old man developed sudden-onset abulia and alien hand syndrome (AHS). MRI revealed bilateral ischemic injury within anterior cerebral artery territory (a complex bilateral corpus callosum infarction1) due to obstruction of a variant bihemispheric A2 branch by a thrombus (figures 1 and 2), also demonstrated on 3D volume-rendered CT angiography (figure 2). The finding of lower-limb deep venous thrombosis in a patient with right-to-left interatrial shunt accounted for the case, given workup was otherwise unremarkable.