Branch atheromatous disease has been recognized as one of the types of stroke which is often associated with clinical deterioration. We investigated the correlation between diffusion weighted imaging (DWI) findings and clinical courses of 33 patients with BADs in the territory of the lenticulostriate arteries. The DWI findings associated with the poor outcomes (modified Rankin Scale ; mRS>or = 3) are (1) the larger lesion size in a direction perpendicular to axial section and (2) the lesions located in the inferior portion of basal ganglia. The findings correlated with progressive motor deficits are (1) the lesions closer to the posterior limb of internal capsule (medial type) and (2) the lesions located in the inferior portion of basal ganglia. These characteristics of DWI may play an important role to distinguish the progressing ischemic strokes as BAD from non-progressing ones.
