Background and purpose: Previous studies have suggested embolic mechanisms for bihemispheric subcortical infarcts involving the anterior and posterior circulation. However, the mechanism of bihemispheric subcortical infarcts in middle cerebral artery (MCA) territories remains uncertain. We describe a patient with acute bihemispheric subcortical infarcts in restricted MCA territories suggesting an embolic mechanism.

Case description: A 62-year-old woman with a history of hypertension and hyperlipidemia suddenly presented with left hemiplegia. Diffusion-weighted and T2-weighted magnetic resolution imaging of the brain showed multiple subcortical high intensity in the MCA territories. There were no acute infarctions in the cerebrum, brain stem, or cerebellum, including cortical lesions. The patient had no carotid, internal carotid artery, or MCA disease.

Conclusion: Bihemispheric subcortical infarcts in the MCA territory are likely to have a proximal embolic source and such infarcts could be associated with multiple subcortical infarcts due to small vessel disease.