Abstract
Border-zone infarcts usually represent cerebral hypoperfusion caused by either hemodynamic or microembolic mechanisms. Although cortical and internal border-zone infarcts have been well recognized, border-zone infarcts formed between small insular cortical penetrating branches of the middle cerebral artery (MCA) and the lenticulostriate arteries have not been described in Japan. Such border-zone infarcts have been reported as deep cerebral infarcts extending to the subinsular region (DCIs) by Wong et al. We now describe 2 patients with DCIs. Patient 1: a 75-year-old man. He was found lying on the floor in a state of unconsciousness. After being transferred to our hospital, his consciousness recovered. He was recognized as having right hemiparesis, dysarthria, and hypophonia. MRI revealed DCIs and MRA showed a left MCA occlusion. Angiography demonstrated that the MCA trunk had been partially recanalized. Patient 2: a101-year-old woman. She noticed left hemiparesis as she was talking with her family. When she was transferred to our hospital, she was found to be somnolent and to have right hemiparesis and dysarthria. MRI revealed DCIs and MRA showed a right MCA occlusion. She then became worse and finally died. Although we could not detect the potential source of embolism, embolic occlusion and recanalization of the MCA trunk were the presumed stroke mechanism. Wong et al. observed 3 patients with DCIs out of 8 caused by cardioembolism. DCIs have been considered to represent a subtype of internal border-zone infarction. Identifying DCIs as border-zone infarcts helps us to understand the pathophysiology of ischemic stroke more precisely.
