Watershed stroke

Watershed infarcts (WI) evolve in hemodynamic risk zones. Clinical picture of WI can be associated to partial epileptic seizures. Diffusion weighted brain magnetic resonance imaging (MRI) allows a clear diagnosis. WI pathogenesis involves either embolic or hemodynamic mechanism. A 69-year old patient presented with sub-acute occurrence of right hemiparesis and partial epileptic seizures of the right arm. Carotid ultrasounds demonstrated occlusion of the right extra-cranial internal carotid artery (ICA) and tight stenosis of the contralateral ICA. Brain Diffusion-Weighted magnetic resonance revealed acute ischemic lesions within the watershed area of the left hemisphere. Our case supports the hypothesis of impaired washout of emboli in low-perfusion brain areas as the mechanism underlying cortical WI.