|
|
|
|
Among patients with unilateral lesions, 10 were embolic (7 cardiac, 3 carotid), 7 were unknown, and one patient had vasospasm from a ruptured aneurysm. Visual field abnormalities predominated over motor, sensory, and language abnormalities . All patients with bilateral posterior border-zone lesions had perioperative hypotension. Prolonged lethargy, bilateral limb weakness, and cortical blindness were common. Embolism, either cardiac of from the parent carotid artery, is the predominant s troke mechanism in unilateral posterior border-zone infarcts, not distal field perfusion failure. Bilateral posterior border-zone infarcts have a distinctive clinical presentation and are caused by systemic hypotension. Variability of irrigation of the major arteries, passage of emboli to border-zone areas, and decreased clearance of emboli in these areas explain the findings in the patients with unilateral lesions. |
|