Brain infarcts in the arterial border zones: Clinical-pathologic correlations

Most brain infarcts are correctly attributed to the circulatory alterations caused by the occlusion of a vessel, usually arterial. In this article, the authors review selected publications dealing with the mechanisms and the clinical expressions of brain infarcts secondary to nonocclusive causes. Hemodynamic crises, usually of cardiac origin, are among the main causes of the so-called arterial border-zone infarcts of the brain. Depending on the etiology and the distribution of the brain lesions, at least three separate neurologic syndromes have been outlined. The most frequently observed syndrome is attributed to the involvement, by the ischemic event, of tissues located in the border zone between the territories of the anterior and middle cerebral arteries. These anterior, bilateral arterial-border-zone infarcts produce a syndrome of bilateral brachial paralysis, with maximal involvement of the proximal limbs musculature, i.e., the "man-in-a-barrel" syndrome. Other neurologic syndromes in patients with arterial-border-zone infarcts are associated with ischemic injury of specific anatomic sites.