A 60-year-old bricklayer was referred to our hospital because of acute bilateral blindness, vertigo, and bifrontal headache occurring within 10 seconds after a violent shock to the right shoulder while he was trying to open a closed door. On physical examination, the patient presented with bilateral tubular vision and strabismus with diplopia consistent with the clinical diagnosis of a "top of the basilar" syndrome. This syndrome is generally associated with an acute transitory embolic

more »

... at the bifurcation of the basilar artery with consequent possible ischemia in the mesencephalic and occipital region. Extensive investigations to detect possible embolic causes (duplex-ultrasound; magnetic resonance angiography of the carotid, vertebral, and basilar arteries; transthoracic echocardiography) were negative. Transesophageal echocardiography, however, showed multiple atheromatous plaques of the aortic arch with mobile peduncles (Figure 1, arrows) . Spiral CT confirmed the presence of atherosclerotic plaques of the aortic arch, one located opposite the left subclavian artery (Figure 2 ). Virtual endoluminal reconstruction by magnetic resonance angiography shows the roof of the aortic arch with the origin of the left subclavian artery and left common carotid artery and their relationship with the plaques (Figure 3) . The causal link between the pedunculated mobile plaques and the cerebral embolism cannot be definitively proved. Nevertheless, the temporal relationship between the shock to this overweight patient and the neurological sequelae in the area supplied by the basilar artery strongly suggest that the nonpenetrating chest trauma may have caused embolization of the large pro-truding atheroma lying just opposite the left subclavian artery. This unique case confirms the importance of the thoracic aorta as a possible source of arterial embolism and the crucial role of transesophageal echocardiography as well as the complementary role of new diagnostic techniques, such as magnetic resonance and spiral CT, for the diagnosis of this condition. Figure 1. Transesophageal echocardiography shows details of a large calcified plaque (22ϫ18 mm) of aortic arch with a mobile peduncle (4ϫ2 mm) on top of plaque. Curved arrows on both sides of the mobile peduncle indicate movement of the peduncle into the aortic lumen.