Abstract
4 cases of thrombosis of the aorta arising from different causes were described. The 1st followed the dislocation of a mural thrombus, the 2d one, a rheumatic carditis, the 3d an impaired circulation in an arteriosclerotic artery, and the 4th a retrograde thrombosis. Attention was directed to the part occlusion of lumbar arteries played in the production of symptoms. Ischemia of the spinal cord follows blockage of the lumbar arteries and produces intermittent claudication of the thighs, weakness of both lower extremities and absence of neurologic signs (Dejerine''s syndrome).