Abstract
Brain damage manifested by convulsions, hemiplegia, or death may result whenever concentrated Diodrast is injected into the cerebral circulation. Reactions are fairly common following cerebral giography but may follow contrast visualization of the thoracic aorta by any method. The greatest danger is in aortography when the maximum dye concentration is in the aortic arch. The reactions probably do not result from vascular spasm but from an alteration in the blood-brain barrier. It is possible to minimize the danger of reactions in aortography by observing certain simple precautions. Treatment of brain damage when it occurs, however, is not satisfactory.