Transient global amnesia and cortical blindness after vertebral angiography: further evidence for the role of arterial spasm.

We describe a series of six patients who experienced severe retrograde amnesia (five cases) or cortical blindness (one case) during selective vertebral angiography. All angiograms were obtained with the same nonionic contrast medium. Analysis of the contrast batch demonstrated no abnormalities, but investigation of the angiographic suite revealed a faulty contrast warming cabinet resulting in injection of contrast material above body temperature. The warming cabinet was withdrawn, and the complication has not recurred. We believe that these symptoms reflect ischemia caused by vertebral arterial spasm.