Brain changes on computed tomography following metrizamide myelography. Significance and therapeutic implications

Three cases of seizures and marked behavioral changes that occurred after intrathecal metrizamide administration are reported. In each case a cranial computed tomographic scan obtained within 24 hours of the ictus showed hyperdensity of the gray matter, and created an optical illusion of diffuse white matter edema. The literature on adverse reactions and their pathogenesis and on brain parenchymal penetration of metrizamide is reviewed.