Late meningeal effects of myelographic contrast media with special reference to metrizamide.

Two hundred and fifty-six myelograms in 192 patients were following by repeat myelography using a water-soluble contrast medium. The films of these re-examinations were analysed for signs of meningeal changes. Adhesive arachnoiditis had developed in five of 46 cases after methiodal sodium, in 24 of 96 cases after iothalamate meglumine, in seven of 12 cases after iocarmate meglumine, in seven of ten cases after iodophendylate, but in none of 90 cases after metrizamide. Dose of contrast medium, observation time and protein concentration of the CSF were found to be factors of importance for the development of adhesive arachnoiditis.