Comparison of iohexol with metrizamide in myelography

Myelography of the lumbar and lower thoracic spine was performed in 46 patients (23 using metrizamide and 23 using iohexol) as a parallel double blind randomized study. Neurological examinations, laboratory testing, and EEG studies were performed before and after myelography, and side effects were recorded. On comparison, adverse reactions were observed in a statistically significant lower number of patients when iohexol was used. The frequency and duration of each single adverse reaction was also lower following use of iohexol, but this was not statistically significant. Three patients had severe reactions following use of metrizamide, and in one patient sharp waves were recorded on EEG. No severe reactions, no mental reactions, and no muscular symptoms were seen following use of iohexol, and we considered this contrast medium better tolerated in the subarachnoid space than metrizamide.