Neurotoxicity of iohexol vs iopamidol in lumbar myelography. Clinical, electrophysiological and brain CT scan correlations.

The potential neurotoxicity of iohexol and iopamidol in lumbar myelography was investigated in 20 patients using three criteria: clinical symptoms, EEG recordings with spectral analysis and CT scans of the brain. There was no significant difference in clinical side-effects between the two groups (Iopaminol, Iohexol). In 10 patients (iopaminol 4, iohexol 6) CT scans revealed an important penetration of the contrast media into the subarachnoid spaces at 3 hours and into the cerebral cortex at 24 hours. This cerebral contamination was unrelated to the headaches experienced by the patients or to the electrophysiological disturbances observed. Spectral analysis in brain-contaminated subjects showed a reduction of delta, beta 1 and beta 2 bands with iohexol. This reduction suggests that EEG activation is less pronounced with this agent than with iopaminol.