Iohexol: a new nonionic contrast medium for myelography and cisternography with markedly reduced neurotoxicity

Nonionic contrast media have been proven safe for intrathecal opacification, but adverse effects, including psycho-organic syndrome and asterixis, have been reported and appear more frequently when contrast medium enters intracranial spaces. Using compressed spectral array (CSA), transient, EEG changes can be monitored more efficiently, and bioelectrical neurotoxicities of various contrast media can be better observed. The nonionic contrast medium, iohexol, was evaluated for safety, patient tolerance, and image quality in studies of the higher regions of the spinal canal and intracranial spaces. Fifty-nine patients received iohexol injections while undergoing myelography, cisternography, or ventriculography. Measurements included detailed neurologic examination, blood pressure and pulse rate, EEG, and CSA EEG analysis. Iohexol provided excellent opacification of the craniocervical region and of brain cisterns. It is safe for use in pericerebral spaces and is exceptionally well tolerated by patients. Due to its safety and convenience for use in myelography, iohexol is expected to facilitate the development and use of new neuroradiologic techniques.