Clinical trial of iohexol for lumbar myelography

Iohexol containing 180 mg I/ml was used in 80 patients for myelography by lumbar injection. By using an adequate volume, between 10 and 20 ml, satisfactory films were obtained in all cases. Minor adverse effects occurred in 12 patients (15%) and were more frequent in women than men; they were headache (5), nausea (3), vomiting (2), back or limb pain (5), and skin rash (1) and were of minor degree in 10 cases, moderate in the other two and lasted more than 24 h in only one case. There was no change in vital signs or neurological examination related to the studies. No patient suffered difficulty with concentration, personality change or seizures. Electroencephalograms performed on 21 patients before and during the 24 h after iohexol showed no seizure or focal activity or any significant change. Repeat lumbar punctures were performed on ten patients during the 24 h following myelography. One of these, a patient with symptoms due to disc prolapse, whose CSF was abnormal prior to the myelogram, showed a slightly increased cellular response. There was no significant change in any other case. Iohexol is a very satisfactory contrast medium for myelography and compares favourably with other non-ionic contrast media.