Iatrogenic lateral rectus palsies. A series of five postmyelographic cases.

The objective of this study was to assess the etiology of lateral rectus palsies in patients undergoing lumbar myelograms with Iopamidol (Isovue; ER Squibb and Sons, Princeton, NJ, USA; Niopam, E Merc, UK.). An audit of the departmental orthoptic record revealed two patients who had suffered abducens palsies after myelograms. A further search revealed three additional patients who had suffered similar complications. The incidence of abducens palsy in patients undergoing myelography with the contrast agent Iopamidol was found to be 1 in 500 in around 2,500 myelograms performed under standard conditions. It would appear that lateral rectus palsy in myelography is the result of the lumbar puncture, the neurotoxic effect of the contrast agent, or a combination of the two in patients with an already compromised neurophysiologic state. This is the first series to associate this problem with Iopamidol. Although usually a serious neurologic symptom, when associated with contrast myelography using Iopamidol it is important to appreciate that such symptoms usually resolve of their own accord.