Cranial Polyneuropathy Secondary to Remote Iophendylate Myelography

A 68-year-old woman with controlled hypertension, and degenerative joint disease of the spine for which she had undergone several myelograms and three surgeries 30-32 years earlier, presented with a 2 year history of painless, oblique, binocular diplopia. Her prior ophthalmic evaluations were consistent with an isolated left trochlear nerve paresis. She had magnetic resonance imaging (MRI) showing multiple foci of T1-weighted hyperintensities around the midbrain and brainstem thought to represent subarachnoid fat from a ruptured dermoid cyst. An extensive evaluation revealed a left trochlear nerve paresis as well as diminished sensation in the distributions of the first and second divisions of the left trigeminal nerve. Review of her MRI and history of myelograms raised the possibility of focal inflammation from intrathecal iophendylate (Pantopaque®). Repeat MRI was obtained that showed T1-weighted hyperintensities similar to her previous MRI, but in this study, T1-weighted fat suppression imaging also was performed and revealed these foci to be of low signal intensity, consistent with retained iophendylate.