Rapid contrast-induced encephalopathy after a small dose of contrast agent: illustrative case

BACKGROUNDContrast-induced encephalopathy is a rare complication of cerebral angiography with only few cases reported to date. This paper reports on contrast-induced encephalopathy mimicking meningoencephalitis following cerebral angiography with iopromide, a subhypertonic nonionic contrast agent.OBSERVATIONSA 50-year-old woman underwent cerebral angiography for assessment of recurrent nasopharyngeal carcinoma with invasion of internal carotid artery. The patient experienced symptoms including a disturbance of consciousness, seizures, frequent blinking, and stiffness in the extremities immediately after angiography of the left common carotid artery using iopromide (4 ml/s, total 6 ml). Computed tomography scans of the brain showed no obvious abnormalities, whereas brain magnetic resonance imaging showed swelling of the left cerebral cortex without signs of ischemia or hemorrhage. The patient was treated with intravenous rehydration, mannitol dehydration, and other supportive treatment. With this treatment, neurological status progressively improved, with complete resolution of symptoms at day 10.LESSONSThis observation highlights that even a small dose of subhypertonic nonionic contrast agent can rapidly induce contrast encephalopathy.

Vasogenic Cerebral Edema following CT Myelogram with Nonionic Omnipaque 300

Computed Tomography (CT) with myelogram is a relatively safe procedure. It requires the use of nonionic contrast agents which, unlike ionic contrast agents, have been associated with low complication rates. We report a case of a 69-year-old female who developed diffuse bilateral cerebral edema following a lumber myelogram with the use of intrathecal nonionic contrast agent Omnipaque (Iohexol) 300. We were able to find one other reported case of cerebral edema following the use of intrathecal nonionic contrast agent in the literature.