On "contrast-induced transient cortical blindness"

After receiving contrast for procedures like cardiac angiogram, some patients may experience contrast-induced transient cortical blindness, usually associated with headache. Any patient who complains of blurred vision after contrast added procedure should be suspected of contrast-induced transient cortical blindness. Blurring of vision may be the prologue of full blindness. It may be associated with nausea, vomiting, aphasia or limb weakness mimicking stroke. Interestingly, CT and MRI findings may be impressive with different findings. Clue to diagnosis is symmetrical white matter edema in the posterior cerebral hemispheres. Most deceiving (if little contrast extravasation occurs) is appearance of either subarachnoid hemorrhage or intracerebral hemorrhage, on noncontrast head CT scan, which is usually done as a first line of workup in such circumstances. Fortunately, symptoms and radiological findings resolve over few next days. Some experts cout this as a form of posterior reversible encephalopathy syndrome (PRES).  Despite all typical symptoms, high vigilence should be kept for any real CVA.



References:

1. Borghi C, Saia F, Marzocchi A, Branzi A. The conundrum of transient cortical blindness following coronary angiography. J Cardiovasc Med (Hagerstown) 2008; 9:1063.

2. Saigal G, Bhatia R, Bhatia S, Wakhloo AK. MR findings of cortical blindness following cerebral angiography: is this entity related to posterior reversible leukoencephalopathy? AJNR Am J Neuroradiol 2004; 25:252. 

3. Velden J, Milz P, Winkler F, et al. Nonionic contrast neurotoxicity after coronary angiography mimicking subarachnoid hemorrhage. Eur Neurol 2003; 49:249.