Contrast-Induced Encephalopathy following Coronary Angiography with No Radiological Features: A Case Report and Literature Review.

Contrast-induced encephalopathy (CIE) following coronary angiography (CAG) is a very rare complication. Radiological signs such as cerebral oedema and cortical enhancement are of great importance in the diagnosis. We report a case of probable CIE in a 76-year-old gentleman following a normal diagnostic CAG that involved 120 mL of the iodinated contrast agent iohexol (Omnipaque 300). At 90 min postprocedure he became acutely confused with a normal non-contrast CT of the head. After 9 days of conservative treatment, the patient recovered spontaneously with no neurological deficits. This case and a review of the literature highlights that contrast-induced neurotoxicity may not always present with the typical radiological signs that are described in association with CIE. Given the excellent prognosis with supportive management only, interventional cardiologists should be well aware of this condition despite the absence of radiological features.