Contrast-Induced Encephalopathy: A Case Series Analysis

Background: Contrast-induced encephalopathy (CIE) is a rare adverse event linked to intravascular use of iodine-containing contrast media. The prevalence of CIE could increase in the future due to growing numbers of endovascular procedures. We provide insights from a case series of 7 patients. Methods: Cases from 3 centers were collected based on existing academic collaborations, and key factors were extracted to illustrate development and management of CIE. Results: In our retrospective case-series analysis of 7 cases from 3 countries, affected patients had an equal distribution of sex (4 women, 3 men) and a median age of 75 (IQR 63-77). Common risk factors included hypertension (5/7), hyperlipidemia (5/7), previous stroke (3/7), and type 2 diabetes (3/7). CIE developed in 3 cases after endovascular thrombectomy (EVT) for stroke, in 2 cases after aneurysm treatment, in 1 case after cardiac catheterization, and in 1 case after diagnostic computed tomography (CT) angiography without an endovascular procedure. The median procedure time was 48 min (IQR 40-81). All patients received non-ionic, low-osmolar contrast agents with volumes ranging from 100-300 ml. Symptom onset was close to contrast administration, with stroke-like neurological deficits being most common (4/7). Prednisolone was the most frequently used medication to treat the symptoms (4/7). Symptom resolution occurred in 4 out of 7 patients within two to several days, and 1 patient died, but without clear connection to CIE. Conclusion: CIE is a rare and possibly underrecognized condition, but fortunately, with a favorable outcome in most cases.