Pathophysiology of Contrast-Induced Neurotoxicity: A Narrative Review of Possible Mechanisms

Background: Contrast-induced neurotoxicity (CIN) is an increasingly observed event following the administration of iodinated contrast. It presents as a spectrum of neurological symptoms, that closely mimic ischaemic stroke, however, CIN remains poorly understood clinical phenomenon. An appreciation of underlying pathophysiological mechanisms is essential to improve clinical understanding and enhance decision making. Methods: A broad literature search of Medline (1946 to December 2022) and Embase (1947 to December 2022) was conducted. Articles discussing the pathophysiology of CIN were reviewed. Summary: Under normal circumstances, contrast agents do not pass the blood-brain barrier. Proposed mechanisms of CIN include blood-brain barrier (BBB) disruption due to factors including ischaemic stroke, uncontrolled hypertension, and possibly contrast agents themselves, amongst others. This is followed by passage of contrast agents across the BBB leading to chemotoxic sequelae of on neural tissue. Key Messages: This review provides a clinically-oriented review on the pathophysiology of CIN to enhance knowledge and improve decision making amongst clinicians.