Contrast-Induced Encephalopathy: A Rare Complication of Angiography in a Patient on Dialysis

Introduction: Contrast-induced encephalopathy (CIE) is a rare complication of contrast use in angiographic procedures. The kidneys filter iodinated contrast agents, making patients with end-stage kidney disease (ESKD) higher risk for CIE. We present a case of CIE to highlight the gravity of early diagnosis in patients with reduced kidney function. Case Description: A 66-year-old woman with hypertension and ESKD on home hemodialysis (HD)(4 times/week; no missed sessions) underwent diagnostic cerebral angiography for aneurysms noted incidentally on MRA during renal transplant evaluation. 300mg of iohexol was given intra-arterially. Patient was initially alert but 30 minutes later was disoriented, aphasic and not following commands. CT head showed no infarction or hemorrhage but noted extensive intracranial arterial atherosclerotic calcifications. Vitals and labs were normal, making other diagnoses unlikely. CIE was considered given the timeline. Mental status improved with urgent dialysis and was baseline after 2 sessions. To our knowledge, this is the first report of CIE in a patient receiving home HD. Discussion: CIE is a severe complication in <0.1% of patients receiving contrast. Incidence increases in CKD(6.8%) and ESKD(37.5%). Pre-existing diabetes, hypotension, dehydration, and large contrast volume also increase risk. Intracranial arterial atherosclerotic calcifications likely affected the disease process in this case. CIE is thought to occur from disruption of the blood-brain barrier and direct neurotoxicity of iodinated contrast. It presents with confusion, headache and agitation to seizures, blindness and stroke-like symptoms onset minutes-days after contrast. Transient cortical blindness is often reported. Treatment is discontinuing contrast, IV hydration, and early and frequent HD in HD patients. Failure to treat in severe cases can cause permanent neurologic damage and death. How the type/timing of dialysis impacts CIE risk is not well understood due to rarity of cases. Our patient recovered following 2 HD sessions, suggesting early and frequent HD is an effective treatment in patients already on HD. This rare case highlights the importance of early CIE recognition to avoid prolonged complications. It is important to also recognize that contrast use has other risks even in patients on dialysis and should be used cautiously.