Contrast-Induced Encephalopathy With Concomitant Procedure-Related Microembolic Ischemic Lesions Following Subclavian Artery Stenting

Contrast-induced encephalopathy (CIE) is a rare and underrecognized neurological complication following exposure to iodinated contrast media. Because its clinical presentation frequently mimics acute ischemic stroke, early differentiation is critical to avoid misdiagnosis and inappropriate management. Although CIE has been described after coronary and cerebral angiography, its occurrence following supra-aortic interventions such as subclavian artery stenting remains exceptionally rare. We report the case of a 68-year-old woman with diabetes mellitus and a prior history of percutaneous coronary intervention who underwent subclavian artery stenting. Within 30 minutes of contrast exposure, she developed acute aphasia and lateralized neurological deficits suggestive of stroke. Initial brain MRI showed no evidence of acute ischemia or hemorrhage, while early electroencephalography demonstrated hemispheric dysfunction with diffuse slowing. The patient was managed conservatively with dual antiplatelet therapy, low-molecular-weight heparin, and aggressive hydration. Neurological deficits improved rapidly, with near-complete clinical recovery within 72 hours. Follow-up imaging revealed only minimal infarct foci insufficient to explain the initial severe presentation, and repeat electroencephalogram (EEG) findings normalized. The temporal relationship with contrast exposure, rapid reversibility of symptoms, and clinicoradiological mismatch supported the diagnosis of CIE with concomitant procedure-related microembolic ischemic lesions. This case highlights CIE as an important stroke mimic following supra-aortic endovascular procedures and underscores the diagnostic value of clinicoradiological dissociation and rapid symptom resolution. Awareness of this entity is essential to prevent unnecessary thrombolytic or invasive interventions. Our report contributes to the limited literature on CIE after subclavian artery stenting and emphasizes the need for heightened clinical suspicion in similar scenarios.