Neurological complications following cerebral angiography: a case of contrast-induced encephalopathy

Contrast-induced encephalopathy (CIE) is a rare but increasingly recognized iatrogenic complication associated with the use of intravascular iodinated contrast agents, particularly during neurovascular procedures. It often presents with acute neurological deficits that mimic ischemic strokes or seizure disorders. Despite its often reversible course, radiological and electroclinical mimicry of other acute conditions poses a diagnostic dilemma. We report the case of an 82-year-old woman with multiple vascular comorbidities who developed acute left hemiparesis and conjugate gaze deviation after diagnostic cerebral angiography. Initial non-contrast CT revealed a dense right middle cerebral artery (MCA) sign, raising concerns about acute large vessel occlusion. However, subsequent angiography revealed no occlusions. Supportive neurocritical care, including hydration and anticonvulsant therapy, resulted in complete neurological recovery within five days. Electroencephalography (EEG) revealed decreased amplitude, indicating focal cortical dysfunction in the right hemisphere without epileptiform activity. Interval imaging confirmed the resolution of right hemispheric edema. This case underscores the diagnostic challenges of CIE, particularly its ability to radiologically and clinically mimic acute ischemic strokes. The absence of EEG epileptiform discharges, despite convulsive symptoms, highlights the non-epileptic mechanisms underlying contrast-induced neurotoxicity. Enhanced interdisciplinary awareness and radiologic vigilance are essential to prevent unnecessary interventions and improve patient outcomes.