Atropine-Associated Central Anticholinergic Syndrome during Carotid Artery Stenting: A Case Report

Acute neurobehavioral deterioration during carotid artery stenting (CAS) requires prompt evaluation for serious neurological complications. We report a patient in their 70s who developed profound hyperactive delirium approximately 15 minutes after receiving prophylactic intravenous atropine (0.25 mg) during CAS. The episode was characterized by severe agitation, bilateral mydriasis, and facial flushing without focal neurological deficits. Repeated angiography and subsequent neuroimaging showed no evidence of thromboembolism, intracranial hemorrhage, cerebral edema, or cerebral hyperperfusion. Contrast-induced encephalopathy and cerebral hyperperfusion syndrome were considered but were less consistent with the overall clinical, temporal, and radiographic findings. The patient returned to neurological and cognitive baseline approximately 16 hours after symptom onset without specific antidotal treatment. The close temporal relationship to atropine exposure and characteristic neurobehavioral and autonomic features favored atropine-associated central anticholinergic syndrome, which should be considered in the differential diagnosis of acute neurobehavioral deterioration during CAS.