Abstract
<title>Abstract</title> <p> Background Delirium is a frequent complication among elderly patients with acute ischemic stroke, particularly in those with underlying neurodegenerative disorders such as Parkinson’s-plus syndromes. In many cases, delirium is multifactorial and may persist despite treatment of apparent precipitating causes such as infection. Case presentation A 75-year-old female with Parkinson’s-plus syndrome and prior cerebrovascular disease presented with persistent delirium characterized by abnormal behavior, irrelevant speech, and fluctuating attention. Symptoms began approximately ten days before her first hospitalization, where encephalitis and urinary tract infection were initially suspected. Subsequent evaluation demonstrated an acute ischemic infarct in the left parietal lobe on a background of chronic cerebrovascular disease with cortical atrophy. Urine cultures grew <italic>Enterococcus faecalis</italic> and <italic>Pseudomonas</italic> species and were treated with culture-guided antimicrobial therapy. Despite improvement in inflammatory markers, delirium persisted and improved only gradually. Conclusions Persistent delirium after stroke often reflects the interaction of structural brain disease, neurodegeneration, infection, and systemic illness. Clinicians should evaluate multiple contributing factors rather than attributing delirium to a single cause. </p>