Delirium in the acute phase after stroke: incidence, risk factors, and outcome.

OBJECTIVES: This prospective cohort study assesses incidence of delirium after stroke. In addition, risk factors during the first week were assessed. Finally, outcome in relation to development of delirium was studied.
METHODS: A total of 527 consecutive patients with stroke (median age, 72 years; range, 29-96 years) were screened for delirium during the first week after admission. We diagnosed delirium with the Confusion Assessment Method. Cognitive functioning prior to the stroke was assessed with the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE). Neurologic deficits were assessed with the NIH Stroke Scale.
RESULTS: A total of 62 patients with stroke (11.8%) developed delirium during the first week of admission. Independent risk factors were preexisting cognitive decline (odds ratio [OR] for IQCODE above 50: 2.6, 95% confidence interval [CI] 1.2-5.7) and infection (OR 3.4, 95% CI 1.7-6.8). Furthermore, right-sided hemispheric stroke (OR 2.0, 95% CI 1.0-3.0), anterior circulation large-vessel stroke (OR 3.4, 95% CI 1.1-10.2), the highest tertile of the NIH Stroke Scale (OR for highest vs lowest tertile 15.1, 95% CI 3.3-69.0), and brain atrophy (OR for highest versus lowest tertile 2.7, 95% CI 1.1-6.8) increased the risk for delirium. Delirium was associated with a worse outcome in terms of duration of hospitalization, mortality, and functional outcome.
CONCLUSIONS: Delirium occurs in almost 1 out of every 8 patients with stroke on a stroke unit and is associated with cognitive decline, infection, right-sided hemispheric stroke, anterior circulation large-vessel stroke, stroke severity, and brain atrophy. Delirium after stroke is associated with a worse outcome.