Delirium in the acute phase after stroke

Abstract

We performed an epidemiological study to study the incidence of delirium after stroke during the first week of admission and analyse the risk factors and outcome in the general Dutch stroke population. We found an incidence of 11.8% in a cohort of 527 patients. Pre-existent cognitive decline, right-sided hemispheric, anterior circulation large vessel stroke, stroke severity, infection and brain atrophy were independent risk factors for delirium. At 1 month after admission delirium after stroke is associated with unfavourable outcome (defined as dead or Barthel Index <12). Since several studies suggest that the main neurochemical correlate of delirium is decreased cholinergic activity, we performed a pilot study on the effect of the acetylcholinesterase inhibitor rivastigmine in patients with delirium after stroke. We showed that it is possible to treat patients with delirium after stroke with rivastigmine, and to increase the dose rapidly if necessary. We investigated cognitive functioning two years after the admission to the stroke unit of patients with a delirium after stroke and a matched control group of patients without a delirium. Delirium after stroke was an independent predictor for severe cognitive impairment and development of dementia after a follow up of 2 years. Since a recent meta-analysis found an association between delirium and the apolipoproteine E (APOE) gene, we investigated the association between the APOE gene and delirium in a stroke population. We did not find an association between APOEε4 and delirium. Finally we developed and validated a practical risk model based on the risk factors found in our previous epidemiological study. Using this model it is possible to reliably predict delirium on the basis of several risk factors. The area under the curve of this model was 0.84 and the sensitivity and specificity were 80% and 75% respectively