Confusional state in stroke - Relation to preexisting dementia, patient characteristics, and outcome

Background and Purpose-Acute confusional state (ACS) is frequent in hospita lized stroke patients. We previously showed that 16% of patients admitted f or a stroke have preexisting dementia. The extent to which preexisting cogn itive decline is associated with a risk of ACS at the acute stage of stroke remains to be systematically examined. The aim of this study was to evalua te the prevalence of ACS in acute stroke patients, to study the influence o f preexisting cognitive decline and other patient characteristics, and to e valuate the influence of ACS on outcome. Methods-We diagnosed ACS using DSM-IV criteria and the Delirium Rating Scal e with a cutoff of 10 in 202 consecutive stroke patients aged 40 years or o lder (median age, 75 years; range, 42 to 101 years). Cognitive functioning before stroke was assessed with the Informant Questionnaire on Cognitive De cline in the Elderly. Results-Forty-nine stroke patients (24.3%; 95% CI, 18.3% to 30.2%) had an A CS during hospitalization. Using logistic regression analysis, we found pre existing cognitive decline (P=0.006) and metabolic or infectious disorders (P=0.008) to be independent predictors of ACS. Functional, but not vital, p rognosis was worse in patients with ACS at discharge and 6 months after str oke. Conclusions-ACS occurs in one fourth of stroke patients older than 40 years . Its occurrence requires inquiry for a preexisting cognitive decline, whic h usually remains unrecognized in the absence of a systematic evaluation.