Poststroke dementia - Incidence and relationship to prestroke cognitive decline

Objective: To evaluate the 3-year incidence of poststroke dementia (PSD) an d the influence of prestroke cognitive decline. Methods: The authors evalua ted prestroke cognitive functions in 202 consecutive stroke patients greate r than or equal to 40 years old using the Informant Questionnaire on Cognit ive Decline in the Elderly (IQCODE), with a cut-off of 104 for the diagnosi s of dementia. Six months and then annually after stroke, dementia was reas sessed. The diagnosis of dementia was based on the International Classifica tion of Diseases, 10th revision criteria in survivors who underwent a visit with a neurologist, or on the IQCODE score obtained by telephone contact w ith the family in survivors who did not. Statistics were performed using li fe-table methods. Results: Thirty-three patients were excluded because of p restroke dementia. In the 169 remaining patients, the cumulative proportion of patients with dementia was 28.5% at the end of the follow-up period, wi th most of PSD occurring during the first 6 months. Using multivariate anal ysis, independent predictors of PSD were aging, preexisting cognitive decli ne, severity of deficit at admission, diabetes mellitus, and silent infarct s. Leukoaraiosis was an independent predictor of PSD when prestroke cogniti ve decline was not taken into account. The presumed etiology of dementia wa s vascular dementia (VaD) in two-thirds of patients and AD in one-third. Co nclusions: The risk of PSD is high, and increased in patients with prestrok e cognitive decline, with about one-third of patients meeting the criteria for AD and two-thirds meeting the criteria for VaD. These results confirm t hat, in stroke patients, an underlying degenerative pathology may play a ro le in the development of PSD.