Pre-stroke dementia does not affect the post-acute care functional outcome of old patients with ischemic stroke

Aim: The purpose of the present study was to evaluate whether a diagnosis of dementia before stroke onset (pre-stroke dementia [PSD]) affects the short-term functional outcome of elderly ischemic stroke patients. Methods: This was a retrospective case-control study comprising of consecutive elderly ischemic stroke patients. Functional outcome was assessed by the Functional Independence Measure scale (FIM) at admission and discharge. Data was analyzed by t-test, chi(2)-test, multiple linear regression analysis and logistic regression. Results: There were 919 patients with acute ischemic stroke, out of whom 11.5% were diagnosed with PSD on index day. Compared with non-PSD patients, those with pre-stroke dementia had a shorter length of stay (P < 0.001), higher rate of female patients (P < 0.001) and lower Mini-Mental State Examination scores (P < 0.001). Both total and motor FIM scores at admission and discharge, and their respective FIM gain scores at discharge were higher in non-PSD compared with PSD patients (P < 0.001). In logistic regression analysis to identify factors predicting successful outcome (defined as total FIM at discharge >= 80), PSD remained as significantly associated with increased risk for adverse outcome on discharge (OR 2.449, CI 1.207-4.970, P = 0.013). Conclusions: The present findings suggest that a diagnosis of pre-stroke dementia is associated with lower FIM scores at admission and discharge in patients with ischemic stroke. Yet, daily motor FIM gains were similar in PSD and non-PSD patients, suggesting that these patients should not be deprived of a post-acute rehabilitation, based on a diagnosis of dementia before stroke onset.