The purpose of this study is to analyze the utility of the Portuguese version of the Wechsler Memory Scale-3rd edition (WMS-III) with demented elderly people, namely its capacity to detect and discriminate between subcortical vascular dementia (SVD) and Alzheimer's disease (AD). We assessed early demented patients (SVD = 16; AD = 36) aged 65 or older who were compared to a control group (n = 40). Both clinical groups were adequately matched in terms of disease severity, overall cognitive functioning, depressive symptomatology, and pre-morbid intelligence. Between-group's differences were evaluated using the Quade's rank analysis of covariance. We also computed indexes and subtests optimal cut-off scores, and the corresponding sensitivity, specificity, and positive and negative predictive values, which were able to successfully discriminate between patients and healthy subjects. The SVD patients had a better overall memory performance than AD patients on the majority of the indexes and the delayed condition subtests of the WMS-III. The AD patients only showed a better performance on digit span subtest. Several measures discriminated patients from healthy subjects. This study suggests some recommendations for the diagnostic accuracy of the Portuguese version of WMS-III in dementia and about differential diagnosis between SVD and AD.
Keywords: Alzheimer's disease; Wechsler Memory Scale-III; memory; subcortical vascular dementia.