Evaluating language comprehension in Alzheimer's disease: The use of the Token Test

Abstract

Objective: To analyze the psychometric properties of the Token test (TT), a verbal comprehension test, and its applicability to the diagnosis of mild Alzheimer's disease (AD). Methods: One hundred and sixty participants (80 AD and 80 controls) performed the TT and a short battery of neuropsychological tests designed to evaluate general cognitive status, working memory and executive functions. Internal consistency, factor structure, correlation with other measures and group comparisons were evaluated. Results: The test evinced good internal consistency and a bi-factorial structure (related to comprehension and attention). Differences between AD and controls were significant, however the TT presented only moderate sensitivity and specificity for the AD diagnosis. Conclusion: The TT showed evidence of good psychometric properties and adequacy for characterizing comprehension deficits in AD, but it was not an appropriate test for the AD detection and diagnosis.