Towards harmonisation of neuropsychological assessment of Alzheimer’s disease in Europe: evidence from novel cognitive makers

Background: Recent EU consensus (Costa, et al. 2017) identifies problems of available tests used for the assessment of Alzheimer’s disease (AD) such as heterogeneity across countries, lack of standardisation, and limited information about psychometric properties. The Free and Cued Selective Reminding Test (FCSRT) and the Visual Short-Term Memory Binding Test (VSTMBT) were recommended as promising tests. They have individually shown marker properties for AD dementia. However, they have never been used together to assess their complementary value in the early detection of AD. This was the aim of this EU study.Methods: We present data from a EU cohort of 344 subjects (116 healthy controls and 228 patients with Mild Cognitive Impairment - MCI) who underwent one-year follow up assessment (± 2 months) at three labs (Edinburgh, Madrid, and Milan). They performed the VSTMBT, the FCSRT, and a battery of standardized neuropsychological tests. Performance was normalised for each country using controls’ data. Normalised data entered stepwise regression models controlling for age and education, and ROC analysis. We investigated the added value of these two tests to predict conversion from MCI to AD (data from three countries) and from healthy ageing to MCI (data from UK and Spain).Results: The MCI to AD conversion rate was 21% (n=48). MCI patients showed impairments on the FCSRT, the VSTMBT, and other neuropsychological functions. A regression model to identify predictors of AD conversion retained the FCSRT and the VSTMBT with a model explaining 15% of the variance (p < 0.001). ROC-derived cut-off scores achieved a combined sensitivity of 85.4%. The FCSRT explained a larger variance (AUC=0.78) than the VSTMBT (AUC=0.67). When we analysed conversion to MCI (7.3%), the combined Sensitivity was 74.4% (p<0.05). The VSTMBT explained a slightly larger variance (AUC=0.668) than the FCSRT (AUC=0.658). Conclusions: The combined used of the FCSRT and VSTMBT provides complementary information and enhance the reliability of the assessment. The FCSRT is a strong predictor in patients within the symptomatic stages while the VSTMBT seems to be stronger in earlier and seemingly pre-symptomatic stages. ReferenceCosta, A., et al. (2017). "The need for harmonisation and innovation of neuropsychological assessment in neurodegenerative dementias in Europe: consensus document of the Joint Program for Neurodegenerative Diseases Working Group." Alzheimers. Res. Ther 9(1): 27.