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Down syndrome cognitive marker's significance in Alzheimer's disease and dementia management
Author(s) -
Mahla Ranjeet Singh
Publication year - 2019
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2019.04.010
Subject(s) - dementia , citation , library science , psychology , medicine , disease , pathology , computer science
I read with great interest the recent study by Startin et al. [1] demonstrating a clinical trial model for evaluation of preclinical and prodromal cognition marker in Down syndrome (DS) associated with Alzheimer’s disease (AD)-linked dementia [1]. This significant study has measured age group effect size for a randomized clinical trial (RCT) on DS (N 5 297) by h2 values from cognition test measures, including simple reaction time (SRT), paired associates learning (PAL), and objectmemory [1]. Comparedwith reference 16-30 years age DS group, significantly poor cognition was observed among people grouped in 41-45 years age DS group (N5 24). People grouped in 46-50 years age DS group (N 5 24) showed significantly low performance for most of the cognition measures. The DS individuals with prodromal dementia (N 5 46/170) perform significantly poor in cognition measures (variance in scores5.12%) when compared with DS with preclinical dementia (N5 68/170), and the effect is more apparent (variance in scores5. 20%) between DSwith clinical dementia (N5 56/170) andDSwith preclinical dementia (N5 68/170) [1]. In this study, Startin et al. used PAL first trial memory score as a primary outcome measure, counting a minimum of 43 individuals with DS in 36-40 year age group, for clinical trial testing treatment (with 90% significance) effect on delay in early cognition decline [1]. The adaptive behavior score total (ABST) counts 56 and 36 samples for DS in 46-50 and 51-55 age groups, respectively, required in aRCT for testing the effect of intervention delaying cognition decline [1]. Appreciably, the study design is unique and involved countermeasures, and modeling scores from primary outcome measure score for counting sample size in RCT is a path-leading research. However, it is not explicit which patients with DS included in this study already had AD. Why are there two different outcome measure scores for effect size calculations, the PAL first trial memory score for 36-40 year age group versus ABST score