Developing a Spatial Navigation Screening Tool for Preclinical Alzheimer's Disease

摘要

Given prior research suggesting that drug therapies may be most efficacious when administered during the preclinical phase of Alzheimer's disease (AD) (Garcia-Alloza et al., 2009; Levites et al., 2006), numerous studies have focused on developing tools sensitive to this preclinical phase. Current methods used to detect preclinical AD (i.e., lumbar puncture or PET scan) can be expensive and/or invasive. Consequently, there remains a need for a non-invasive and cost-effective screening measure that could be administered prior to the provision of a lumbar puncture or PET scan.;Considering that the hippocampus is affected early during the course of the disease, cognitive abilities associated with this structure, such as spatial navigation abilities, may be expected to be impaired. This hypothesis is supported by a previous study, which found that a cognitive mapping task was sensitive to preclinical AD (Allison et al., 2016). Unfortunately, this task took approximately 1.5 hours to administer, which would be time-prohibitive in a clinical setting. Furthermore, the psychometric properties (e.g., reliability and validity) of this task were not examined. Therefore, the overall goal of the current study was to take the next steps in developing a spatial navigation-related task that could eventually be used in a clinical setting to screen for preclinical AD.;The current study had three specific aims to determine the most optimal task. The first aim was to assess the reliability (i.e., internal consistency and test-retest stability) of six spatial navigation-related tasks. The second aim was to assess the diagnostic accuracy of six spatial navigation-related tasks using receiver operating characteristic (ROC) analyses. The third aim assessed the validity (i.e., convergent and discriminant validity) of the six spatial navigation-related tasks. The six tasks were as follows: a modified version of the previous cognitive mapping task, two relational binding tasks, a perspective taking task, as well as informant and self-report questionnaires asking about changes in navigation abilities. The results of this work revealed that aspects of a cognitive mapping task and a self-report questionnaire represent reliable and valid screening tools with strong diagnostic sensitivity for preclinical AD.