P3‐025: USE OF A MODIFIED HIDDEN PATHWAY MAZE TEST IN PATIENTS WITH ALZHEIMER'S DISEASE DEMENTIA

Abstract

Maze tests have a long history as measures of visuospatial learning and executive function. The importance of impairments in both visuospatial learning and executive dysfunction has been increasingly recognized in early AD. In contrast to presented mazes, hidden pathway mazes use underlying rule sets to create decision points meaning additional data, such as different types of error, are obtained and can be used to more fully characterize performance and cognitive impairment. Computerized versions (e.g. the Groton Maze Learning Test [GMLT]) provide even greater analytical scope than manual tests. However, use of extensive rule sets may prove challenging in AD dementia. Here we present basic psychometric analyses for a simplified GMLT in mild-moderate AD dementia. The modified GMLT uses a 28-step pathway hidden in a 10x10 tile grid. The pathway is found by selecting one tile at a time revealing a green checkmark which remains visible if correct. A more limited set of instructions is given compared to the usual test. Five trials are given, with the number of errors recorded. A single, reverse recall trial is also given after a short delay. Data were collected in a PIb clinical trial in AD patients with MMSE 12–24 (NCT03456349). Analyses were performed for missingness of data, presence of floor and ceiling effects, test retest reliability and learning/practice effects. Data were collected for 59 patients at the baseline assessment (mean age 73.3 [SD 7.58]; 72.9% female). No ceiling effect was present in the population. Whilst there is no theoretical floor (maximum number of errors), several patients made greater numbers of errors (>20 per trial) suggesting a proportion of the trial population found the test challenging. Data will be reported exploring the impact of cognitive impairment on test length, completion and reliability. Hidden pathway maze learning may be a valuable probe of short-term memory and executive function in AD. Whilst the removal of complex rule sets may make the test more feasible in the dementia stages of the disease, increasing severity of impairment may limit utility for some patients.