Short Digital Spatial Memory Test Detects Impairment in Alzheimer's Disease and Mild Cognitive Impairment

Background: Impairment in navigation abilities and object location memory are often seen in early-stage Alzheimer's Disease (AD), yet these constructs are not included in standard neuropsychological assessment. We investigated the differential ability of a short digital spatial memory test in mild AD dementia and mild cognitive impairment (MCI). Methods: 21 patients with AD dementia (66.9 +/- 6.9; 47% female), 22 patients with MCI (69.6 +/- 8.3; 46% female) and 21 patients with subjective cognitive decline (SCD) (62.2 +/- 8.9; 48% female) from the Amsterdam Dementia Cohort performed the Object Location Memory Test (OLMT), consisting of a visual perception and memory trial, and the Virtual Tubingen (VT) test, consisting of a scene recognition, route continuation, route ordering and distance comparison task. The correlations with other cognitive domains were examined. Results: Patients with mild AD dementia (Z: -2.51 +/- 1.15) and MCI (Z: -1.81 +/- 0.92) performed worse than participants with SCD (Z: 0.0 +/- 1.0) on the OLMT. Scene recognition and route continuation were equally impaired in patients with AD dementia (Z: -1.14 +/- 0.73; Z: -1.44 +/- 1.13) and MCI (Z: -1.37 +/- 1.25; Z: -1.21 +/- 1.07). Route ordering was only impaired in patients with MCI (Z: -0.82 +/- 0.78). Weak to moderate correlations were found between route continuation and memory (r(64) = 0.40, p < 0.01), and between route ordering and attention (r(64) = 0.33, p < 0.01), but not for the OLMT. Conclusion: A short digital spatial memory test battery was able to detect object location memory and navigation impairment in patients with mild AD dementia and MCI, highlighting the value of incorporating such a test battery in standard neuropsychological assessment.

Automated summary

In this study, a short digital spatial memory test was able to detect object location memory and navigation impairment in patients with mild AD dementia and MCI, highlighting the value of incorporating such a test battery in standard neuropsychological assessment. The results indicated that scene recognition and route continuation were equally impaired in patients with AD dementia and MCI, while route ordering was only impaired in patients with MCI. Weak to moderate correlations were found between route continuation and memory, and between route ordering and attention, but not for the OLMT.