Spatial navigation measured by the Floor Maze Test in patients with subjective cognitive impairment, mild cognitive impairment, and mild Alzheimer's disease

Background: Impaired spatial navigation is an early sign of Alzheimer's disease (AD), but this can be difficult to assess in clinical practice. We examined how the performance on the Floor Maze Test (FMT), which combines navigation with walking, differed between patients with subjective cognitive impairment (SCI), mild cognitive impairment (MCI), and mild AD. We also explored if there was a significant relationship between the FMT and the cognitive tests or sociodemographic factors. Methods: The study included 128 patients from a memory clinic classified as having SCI (n = 19), MCI (n = 20), and mild AD (n = 89). Spatial navigation was assessed by having the patients walk through the FMT, a two-dimensional maze. Both timed measures and number of errors were recorded. Cognitive function was assessed by the Word List Memory test, the Clock Drawing test, the Trail Making tests (TMT) A and B, and the Mini Mental Status Examination (MMSE). Results: The patients with MCI were slower than those with SCI, while the patients with mild AD more frequently completed the FMT with errors or gave up than the patients with MCI. Performance on the FMT was significantly associated with executive function (measured by TMT-B). Conclusions: The performances on the FMT worsened with increasing severity of cognitive impairment, and the FMT was primarily associated with executive function. The explained variance was relatively low, which may indicate that the standard cognitive test battery does not capture impairments of spatial navigation.