The complementary role of egocentric and allocentric spatial navigation tasks for the diagnosis of Alzheimer's...

Spatial navigation impairments represent one of the earliest cognitive changes in patients suffering from Alzheimer's disease (AD), with their underlying neural circuits overlapping regions affected by AD neuropathology. Despite substantial evidence suggesting different navigational impairments across the AD continuum, the diagnostic utility of specific spatial strategies as cognitive markers remains poorly investigated. This diagnostic meta-analysis aimed to systematically evaluate the sensitivity and specificity of egocentric, allocentric, and frame-switching navigation deficits in distinguishing individuals with AD from cognitively healthy controls. First, we carried out a systematic search to identify studies assessing spatial navigation across the AD continuum, compared to cognitively healthy controls or non-AD dementias. Nineteen studies, comprising 1884 participants, were included. Then, meta-analyses quantified diagnostic accuracy (sensitivity, specificity, diagnostic odds ratios) of spatial navigation tasks. Results revealed complementary diagnostic profiles across spatial strategies, supporting their complementary use for AD detection. Allocentric tasks demonstrated balanced diagnostic performance, correctly identifying 84 % of AD cases while accurately classifying 83 % of cognitively healthy individuals. Frame-switching tasks provided high AD detection (84 % sensitivity) but reduced specificity (66 %), making them valuable for excluding AD but less reliable for confirming it. Combined egocentric-allocentric tasks achieved the highest specificity (94 %), while egocentric tasks showed good specificity (81 %) but limited sensitivity (72 %), suggesting that egocentric abilities remain preserved until advanced disease stages. Taken together, these findings suggest that a strategic approach to spatial navigation assessment is crucial for AD detection.