NavegApp, a serious game for assessing spatial cognition: Diagnostic accuracy in preclinical and prodromal Alzheimer's disease.

Alzheimer's Disease (AD) is the leading cause of dementia worldwide, yet early detection remains challenging due to limited access to biomarker-based diagnostic tools, especially in low- and middle-income countries. This study aims to evaluate the diagnostic accuracy of NavegApp, a serious game developed to assess Spatial Cognition (SC), in distinguishing individuals at various stages of AD, including asymptomatic and symptomatic PSEN1-E280A mutation carriers. A cross-sectional sample of 226 participants underwent neurological and neuropsychological evaluations alongside NavegApp targeting allocentric navigation, mental rotation, and visuospatial memory. Results showed excellent diagnostic accuracy for distinguishing symptomatic PSEN1-E280A carriers from asymptomatic carriers and healthy controls, particularly in allocentric navigation metrics (AUC-ROC = 0.94-0.97). However, in asymptomatic participants, diagnostic performance was modest (AUC ≈ 0.57-0.60), indicating limited discriminative capacity at the preclinical stage. Cross-sectional comparisons detected prodromal-stage deficits in visuospatial and mental rotation tasks, whereas diagnostic accuracy for distinguishing sporadic MCI from health controls was moderate to low. These findings demonstrate the feasibility of NavegApp as a digital tool for cognitive assessment, with potential applicability in cognitive screening for underserved communities. Further research must validate its use across diverse settings and establish its integration into clinical practice for early AD detection.