A non-invasive hidden-goal test for spatial orientation deficit detection in subjects with suspected mild cognitive impairment

Background: There is a need for highly sensitive and specific tests and biomarkers that would allow preclinical diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD), which would also enable timely intervention. New method: We have developed a new system (ALZENTIA) to help detect early MCI, mainly caused by AD. The system is based on a hidden-goal task (HGT) in which the human subject has to find a target that is not visible; as such, the navigation is based on a previously memorized target position, in relation to the starting position (egocentric variant) and/or other navigational landmarks (allocentric variant of the task). We present our preliminary results obtained in 33 patients with MCI and 91 healthy controls (HC). Results and comparison with existing methods: Between-group differences in the average error measured in allocentric, egocentric, and combined allocentric-egocentric subtests were statistically significant in MCI compared to HC. The high negative predictive values suggested high discriminative capacity and diagnostic potential for the HGT test as a tool to detect subjects in healthy population who will progress to MCI. Considering the low sensitivity of the Mini-Mental Status Examination and Montreal Cognitive Assessment tests, we believe that HGT can improve early identification of MCI patients who will progress to AD. Conclusion: The HGT carried out with the ALZENTIA system proved to be a reliable screening test to identify individuals with MCI from an aging cohort.