Spatial orientation tasks show moderate to high accuracy for the diagnosis of mild cognitive impairment: a systematic literature review.

Spatial disorientation has been observed in mild cognitive impairment (MCI) and is associated with a higher risk of progression to Alzheimer's disease (AD). However, there is no gold standard assessment for spatial orientation and paper-and-pencil tests lack ecological validity. Recently, there has been an increasing number of studies demonstrating the role of spatial disorientation as a cognitive marker of pathological decline, shedding new light on its importance for MCI. This systematic review aimed to investigate the accuracy of spatial orientation tasks for the diagnosis of MCI by comparison with cognitively healthy elderly. The search was conducted in the databases Medical Literature Analysis and Retrieval System Online (MEDLINE/PubMed), Web of Science, Scopus, Excerpta Medica Database (Embase), Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs) and Scientific Electronic Library Online (SciELO). Only original studies reporting spatial orientation assessment in MCI patients compared to a healthy control group were included. Studies were excluded if the MCI classification did not follow well described criteria and/or if accuracy results of spatial orientation assessment were not provided. Seven studies met the eligibility criteria, describing a variety of spatial orientation assessments including questionnaires, paper-and-pencil, office-based route learning, and computer-based and virtual reality tasks. Spatial orientation tasks demonstrated moderate to high accuracy in detecting elderly with MCI compared to cognitively healthy elderly, with areas under the curve (AUC) ranging from 0.77 to 0.99. However, important methodological issues were found in the selected studies which should be considered when interpreting results. Although the inclusion of spatial orientation assessments in MCI evaluations seems to have significant value, further studies are needed to clarify their true capacity to distinguish pathological from non-pathological aging.