The entorhinal cortex atrophy score for diagnostic distinction between phases of the Alzheimer's disease continuum

Background: Alzheimer's disease (AD) is the most common type of dementia, causing functional impairment in millions of individuals and accounting for a large amount of healthcare costs. The entorhinal cortex appears to be one of the first brain structures affected by AD in its early stages. The Entorhinal Cortex Atrophy (ERICA) score is a visual atrophy score used by neuroradiologists in clinical practice for the diagnosis of AD. Objective: To analyze the effectiveness of the ERICA score for distinguishing between patients with subjective cognitive decline (SCD), mild cognitive impairment (MCI), and AD dementia. Methods: A systematic review of the literature was conducted on the Science Direct, PubMed, Virtual Health Library, and Cochrane databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of 1,413 studies identified, 6 were ultimately included in the present review, comprising 844 participants: 2 retrospective cohort studies and 4 cross-sectional studies. The methodological quality of the studies was assessed using the Newcastle-Ottawa scale. The focus was on the diagnostic performance of the ERICA score in the continuum phases of AD. Results: The ERICA score had lower sensitivity than the medial temporal lobe atrophy (MTA) score but higher specificity, reinforcing its importance for diagnostic accuracy, especially in contexts of clinical uncertainty. The ERICA score showed reproducibility between examiners similar to or greater than that of the MTA score. There are a few heterogeneous studies in the current literature on the applicability of the ERICA score in clinical practice. Conclusion: Diagnostic accuracy of the ERICA score is satisfactory in differentiating SCD or MCI from AD dementia.