Background: Structural magnetic resonance imaging (MRI) is routinely performed in patients with mild cognitive impairment (MCI), but diagnostic accuracy to detect early cerebral atrophy is limited.
Objective: To validate the visual entorhinal cortex atrophy (ERICA) rating scale regarding diagnosis, biomarker status, neuropsychological profile, and dementia risk in MCI.
Methods: The ERICA score was retrospectively assessed regarding its discrimination of MCI (n = 80) from subjective cognitive decline and Alzheimer's disease (AD) dementia (n = 60, respectively), its prediction of conversion to dementia (median follow-up 28 months) and amyloid/tau biomarker status, and its association with neuropsychological tests.
Results: The ERICA score achieved 97% positive predictive value (PPV) for the presence of MCI. Discrimination between MCI and AD dementia (area under the curve: 0.71) was comparable to volumetry, and superior to the medial temporal lobe atrophy (MTA) score (p = 0.006). The PPV of the ERICA score for conversion to dementia was 83%, equivalent to tau status. It achieved 90% PPV for conversion when combined with tau, and 100% negative predictive value with verbal recall. While no measure predicted the predominantly positive amyloid status, the ERICA score was at least comparable to volumetry, and superior to the MTA score in predicting tau positivity (92% PPV for phospho-tau). The ERICA score was associated with verbal learning and memory, and, unlike the MTA score, also with AD-specific deficits in cued verbal recall.
Conclusion: The ERICA score is a simple and valuable tool to exploit structural MRI for diagnosis and prognosis in MCI and is non-inferior to volumetry.
Keywords: Alzheimer’s disease; entorhinal cortex; magnetic resonance imaging; mild cognitive impairment.