ERICA scale magnetic resonance imaging assessment in Alzheimer’s disease and primary age-related tauopathy.

Background Even though entorhinal cortex atrophy is an early finding in Alzheimer’s disease (AD), its characterization in primary age-related tauopathy (PART) and the relationship with AD neuropathologies is understudied. Purpose To assess differences in the entorhinal cortex using the MRI visual rating scale for regional atrophy (ERICA), between PART and AD, while assessing its relationship with clinical impairment. Materials and Methods Retrospective study based on the National Alzheimer’s Coordinating Center database, with participants’ last clinical visit and MRI scans ≤ 4 years from death. Two raters assessed the ERICA score and the CDR Sum of Boxes (CDR-SB) was considered for clinical evaluation. Groups were created according to the Consortium to Establish a Registry for Alzheimer’s disease (CERAD) score: 0 (PART), 1 (mild AD), 2 (moderate AD), 3 (severe AD). Cross-sectional differences were assessed, followed by evaluation of differences between the ERICA score. Linear regression was used to assess the relationship between ERICA score and CDR-SB. Results 305 participants (mean age, 77 years ± 12 [SD]; 185 male) were studied: 70 PART, 37 mild AD, 83 moderate AD, and 114 severe AD. After correcting for age and sex, significant differences were found in the ERICA score between CERAD 0 and 3 ( p  < 0.001), 1 and 3 ( p  = 0.002), and PART and the AD continuum (i.e. CERAD 1–3) ( p  < 0.001), as were also significant correlations found between the ERICA score and the CDR-SB in PART ( p  < 0.001, R  = 0.41) and in the AD continuum ( p  < 0.001, R  = 0.48). Conclusion These findings support the use of the ERICA score across the AD continuum.