Medial Temporal Lobe Atrophy in Predementia Alzheimer's Disease: A Longitudinal Multi-Site Study Comparing Staging and A/T/N in a Clinical Research Cohort

• Published in: Journal of Alzheimer's disease 2023
• Main Authors: Jarholm, Jonas Alexander, Bjørnerud, Atle, Dalaker, Turi Olene, Akhavi, Mehdi Sadat, Kirsebom, Bjørn-Eivind, Pålhaugen, Lene, Nordengen, Kaja, Grøntvedt, Gøril Rolfseng, Nakling, Arne Exner, Kalheim, Lisa Flem, Almdahl, Ina Selseth, Teceläo, Sandra Raquel Ramos, Fladby, Tormod, Selnes, Per
• Format: Article
• Language: English
• ISSN: 1387-2877; 1875-8908
• DOI: 10.3233/JAD-221274

Background: Atrophy of the medial temporal lobe (MTL) is a biological characteristic of Alzheimer’s disease (AD) and can be measured by segmentation of magnetic resonance images (MRI). Objective: To assess the clinical utility of automated volumetry in a cognitively well-defined and biomarker-classified multi-center longitudinal predementia cohort. Methods: We used Automatic Segmentation of Hippocampal Subfields (ASHS) to determine MTL morphometry from MRI. We harmonized scanner effects using the recently developed longitudinal ComBat. Subjects were classified according to the A/T/N system, and as normal controls (NC), subjective cognitive decline (SCD), or mild cognitive impairment (MCI). Positive or negative values of A, T, and N were determined by cerebrospinal fluid measurements of the Aβ42/40 ratio, phosphorylated and total tau. From 406 included subjects, longitudinal data was available for 206 subjects by stage, and 212 subjects by A/T/N. Results: Compared to A–/T–/N– at baseline, the entorhinal cortex, anterior and posterior hippocampus were smaller in A+/T+orN+. Compared to NC A– at baseline, these subregions were also smaller in MCI A+. Longitudinally, SCD A+ and MCI A+, and A+/T–/N– and A+/T+orN+, had significantly greater atrophy compared to controls in both anterior and posterior hippocampus. In the entorhinal and parahippocampal cortices, longitudinal atrophy was observed only in MCI A+ compared to NC A–, and in A+/T–/N– and A+/T+orN+ compared to A–/T–/N–. Conclusion: We found MTL neurodegeneration largely consistent with existing models, suggesting that harmonized MRI volumetry may be used under conditions that are common in clinical multi-center cohorts.