AUTHOR=Jaramillo-Jimenez Alberto , Giil Lasse M. , Tovar-Rios Diego A. , Borda Miguel Germán , Ferreira Daniel , Brønnick Kolbjørn , Oppedal Ketil , Aarsland Dag 

TITLE=Association Between Amygdala Volume and Trajectories of Neuropsychiatric Symptoms in Alzheimer's Disease and Dementia With Lewy Bodies

JOURNAL=Frontiers in Neurology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.679984

DOI=10.3389/fneur.2021.679984

ISSN=1664-2295

ABSTRACT=<p><bold>Introduction:</bold> The amygdala is implicated in psychiatric illness. Even as the amygdala undergoes significant atrophy in mild dementia, amygdala volume is underexplored as a risk factor for neuropsychiatric symptoms (NPS).</p><p><bold>Objective:</bold> To analyze the association between baseline amygdala volume and the longitudinal trajectories of NPS and cognitive decline in Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) over 5 years.</p><p><bold>Methods:</bold> Eighty-nine patients with mild dementia were included (AD = 55; DLB = 34). Amygdala volume was segmented from structural magnetic resonance images (sMRI) using a semi-automatic method (Freesurfer 6.0) and normalized by intracranial volumes. The intracranial volume-normalized amygdala was used as a predictor of the Neuropsychiatric Inventory (NPI) total score, ordinal NPI item scores (0 = absence of symptoms, 1–3 = mild symptoms, ≥4 = clinically relevant symptoms), and Mini-Mental State Examination (MMSE) as measured annually over 5 years using gamma, ordinal, and linear mixed-effects models, respectively. The models were adjusted for demographic variables, diagnosis, center of sMRI acquisition, and cognitive performance. Multiple testing-corrected <italic>p</italic>-values (<italic>q</italic>-values) are reported.</p><p><bold>Results:</bold> Larger intracranial volume-normalized amygdala was associated with less agitation/aggression (odds ratio (OR) = 0.62 [0.43, 0.90], <italic>p</italic> = 0.011, <italic>q</italic> = 0.038) and less MMSE decline per year (fixed effect = 0.70, [0.29, 1.03], <italic>p</italic> = 0.001, <italic>q</italic> = 0.010) but more depression (OR = 1.49 [1.09, 2.04], <italic>p</italic> = 0.013, <italic>q</italic> = 0.040).</p><p><bold>Conclusions:</bold> Greater amygdala volume in mild dementia is associated with lower odds of developing agitation/aggression, but higher odds of developing depression symptoms during the 5-year study period.</p>