Alteration in amygdala subfield volumes and their association with cognition in mild cognitive impairment

• Published in: Journal of neurology Vol. 271; no. 8; pp. 5460 - 5467
• Main Authors: Singh, Sadhana, Malo, Palash Kumar, Stezin, Albert, Mensegere, Abhishek L., Issac, Thomas Gregor
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-08-2024; Springer Nature B.V
• Subjects: Aged; Amygdala; Amygdala - diagnostic imaging; Amygdala - pathology; Cognition; Cognition - physiology; Cognitive ability; Cognitive Dysfunction - diagnostic imaging; Cognitive Dysfunction - etiology; Cognitive Dysfunction - pathology; Cognitive Dysfunction - physiopathology; Female; Humans; Magnetic Resonance Imaging; Male; Medicine; Medicine & Public Health; Memory; Middle Aged; Neurology; Neuropsychological Tests; Neuroradiology; Neurosciences; Original Communication; Statistical analysis; Amygdala subfields; Magnetic resonance imaging; Mild cognitive impairment; Cognitive functions
• ISSN: 0340-5354; 1432-1459; 1432-1459
• DOI: 10.1007/s00415-024-12500-3

Background
The amygdala has an important role in cognitive and affective functions. The involvement of amygdala and related limbic structures is implicated in many aspects of memory and emotion in mild cognitive impairment (MCI). In the present study, we aimed to compare the volumetric measurements of amygdala and its subfields as well as their association with cognitive functions in stable MCI (sMCI).
Methods
We performed Addenbrooke’s cognitive examination III (ACE-III) test, as well as high-resolution T1-weighted images from 31 participants with sMCI and 31 age-matched healthy controls. The amygdala subfield volumes were extracted using Freesurfer software, and group differences were assessed using general linear model (GLM) with age, gender, education and estimated intracranial volume (ICV) as covariates. Partial correlation was also calculated between cognitive scores and volumes of amygdala subfields in healthy controls and sMCI participants controlling for estimated ICV.
Results
sMCI participants exhibited significantly reduced volumes in most of the right amygdala subfields, including basal nucleus, accessory basal nucleus, central nucleus, medial nucleus, corticoamygdaloid transition area, and whole amygdala, as well as significantly reduced right amygdala/hippocampus ratio compared to healthy controls. In addition, our results revealed statistically significant positive correlations between ACE memory scores and the volumes of right central nucleus, right medial nucleus, right cortical nucleus, and the right whole amygdala, in sMCI.
Conclusions
Our findings revealed volumetric reductions in most of the right amygdala subfields along with its association with the memory functions in sMCI. These findings provide valuable insights into the underlying anatomical factors contributing to neurocognitive symptoms in MCI.