ISSN 1225-8709 (Print)
ISSN 2005-7571 (Online)
Volume 26, Number 1 (1/2019)
Original Article <page. 22-31 >

Morphologic Alterations in Amygdala Subregions of Adult Patients with Bipolar Disorder

Hyun-Jae Lee, MD1;Kyu-Man Han, MD1;Aram Kim, BS2;Wooyoung Kang, BS2;Youbin Kang, BS2;June Kang, PhD3;Eunsoo Won, MD4;Woo-Suk Tae, PhD5; and Byung-Joo Ham, MD1,2,5;

1;Department of Psychiatry, Korea University Anam Hospital, Korea University College of Medicine, Seoul, 2;Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 3;Department of Brain and Cognitive Engineering, Korea University, Seoul, 4;Department of Psychiatry, CHA Bundang Medical Center, CHA University, Seongnam, 5;Brain Convergence Research Center, Korea University Anam Hospital, Seoul, Korea

Objectives : Previous studies have revealed inconsistent results on amygdala volume in adult bipolar disorder (BD) patients compared to healthy controls (HC). Since the amygdala encompasses multiple subregions, the subtle volume changes in each amygdala nucleus might have not been fully reflected in the measure of the total amygdala volume, causing discrepant results. Thus, we aimed to investigate volume changes in each amygdala subregion and their association with subtypes of BD, lithium use and clinical status of BD.

Methods : Fifty-five BD patients and 55 HC underwent T1-weighted structural magnetic resonance imaging. We analyzed volumes of the whole amygdala and each amygdala subregion, including the anterior amygdaloid area, cortico-amygdaloid transition area, basal, lateral, accessory basal, central, cortical, medial and paralaminar nuclei using the atlas in the FreeSurfer. The volume difference was analyzed using a one-way analysis of covariance with individual volumes as dependent variables, and age, sex, and total intracranial volume as covariates.

Results : The volumes of whole right amygdala and subregions including basal nucleus, accessory basal nucleus, anterior amygdaloid area, and cortico-amygdaloid transition area in the right amygdala of BD patients were significantly smaller for the HC group. No significant volume difference between bipolar I disorder and bipolar II disorder was found after the Bonferroni correction. The trend of larger volume in medial nucleus with lithium treatment was not significant after the Bonferroni correction. No significant correlation between illness duration and amygdala volume, and insignificant negative correlation were found between right central nucleus volume and depression severity.

Conclusions : Significant volume decrements of the whole amygdala, basal nucleus, accessory basal nucleus, anterior amygdaloid area, and cortico-amygdaloid transition area were found in the right hemisphere in adult BD patients, compared to HC group. We postulate that such volume changes are associated with altered functional activity and connectivity of amygdala nuclei in BD.


Key words : Bipolar disorder;Magnetic resonance imaging;Amygdala;Basolateral nuclear complex;Image processing, computer-assisted;Lithium.

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