Higher rightward laterality of the hippocampal tail and its association with early trauma in panic disorder
Joonho Lee 1, Yoonsu Song 1, Eunsoo Won 1, Minji Bang 1, Sang-Hyuk Lee 1, 2*
1Department of Psychiatry, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Republic of Korea, 2Department of Clinical Pharmacology and Therapeutics, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Republic of Korea
Received: September 24, 2019; Revised: January 21, 2020; Accepted: February 17, 2020; Published online: February 17, 2020.
© The Korean College of Neuropsychopharmacology. All rights reserved.

Objective: Early trauma (ET) is widely recognized as a contributing factor to the development of panic disorder (PD) in patients. However, there is a dearth of research on the specific volumes of hippocampal subregions and their laterality with respect to ET and PD.
Methods: A total of 30 subjects with PD and 30 age- and sex-matched healthy controls (HCs) were included in this study. All the subjects were evaluated by 3T-magnetic resonance imaging (MRI). FreeSurfer version 6.0 was used for volumetric analysis of the hippocampal subregions and their laterality. A shortened version of the Early Trauma Inventory Self Report (ETISR) as well as Anxiety Sensitivity Inventory-Revised (ASI-R), and Panic Disorder Severity Scale were utilized for analysis.
Results: Multivariate analysis of variance showed that the volume of the right hippocampal tail and laterality indices (LIs) of the hippocampal body and tail were significantly larger in subjects with PD relative to HCs. The significance of the observations remained unchanged after multivariate analysis of covariance, controlling for age, sex, years of education, medication, depressive symptoms, and intracranial volume as covariates. The LIs of the hippocampal tails that showed a significant correlation to ETISR emotional and physical subscales were also associated with ASI-R for cardiovascular symptoms in PD.
Conclusions: Our study displayed an increased rightward lateralization of the hippocampal tails in subjects with PD compared with HCs. This alteration in the brain, which was associated with early emotional and physical trauma, would negatively affect anxiety sensitivity to cardiovascular symptoms in subjects with PD.
Keywords: panic disorder, hippocampus, hippocampal tail, laterality, early trauma, neuroimaging