ISSN 1225-8709 (Print)
ISSN 2005-7571 (Online)
Volume 24, Number 4 (4/2017)
Original Article <page. 225-34 >

Alterations of Cortical Folding Patterns in Patients with Bipolar I Disorder : Analysis of Local Gyrification Index

Junyong Lee, MD1;Kyu-Man Han, MD2;Eunsoo Won, MD1;Min-Soo Lee, MD1; and Byung-Joo Ham, MD1;

1;Department of Psychiatry, Korea University Anam Hospital, Korea University College of Medicine, Seoul, 2;Department of Psychiatry, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea

Objectives : Local gyrification reflects the early neural development of cortical connectivity, and is regarded as a potential neural endophenotype in psychiatric disorders. Several studies have suggested altered local gyrification in patients with bipolar I disorder (BD-I). The purpose of the present study was to investigate the alterations in the cortical gyrification of whole brain cortices in patients with BD-I.

Methods : Twenty-two patients with BD-I and age and sex-matched 22 healthy controls (HC) were included in this study. All participants underwent T1-weighted structural magnetic resonance imaging (MRI). The local gyrification index (LGI) of 66 cortical regions were analyzed using the FreeSurfer (Athinoula A. Martinos Center for Biomedical Imaging). One-way analysis of covariance (ANCOVA) was used to analyze the difference of LGI values between two groups adjusting for age and sex as covariates.

Results : The patients with BD-I showed significant hypogyria in the left pars opercularis (uncorrected-p = 0.049), the left rostral anterior cingulate gyrus (uncorrected-p = 0.012), the left caudal anterior cingulate gyrus (uncorrected-p = 0.033). However, these findings were not significant after applying the multiple comparison correction. Severity or duration of illness were not significantly correlated with LGI in the patients with BD-I.

Conclusions : Our results of lower LGI in the anterior cingulate cortex and the ventrolateral prefrontal cortex in the BD-I group implicate that altered cortical gyrification in neural circuits involved in emotion-processing may contribute to pathophysiology of BD-I.

Key words : Local gyrification index;Bipolar disorder;Ventrolateral prefrontal cortex;Anterior cingulate cortex;Emotion-processing neural circuit.


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