Dongsheng Lv1, Wuhong Lin2, Zhimin Xue3, Weidan Pu4, Qing Yang5, Xiaojun Huang3, Li Zhou3, Lihua Yang6, Zhening Liu7. 1. Institute of Mental Health, Second Xiangya Hospital of Central South University, Changsha, China; Institute of Mental Health, Inner Mongolia Autonomous Region, Hohhot, China. 2. School of Mathematics and Computational Science, Sun Yat-sen University, Guangzhou, China. 3. Institute of Mental Health, Second Xiangya Hospital of Central South University, Changsha, China. 4. Medical Psychological Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan, China. 5. Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA. 6. School of Mathematics and Computational Science, Sun Yat-sen University, Guangzhou, China; Key Laboratory of Computational Science, Sun Yat-sen University, Guangzhou, China. Electronic address: mcsylh@mail.sysu.edu.cn. 7. Institute of Mental Health, Second Xiangya Hospital of Central South University, Changsha, China; State Key Laboratories of Medical Genetics, Central South University, Changsha, China. Electronic address: zningl@163.com.
Abstract
BACKGROUND: Retardation of thought is a crucial clinical feature in patients with bipolar depression, characterized by dysfunctional semantic processing and language communication. However, the underlying neuropathological mechanisms remain largely unknown. The objective of this study was to evaluate the disruption in resting-state functional connectivity in 90 different brain regions during the depressive episodes of bipolar disorder and during disease remission. METHODS: Applying the whole brain and language regions of interest methods to the resting-state functional magnetic resonance imaging data, we explored the discrepancies in 90 brain regions' functional connectivity in 42 patients with bipolar disorder - 23 experiencing a depressive episode and 19 in remission - and 28 healthy controls matched for gender, age, and education. RESULTS: Bipolar depressive patients had significantly reduced connectivity strength in the language regions relative to healthy controls. Specifically, the affected regions included the left triangular part of the inferior frontal gyrus, left opercular part of the inferior frontal gyrus, left middle temporal gyrus, and left angular gyrus. However, no significant differences in these regions were observed between bipolar patients in remission and healthy controls. Furthermore, the decreased connectivity strength between the left middle temporal gyrus and right lingual gyrus showed significant positive correlation with the scores on the Hamilton Depression Rating Scale. LIMITATIONS: Bipolar depressive patients received treatment of benzodiazepines, which may confound the findings. CONCLUSIONS: Our results illustrated that connectivity disturbances in the language regions may change depending on the disease phase of bipolar disorder.
BACKGROUND:Retardation of thought is a crucial clinical feature in patients with bipolar depression, characterized by dysfunctional semantic processing and language communication. However, the underlying neuropathological mechanisms remain largely unknown. The objective of this study was to evaluate the disruption in resting-state functional connectivity in 90 different brain regions during the depressive episodes of bipolar disorder and during disease remission. METHODS: Applying the whole brain and language regions of interest methods to the resting-state functional magnetic resonance imaging data, we explored the discrepancies in 90 brain regions' functional connectivity in 42 patients with bipolar disorder - 23 experiencing a depressive episode and 19 in remission - and 28 healthy controls matched for gender, age, and education. RESULTS:Bipolar depressivepatients had significantly reduced connectivity strength in the language regions relative to healthy controls. Specifically, the affected regions included the left triangular part of the inferior frontal gyrus, left opercular part of the inferior frontal gyrus, left middle temporal gyrus, and left angular gyrus. However, no significant differences in these regions were observed between bipolarpatients in remission and healthy controls. Furthermore, the decreased connectivity strength between the left middle temporal gyrus and right lingual gyrus showed significant positive correlation with the scores on the Hamilton Depression Rating Scale. LIMITATIONS: Bipolar depressivepatients received treatment of benzodiazepines, which may confound the findings. CONCLUSIONS: Our results illustrated that connectivity disturbances in the language regions may change depending on the disease phase of bipolar disorder.