Oct, 1, 2023

Vol.30 No.2, pp. 84-88


Review

  • Korean Journal of Biological Psychiatry
  • Volume 12(2); 2005
  • Article

Review

Korean Journal of Biological Psychiatry 2005;12(2):123-35. Published online: Feb, 1, 2005

The Differences of EEG Coherence between Schizophrenia and Bipolar Disorder

  • Yong-Kyu Kim, MD1;Jae-Kong Shin, MD2;Chong-Won Park, MD1;Kyung Sue Hong, MD, PhD3;Seung-Yeoun Lee, PhD4;Hong-Seok Oh, MD1;Yong-Suk Lee, MD1;Yong-Tae Kwak, MD, PhD5;Jae Seung Chang, MD6; and Yu-Sang Lee, MD1;
    1;Yong-In Mental Hospital, Yongin, 2;Kyunggi Provincial Hospital For The Elderly, Yongin, 3;Department of Psychiatry, Sungkyunkwan University School of Medicine, Samsung Seoul Hospital, Seoul, 4;Department of Applied Mathematics, Sejong University, Seoul, 5;Hyoja Geriatric Hospital, Yongin, 6;Department of Neuropsychiatry and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
Abstract

ObjectivesEEG coherence could imply the connectivity between two different areas of the brain, which is known to be important in the pathophysiology of bipolar I disorder(BPD I) and schizophrenia. The authors investigated EEG coherence in patients with BPD I and schizophrenia to examine the connectivity of the neural circuit.

Methods
EEGs were recorded in 15 schizophrenia and 14 bipolar disorder patients, and 14 age-matched normal control subjects from 16 electrodes with linked-ear reference. Spectral parameters and coherence were calculated for the alpha bandwidth(8-13Hz) by a multi-channel autoregressive model using 20 artifact-free 2-seconds epochs and the differences were compared among three groups by two different statistical methods;F-test and Kruskal-Wallis test. Furthermore, when there were significant differences among three groups, Scheffe's multiple comparison tests were provided and Jonckheere-Terpstra tests for the ordered alternative were given.

Results
In the intra-hemispheric comparison, left frontal coherence was increased in order of control, BPD I and schizophrenia. In the inter-hemispheric comparison, 1) inter-prefrontal coherence in BPD I was significantly higher than in normal controls, and 2) inter-prefrontal coherence in schizophrenia was significantly lower than in controls.

Conclusion
These results suggest that 1) both schizophrenia and BPD I are diseases having the abnormality of neural circuit connectivity in both frontal and prefrontal lobes, and 2) the abnormality is more severe in schizophrenia than in BPD I. Furthermore, the data support that a common pathogenetic process may reside in both schizophrenia and BPD I.

Keywords EEG;Coherence;Schizophrenia;Bipolar disorder.