Altered thalamic subregion functional networks in patients with treatment-resistant schizophrenia

Woo-Sung Kim; Jie Shen; Uyanga Tsogt; Soyolsaikhan Odkhuu; Young-Chul Chung

doi:10.5498/wjp.v12.i5.693

Altered thalamic subregion functional networks in patients with treatment-resistant schizophrenia

World J Psychiatry. 2022 May 19;12(5):693-707. doi: 10.5498/wjp.v12.i5.693.

Authors

Woo-Sung Kim¹, Jie Shen¹, Uyanga Tsogt¹, Soyolsaikhan Odkhuu¹, Young-Chul Chung²

Affiliations

¹ Department of Psychiatry, Jeonbuk National University, Jeon-ju 54907, South Korea.
² Department of Psychiatry, Jeonbuk National University, Jeon-ju 54907, South Korea. chungyc@jbnu.ac.kr.

Abstract

Background: The thalamus plays a key role in filtering information and has extensive interconnectivity with other brain regions. A large body of evidence points to impaired functional connectivity (FC) of the thalamocortical pathway in schizophrenia. However, the functional network of the thalamic subregions has not been investigated in patients with treatment-resistant schizophrenia (TRS).

Aim: To identify the neural mechanisms underlying TRS, we investigated FC of thalamic sub-regions with cortical networks and voxels, and the associations of this FC with clinical symptoms. We hypothesized that the FC of thalamic sub-regions with cortical networks and voxels would differ between TRS patients and HCs.

Methods: In total, 50 patients with TRS and 61 healthy controls (HCs) matched for age, sex, and education underwent resting-state functional magnetic resonance imaging (rs-fMRI) and clinical evaluation. Based on the rs-fMRI data, we conducted a FC analysis between thalamic subregions and cortical functional networks and voxels, and within thalamic subregions and cortical functional networks, in the patients with TRS. A functional parcellation atlas was used to segment the thalamus into nine subregions. Correlations between altered FC and TRS symptoms were explored.

Results: We found differences in FC within thalamic subregions and cortical functional networks between patients with TRS and HCs. In addition, increased FC was observed between thalamic subregions and the sensorimotor cortex, frontal medial cortex, and lingual gyrus. These abnormalities were associated with the pathophysiology of TRS.

Conclusion: Our findings suggest that disrupted FC within thalamic subregions and cortical functional networks, and within the thalamocortical pathway, has potential as a marker for TRS. Our findings also improve our understanding of the relationship between the thalamocortical pathway and TRS symptoms.

Keywords: Functional connectivity; Rs-fMRI; Thalamocortical pathway; Thalamus; Treatment-resistant schizophrenia.