Functional connectivity changes are correlated with sleep improvement in chronic insomnia patients after rTMS treatment

Lin Zhu; Ge Dang; Wei Wu; Junhong Zhou; Xue Shi; Xiaolin Su; Huixia Ren; Zian Pei; Xiaoyong Lan; Chongyuan Lian; Peng Xie; Yi Guo

doi:10.3389/fnins.2023.1135995

Functional connectivity changes are correlated with sleep improvement in chronic insomnia patients after rTMS treatment

Front Neurosci. 2023 Apr 17:17:1135995. doi: 10.3389/fnins.2023.1135995. eCollection 2023.

Authors

Lin Zhu¹, Ge Dang¹, Wei Wu², Junhong Zhou³, Xue Shi¹, Xiaolin Su¹, Huixia Ren⁴, Zian Pei⁵, Xiaoyong Lan⁵, Chongyuan Lian⁵, Peng Xie⁶, Yi Guo^{1

5}

Affiliations

¹ Department of Neurology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong, China.
² Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States.
³ Hebrew Seniorlife, Hinda and Arthur Marcus Institute for Aging Research, Harvard Medical School, Boston, MA, United States.
⁴ Department of Geriatrics, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong, China.
⁵ Shenzhen Bay Laboratory, Shenzhen, Guangdong, China.
⁶ NHC Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.

Abstract

Background: Repetitive transcranial magnetic stimulation (rTMS) has been increasingly used as a treatment modality for chronic insomnia disorder (CID). However, our understanding of the mechanisms underlying the efficacy of rTMS is limited.

Objective: This study aimed to investigate rTMS-induced alterations in resting-state functional connectivity and to find potential connectivity biomarkers for predicting and tracking clinical outcomes after rTMS.

Methods: Thirty-seven patients with CID received a 10-session low frequency rTMS treatment applied to the right dorsolateral prefrontal cortex. Before and after treatment, the patients underwent resting-state electroencephalography recordings and a sleep quality assessment using the Pittsburgh Sleep Quality Index (PSQI).

Results: After treatment, rTMS significantly increased the connectivity of 34 connectomes in the lower alpha frequency band (8-10 Hz). Additionally, alterations in functional connectivity between the left insula and the left inferior eye junction, as well as between the left insula and medial prefrontal cortex, were associated with a decrease in PSQI score. Further, the correlation between the functional connectivity and PSQI persisted 1 month after the completion of rTMS as evidenced by subsequent electroencephalography (EEG) recordings and the PSQI assessment.

Conclusion: Based on these results, we established a link between alterations in functional connectivity and clinical outcomes of rTMS, which suggested that EEG-derived functional connectivity changes were associated with clinical improvement of rTMS in treating CID. These findings provide preliminary evidence that rTMS may improve insomnia symptoms by modifying functional connectivity, which can be used to inform prospective clinical trials and potentially for treatment optimization.

Keywords: DLPFC; EEG; chronic insomnia disorder; functional connectivity; rTMS.