Analgesic efficacy of theta-burst stimulation for postoperative pain

Ming Cheng; Xianwei Che; Yang Ye; Changlin He; Liang Yu; Yating Lv; Paul B Fitzgerald; Robin F H Cash; Bernadette M Fitzgibbon

doi:10.1016/j.clinph.2023.02.174

Analgesic efficacy of theta-burst stimulation for postoperative pain

Clin Neurophysiol. 2023 May:149:81-87. doi: 10.1016/j.clinph.2023.02.174. Epub 2023 Mar 9.

Authors

Ming Cheng¹, Xianwei Che², Yang Ye³, Changlin He¹, Liang Yu⁴, Yating Lv³, Paul B Fitzgerald⁵, Robin F H Cash⁶, Bernadette M Fitzgibbon⁷

Affiliations

¹ Anaesthesiologic Department, the Affiliated Hospital of Hangzhou Normal University, Hangzhou, China.
² Centre for Cognition and Brain Disorders, the Affiliated Hospital of Hangzhou Normal University, Hangzhou, China; Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, China. Electronic address: xwcheswu@gmail.com.
³ Centre for Cognition and Brain Disorders, the Affiliated Hospital of Hangzhou Normal University, Hangzhou, China; Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, China.
⁴ Department of Pain, the Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
⁵ School of Medicine and Psychology, The Australian National University, Australian Capital Territory, Australia.
⁶ Melbourne Neuropsychiatry Centre, The University of Melbourne, Victoria, Australia; Department of Biomedical Engineering, The University of Melbourne, Victoria, Australia.
⁷ School of Medicine and Psychology, The Australian National University, Australian Capital Territory, Australia; Monarch Research Institute, Monarch Mental Health Group, Australia; Faculty of Medicine, Nursing, and Health Sciences, Monash University, Melbourne, Australia.

PMID: 36933324
DOI: 10.1016/j.clinph.2023.02.174

Abstract

Objective: Repetitive transcranial magnetic stimulation (rTMS) may be a relevant method to assist postoperative pain. However, studies to date have only used conventional 10 Hz rTMS and targeted the DLPFC for postoperative pain. A more recent form of rTMS, termed intermittent Theta Burst Stimulation (iTBS), enables to increase cortical excitability in a short period of time. This preliminary double-blind, randomised, sham controlled study was designed to evaluate the efficacy of iTBS in postoperative care across two distinct stimulation targets.

Methods: A group of 45 patients post laparoscopic surgery were randomised to receive a single session of iTBS over either the dorsolateral prefrontal cortex (DLPFC), primary motor cortex (M1), or Sham stimulation (1:1:1 ratio). Outcome measurements were number of pump attempts, total anaesthetic volume used, and self-rated pain experience, assessed at 1 hour, 6 hours, 24 hours, and 48 hours post stimulation. All randomised patients were analysed (n = 15 in each group).

Results: Compared to Sham stimulation, DLPFC-iTBS reduced pump attempts at 6 (DLPFC = 0.73 ± 0.88, Sham = 2.36 ± 1.65, P = 0.031), 24 (DLPFC = 1.40 ± 1.24, Sham = 5.03 ± 3.87, P = 0.008), and 48 (DLPFC = 1.47 ± 1.41, Sham = 5.87 ± 4.34, P = 0.014) hours post-surgery, whereby M1 stimulation had no effect. No group effect was observed on total anaesthetics, which was mainly provided through the continuous administration of opioids at a set speed for each group. There was also no group or interaction effect on pain ratings. Pump attempts were positively associated with pain ratings in the DLPFC (r = 0.59, P = 0.02) and M1 (r = 0.56, P = 0.03) stimulation.

Conclusions: Our findings show that iTBS to the DLPFC reduces pump attempts for additional anaesthetics following a laparoscopic surgery. However, reduced pump attempts by DLPFC stimulation did not translate into a significantly smaller volume of total anaesthetic, due to the continuous administration of opioids at a set speed for each group.

Significance: Our findings therefore provide preliminary evidence for iTBS targeting the DLPFC to be used to improve postoperative pain management.

Keywords: DLPFC; Motor cortex; Postoperative pain; TBS.

Publication types

Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Analgesics
Double-Blind Method
Humans
Pain, Postoperative* / diagnosis
Pain, Postoperative* / drug therapy
Prefrontal Cortex / physiology
Transcranial Magnetic Stimulation* / methods

Substances

Analgesics