Repetitive transcranial magnetic stimulation over the posterior parietal cortex improves functional recovery in nonresponsive patients: A crossover, randomized, double-blind, sham-controlled study

Chengwei Xu; Wanchun Wu; Xiaochun Zheng; Qimei Liang; Xiyan Huang; Haili Zhong; Qiuyi Xiao; Yue Lan; Yang Bai; Qiuyou Xie

doi:10.3389/fneur.2023.1059789

Repetitive transcranial magnetic stimulation over the posterior parietal cortex improves functional recovery in nonresponsive patients: A crossover, randomized, double-blind, sham-controlled study

Front Neurol. 2023 Feb 16:14:1059789. doi: 10.3389/fneur.2023.1059789. eCollection 2023.

Authors

Chengwei Xu¹, Wanchun Wu¹, Xiaochun Zheng¹, Qimei Liang¹, Xiyan Huang¹, Haili Zhong¹, Qiuyi Xiao¹, Yue Lan¹, Yang Bai^{2

3}, Qiuyou Xie¹

Affiliations

¹ Department of Rehabilitation Medicine, Joint Research Centre for Disorders of Consciousness, Zhujiang Hospital of Southern Medical University, Guangzhou, China.
² Department of Rehabilitation Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.
³ School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, China.

Abstract

Background: Recent studies have shown that patients with disorders of consciousness (DoC) can benefit from repetitive transcranial magnetic stimulation (rTMS) therapy. The posterior parietal cortex (PPC) is becoming increasingly important in neuroscience research and clinical treatment for DoC as it plays a crucial role in the formation of human consciousness. However, the effect of rTMS on the PPC in improving consciousness recovery remains to be studied.

Method: We conducted a crossover, randomized, double-blind, sham-controlled clinical study to assess the efficacy and safety of 10 Hz rTMS over the left PPC in unresponsive patients. Twenty patients with unresponsive wakefulness syndrome were recruited. The participants were randomly divided into two groups: one group received active rTMS treatment for 10 consecutive days (n = 10) and the other group received sham treatment for the same period (n = 10). After a 10-day washout period, the groups crossed over and received the opposite treatment. The rTMS protocol involved the delivery of 2000 pulses/day at a frequency of 10 Hz, targeting the left PPC (P3 electrode sites) at 90% of the resting motor threshold. The primary outcome measure was the JFK Coma Recovery Scele-Revised (CRS-R), and evaluations were conducted blindly. EEG power spectrum assessments were also conducted simultaneously before and after each stage of the intervention.

Result: rTMS-active treatment resulted in a significant improvement in the CRS-R total score (F = 8.443, p = 0.009) and the relative alpha power (F = 11.166, p = 0.004) compared to sham treatment. Furthermore, 8 out of 20 patients classified as rTMS responders showed improvement and evolved to a minimally conscious state (MCS) as a result of active rTMS. The relative alpha power also significantly improved in responders (F = 26.372, p = 0.002) but not in non-responders (F = 0.704, p = 0.421). No adverse effects related to rTMS were reported in the study.

Conclusions: This study suggests that 10 Hz rTMS over the left PPC can significantly improve functional recovery in unresponsive patients with DoC, with no reported side effects.

Clinical trial registration: www.ClinicalTrials.gov, identifier: NCT05187000.

Keywords: EEG; disorders of consciousness; randomized control trial; repetitive transcranial magnetic stimulation; unresponsive wakefulness syndrome/vegetative state.

Associated data

ClinicalTrials.gov/NCT05187000

Grants and funding

The study was supported by grants from the National Natural Science Foundation of China (no. 82171174, 81974154, and 81801119) and the Key Realm R&D Program of Guangzhou (no. 202007030005). The funding organizations played no further role in study design, data collection, analysis, interpretation, or paper writing.