A Protocol for Robot-assisted Neuronavigated Transcranial Magnetic Stimulation Targeting Individualized Brain Networks in Bipolar Disorder

Summary

This study proposes a method to ameliorate cognitive impairment during remission of bipolar disorder by robotic neuronavigated transcranial magnetic stimulation.

Abstract

Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique capable of modulating cortical plasticity and has been increasingly applied in the treatment of psychiatric disorders. However, conventional TMS often targets a single brain region and may suffer from imprecise coil positioning, potentially limiting its therapeutic efficacy. Robotic neuronavigated transcranial magnetic stimulation (RNNMS) is a precise TMS intervention modality, which is based on the structural magnetic resonance imaging (MRI) data of the human brain to formulate individualized stimulation targets and improve the accuracy of stimulation with the help of robotic arm guidance. Through brain imaging analysis, we selected stimulation target based on brain regions with abnormal functional connectivity in bipolar disorder (BD) patients, and customized intervention targets based on the structural magnetic resonance of each patient, and used robotic neuronavigated TMS to precisely intervene on the corresponding targets of the patients to reduce the possibility of ineffective stimulation due to coil shift during the whole intervention process, thus improving the cognitive impairments of the patients with BD. This protocol describes our approach to targeting patients based on their brain network images and demonstrates in detail the procedure for performing robotic neuronavigated TMS interventions on patients.

Introduction

Repetitive transcranial magnetic stimulation (rTMS) is currently the most widely used non-invasive neuromodulation technique to stimulate cortical areas of the brain, mainly through brief magnetic field pulses. Currently, rTMS has been approved by the Food and Drug Administration (FDA) for the treatment of major depressive disorder (MDD). rTMS has a response and remission rate of < 50% and < 20%, respectively, in MDD patients unresponsive to medication¹. Several studies on depression TMS in bipolar disorder (BD) have achieved positive efficacy, but the number of studies addressing cognitive impairment in BD is small and needs to be furt....

Protocol

This study was reviewed and approved by the Ethics Committee of the First Affiliated Hospital, Zhejiang University School of Medicine, in accordance with the Declaration of Helsinki, and this study has been registered with the Chinese Clinical Trial Registry (http://www.chictr.org.cn/enIndex.aspx), with the registration number ChiCTR2000030675. Here, the patients were recruited from the psychiatric outpatient clinic of the First Affiliated Hospital, Zhejiang University School of Medicine. All participants were thoroughly informed about the purpose, procedures, potential risks, and benefits of the study, and written informed consent was obtained prior to participation.....

Results

In this study, the THINC-it tool was used to assess cognitive changes in patients before and after treatment. Table 1 shows the baseline situation of the two groups of patients, in which there was no difference between the two groups at baseline in any of the six indicators related to cognitive function. Whereas a significant interaction was found in the indicator Symbol Check (Accuracy), no significant interaction was found for several other indicators (Table 2). Although there was no s.......

Discussion

This protocol proposes to identify targets based on V1-ACC functional connectivity and to improve cognitive impairment in bipolar disorder using rTMS at 10 Hz under robotic neural navigation. Assessment of patients' cognitive function before and after the intervention by the THINC-it tool revealed that the trend of cognitive improvement was more pronounced in patients who underwent active TMS stimulation.

The key steps in the protocol mainly include target customization and rTMS interventi.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Black Dolphin Navigation TMS Robot	Xi’an Solide Brain Modulation	SmarPhin S-50	Integrated system with active/sham coils, TMS robot, optical tracking, tracking headband, neuronavigation, and earplugs; enables MRI-guided targeting and real-time coil–target distance monitoring.
GE Signa Premier 3.0T MRI Scanner	GE Healthcare	https://www.gehealthcare.com/products/magnetic-resonance-imaging/3t-mri-scanners
THINC-it Cognitive Assessment Tool	Lundbeck	1.26 1	Includes four cognitive tasks and one self-report scale, assessing attention/concentration/alertness, working memory, and executive function.