Exploring the Cortical Hemodynamic Variability of Prefrontal ITBS: a Concurrent TBS/fNIRS Study

NCT ID: NCT06104462

Last Updated: 2024-09-19

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 40 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-10-18
• Study Completion Date: 2025-04-30

Brief Summary

An increasing number of studies have used the intermittent theta-burst stimulation (iTBS) protocol to investigate neural plasticity non-invasively in the prefontal cortex in healthy humans and in patients with psychiatric disorders. However, the variability in the neurophysiological response to iTBS stimulation is high. The cause of this variability is multifactorial and to some degree still unknown. Therefore, the current study explores inter- and intra-individual factors that are potentially moderating iTBS-induced excitability changes. A greater understanding of these determinants would be highly valuable for optimizing the therapeutic application of iTBS.

Detailed Description

The investigators will measure the cortical excitability induced by iTBS with concurrent TBS/fNIRS technique in the same healthy individuals on multiple testing days. Meanwhile, several potential inter- (age, gender, etc.) and intra-individual factors (daily mood, daily physical activity levels, etc.) recently identified in non-invasive transcranial brain stimulation studies will be assessed before applying iTBS to the same individual on each testing day.

Conditions

Healthy

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Cortical hemodynamic variability of iTBS and its courses

A group of healthy adults shall undergo repeated experimental visits with concurrent TBS/fNIRS (3≤repetition≤15). An interval of at least two days (48 hours) between the visits is required to minimize carry-over effects from the iTBS protocols.

Inter- (age, gender, personality inventory, etc.) and intra-individual factors (daily mood, daily sleep quality, physical activity levels, etc.) that are potentially moderating iTBS-induced excitability changes will be explored.

Group Type: EXPERIMENTAL

Intermittent theta burst stimulation (iTBS)

Intervention Type: DEVICE

The iTBS protocol consists of 20 trains of stimulation. Each train comprises ten 3-pulse bursts, delivered at an intra-burst frequency of 50 Hz, with a 5 Hz overall frequency, followed by 8 seconds of rest. A total of 600 pulses (10*3*20) will be administered in this 3-minute iTBS protocol. Concurrent TBS/fNIRS stimulation will be applied over the left DLPFC at an intensity of 90% of the resting motor threshold (RMT), which is considered appropriate to ensure compliance and elicit robust DLPFC activation.

Considering that the fNIRS optode beneath the coil increases the distance between the TMS coil and the skull by 10 mm, we will use the equation AdjMT% = MT + 2.8 * (Dsitex - Dm1). Therefore, 2.8 * 10 = 28% will be added to the normal intensity. The stimulation site over the DLPFC will be determined by the MNI coordinate (x-38, y+44, z+26) reported in previous studies.

Interventions

Intermittent theta burst stimulation (iTBS)

The iTBS protocol consists of 20 trains of stimulation. Each train comprises ten 3-pulse bursts, delivered at an intra-burst frequency of 50 Hz, with a 5 Hz overall frequency, followed by 8 seconds of rest. A total of 600 pulses (10*3*20) will be administered in this 3-minute iTBS protocol. Concurrent TBS/fNIRS stimulation will be applied over the left DLPFC at an intensity of 90% of the resting motor threshold (RMT), which is considered appropriate to ensure compliance and elicit robust DLPFC activation.

Considering that the fNIRS optode beneath the coil increases the distance between the TMS coil and the skull by 10 mm, we will use the equation AdjMT% = MT + 2.8 * (Dsitex - Dm1). Therefore, 2.8 * 10 = 28% will be added to the normal intensity. The stimulation site over the DLPFC will be determined by the MNI coordinate (x-38, y+44, z+26) reported in previous studies.

Intervention Type: DEVICE

Other Intervention Names

Repetitive transcranial magnetic stimulation (rTMS)

Eligibility Criteria

Inclusion Criteria

• healthiness based on history and psychiatric assessment
• being able to hear and understand the verbal instructions
• completed at least 6 years of formal education

Exclusion Criteria

• a current or past diagnosis of psychiatric, neurological disorders, or severe internal illness
• any conditions that will contraindicate to iTBS or fNIRS
• psychiatric disorders in their first-degree relatives
• pregnancy

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

The Hong Kong Polytechnic University

OTHER

Sponsor Role: lead

Responsible Party

Dr Georg Kranz

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Georg Kranz, PhD

Role: PRINCIPAL_INVESTIGATOR

The Hong Kong Polytechnic University

Locations

The Hong Kong Polytechnic University

Hong Kong, , Hong Kong

Site Status: RECRUITING

Countries

Hong Kong

Central Contacts

Georg Kranz, PhD

Role: CONTACT

georg.kranz@polyu.edu.hk

2766 ext. 4838

Weili Xia, MSc

Role: CONTACT

weili-adam.xia@connect.polyu.hk

92859726

Facility Contacts

Georg Kranz, PhD

Role: primary

georg.kranz@polyu.edu.hk

2766 ext. 4838

Other Identifiers

HSEARS20220812002-02

Identifier Type: -

Identifier Source: org_study_id