The Immediate Effects of Intermittent Theta Burst Stimulation on Intracortical Excitability of the Primary Motor Cortex in Patients With Chronic Stroke

Stroke Clinical Trial

Official title:

The Immediate Effects of Intermittent Theta Burst Stimulation on Intracortical Excitability of the Primary Motor Cortex in Patients With Chronic Stroke: A Concurrent TMS-EEG Sham-controlled Crossover Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05509686
• Other study ID #: HSEARS20200621001
• Status: Completed
• Phase: N/A
• Start date: July 15, 2020
• Est. completion date: May 15, 2022

Study information

• Verified date: August 2022
• Source: The Hong Kong Polytechnic University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This study is to investigate the immediate effects of intermittent theta burst stimulation (iTBS) on intracortical excitatory and inhibitory circuits, neural connectivity, and network properties in patients with chronic stroke, using transcranial magnetic stimulation and electroencephalogram (TMS-EEG) and TMS-electromyography (EMG) and approaches.

Description:

The neurophysiological effect of intermittent theta burst stimulation (iTBS) has been examined with TMS-electromyography (EMG)-based outcomes in healthy people; however, its effects in intracortical excitability and inhibition are largely unknown in patients with stroke. Concurrent transcranial magnetic stimulation and electroencephalogram (TMS-EEG) recording can be used to investigate both intracortical excitatory and inhibitory circuits of the primary motor cortex (M1) and the property of brain networks.

This study is to investigate the immediate effects of iTBS on intracortical excitatory and inhibitory circuits, neural connectivity, and network properties in patients with chronic stroke, using TMS-EEG and TMS-EMG approaches.

In this randomized, sham-controlled, crossover study, 21 patients with chronic stroke receive two separate stimulation conditions: a single-session iTBS or sham stimulation applied to the ipsilesional M1, in two separate visits, with a washout period of five to seven days between the two visits after crossover. A battery of TMS-EMG and TMS-EEG measurements are taken before and immediately after stimulation during the visit.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 21
• Est. completion date: May 15, 2022
• Est. primary completion date: July 30, 2021
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

1. suffered from first-ever, ischemic or hemorrhagic, unilateral stroke, verified by neuroimaging examinations such as CT or MRI.

2. detectable motor evoked potentials from the affected first dorsal interosseous muscle;

3. provided written informed consent.

Exclusion Criteria:

1. had any contraindication to transcranial magnetic stimulation;

2. had a known neurological disease excluding stroke, or psychiatric disease;

3. were using a psychostimulant, sedative, antidepressant, or antiepileptic medication.

Related Conditions & MeSH terms

• Stroke

Intervention

Device:
• Intermittent theta burst stimulation (iTBS)
A single-session standard 600-pulse intermittent theta burst stimulation (iTBS) is applied to the ipsilesional primary motor cortex.
• Sham intermittent theta burst stimulation (iTBS)
The sham stimulation is the same as that of iTBS, but the coil is placed five centimeters away from the scalp. Electrical field simulation shows that the setups for sham stimulation would not induce any valid cortical activation.

Locations

Country	Name	City	State
Hong Kong	Kenneth FONG	Hong Kong

Sponsors (1)

Lead Sponsor	Collaborator
The Hong Kong Polytechnic University

Country where clinical trial is conducted

Hong Kong, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Transcranial magnetic stimulation-evoked potential	Single pulses evoked an initial response in electroencephalogram, followed by a series of time- and phase-locked positive and negative deflections which could spread to the connected brain areas. The evoked potential is called transcranial magnetic stimulation-evoked potential.	Baseline (before iTBS stimulation)
Primary	Transcranial magnetic stimulation-evoked potential	Single pulses evoked an initial response in electroencephalogram, followed by a series of time- and phase-locked positive and negative deflections which could spread to the connected brain areas. The evoked potential is called transcranial magnetic stimulation-evoked potential.	10 minutes after a single-session iTBS stimulation
Primary	Motor evoked potential (MEP)	Single TMS pulses with suprathreshold intensity (120% of resting motor threshold of the stimulated cortex) applied to the primary motor cortex (M1) can produce recordable MEPs in contralateral muscles; additionally, the peak-to-peak amplitude of MEPs can be used to represent the corticospinal excitability	Baseline (before iTBS stimulation)
Primary	Motor evoked potential (MEP)	Single TMS pulses with suprathreshold intensity (120% of resting motor threshold of the stimulated cortex) applied to the primary motor cortex (M1) can produce recordable MEPs in contralateral muscles; additionally, the peak-to-peak amplitude of MEPs can be used to represent the corticospinal excitability	10 minutes after a single-session iTBS stimulation
Secondary	Cortical silent period	The cortical silent period (cSP) is a protocol measuring the intracortical inhibition, in which suprathreshold test pulses (120% of resting motor threshold of the stimulated cortex) are applied to the contralateral M1, while participants sustain 30% maximum voluntary contraction. Specifically, cSP refers to the interruption of background electromyographic (EMG) activity after the TMS pulse.	Baseline (before iTBS stimulation)
Secondary	Cortical silent period	The cortical silent period (cSP) is a protocol measuring the intracortical inhibition, in which suprathreshold test pulses (120% of resting motor threshold of the stimulated cortex) are applied to the contralateral M1, while participants sustain 30% maximum voluntary contraction. Specifically, cSP refers to the interruption of background electromyographic (EMG) activity after the TMS pulse.	10 minutes after a single-session iTBS stimulation
Secondary	Short-interval intracortical inhibition	Short-interval intracortical inhibition (SICI) is a form of paired-pulse protocol, in which a subthreshold conditioning pulse is delivered 2 ms before a suprathreshold test pulse. Theoretically, the amplitude of motor-evoked potentials (MEPs) evoked by a test pulse at a given intensity is suppressed compared with that evoked by a single pulse at the same intensity. Eight trials are recorded, with inter-trial intervals ranging from 4 s to 5 s. The intensity of test pulses is fixed at 120% of the resting motor threshold, and the intensity of the conditioning pulse is set at 80% of the resting motor threshold. The result of SICI is expressed as the ratio of a paired-pulse MEP amplitude to a single-pulse MEP amplitude.	Baseline (before iTBS stimulation)
Secondary	Short-interval intracortical inhibition	Short-interval intracortical inhibition (SICI) is a form of paired-pulse protocol, in which a subthreshold conditioning pulse is delivered 2 ms before a suprathreshold test pulse. Theoretically, the amplitude of motor-evoked potentials (MEPs) evoked by a test pulse at a given intensity is suppressed compared with that evoked by a single pulse at the same intensity. Eight trials are recorded, with inter-trial intervals ranging from 4 s to 5 s. The intensity of test pulses is fixed at 120% of the resting motor threshold, and the intensity of the conditioning pulse is set at 80% of the resting motor threshold. The result of SICI is expressed as the ratio of a paired-pulse MEP amplitude to a single-pulse MEP amplitude.	10 minutes after a single-session iTBS stimulation
Secondary	Intracortical facilitation	The setups for the intensity of intracortical facilitation (ICF) are almost the same as those for SICI; however, the interstimulus interval is longer, 10 ms. Eight trials are recorded, with inter-trial intervals ranging from 4 s to 5 s. The intensity of test pulses is fixed at 120% of the resting motor threshold, and the intensity of the conditioning pulse is set at 80% of the resting motor threshold. The result of ICF is expressed as the ratio of a paired-pulse MEP amplitude to a single-pulse MEP amplitude.	Baseline (before iTBS stimulation)
Secondary	Intracortical facilitation	The setups for the intensity of intracortical facilitation (ICF) are almost the same as those for SICI; however, the interstimulus interval is longer, 10 ms. Eight trials are recorded, with inter-trial intervals ranging from 4 s to 5 s. The intensity of test pulses is fixed at 120% of the resting motor threshold, and the intensity of the conditioning pulse is set at 80% of the resting motor threshold. The result of ICF is expressed as the ratio of a paired-pulse MEP amplitude to a single-pulse MEP amplitude.	10 minutes after a single-session iTBS stimulation