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Completed

NCT Number: NCT05509686

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

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.

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Key information

Conditions

Stroke Brain Diseases Cardiovascular Diseases Central Nervous System Diseases Cerebrovascular Disorders Nervous System Diseases Vascular Diseases

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Kenneth FONG

Hong Kong, 000000

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • suffered from first-ever, ischemic or hemorrhagic, unilateral stroke, verified by neuroimaging examinations such as CT or MRI.
  • detectable motor evoked potentials from the affected first dorsal interosseous muscle;
  • provided written informed consent.

Exclusion criteria

  • had any contraindication to transcranial magnetic stimulation;
  • had a known neurological disease excluding stroke, or psychiatric disease;
  • were using a psychostimulant, sedative, antidepressant, or antiepileptic medication.

Treatment and study plan

intermittent theta burst stimulation (iTBS)

Device

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)

Device

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.

Primary outcomes

  1. Transcranial magnetic stimulation-evoked potential

    Time frame: Baseline (before iTBS stimulation)

    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.

  2. Transcranial magnetic stimulation-evoked potential

    Time frame: 10 minutes after a single-session iTBS stimulation

    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.

  3. Motor evoked potential (MEP)

    Time frame: Baseline (before iTBS stimulation)

    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

  4. Motor evoked potential (MEP)

    Time frame: 10 minutes after a single-session iTBS stimulation

    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

Secondary outcomes

  1. Cortical silent period

    Time frame: Baseline (before iTBS stimulation)

    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.

  2. Cortical silent period

    Time frame: 10 minutes after a single-session iTBS stimulation

    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.

  3. Short-interval intracortical inhibition

    Time frame: Baseline (before iTBS stimulation)

    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.

  4. Short-interval intracortical inhibition

    Time frame: 10 minutes after a single-session iTBS stimulation

    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.

  5. Intracortical facilitation

    Time frame: Baseline (before iTBS stimulation)

    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.

  6. Intracortical facilitation

    Time frame: 10 minutes after a single-session iTBS stimulation

    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.

Sponsors and collaborators

Lead sponsor

The Hong Kong Polytechnic University

Other

Registry information

Official study 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

Important dates

Study start
2020
Primary completion
2021
Study completion
2022
First posted
Aug 22, 2022
Registry last updated
Aug 22, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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