An interventional study of Intermittent theta burst stimulation (iTBS) and Sham intermittent theta burst stimulation (iTBS) in Stroke, sponsored by The Hong Kong Polytechnic University. Completed at 1 site in Hong Kong. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2022-08-22.
Sponsored by The Hong Kong Polytechnic University · Not applicable, Interventional, and Treatment
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.
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.
7,283 studies on the registry are indexed under Stroke; 2,013 are open to participants now.
This study's enrollment of 21 is below the median of 50 across 5,366 interventional studies indexed under Stroke.
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The classical 600-pulse iTBS protocol is delivered to the motor hotspot over the ipsilesional hemisphere.
Device: 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.
Device: Sham intermittent theta burst stimulation (iTBS)
A single-session standard 600-pulse intermittent theta burst stimulation (iTBS) is applied to the ipsilesional primary motor cortex.
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.
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.
Time frame: Baseline (before iTBS stimulation)
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.
Time frame: 10 minutes after a single-session iTBS stimulation
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
Time frame: Baseline (before iTBS stimulation)
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
Time frame: 10 minutes after a single-session iTBS stimulation
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.
Time frame: Baseline (before iTBS stimulation)
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.
Time frame: 10 minutes after a single-session iTBS stimulation
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.
Time frame: Baseline (before iTBS stimulation)
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.
Time frame: 10 minutes after a single-session iTBS stimulation
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.
Time frame: Baseline (before iTBS stimulation)
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.
Time frame: 10 minutes after a single-session iTBS stimulation
Plan to share: No — The data will be shared for research purpose upon reasonable request.
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The Hong Kong Polytechnic University