The Modulatory Effect of Low-intensity Priming Intermittent Theta Burst Stimulation on Motor Cortex Poststroke: a Concurrent TMS-EEG Study
- Conditions
- Stroke
- Interventions
- Device: Transcranial magnetic stimulation
- Registration Number
- NCT06241508
- Lead Sponsor
- The Hong Kong Polytechnic University
- Brief Summary
Background: The optimization of the intensity of priming theta burst stimulation increases the probability of success in a randomized controlled trial. We hypothesize that priming intermittent theta burst stimulation (iTBS) with a low-intensity continuous theta burst stimulation (cTBS) will yield superior effects than our original priming protocol in healthy adults and patients after stroke.
Methods: 15 healthy adults and 15 stroke patients will undergo three separate experimental conditions: a low-intensity priming stimulation (55% resting motor threshold \[RMT\] cTBS+70% RMT iTBS), a conventional-intensity priming stimulation (70% RMT cTBS+70% RMT iTBS), and a nonpriming control. The alterations in cortical excitation/inhibition and its impacts on motor behaviors will be evaluated following stimulation.
Significance: The findings will inform future clinical trials investigating the optimized priming iTBS in promoting poststroke recovery.
- Detailed Description
Background: The optimization of the intensity of priming theta burst stimulation increases the probability of success in a randomized controlled trial. We hypothesize that priming intermittent theta burst stimulation (iTBS) with a low-intensity continuous theta burst stimulation (cTBS) will yield superior effects than our original priming protocol in healthy adults and patients after stroke.
Methods: 15 healthy adults and 15 stroke patients will undergo three separate experimental conditions: a low-intensity priming stimulation (55% resting motor threshold \[RMT\] cTBS+70% RMT iTBS), a conventional-intensity priming stimulation (70% RMT cTBS+70% RMT iTBS), and a nonpriming control. The alterations in cortical excitation/inhibition and its impacts on motor behaviors will be evaluated following stimulation.
Significance: The findings will inform future clinical trials investigating the optimized priming iTBS in promoting poststroke recovery.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 30
- (1) have a diagnosis of monohemispheric ischemic or hemorrhagic stroke, with time after stroke onset≥6 months;
- (2) aged between 18 and 80 years old;
- (3) with residual upper limb functions from 2-6 levels in the Functional Test for the Hemiplegic Upper Extremity, i.e., moderately impaired overall upper extremity functions.
- (4) able to give informed written consent to participate in the study.
- (1) any contraindications to TMS (screened by the safety checklist by Rossi [12]); -
- (2) any concomitant neurological disease;
- (3) any sign of moderate-to-severe cognitive problems, i.e., Montreal cognitive assessment (MoCA)<19/30
- (4) Modified Ashworth score>2 in hand, wrist or elbow extensor muscle in the hemiparetic upper extremity.
In addition, a group of age-matched, right-hand dominant healthy adults without any known neurological diseases will be enrolled. Healthy adults with any contraindications to TMS will be excluded.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Conventional intensity priming intermittent theta burst stimulation Transcranial magnetic stimulation Theta burst stimulation (TBS) is a potent form of repetitive transcranial magnetic stimulation (rTMS). Standard 600-pulse intermittent theta burst stimulation (iTBS) can enhance the corticomotor excitability, whereas standard 600-pulse continuous theta burst stimulation (cTBS) can suppress the corticomotor excitability. Sham stimulation uses an extreme low stimulation intensity which will not influence with corticomotor excitability. In the present study, real stimulation will be delivered in an intensity of 55% (low-intensity) or 70% (conventional intensity) individual resting motor threshold while sham stimulation will be delivered in an intensity of 20% (ineffective) individual resting motor threshold. Conventional intensity priming intermittent theta burst stimulation will use a session of 70% RMT cTBS followed by a session of 70% RMT iTBS. Both sessions will be applied to the ipsilesional primary motor cortex. Low-intensity priming intermittent theta burst stimulation Transcranial magnetic stimulation Theta burst stimulation (TBS) is a potent form of repetitive transcranial magnetic stimulation (rTMS). Standard 600-pulse intermittent theta burst stimulation (iTBS) can enhance the corticomotor excitability, whereas standard 600-pulse continuous theta burst stimulation (cTBS) can suppress the corticomotor excitability. Sham stimulation uses an extreme low stimulation intensity which will not influence with corticomotor excitability. In the present study, real stimulation will be delivered in an intensity of 55% (low-intensity) or 70% (conventional intensity) individual resting motor threshold while sham stimulation will be delivered in an intensity of 20% (ineffective) individual resting motor threshold. Low-intensity priming intermittent theta burst stimulation will use a session of 55% RMT cTBS followed by a session of 70% RMT iTBS. Both sessions will be applied to the ipsilesional primary motor cortex. Standard, nonpriming intermittent theta burst stimulation Transcranial magnetic stimulation Theta burst stimulation (TBS) is a potent form of repetitive transcranial magnetic stimulation (rTMS). Standard 600-pulse intermittent theta burst stimulation (iTBS) can enhance the corticomotor excitability, whereas standard 600-pulse continuous theta burst stimulation (cTBS) can suppress the corticomotor excitability. Sham stimulation uses an extreme low stimulation intensity which will not influence with corticomotor excitability. In the present study, real stimulation will be delivered in an intensity of 55% (low-intensity) or 70% (conventional intensity) individual resting motor threshold while sham stimulation will be delivered in an intensity of 20% (ineffective) individual resting motor threshold. Nonpriming priming intermittent theta burst stimulation will use a session of 20% RMT cTBS followed by a session of 70% RMT iTBS. Both sessions will be applied to the ipsilesional primary motor cortex.
- Primary Outcome Measures
Name Time Method The isometric force control task 15-min after completion of stimulation sessions Force data will be collected using a load cell (Force sensor ZNHM, Chino sensor, China). To assess maximal voluntary contraction (MVC) of the hand grip, three trials will be conducted using both paretic and nonparetic hands (or the dominant and non-dominant hands for healthy controls). Subsequently, separate tests will be performed to measure submaximal isometric force at 20% and 50% of the maximal voluntary force (MVF). Each trial will last for 20 seconds, with a 60-second intertrial interval to prevent fatigue. A total of 5 trials will be conducted for each level of muscle contraction. Muscle strength will be evaluated by calculating the mean force output, while the variability of force control will be assessed by calculating the coefficient of variation of force, i.e., the standard deviation of force/mean force output × 100%.
Transcranial magnetic stimulation-evoked potential 5-min after completion of stimulation sessions 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.
- Secondary Outcome Measures
Name Time Method
Trial Locations
- Locations (1)
Jack Jiaqi Zhang
🇭🇰Hong Kong, Hong Kong