The Modulatory Effect of Low-intensity Priming Intermittent Theta Burst Stimulation on Motor Cortex Poststroke: a Concurrent TMS-EEG Study

The Hong Kong Polytechnic University

Status: Completed

Conditions: Stroke

Treatments: Device: Transcranial magnetic stimulation

Study type: Interventional

Funder types: Other

Identifiers

NCT06241508

HSEARS20231104003

Details and patient eligibility

About

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: 20 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.

Full 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: 20 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.

Enrollment: 20 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• (1) have a diagnosis of 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 2-7 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.

Exclusion criteria

• (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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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20 participants in 3 patient groups

Low-intensity priming intermittent theta burst stimulation

Experimental group

Description:

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.

Treatment:

Device: Transcranial magnetic stimulation

Conventional intensity priming intermittent theta burst stimulation

Experimental group

Description:

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.

Treatment:

Device: Transcranial magnetic stimulation

Standard, nonpriming intermittent theta burst stimulation

Active Comparator group

Description:

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.

Treatment:

Device: Transcranial magnetic stimulation