Effects of Theta Burst Stimulation on Modulation of Mirror Illusion-induced Rhythm Suppression in Stroke
Condition: Stroke; Hemiplegia
MeSH terms: Stroke; Hemiplegia; Illusions
Study type: Interventional

Summary: 
      The study aims to test the hypothesis that rTMS in the form of theta burst stimulation (TBS)
      over the ipsilateral and contralateral motor cortices can modulate mirror illusion-induced
      rhythm suppression while observing unilateral arm movement in stroke individuals. The
      investigators further hypothesize that this intervention will lead to the revision of
      interhemispheric asymmetry. Finally, this study will also explore the longitudinal
      relationship between rhythm suppression and motor recovery as indicated by motor excitability
      in the form of MEP. The results of this study will provide significant new information
      regarding neurophysiological motor relearning mechanisms which could inform the development
      and evaluation of innovative treatments for individuals with stroke
    

Detailed description: 
      Stroke is the leading cause of physical disability. Facilitating the process of motor
      relearning would greatly accelerate the rehabilitation of motor functions and elicit positive
      neuroplasticity of the damaged brain area. Previous research has already explored the
      feasibility of motor priming techniques embedded in stroke rehabilitation programs using
      strategies such as non-invasive brain stimulation (NIBS) and mirror therapy (MT). These
      treatments are usually implemented along with the standardized rehabilitation, sequentially
      or simultaneously, and have been demonstrated to be more effective than the standardized
      rehabilitation programs alone.

      Mirror neuron, as indicated traditionally by the decrease in the amplitude of Mu rhythm, i.e.
      a suppression over central electrodes of electroencephalography (EEG), reflects the "seeing"
      of movement after "perception". Such oscillations are based on neural substrates that are
      discharged during the observation and execution of a motor act, which is also associated with
      other human functions, such as imitation, language, etc. The core mirror neuron system (MNS)
      is thought to be located in the premotor and the primary sensorimotor cortices, indicating
      that motor learning could be enhanced during action observation and overt movement.

      Preliminary research has shown that repetitive Transcranial Magnetic Stimulation (rTMS) can
      enhance the corticomotor excitability in mirror neurons during both observation of movement
      (by others) or imagined movement in healthy subjects; in particular, as measured by enhanced
      motor evoked potentials (MEP). Increases in MEP has also been induced by short-term action
      observation and mirror visual feedback in stroke survivors. However, it is not yet known if
      MNS can be activated by TMS in MT following a stroke, and the relationship between mirror
      neuron activation and clinical improvements in stroke remains unclear.

      The investigators have already published preliminary findings in patients with hemiplegic
      upper extremity, rTMS, and MT. Here, the investigators propose to test the hypothesis that
      rTMS in the form of theta-burst stimulation (TBS) over the ipsilateral and contralateral
      motor cortices can modulate mirror illusion-induced rhythm suppression while observing
      unilateral arm movement in stroke individuals. The investigators further hypothesize that
      this intervention will lead to the revision of interhemispheric asymmetry. Finally, this
      study will also explore the longitudinal relationship between rhythm suppression and motor
      recovery as indicated by motor excitability in the form of MEP. The results of this study
      will provide significant new information regarding neurophysiological motor relearning
      mechanisms which could inform the development and evaluation of innovative treatments for
      individuals with stroke
    

Intervention name(s): Intermittent theta burst stimulation; Mirror Therapy; Sham intermittent theta burst stimulation; Sham mirror Therapy
Intervention type(s): Device; Behavioral; Device; Behavioral
Intervention description(s): iTBS (20 trains of ten bursts at eight-second intervals, 600 stimuli, 200-second per session) will be delivered to the ipsilesional hemisphere in stroke patients, by using a butterfly shape coil.; Participants will practice the movements with the non-affected hand and try moving the affected arm at the same time to synchronize with the non-affected hand (illusion on the mirror). The movement practice will involve 5 table-top tasks and the participant will be instructed to perform as many trials as possible in each session with a maximum of 30 trials per task, giving a total of 150 trials per session, lasting for 20 minutes.; iTBS (20 trains of ten bursts at eight-second intervals, 600 stimuli, 200-second per session) will be delivered to the ipsilesional hemisphere in stroke patients. However, a sham coil will be used, which is not associated with any stimulation effect on the brain.; In sham mirror therapy, the mirror will be covered. Participants will practice the movements with the non-affected hand and try moving the affected arm at the same time to move the non-affected hand. The participants cannot receive mirror visual feedback of the paretic upper extremity movement during the therapy. Same as mirror therapy, the movement practice will involve 5 table-top tasks and the participant will be instructed to perform as many trials as possible in each session with a maximum of 30 trials per task, giving a total of 150 trials per session, lasting for 20 minutes.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Stroke; upper extremity; intermittent theta burst stimulation; mirror visual feedback; event-related desynchronization