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

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

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.

Inclusion Criteria:

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

Exclusion Criteria:

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