THE EFFECT OF INTERMITTENT THETA BURST STIMULATION ON BICEPS CORTICOMOTOR EXCITABILITY IN NON-IMPAIRED INDIVIDUALS AND INDIVIDUALS WITH TETRAPLEGIA

Neuromodulation of the primary motor cortex (M1) in pair with physical therapy may be a promising method for improving motor outcomes after spinal cord injury (SCI). Increased excitability of the corticospinal motor pathways (i.e. corticomotor excitability) has shown to be associated with improved motor learning and skill acquisition. Intermittent theta burst stimulation (iTBS) is a form of non-invasive brain stimulation which can increase corticomotor excitability, as measured by an increase in the amplitude of motor evoked potentials (MEPs). However, the ability for iTBS to increase the corticomotor excitability of proximal muscles such as the biceps, and muscles affected by spinal cord injury is currently unclear. Therefore, the purpose of the present studies was to determine the effect of iTBS on the corticomotor excitability of the biceps, as measured by MEP amplitudes, in non-impaired individuals and individuals with tetraplegia. Participants completed three sessions of the protocol, each including sham and active iTBS. Sessions were separated by a minimum of three days to prevent the potential for carry over effects. Results showed no change in nMEP amplitude after either sham or active iTBS in the non-impaired group. However, the SCI group showed an increase in nMEP amplitude after active iTBS relative to sham, suggesting an increase in corticomotor excitability. While further research is needed before combinatorial therapies can be achieved, this study suggests that iTBS may be a promising method for improving motor function in those with tetraplegia