Continuous theta burst stimulation over the contralesional sensory and motor cortex enhances motor learning post-stroke

Abstract

The current study investigated the contributions of contralesional primary somatosensory cortex (S1c) to motor learning deficits post-stroke. For three days, continuous theta burst (cTBS) was delivered over the contralesional hemisphere prior to practicing a serial targeting task. cTBS was delivered over either S1c, contralesional primary motor cortex (M1c) or as control stimulation (n=4/group). Change in motor ability was assessed from initial performance to a delayed retention test using a serial targeting task and a subset of items from the Wolf Motor Function Test. Practice preceded by cTBS over either M1c or S1c resulted in large decreases in movement time compared to practice preceded by control stimulation. M1c cTBS resulted in larger decreases in peak velocity and peak acceleration compared to control and S1c cTBS. In contrast, S1c cTBS resulted in larger reductions in time to initiate movement and time to complete the WMFT compared to control and M1c cTBS. These preliminary findings suggest that stimulation of either M1c or S1c can enhance the benefits of practice. However, changes in M1c and S1c excitability may contribute to different aspects of post-stroke motor deficits that may differentially impact rehabilitation.