Continuous theta-burst rTMS over primary somatosensory cortex modulates tactile perception on the hand

OBJECTIVE: Theta-burst stimulation (TBS) over the primary somatosensory cortex (SI) alters cortical excitability, and in its intermittent form (iTBS) improves tactile spatial acuity. The effects of continuous TBS (cTBS) on tactile acuity remain unknown. The present study examined the influence of cTBS over SI on temporal and spatial tactile acuity on the contralateral hand. METHODS: In separate experiments, temporal discrimination threshold (TDT) and spatial amplitude discrimination threshold (SDT) were obtained from the right hand before and for up to 34 min following real and sham cTBS (600 pulses) over left-hemisphere SI. RESULTS: CTBS reduced temporal and spatial tactile acuity for up to 18 min following real cTBS. Tactile acuity was unaltered in the groups receiving sham cTBS. CONCLUSIONS: CTBS over SI impairs both temporal and spatial domains of tactile acuity for a similar duration. SIGNIFICANCE: CTBS over SI appears to decrease neural activity within targeted cortex and has potential utility in reducing excessive sensory processing.