Yuichiro Shirota1, Suman Dhaka2, Walter Paulus3, Martin Sommer4. 1. Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany. Electronic address: yshirota-tky@umin.ac.jp. 2. Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany; Indian Institute of Technology, Guwahati, Assam, India. Electronic address: dhaka.ssuman@gmail.com. 3. Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany. Electronic address: wpaulus@med.uni-goettingen.de. 4. Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany. Electronic address: msommer@gwdg.de.
Abstract
BACKGROUND: Transcranial magnetic stimulation (TMS) with different current directions can activate different sets of neurons. Current direction can also affect the results of repetitive TMS. OBJECTIVE: To test the influence of uni-directional intermittent theta burst stimulation (iTBS) using different current directions, namely posteroanterior (PA) and anteroposterior (AP), on motor behaviour. METHODS: In a cross-over design, PA- and AP-iTBS was applied over the left primary motor cortex in 19 healthy, right-handed volunteers. Performance of a finger-tapping task was recorded before and 0, 10, 20, and 30min after the iTBS. The task was conducted with the right and left hands separately at each time point. As a control, AP-iTBS with reduced intensity was applied to 14 participants in a separate session (APweak condition). RESULTS: The finger-tapping count with the left hand was decreased after PA-iTBS. Neither AP- nor APweak-iTBS altered the performance. CONCLUSIONS: Current direction had a significant impact on the after-effects of iTBS.
BACKGROUND: Transcranial magnetic stimulation (TMS) with different current directions can activate different sets of neurons. Current direction can also affect the results of repetitive TMS. OBJECTIVE: To test the influence of uni-directional intermittent theta burst stimulation (iTBS) using different current directions, namely posteroanterior (PA) and anteroposterior (AP), on motor behaviour. METHODS: In a cross-over design, PA- and AP-iTBS was applied over the left primary motor cortex in 19 healthy, right-handed volunteers. Performance of a finger-tapping task was recorded before and 0, 10, 20, and 30min after the iTBS. The task was conducted with the right and left hands separately at each time point. As a control, AP-iTBS with reduced intensity was applied to 14 participants in a separate session (APweak condition). RESULTS: The finger-tapping count with the left hand was decreased after PA-iTBS. Neither AP- nor APweak-iTBS altered the performance. CONCLUSIONS: Current direction had a significant impact on the after-effects of iTBS.