Repetitive stimulation of premotor cortex affects primary motor cortex excitability and movement preparation

Stinear, Cathy M.; Barber, P. Alan; Coxon, James P.; Verryt, Toby S.; Acharya, Pratima P.; Byblow, Winston D.

doi:10.1016/j.brs.2009.01.001

« Previous Next »BRAIN STIMULATION: Basic, Translational, and Clinical Research in Neuromodulation
Volume 2, Issue 3 , Pages 152-162, July 2009

Repetitive stimulation of premotor cortex affects primary motor cortex excitability and movement preparation

Cathy M. Stinear, PhD
- Movement Neuroscience Laboratory, Department of Sport and Exercise Science, University of Auckland, Auckland, New Zealand
- Department of Medicine, University of Auckland, Auckland, New Zealand
- Correspondence: Dr. Cathy M. Stinear, Department of Medicine, University of Auckland, Private Bag 92019, Auckland, New Zealand.
P. Alan Barber, MD, PhD
- Department of Medicine, University of Auckland, Auckland, New Zealand
James P. Coxon, PhD
- Centre for Movement Control and Neuroplasticity, Department of Biomedical Kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium
Toby S. Verryt, BSc(Hons)
- Department of Medicine, University of Auckland, Auckland, New Zealand
Pratima P. Acharya, RN
- Movement Neuroscience Laboratory, Department of Sport and Exercise Science, University of Auckland, Auckland, New Zealand
Winston D. Byblow, PhD
- Movement Neuroscience Laboratory, Department of Sport and Exercise Science, University of Auckland, Auckland, New Zealand

Received 26 November 2008; received in revised form 8 January 2009; accepted 8 January 2009. published online 02 March 2009.

Background

Repetitive transcranial magnetic stimulation can be used to explore functional connectivity between cortical areas.

Objective

To determine the effects of two theta burst stimulation (TBS) patterns (intermittent, iTBS; and continuous, cTBS) of left dorsal premotor cortex (PMd).

Methods

Left PMd was identified in 11 participants using functional magnetic resonance imaging (fMRI), during performance of complex sequential finger movements. Each participant received iTBS, cTBS, or sham TBS of left PMd in three separate sessions within a randomized, single-blind design. The speed and accuracy of simple and complex sequential reaction time (RT) task performance was measured before and after TBS. The excitability of primary motor cortex (M1) bilaterally, and interhemispheric facilitation from left PMd to right M1, were also measured before and after TBS.

Results

iTBS sped up the preparation of complex sequences performed with the right hand, with no detectable changes in M1 excitability. RT performance was maintained after cTBS, in the presence of increased left M1 excitability and suppressed right M1 excitability.

Conclusions

Facilitatory and inhibitory TBS protocols applied to left PMd differentially alter corticomotor excitability and behavior, which suggests that these protocols affect different neuronal populations.

Keywords: corticomotor, fMRI, reaction time, TBS, TMS