Does Microstructure Alter Rapidly After rTMS? Evidence From Quadripulse Stimulation

Several studies have reported immediate microstructural changes in the human brain following behavioural training. However, it remains unclear whether such changes occur after repetitive stimulation of a single brain region using repetitive Transcranial Magnetic Stimulation (rTMS). This is challenged by the large inter-individual variability in rTMS after-effect, while this knowledge is crucial for clarifying the mechanism of rTMS. In this webinar, Dr Ikko Kimura presents the recently published study investigating the immediate microstructural effects of quadri-pulse stimulation (QPS), a patterned rTMS protocol known for inducing relatively strong and robust after-effects. Sixteen right-handed, healthy adults participated in excitatory and inhibitory protocols of QPS over the left primary motor cortex. Using diffusion and resting-state functional MRI, they assessed changes in microstructures and functions after QPS. The results revealed no significant microstructural changes in the cerebral cortex after either protocol of QPS. Furthermore, microstructural changes were not correlated with the functional changes in any brain region. These findings suggest that repetitive stimulation of a single brain region may be insufficient to induce immediate microstructural changes. Speaker: Dr Ikko Kimura Dr Ikko Kimura specialises in neuromodulation and neuroimaging. He has completed his clinical residency at Osaka University Hospital and earned a PhD in Science from Osaka University. After that, Dr Kimura joined the RIKEN Institute as a Special Postdoctoral Researcher, where he advanced neuroimaging methods, particularly for high-resolution laminar MRI. Currently, Dr Kimura is a postdoctoral researcher at the Danish Research Centre for Magnetic Resonance (DRCMR) at Copenhagen University Hospital - Amager and Hvidovre, where he focuses on simulating the after-effects of transcranial electrical stimulation (tES) to optimize neuromodulation therapies. ____________________________________________________________ Launched in 2020, the Brainbox Initiative Webinar Series is a free resource designed to stimulate the ongoing discussion and promotion of the fascinating work being carried out in the field of non-invasive brain stimulation and imaging research. Our webinars are hosted by a global range of guest speakers from academia and industry alike to provide a broad, accessible, and engaging series of talks and discussions that is open to everyone. We will continue to add further webinars to this series over time, so make sure to check back our YouTube channel to ensure that you don’t miss any talks. Visit our website to learn more about our annual Non-Invasive Brain Stimulation conference, workshops, and range of awards: https://brainbox-initiative.com