P221 Cerebellar theta burst stimulation modulates the neural activity of interconnected parietal and motor areas. Issue 3 (March 2017)

• Record Type: Journal Article
• Authors: Casula, E.P.; Ponzo, V.; Bassi, M. Stampanoni; Veniero, D.; Caltagiron, C.; Koch, G.
• Is Part Of: Clinical neurophysiology. Volume 128:Issue 3(2017:Mar.)
• Page Start: e121
• Page End: e122
• Publication Date: 2017-03
• Subjects: Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2016.10.338
• Languages: English
• ISSNs: 1388-2457

Abstract

Abstract : Question: Voluntary movement control and execution are regulated by the influence of the cerebellar output over different interconnected cortical areas, through dentato-thalamo connections. However, in humans, connectivity and plasticity dynamics of the cerebellar-thalamo-cortical connections have been only indirectly explored. Methods: In the present study we applied in a group of healthy volunteers transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to directly assess the effects of three theta-burst stimulation (TBS) protocols (intermittent, continuous and sham) over the primary motor cortex (M1) and the posterior parietal cortex (PPC) of the contralateral hemisphere. Results: We found a TBS-dependent bidirectional modulation over TMS-evoked activity; specifically, cTBS increased whereas iTBS decreased activity between 100 and 200 ms after TMS, in a similar manner over both M1 and PPC areas. On the oscillatory domain, TBS induced specific changes over M1 natural frequencies of oscillation: TMS-evoked alpha activity was decreased by cTBS whereas beta activity was enhanced by iTBS. No effects were observed after sham stimulation. Conclusions: Our data provide novel evidence showing that the cerebellum exerts its control on the cortex likely by impinging on specific set of interneurons dependent on GABA-ergic activity. We show that cerebellar TBS modulates cortical excitability of distant interconnected cortical areas by acting through common temporal, spatial and frequency domains.