S181. Optimizing the neuroplastic effects of cathodal transcranial direct current stimulation (tDCS) over the primary motor cortex. (May 2018)

• Record Type: Journal Article
• Authors: Kuo, Min-Fang; Mosayebi, Mohsen; Jamil, Asif; Nitsche, Michael A.
• Is Part Of: Clinical neurophysiology. Volume 129(2018)Supplement 1
• Page Start: e209
• Publication Date: 2018-05
• Subjects: Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2018.04.541
• Languages: English
• ISSNs: 1388-2457

Abstract

Abstract : Introduction: Transcranial direct current stimulation (tDCS) can non-invasively induce polarity-dependent excitability alterations in the human motor cortex lasting more than an hour after stimulation. Clinical application with encouraging results have been reported in several pilot studies, but the optimal stimulation protocols remain to be determined. Methods: We systemically explored the association between tDCS parameters (intensity, duration) and induced after-effects on motor cortex excitability. Cathodal tDCS was applied in three different intensities (1, 2 and 3 mA) and durations (15, 20 and 30mins) on 16 young healthy subjects and the after-effects were monitored with TMS-induced motor evoked potentials (MEP) until the next day evening after stimulation. The results revealed nonlinear after-effects, which might be caused by calcium dynamics relevant for long term depression and potentiation induction. Results: The results revealed that 1 mA −15 min, 1 mA −30 min and 3 mA −20 min induced LTD-like plasticity, while LTP-like plasticity was observed after 2 mA stimulation for 20 min. It was shown that there is a nonlinear modulatory effect of stimulation intensity/duration on neuroplasticity, which might be caused by calcium dynamics relevant for long-term depression and potentiation induction. Conclusion: Our study thus provides further insights on the dependency of tDCS-induced neuroplasticity on the stimulation parameters, and therefore delivers crucial information for future clinical applications.