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P252 Does anodal tDCS of the premotor cortex enhance the effects of motor imagery on motor sequence learning?
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Abstracts / Clinical Neurophysiology 128 (2017) e1–e163
Greifswald, Functional Imaging, Diagnostic Radiology, Greifswald, Germany, b BDH-Klinik, Greifswald, Germany, c University Medicine, Neurology, Greifswald, Germany) ⇑
Corresponding author.
Introduction: The effect of intracortical facilititation (ICF) is independent from hemispheric dominance and handedness (Bäumer et al., 2007). Short term training selectively increases excitability over the contralateral primary motor cortex (M1c) of the trained hand (e.g. Lotze et al., 2003). M1-excitability measurements after long-term training (several weeks) are rare but – to our knowledge – are even absent for ICF-parameters. Objectives: To evaluate effects of ICF during a two week comprehensive period of training of the left hand in strongly right handed healthy participants. Materials and ethods: Thirteen strongly right-handed healthy participants (23 ± 3.5 years; 6 women) underwent a two-week arm ability training (AAT) for their left, nondominant hand for one hour per day (Platz, 2004). Performance increase was expressed as percentual changes over time and averaged over all eight AAT-tasks. Focal TMS was delivered to the optimal scalp position for activation of the musculus abductor policis brevis (APB) of each hand using a figure-ofeight coil. Resting motor threshold (rMT) and intracortical facilitation (ICF; test stimulus intensity 120% rMT; conditioning stimulus 80% rMT; interstimulus interval 10 ms) were used as measures of corticomotor excitability. Results: Training resulted in considerable improvement of the trained left (30 ± 3.5%) hand, but – to a lesser extent – also the non-trained right hand (18 ± 5.4%) performance. RMT was not altered over time. For ICF we found a strong time effect in ANOVA; but post hoc t-tests showed only a relevant decrease over time for the untrained side (T(12) = 3.33; p = 0.006; Fig. 1). Conclusion: Our study showed no significant changes in ICF for the trained hand side, but a decrease for the non trained hand’s motor cortex. It has been demonstrated that the interaction between an increase of unilateral movement and 10 h unilateral immobilization of the other hand is critical for excitability effects over M1c (Avanzino et al., 2011). We argue that interhemispheric changes induced by unilateral limb training of the non-dominant hand might be multifactorial; here we observed an increased interhemispheric
balance in ICF after training the less experienced, and presumably in spontaneous behavior less intensively used hand. doi:10.1016/j.clinph.2016.10.365
P252 Does anodal tDCS of the premotor cortex enhance the effects of motor imagery on motor sequence learning?—A. Saimpont a,*, O. Richard a, P. Chabaud a, P.L. Jackson b, A. Guillot a, C. Collet a (a LIBM – Université de Lyon – Université Lyon 1, STAPS, Villeurbanne, France, b CIRRIS – Université Laval, Psychologie, Québec, Canada) ⇑
Corresponding author.
Introduction: There is ample evidence that motor imagery (MI) training – i.e. the mental repetition of movements without corresponding actual execution – contributes to enhance motor
Figure 1.
Mean numbers of correct sequences at pretest and posttest for the real and sham conditions.
Figure 2.
Relation between performance improvement (in percentage) and self-reported levels of MI vividness during MI training.
Abstracts / Clinical Neurophysiology 128 (2017) e1–e163
performance. Such positive effects are greater when MI is accompanied by anodal tDCS applied over the primary motor cortex (Foerster et al., 2013; Saimpont et al., 2016). While the premotor cortex is known to be active during MI (Hetu et al., 2013), its role on motor performance improvement by MI training needs to be clarified. Objective: The main aim of this study was to examine whether anodal tDCS applied over the premotor cortex might enhance the effect of MI training on the learning of a finger tapping task. Materials and methods: The experiment was conducted in a double-blinded sham-controlled crossover design. Twelve righthanded young adults (mean age = 22.4 ± 2.5 years, 5 females) participated in two experimental sessions. During each session, participants performed MI training for 13 min combined either with anodal tDCS (current intensity = 1.5 mA, current density = 0.06 mA/ cm2) over the right premotor cortex (FC2 location in the 10–20 system), or with sham stimulation over the same region. Motor imagery training consisted in mentally rehearsing an 8-item complex finger sequence with the left hand. Before (Pretest) and immediately after (Posttest) MI training, participants physically repeated the sequence as fast and accurately as possible. Results showed a significant increase in the number of correct sequences after MI training in both conditions (p < .001, g2 = .87); performance improvement was however not significantly different between conditions (p = .27, g2 = .11); see Fig. 1. Interestingly, we found a significant correlation between performance improvements and self-reported levels of MI vividness during MI training in both conditions (real: R = 0.68, sham: R = 0.64); see Fig. 2. Conclusion: Results suggest that the positive effects of MI training on motor sequence learning do not primarily result from an increase in activity in the premotor cortex. More participants will confirm/ infirm these preliminary results.
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effects in children. Unique tDCS effects may occur in the developing brain, confounding trial design in disabled children. We investigated the neurophysiology underlying tDCS-induced enhancement of motor learning. Methods: 24 healthy right-handed children trained their left hand on the Purdue Pegboard Test (PPT) over 3 consecutive days while receiving primary motor cortex (M1) tDCS as: (1) contralateral 1 mA anodal, (2) ipsilateral 1 mA cathodal, (3) ipsilateral 2 mA cathodal or (4) sham. Stimulation was applied for the first 20 min of training each day. Transcranial magnetic stimulation explored bihemispheric M1 neurophysiology at baseline and post-training. Outcomes included cortical excitability, short-interval intracortical inhibition (SICI), intracortical facilitation, cortical silent periods (cSP) and interhemispheric inhibition (IHI). Results: All active tDCS paradigms enhanced motor learning by approximately 40% compared to sham (p < 0.001). Baseline PPT scores were negatively correlated with right M1 cSP (r = 0.541) and positively correlated with SICI (r = 0.420). Anodal tDCS increased cortical excitability (p < 0.05) whereas 2 mA cathodal tDCS reduced excitability and increased SICI (p < 0.05). Transcallosal inhibition effects included increased IHI with anodal tDCS (p < 0.05) and decreased IHI with 1 and 2 mA cathodal tDCS (p < 0.05). Training alone (sham) was not associated with measureable changes in neurophysiology. Conclusions: tDCS enhancement of motor learning in healthy children is associated with changes in cortical excitability, intracortical and transcallosal inhibition. Intracortical inhibition may be associated with lower motor function. Elucidation of tDCS mechanisms of neuromodulation will inform optimization of stimulation parameters when applying tDCS to children with cerebral palsy. doi:10.1016/j.clinph.2016.10.367
doi:10.1016/j.clinph.2016.10.366
P253 Neurophysiological mechanisms of transcranial direct-current stimulation-enhanced motor learning in healthy children— P. Ciechanski *, E. Zewdie, A. Kirton (University of Calgary, Calgary, Canada) ⇑
Corresponding author.
P254 The interaction of cross-limb transfer gains, intermittent thetaburst stimulation and subsequent learning in young and older adults—T. Stöckel a,b,*, P. Reissig b, M.R. Hinder b (a University of Rostock, Rostock, Germany , b University of Tasmania, Hobart, TAS, Australia) ⇑
Introduction: Transcranial direct-current stimulation (tDCS) enhances motor learning in adults. We recently demonstrated robust
Figure 1.
Corresponding author.
Introduction: Recently we found evidence that following right hand motor training intermittent theta-burst stimulation (iTBS)
Abstracts / Clinical Neurophysiology 128 (2017) e1–e163
Greifswald, Functional Imaging, Diagnostic Radiology, Greifswald, Germany, b BDH-Klinik, Greifswald, Germany, c University Medicine, Neurology, Greifswald, Germany) ⇑
Corresponding author.
Introduction: The effect of intracortical facilititation (ICF) is independent from hemispheric dominance and handedness (Bäumer et al., 2007). Short term training selectively increases excitability over the contralateral primary motor cortex (M1c) of the trained hand (e.g. Lotze et al., 2003). M1-excitability measurements after long-term training (several weeks) are rare but – to our knowledge – are even absent for ICF-parameters. Objectives: To evaluate effects of ICF during a two week comprehensive period of training of the left hand in strongly right handed healthy participants. Materials and ethods: Thirteen strongly right-handed healthy participants (23 ± 3.5 years; 6 women) underwent a two-week arm ability training (AAT) for their left, nondominant hand for one hour per day (Platz, 2004). Performance increase was expressed as percentual changes over time and averaged over all eight AAT-tasks. Focal TMS was delivered to the optimal scalp position for activation of the musculus abductor policis brevis (APB) of each hand using a figure-ofeight coil. Resting motor threshold (rMT) and intracortical facilitation (ICF; test stimulus intensity 120% rMT; conditioning stimulus 80% rMT; interstimulus interval 10 ms) were used as measures of corticomotor excitability. Results: Training resulted in considerable improvement of the trained left (30 ± 3.5%) hand, but – to a lesser extent – also the non-trained right hand (18 ± 5.4%) performance. RMT was not altered over time. For ICF we found a strong time effect in ANOVA; but post hoc t-tests showed only a relevant decrease over time for the untrained side (T(12) = 3.33; p = 0.006; Fig. 1). Conclusion: Our study showed no significant changes in ICF for the trained hand side, but a decrease for the non trained hand’s motor cortex. It has been demonstrated that the interaction between an increase of unilateral movement and 10 h unilateral immobilization of the other hand is critical for excitability effects over M1c (Avanzino et al., 2011). We argue that interhemispheric changes induced by unilateral limb training of the non-dominant hand might be multifactorial; here we observed an increased interhemispheric
balance in ICF after training the less experienced, and presumably in spontaneous behavior less intensively used hand. doi:10.1016/j.clinph.2016.10.365
P252 Does anodal tDCS of the premotor cortex enhance the effects of motor imagery on motor sequence learning?—A. Saimpont a,*, O. Richard a, P. Chabaud a, P.L. Jackson b, A. Guillot a, C. Collet a (a LIBM – Université de Lyon – Université Lyon 1, STAPS, Villeurbanne, France, b CIRRIS – Université Laval, Psychologie, Québec, Canada) ⇑
Corresponding author.
Introduction: There is ample evidence that motor imagery (MI) training – i.e. the mental repetition of movements without corresponding actual execution – contributes to enhance motor
Figure 1.
Mean numbers of correct sequences at pretest and posttest for the real and sham conditions.
Figure 2.
Relation between performance improvement (in percentage) and self-reported levels of MI vividness during MI training.
Abstracts / Clinical Neurophysiology 128 (2017) e1–e163
performance. Such positive effects are greater when MI is accompanied by anodal tDCS applied over the primary motor cortex (Foerster et al., 2013; Saimpont et al., 2016). While the premotor cortex is known to be active during MI (Hetu et al., 2013), its role on motor performance improvement by MI training needs to be clarified. Objective: The main aim of this study was to examine whether anodal tDCS applied over the premotor cortex might enhance the effect of MI training on the learning of a finger tapping task. Materials and methods: The experiment was conducted in a double-blinded sham-controlled crossover design. Twelve righthanded young adults (mean age = 22.4 ± 2.5 years, 5 females) participated in two experimental sessions. During each session, participants performed MI training for 13 min combined either with anodal tDCS (current intensity = 1.5 mA, current density = 0.06 mA/ cm2) over the right premotor cortex (FC2 location in the 10–20 system), or with sham stimulation over the same region. Motor imagery training consisted in mentally rehearsing an 8-item complex finger sequence with the left hand. Before (Pretest) and immediately after (Posttest) MI training, participants physically repeated the sequence as fast and accurately as possible. Results showed a significant increase in the number of correct sequences after MI training in both conditions (p < .001, g2 = .87); performance improvement was however not significantly different between conditions (p = .27, g2 = .11); see Fig. 1. Interestingly, we found a significant correlation between performance improvements and self-reported levels of MI vividness during MI training in both conditions (real: R = 0.68, sham: R = 0.64); see Fig. 2. Conclusion: Results suggest that the positive effects of MI training on motor sequence learning do not primarily result from an increase in activity in the premotor cortex. More participants will confirm/ infirm these preliminary results.
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effects in children. Unique tDCS effects may occur in the developing brain, confounding trial design in disabled children. We investigated the neurophysiology underlying tDCS-induced enhancement of motor learning. Methods: 24 healthy right-handed children trained their left hand on the Purdue Pegboard Test (PPT) over 3 consecutive days while receiving primary motor cortex (M1) tDCS as: (1) contralateral 1 mA anodal, (2) ipsilateral 1 mA cathodal, (3) ipsilateral 2 mA cathodal or (4) sham. Stimulation was applied for the first 20 min of training each day. Transcranial magnetic stimulation explored bihemispheric M1 neurophysiology at baseline and post-training. Outcomes included cortical excitability, short-interval intracortical inhibition (SICI), intracortical facilitation, cortical silent periods (cSP) and interhemispheric inhibition (IHI). Results: All active tDCS paradigms enhanced motor learning by approximately 40% compared to sham (p < 0.001). Baseline PPT scores were negatively correlated with right M1 cSP (r = 0.541) and positively correlated with SICI (r = 0.420). Anodal tDCS increased cortical excitability (p < 0.05) whereas 2 mA cathodal tDCS reduced excitability and increased SICI (p < 0.05). Transcallosal inhibition effects included increased IHI with anodal tDCS (p < 0.05) and decreased IHI with 1 and 2 mA cathodal tDCS (p < 0.05). Training alone (sham) was not associated with measureable changes in neurophysiology. Conclusions: tDCS enhancement of motor learning in healthy children is associated with changes in cortical excitability, intracortical and transcallosal inhibition. Intracortical inhibition may be associated with lower motor function. Elucidation of tDCS mechanisms of neuromodulation will inform optimization of stimulation parameters when applying tDCS to children with cerebral palsy. doi:10.1016/j.clinph.2016.10.367
doi:10.1016/j.clinph.2016.10.366
P253 Neurophysiological mechanisms of transcranial direct-current stimulation-enhanced motor learning in healthy children— P. Ciechanski *, E. Zewdie, A. Kirton (University of Calgary, Calgary, Canada) ⇑
Corresponding author.
P254 The interaction of cross-limb transfer gains, intermittent thetaburst stimulation and subsequent learning in young and older adults—T. Stöckel a,b,*, P. Reissig b, M.R. Hinder b (a University of Rostock, Rostock, Germany , b University of Tasmania, Hobart, TAS, Australia) ⇑
Introduction: Transcranial direct-current stimulation (tDCS) enhances motor learning in adults. We recently demonstrated robust
Figure 1.
Corresponding author.
Introduction: Recently we found evidence that following right hand motor training intermittent theta-burst stimulation (iTBS)