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P043 Deep brain stimulation of Subthalamic nucleus and L-dopa modulate TMS-evoked cortical activity in Parkinson’s disease patients
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Abstracts / Clinical Neurophysiology 128 (2017) e1–e163
(I/O curves) were collected from the contralateral first dorsal interosseus (FDI) muscle. Post stimulation, participants sat in front of a 15” laptop computer screen and watched a 30-min movie of actors yawning. Whilst watching the movie, participants were asked to either suppress yawning or yawn freely. In order to measure the propensity to yawn, participants were recorded using a webcam. Two independent raters, blinded to condition, counted the number of yawns from the participant recordings. The inter-rater reliability was calculated using Chronbach’s alpha. Results & conclusion: Participants yawned significantly more in the free condition compared to the suppress condition. Multiple linear regression showed that the propensity to yawn was not significantly related to I/O curves. Moreover, no linear relationship was observed between I/O curves and resting motor threshold. Results show that the propensity to yawn might not be related to individual I/O curves. Future studies could include further TMS parameters such as SICI.
Conclusions: Our data reveal that bilateral STN-DBS induces a significant modulation of cortical global reactivity at early components. The association of LD therapy produces additional distinct modulation of later components. These findings could be related to cortical induced modulation of GABAergic intracortical activity. doi:10.1016/j.clinph.2016.10.169
P044 The effect of transcutaneous vagal nerve stimulation on experimental heat pain – A crossover blinded sham- and placebocontrolled investigation—H. Hacker a,*, N. Möller a, a a a,b a N.N. Gürtlerz , K. Hahnenkamp , T.I. Usichenko ( University Medicine Greifswald, Anesthesiology, Greifswald, Canada, b McMaster University, Anesthesia, Hamilton, Canada) ⇑
Corresponding author.
References Dijksterhuis A et al. The perception-behavior expressway: automatic effects of social perception on social behaviour. Adv Exp Social Psychol 2001;33:1–39. Platek SM, Mohamed FB, Gallup Jr GG. Contagious yawning and the brain. Cognitive Brain Res 2005;23:448–52. Schürmann M et al. Yerning to yawn: the neural basis of contagious yawning. NeuroImage 2005;24:1260–4. doi:10.1016/j.clinph.2016.10.168
P043 Deep brain stimulation of Subthalamic nucleus and L-dopa modulate TMS-evoked cortical activity in Parkinson’s disease patients—E.P. Casula *, M.C. Pellicciari, V. Ponzo, M. Stampanoni Bassi, D. Veniero, A. Peppe, L. Brusa, A. Stefani, G. Koch (Noninvasive Brain Stimulation Unit, Santa Lucia Foundation, Rome, Italy) ⇑
Corresponding author.
Question: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) represents an effective therapy in Parkinson’s disease (PD). The effects of STN-DBS on cortical reactivity are still poorly understood. By combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG), we explored the effects of STNDBS either alone or in combination with levodopa (LD), on cortical activity evoked by TMS of the primary motor cortex (M1) in a sample of PD patients chronically treated with STN implantation. Methods: Six advanced PD patients treated with STN-DBS were tested in three clinical conditions on distinct days: (i) on therapy/ on DBS; (ii) off therapy/on DBS; (iii) off therapy/off DBS. In each condition, 80 single TMS pulses were delivered over left M1 while simultaneously acquiring EEG. We evaluated TMS-induced changes in the time domain and in the time/frequency domain. Results: In the OFF/ON condition there was a significant increase of GMFP peaking at 60–70 ms (P2) compared to OFF/OFF condition. In ON/ON condition a significant increase of GMFP peaking at 60– 70 ms (P2) and at 100 ms (P3) was observed compared to OFF/OFF condition. Time/frequency analysis showed a synchronization of activity in the 10–17 Hz range over central-posterior region within the P2 time window in the OFF/ON condition compared to OFF/ OFF. The same analysis conducted on the P3 time window revealed a synchronization of activity in the 11–16 Hz range of frequency over central regions when comparing OFF/ON condition to ON/ON.
Question: Transcutaneous vagal nerve stimulation (TVNS) is a promising treatment for acute and chronic pain (Busch et al., 2013), however the testing of TVNS within the experimental pain models yielded controversial results (Busch et al., 2013; Laqua et al., 2013). The aim was to investigate the effect of TVNS on perception of repetitive heat pain stimuli (RHPS) in comparison with sham and placebo procedure in healthy volunteers. Methods: Forty-nine participants (25 females) underwent 4 RHPS sessions within an interval of 48 h in-between. During each session, 90 heat stimuli of individual pain tolerance temperature (ramp rate 20 °C/s, pulse duration 0.8 s, frequency of stimulation 0.33 Hz) were applied to the forearm using a CHEPS thermode (Medoc, Israel). The first (baseline) session was performed without intervention, during three following sessions either TVNS, sham (earlobe stimulation) or placebo condition were applied in a random crossover manner. Participants rated the perceived pain intensity of the first and each 10th stimulus using numeric rating scale 0–100. Data was analysed using ANOVA and Bonferroni adjusted multiple comparisons. Results: Participants reported less pain during all interventional methods compared to baseline (p < 0.001, Fig. 1), whereas pain under TVNS was lower than under placebo procedure after 30 stimuli (p = 0.038, Fig. 1). The effect of TVNS and sham stimulation on RHPS perception was comparable. Conclusion: We could confirm the hypoalgesic effects of TVNS, but these effects were not distinguishable from sham intervention in our
Figure 1: Pain ratings of repetitive heat pain stimulation were reduced under TVNS, sham and placebo procedures in comparison with baseline (** p<0.001). Pain Intensities after 30 stimuli were lower under TVNS compared to placebo (*p<0.038). Data given as mean ± SEM.
Abstracts / Clinical Neurophysiology 128 (2017) e1–e163
(I/O curves) were collected from the contralateral first dorsal interosseus (FDI) muscle. Post stimulation, participants sat in front of a 15” laptop computer screen and watched a 30-min movie of actors yawning. Whilst watching the movie, participants were asked to either suppress yawning or yawn freely. In order to measure the propensity to yawn, participants were recorded using a webcam. Two independent raters, blinded to condition, counted the number of yawns from the participant recordings. The inter-rater reliability was calculated using Chronbach’s alpha. Results & conclusion: Participants yawned significantly more in the free condition compared to the suppress condition. Multiple linear regression showed that the propensity to yawn was not significantly related to I/O curves. Moreover, no linear relationship was observed between I/O curves and resting motor threshold. Results show that the propensity to yawn might not be related to individual I/O curves. Future studies could include further TMS parameters such as SICI.
Conclusions: Our data reveal that bilateral STN-DBS induces a significant modulation of cortical global reactivity at early components. The association of LD therapy produces additional distinct modulation of later components. These findings could be related to cortical induced modulation of GABAergic intracortical activity. doi:10.1016/j.clinph.2016.10.169
P044 The effect of transcutaneous vagal nerve stimulation on experimental heat pain – A crossover blinded sham- and placebocontrolled investigation—H. Hacker a,*, N. Möller a, a a a,b a N.N. Gürtlerz , K. Hahnenkamp , T.I. Usichenko ( University Medicine Greifswald, Anesthesiology, Greifswald, Canada, b McMaster University, Anesthesia, Hamilton, Canada) ⇑
Corresponding author.
References Dijksterhuis A et al. The perception-behavior expressway: automatic effects of social perception on social behaviour. Adv Exp Social Psychol 2001;33:1–39. Platek SM, Mohamed FB, Gallup Jr GG. Contagious yawning and the brain. Cognitive Brain Res 2005;23:448–52. Schürmann M et al. Yerning to yawn: the neural basis of contagious yawning. NeuroImage 2005;24:1260–4. doi:10.1016/j.clinph.2016.10.168
P043 Deep brain stimulation of Subthalamic nucleus and L-dopa modulate TMS-evoked cortical activity in Parkinson’s disease patients—E.P. Casula *, M.C. Pellicciari, V. Ponzo, M. Stampanoni Bassi, D. Veniero, A. Peppe, L. Brusa, A. Stefani, G. Koch (Noninvasive Brain Stimulation Unit, Santa Lucia Foundation, Rome, Italy) ⇑
Corresponding author.
Question: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) represents an effective therapy in Parkinson’s disease (PD). The effects of STN-DBS on cortical reactivity are still poorly understood. By combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG), we explored the effects of STNDBS either alone or in combination with levodopa (LD), on cortical activity evoked by TMS of the primary motor cortex (M1) in a sample of PD patients chronically treated with STN implantation. Methods: Six advanced PD patients treated with STN-DBS were tested in three clinical conditions on distinct days: (i) on therapy/ on DBS; (ii) off therapy/on DBS; (iii) off therapy/off DBS. In each condition, 80 single TMS pulses were delivered over left M1 while simultaneously acquiring EEG. We evaluated TMS-induced changes in the time domain and in the time/frequency domain. Results: In the OFF/ON condition there was a significant increase of GMFP peaking at 60–70 ms (P2) compared to OFF/OFF condition. In ON/ON condition a significant increase of GMFP peaking at 60– 70 ms (P2) and at 100 ms (P3) was observed compared to OFF/OFF condition. Time/frequency analysis showed a synchronization of activity in the 10–17 Hz range over central-posterior region within the P2 time window in the OFF/ON condition compared to OFF/ OFF. The same analysis conducted on the P3 time window revealed a synchronization of activity in the 11–16 Hz range of frequency over central regions when comparing OFF/ON condition to ON/ON.
Question: Transcutaneous vagal nerve stimulation (TVNS) is a promising treatment for acute and chronic pain (Busch et al., 2013), however the testing of TVNS within the experimental pain models yielded controversial results (Busch et al., 2013; Laqua et al., 2013). The aim was to investigate the effect of TVNS on perception of repetitive heat pain stimuli (RHPS) in comparison with sham and placebo procedure in healthy volunteers. Methods: Forty-nine participants (25 females) underwent 4 RHPS sessions within an interval of 48 h in-between. During each session, 90 heat stimuli of individual pain tolerance temperature (ramp rate 20 °C/s, pulse duration 0.8 s, frequency of stimulation 0.33 Hz) were applied to the forearm using a CHEPS thermode (Medoc, Israel). The first (baseline) session was performed without intervention, during three following sessions either TVNS, sham (earlobe stimulation) or placebo condition were applied in a random crossover manner. Participants rated the perceived pain intensity of the first and each 10th stimulus using numeric rating scale 0–100. Data was analysed using ANOVA and Bonferroni adjusted multiple comparisons. Results: Participants reported less pain during all interventional methods compared to baseline (p < 0.001, Fig. 1), whereas pain under TVNS was lower than under placebo procedure after 30 stimuli (p = 0.038, Fig. 1). The effect of TVNS and sham stimulation on RHPS perception was comparable. Conclusion: We could confirm the hypoalgesic effects of TVNS, but these effects were not distinguishable from sham intervention in our
Figure 1: Pain ratings of repetitive heat pain stimulation were reduced under TVNS, sham and placebo procedures in comparison with baseline (** p<0.001). Pain Intensities after 30 stimuli were lower under TVNS compared to placebo (*p<0.038). Data given as mean ± SEM.