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O204 Simultaneous bi-hemispheric repetitive transcranial magnetic stimulation for upper limb motor recovery in chronic stroke: A double blind placebo controlled study
Abstracts / Clinical Neurophysiology 128 (2017) e178–e303
O202 Combining the strengths of passive functional mapping and electrical cortical stimulation—Robert Prueckl 1, Christopher Kapeller 1, Johannes Gruenwald 1, Christoph Guger 1, Francisco Fernandes 2, Martin Walchshofer 2, Alexander Heilinger 2,*, Hiroshi Ogawa 3, Kyousuke Kamada 3, Milena Korostenskaja 4 (1 Guger Technologies OG, Research & Development, Schiedlberg, Austria, 2 G.tec medical engineering GmbH, Research & Development, Schiedlberg, Austria, 3 Asahikawa Medical University, Neurosurgery, Asahikawa, Japan, 4 Florida Hospital for Children, Neurosurgery, Orlando, USA) Background: The identification of eloquent cortex, surrounding the seizure onset zone, is important for predictable surgical outcome in epilepsy patients. The symptoms during electrical cortical stimulation (ECS) lead to a functional map that includes motor, sensory, and other functions. In this study we test whether a prevenient high-gamma mapping (HGM) with electrocorticography can guide ECS mapping and therefore optimizes it in terms of time and stimulation related risks. Methods: Four patients underwent clinical ECS mapping and volunteered for an HGM session. The results enable an evaluation of the potential HGM contribution to the effectiveness of the ECS protocol. During HGM sessions, all patients performed hand movement, tongue movement, and listened to words. As a measure, the significance of guidance derives from a bootstrapping approach and indicates whether the HGM-guided ECS outperforms a random guidance. Additionally the potential reduction of required stimulations was calculated. Results: On average, 52 electrode pairs were stimulated, where on average 18.8 electrodes relate to motor, sensory, or language-related functions. The number of required ECS stimulations could have been reduced to 31.3 electrodes on average (60.2%). Even with the reduced number of stimulations, all the electrodes that have originally been revealed, were identified. The HGM mapping significantly improves the ECS protocol for all four subjects (p < 0.05). Conclusions: Compared to pure ECS, the proposed combined approach greatly reduces the required overall mapping time/effort as the HGM initially highlights the potential stimulation targets. We are encouraged that the presented system improves functional mapping in clinical practice. Keywords: Neurosurgery, ECS, Functional mapping, Brain stimulation, Epilepsy, Brain tumour, ECoG doi:10.1016/j.clinph.2017.07.210
O203 Neuromodulation of lower limb motor circuitry with transcutaneous lumbar spinal cord direct current stimulation— Mamede De Carvalho 1, Mariana Pereira 1, Sofia Fernandes 2, Pedro Cavaleiro Miranda 2 (1 Institute of Physiology, Faculty of Medicine, University of Lisbon, Instituto de Medicina Molecular, Lisboa, Portugal, 2 Faculdade de Ciências, Universidade de Lisboa, Instituto de Biofísica e Engenharia Biomédica, Lisboa, Portugal) Objectives: The advent of transcranial direct current stimulation (tDCS) introduced growing interest in modulating spinal circuits, altered in many neurologic conditions. Transcutaneous spinal direct current stimulation (tsDCS) of cervical and thoracic spine regions was observed to modulate sensory and motor responses. Combining clinical studies with computational modelling can be a powerful tool to establish tsDCS protocols for specific therapeutic purposes. The aim of this study was to measure the effects of
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tsDCS delivered on the lumbar region on motor spinal responses and observe if these were consistent with the electric field (E-field) distribution predicted in the spinal cord using a computational model. Methods: The exploratory study design was double-blind crossover pseudo-randomized. tsDCS was delivered for 15 min (anodal, cathodal, sham) at L2 vertebra level (2.5 mA, 90 C/cm2) in 15 healthy subjects. The F-wave, H-reflex, cortical silent period, motor evoked potential and sympathetic skin response were analysed. Statistical methods were applied with Bonferroni correction for multiple comparisons (p = 0.05). A human volume conductor model was obtained from available databases. E-field distributions in the spinal grey matter (GM) and white matter (WM) were calculated considering the same protocol and tissue conductivities based on literature review. Results: We observed the increase of the F-wave mean latency, however this was independent of the type of intervention. No other differences were observed (p > 0.05, Bonferroni corrected). The Efield magnitude predicted for the lumbosacral spinal GM and WM was <0.15 V/m. During tDCS, the E-field in the motor cortex is >0.15 V/m in protocols with observed modulation of motor responses. Discussion: Therefore, the E-field obtained is not sufficient to ensure neuromodulation, which is consistent with the absence of effects observed. The tsDCS protocol applied did not change motor response to delivered stimulus, having no effect on lumbosacral motor circuits. Conclusions: Future studies should address diversified protocols sustained in computational models. Significance: Computer models of E-field for tsDCS should be optimized to increase chances of a biological effect. Keywords: tsDCS, Spinal cord, Modulation, Neurophysiology, Computational modelling doi:10.1016/j.clinph.2017.07.211
O204 Simultaneous bi-hemispheric repetitive transcranial magnetic stimulation for upper limb motor recovery in chronic stroke: A double blind placebo controlled study—Raffaella Chieffo 1, Giuseppe Scopelliti 1, Mario Fichera 1, Giovanni Di Maggio 1, Roberto Santangelo 1, Simone Guerrieri 1, Elise Houdayer 1, Abraham Zangen 2, Giancarlo Comi 1, Letizia Leocani 1 (1 Hospital San Raffaele, Department of Neurology, Milan, Italy, 2 Ben-Gurion University, Department of Life Sciences, Beer-Sheva, Israel) Objective: repetitive transcranial magnetic stimulation (rTMS) is a promising intervention for the treatment of post-stroke motor deficits. Since the crucial role of non-primary motor cortices and contralesional brain areas is emerging for motor recovery in chronic stroke; we assessed safety and efficacy of bilateral rTMS over the motor areas associated to physical training (PT) on upper extremity (UE) motor function. Methods: double-blind, placebo-controlled trial on 20 patients with chronic stroke conditioning moderate to mild upper limb motor impairment. Eleven sessions of high frequency rTMS were delivered with the H-coil over the motor areas bilaterally. Subjects were randomly allocated to the real rTMS plus PT or the placebo (sham) rTMS plus PT. UE impairment was evaluated by the Fugl-Meyer assessment for UE (FM-UE), Modified Ashworth Scale (MAS) and hand grip strength at baseline (T0), after treatment (T1) and onemonth follow-up (T2).
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Abstracts / Clinical Neurophysiology 128 (2017) e178–e303
Results: no serious adverse events were reported. At T1 FM-UE significantly improved in both groups, while at T2 the improvement was significant only for the real group. The improvement was significantly higher in the real compared with the sham group. In the real group, greater improvement in FM-UE was found in patients moderately impaired compared with less impaired at baseline. Spasticity and hand grip strength also significantly improved in the real group at T1 and amelioration of spasticity persisted also at T2. Conclusion: bilateral high-frequency rTMS with H-coil associated with PT is safe and enhances the effect of PT alone. Although plegic patients were not included, subjects with moderate rather than mild motor impairment may mainly benefit from this stimulation protocol.
Keywords: rTMS, H-coil, Stroke, Recovery doi:10.1016/j.clinph.2017.07.212
O205 Motor event-related desynchronization/synchronization (ERD/ERS) is modulated by transcranial static magnetic field stimulation (tSMS)—Gurutzi Azcona 1, Manuel Alegre 2, Guglielmo Foffani 3 (1 Complejo Hospitalario de Navarra, Clinical Neurophysiology, Pamplona, Spain, 2 Clínica Universidad de Navarra, Clinical Neurophysiology, Pamplona, Spain, 3 Hospital Universitario HM Puerta del Sur, Center for Neuroscience, Madrid, Spain) Objectives: There is a growing interest about the potential use of non-invasive neuromodulation as treatment for different neurologic and psychiatric conditions. Transcranial static magnetic field stimulation (tSMS) is very simple to use and has shown significant effects on cortical excitability. Our aim was to analyze the effect of tSMS on movement-related cortical oscillatory activity. Methods: We performed a randomized parallel sham-controlled study in healthy volunteers to investigate the changes in alpha and beta motor ERD/ERS induced by 30-min tSMS of the motor cortex. We recorded 6 EEG channels from 20 healthy volunteers who performed a minimum of 100 hand ballistic movements, before and after stimulation (tSMS or sham stimulation in two different sessions). ERD/ERS was computed by means of Gabor transforms. Results: We observed a reduction of the amplitude of the alpha ERD and alpha ERS after tSMS, that was not observed after sham stimulation. The effect of tSMS lasted for at least 30 min. There was no effect on beta ERD/ERS. Discussion: tSMS over the motor cortex has been shown to decrease cortical excitability as measured by motor evoked potentials (MEPs) induced with transcranial magnetic stimulation. Our results show that it also has a selective effect on the oscillatory behaviour of the motor cortex. Conclusions: Alpha motor ERD/ERS is modulated by transcranial static magnetic field stimulation, while beta ERD/ERS is not. Significance: The changes induced by tSMS in the motor cortex include dynamic modulation of cortical activity. Keywords: Transcranial static magnetic fields stimulation, Eventrelated synchronization, Event-related desynchronization doi:10.1016/j.clinph.2017.07.213
O206 The efficacy of repetitive transcranial magnetic stimulation in treating patients with chronic daily headache—Ann Abdel Kader 1, Ebtesam Fahmy 2, Ayatullah Ahmad 1, Amira Labib 1,*, Leqaa Elmekkawy 1 (1 Cairo University, Department of Clinical Neurophysiology, Cairo, Egypt, 2 Cairo University, Department of Neurology, Cairo, Egypt) Objectives: Headache is the most prevalent pain disorder, affecting around 66% of the global population. This study aimed to investigate the efficacy of high-frequency repetitive transcranial magnetic stimulation (rTMS) over the left DLPFC in treating patients with primary chronic daily headaches (chronic tension type headache and chronic migraine). Methods: Twenty-seven patients participated in the study, divided into two groups: a study group (sixteen patients) and a control group (eleven patients). Treatment consisted of twelve high frequency (5 Hz) real rTMS sessions, delivered over the left DLPFC, every other day excluding weekends, whereas sham rTMS was used for the control group. Measures of attack frequency, headache intensity and headache index were recorded before and after treatment. Results: Patients of the study group, after real rTMS stimulation, showed a high statistically significant reduction of the measured headache parameters compared to the control group (Pvalue < 0.001) and the percentage of improvement was 94.5%. No significant reduction of headache parameters, after sham rTMS stimulation, was observed in the control group (P-value > 0.05) and percentage of improvement was 7.9%. Discussion: Results came in agreement with most of other studies done in this field. Conclusion:High-frequency rTMS is effective in reducing chronic tension headache and chronic migraine. Significance: This finding runs with the approval of the suggested role of DLPFC in pain control. This might open opinions for new treatment strategies in tension type headache and migraine prevention.
Keywords: Repetitive transcranial magnetic stimulation (rTMS), Chronic tension type headache (CTTH), Chronic migraine (CM) doi:10.1016/j.clinph.2017.07.214
O207 Safety and effects on motor cortex excitability of five closely repeated cathodal transcranial direct current stimulations— Antonino Uncini 1,2, Filippo Zappasodi 1,2, Gabriella Musumeci 3, Riccardo Navarra 1,2, Massimo Caulo 1,2, Vincenzo Di Lazzaro 4 (1 University ‘‘G. d’Annunzio” Chieti-Pescara, Italy, 2 Department of Neuroscience, Imaging and Clinical Sciences, Chieti, Italy, 3 Università Campus Bio-Medico di Roma, Department of Medicine, Rome, Italy, 4 Università Campus Bio-Medico di Roma, Department of Medicine, Chieti, Italy) Objective: To assess safety and effects of five cathodal-tDCS (charge density 342,857 C/m2) delivered at increasing time intervals in 25 h. Methods: Safety was defined as absence of serious adverse events and assessed by magnetic resonance imaging and spectroscopy. Effects on cortical excitability were evaluated by motor evoked potential (MEP) amplitudes. Inter-individual MEP variability was calculated by the standard error of mean at baseline and subjects were classified on the basis of the ratio between normalized MEPs after the first stimulation compared to baseline.
O202 Combining the strengths of passive functional mapping and electrical cortical stimulation—Robert Prueckl 1, Christopher Kapeller 1, Johannes Gruenwald 1, Christoph Guger 1, Francisco Fernandes 2, Martin Walchshofer 2, Alexander Heilinger 2,*, Hiroshi Ogawa 3, Kyousuke Kamada 3, Milena Korostenskaja 4 (1 Guger Technologies OG, Research & Development, Schiedlberg, Austria, 2 G.tec medical engineering GmbH, Research & Development, Schiedlberg, Austria, 3 Asahikawa Medical University, Neurosurgery, Asahikawa, Japan, 4 Florida Hospital for Children, Neurosurgery, Orlando, USA) Background: The identification of eloquent cortex, surrounding the seizure onset zone, is important for predictable surgical outcome in epilepsy patients. The symptoms during electrical cortical stimulation (ECS) lead to a functional map that includes motor, sensory, and other functions. In this study we test whether a prevenient high-gamma mapping (HGM) with electrocorticography can guide ECS mapping and therefore optimizes it in terms of time and stimulation related risks. Methods: Four patients underwent clinical ECS mapping and volunteered for an HGM session. The results enable an evaluation of the potential HGM contribution to the effectiveness of the ECS protocol. During HGM sessions, all patients performed hand movement, tongue movement, and listened to words. As a measure, the significance of guidance derives from a bootstrapping approach and indicates whether the HGM-guided ECS outperforms a random guidance. Additionally the potential reduction of required stimulations was calculated. Results: On average, 52 electrode pairs were stimulated, where on average 18.8 electrodes relate to motor, sensory, or language-related functions. The number of required ECS stimulations could have been reduced to 31.3 electrodes on average (60.2%). Even with the reduced number of stimulations, all the electrodes that have originally been revealed, were identified. The HGM mapping significantly improves the ECS protocol for all four subjects (p < 0.05). Conclusions: Compared to pure ECS, the proposed combined approach greatly reduces the required overall mapping time/effort as the HGM initially highlights the potential stimulation targets. We are encouraged that the presented system improves functional mapping in clinical practice. Keywords: Neurosurgery, ECS, Functional mapping, Brain stimulation, Epilepsy, Brain tumour, ECoG doi:10.1016/j.clinph.2017.07.210
O203 Neuromodulation of lower limb motor circuitry with transcutaneous lumbar spinal cord direct current stimulation— Mamede De Carvalho 1, Mariana Pereira 1, Sofia Fernandes 2, Pedro Cavaleiro Miranda 2 (1 Institute of Physiology, Faculty of Medicine, University of Lisbon, Instituto de Medicina Molecular, Lisboa, Portugal, 2 Faculdade de Ciências, Universidade de Lisboa, Instituto de Biofísica e Engenharia Biomédica, Lisboa, Portugal) Objectives: The advent of transcranial direct current stimulation (tDCS) introduced growing interest in modulating spinal circuits, altered in many neurologic conditions. Transcutaneous spinal direct current stimulation (tsDCS) of cervical and thoracic spine regions was observed to modulate sensory and motor responses. Combining clinical studies with computational modelling can be a powerful tool to establish tsDCS protocols for specific therapeutic purposes. The aim of this study was to measure the effects of
e243
tsDCS delivered on the lumbar region on motor spinal responses and observe if these were consistent with the electric field (E-field) distribution predicted in the spinal cord using a computational model. Methods: The exploratory study design was double-blind crossover pseudo-randomized. tsDCS was delivered for 15 min (anodal, cathodal, sham) at L2 vertebra level (2.5 mA, 90 C/cm2) in 15 healthy subjects. The F-wave, H-reflex, cortical silent period, motor evoked potential and sympathetic skin response were analysed. Statistical methods were applied with Bonferroni correction for multiple comparisons (p = 0.05). A human volume conductor model was obtained from available databases. E-field distributions in the spinal grey matter (GM) and white matter (WM) were calculated considering the same protocol and tissue conductivities based on literature review. Results: We observed the increase of the F-wave mean latency, however this was independent of the type of intervention. No other differences were observed (p > 0.05, Bonferroni corrected). The Efield magnitude predicted for the lumbosacral spinal GM and WM was <0.15 V/m. During tDCS, the E-field in the motor cortex is >0.15 V/m in protocols with observed modulation of motor responses. Discussion: Therefore, the E-field obtained is not sufficient to ensure neuromodulation, which is consistent with the absence of effects observed. The tsDCS protocol applied did not change motor response to delivered stimulus, having no effect on lumbosacral motor circuits. Conclusions: Future studies should address diversified protocols sustained in computational models. Significance: Computer models of E-field for tsDCS should be optimized to increase chances of a biological effect. Keywords: tsDCS, Spinal cord, Modulation, Neurophysiology, Computational modelling doi:10.1016/j.clinph.2017.07.211
O204 Simultaneous bi-hemispheric repetitive transcranial magnetic stimulation for upper limb motor recovery in chronic stroke: A double blind placebo controlled study—Raffaella Chieffo 1, Giuseppe Scopelliti 1, Mario Fichera 1, Giovanni Di Maggio 1, Roberto Santangelo 1, Simone Guerrieri 1, Elise Houdayer 1, Abraham Zangen 2, Giancarlo Comi 1, Letizia Leocani 1 (1 Hospital San Raffaele, Department of Neurology, Milan, Italy, 2 Ben-Gurion University, Department of Life Sciences, Beer-Sheva, Israel) Objective: repetitive transcranial magnetic stimulation (rTMS) is a promising intervention for the treatment of post-stroke motor deficits. Since the crucial role of non-primary motor cortices and contralesional brain areas is emerging for motor recovery in chronic stroke; we assessed safety and efficacy of bilateral rTMS over the motor areas associated to physical training (PT) on upper extremity (UE) motor function. Methods: double-blind, placebo-controlled trial on 20 patients with chronic stroke conditioning moderate to mild upper limb motor impairment. Eleven sessions of high frequency rTMS were delivered with the H-coil over the motor areas bilaterally. Subjects were randomly allocated to the real rTMS plus PT or the placebo (sham) rTMS plus PT. UE impairment was evaluated by the Fugl-Meyer assessment for UE (FM-UE), Modified Ashworth Scale (MAS) and hand grip strength at baseline (T0), after treatment (T1) and onemonth follow-up (T2).
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Abstracts / Clinical Neurophysiology 128 (2017) e178–e303
Results: no serious adverse events were reported. At T1 FM-UE significantly improved in both groups, while at T2 the improvement was significant only for the real group. The improvement was significantly higher in the real compared with the sham group. In the real group, greater improvement in FM-UE was found in patients moderately impaired compared with less impaired at baseline. Spasticity and hand grip strength also significantly improved in the real group at T1 and amelioration of spasticity persisted also at T2. Conclusion: bilateral high-frequency rTMS with H-coil associated with PT is safe and enhances the effect of PT alone. Although plegic patients were not included, subjects with moderate rather than mild motor impairment may mainly benefit from this stimulation protocol.
Keywords: rTMS, H-coil, Stroke, Recovery doi:10.1016/j.clinph.2017.07.212
O205 Motor event-related desynchronization/synchronization (ERD/ERS) is modulated by transcranial static magnetic field stimulation (tSMS)—Gurutzi Azcona 1, Manuel Alegre 2, Guglielmo Foffani 3 (1 Complejo Hospitalario de Navarra, Clinical Neurophysiology, Pamplona, Spain, 2 Clínica Universidad de Navarra, Clinical Neurophysiology, Pamplona, Spain, 3 Hospital Universitario HM Puerta del Sur, Center for Neuroscience, Madrid, Spain) Objectives: There is a growing interest about the potential use of non-invasive neuromodulation as treatment for different neurologic and psychiatric conditions. Transcranial static magnetic field stimulation (tSMS) is very simple to use and has shown significant effects on cortical excitability. Our aim was to analyze the effect of tSMS on movement-related cortical oscillatory activity. Methods: We performed a randomized parallel sham-controlled study in healthy volunteers to investigate the changes in alpha and beta motor ERD/ERS induced by 30-min tSMS of the motor cortex. We recorded 6 EEG channels from 20 healthy volunteers who performed a minimum of 100 hand ballistic movements, before and after stimulation (tSMS or sham stimulation in two different sessions). ERD/ERS was computed by means of Gabor transforms. Results: We observed a reduction of the amplitude of the alpha ERD and alpha ERS after tSMS, that was not observed after sham stimulation. The effect of tSMS lasted for at least 30 min. There was no effect on beta ERD/ERS. Discussion: tSMS over the motor cortex has been shown to decrease cortical excitability as measured by motor evoked potentials (MEPs) induced with transcranial magnetic stimulation. Our results show that it also has a selective effect on the oscillatory behaviour of the motor cortex. Conclusions: Alpha motor ERD/ERS is modulated by transcranial static magnetic field stimulation, while beta ERD/ERS is not. Significance: The changes induced by tSMS in the motor cortex include dynamic modulation of cortical activity. Keywords: Transcranial static magnetic fields stimulation, Eventrelated synchronization, Event-related desynchronization doi:10.1016/j.clinph.2017.07.213
O206 The efficacy of repetitive transcranial magnetic stimulation in treating patients with chronic daily headache—Ann Abdel Kader 1, Ebtesam Fahmy 2, Ayatullah Ahmad 1, Amira Labib 1,*, Leqaa Elmekkawy 1 (1 Cairo University, Department of Clinical Neurophysiology, Cairo, Egypt, 2 Cairo University, Department of Neurology, Cairo, Egypt) Objectives: Headache is the most prevalent pain disorder, affecting around 66% of the global population. This study aimed to investigate the efficacy of high-frequency repetitive transcranial magnetic stimulation (rTMS) over the left DLPFC in treating patients with primary chronic daily headaches (chronic tension type headache and chronic migraine). Methods: Twenty-seven patients participated in the study, divided into two groups: a study group (sixteen patients) and a control group (eleven patients). Treatment consisted of twelve high frequency (5 Hz) real rTMS sessions, delivered over the left DLPFC, every other day excluding weekends, whereas sham rTMS was used for the control group. Measures of attack frequency, headache intensity and headache index were recorded before and after treatment. Results: Patients of the study group, after real rTMS stimulation, showed a high statistically significant reduction of the measured headache parameters compared to the control group (Pvalue < 0.001) and the percentage of improvement was 94.5%. No significant reduction of headache parameters, after sham rTMS stimulation, was observed in the control group (P-value > 0.05) and percentage of improvement was 7.9%. Discussion: Results came in agreement with most of other studies done in this field. Conclusion:High-frequency rTMS is effective in reducing chronic tension headache and chronic migraine. Significance: This finding runs with the approval of the suggested role of DLPFC in pain control. This might open opinions for new treatment strategies in tension type headache and migraine prevention.
Keywords: Repetitive transcranial magnetic stimulation (rTMS), Chronic tension type headache (CTTH), Chronic migraine (CM) doi:10.1016/j.clinph.2017.07.214
O207 Safety and effects on motor cortex excitability of five closely repeated cathodal transcranial direct current stimulations— Antonino Uncini 1,2, Filippo Zappasodi 1,2, Gabriella Musumeci 3, Riccardo Navarra 1,2, Massimo Caulo 1,2, Vincenzo Di Lazzaro 4 (1 University ‘‘G. d’Annunzio” Chieti-Pescara, Italy, 2 Department of Neuroscience, Imaging and Clinical Sciences, Chieti, Italy, 3 Università Campus Bio-Medico di Roma, Department of Medicine, Rome, Italy, 4 Università Campus Bio-Medico di Roma, Department of Medicine, Chieti, Italy) Objective: To assess safety and effects of five cathodal-tDCS (charge density 342,857 C/m2) delivered at increasing time intervals in 25 h. Methods: Safety was defined as absence of serious adverse events and assessed by magnetic resonance imaging and spectroscopy. Effects on cortical excitability were evaluated by motor evoked potential (MEP) amplitudes. Inter-individual MEP variability was calculated by the standard error of mean at baseline and subjects were classified on the basis of the ratio between normalized MEPs after the first stimulation compared to baseline.