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Transcranial direct current stimulation and cortical indicators of relaxation
Abstracts / Brain Stimulation 8 (2015) 395e411
rehabilitation of their motor system. We investigate if transcranial direct current stimulation (tDCS) of the motor cortex elevates the degree and intensity of spontaneous motor imagery in resting states in comparison with a sham-tDCS condition. We report on tDCS-induced motor imagery in waking resting state as well as REM sleep, a state of consciousness that has been associated with motor learning and rehearsal. Our model of motor imagery could be used to design rehabilitation protocols especially for such temporarily immobile clinical patients who cannot perform certain motor imagery tasks, such as dementia patients, patients with psychological disorders, infants with developmental and motor disorders, and coma patients.
405
Results: 10 IPS patients were implanted. They underwent stereotactic DBS electrode insertion into the subthalamic nucleus (STN) using Boston Scientific VerciseÔ system. No intraoperative complications occurred. Conclusions: A visualization system may offer an improvement of programming in respect to symptom reduction as well as reduction of programming time and minimizing electrical consumption and thus increased battery life. Our experience shows this visualization system to be feasible and easy to use. However, its real life significance has to be revealed in clinical studies.
305 302 Transcranial direct current stimulation and cortical indicators of relaxation C. Speth , J. Speth , T. Harley University of Dundee, UK Can we use transcranial direct current stimulation (tDCS) to induce relaxation? Current relaxation techniques are feasible for only a limited group of people, as they require training, rehearsal and are difficult or even contraindicated under several common psychological dispositions (e.g. relaxation induced anxiety). Brain stimulation techniques such as tDCS could be a new approach to relaxation protocols. In an experimental setting with healthy participants, anodal and cathodal transcranial direct current stimulation is used above the C3 scalp position during an EEG controlled relaxation session. We report changes in frequency band power induced by the stimulation condition. The results of this study on healthy participants could lay the groundwork for future studies aiming at viable clinical applications of the technique.
304 Modelling Volume of Tissue Activated for Deep Brain Stimulation Jan Vesper MD, PhD, Gregor Bara MD, Stefan Schu MD, Phillip Slotty MD, Jarek Maciaczyk MD, PhD University Duesseldorf, Duesseldorf, Germany Introduction: DBS technology wise we have encountered the development of traditional constant voltage neurostimulators towards constant current systems with multi independent power sources allowing field shaping. These new stimulators deliver constant current to the brain tissue, irrespective of impedance changes that occur around the electrode, and enable more specific steering of current towards targeted regions of interest. It is thought that therapeutic efficacy elucidated by DBS largely depends on activation of a specific target volume whereas side effects result from activation of surrounding tissue. Therefore DBS surgery requires precise targeting of the electrode in the brain. However, even with the stereotactic based surgical techniques, excessive programming time is needed for an adequate therapeutic effect. Most often this programming practice is based on trial and error and focuses on acute as well as delayed effects. A visualization system for shaping the electric field in an anatomically appropriate manner could improve clinical outcome whilst reducing side effects as well as decreasing programming time and power consumption. Methods: Target areas were identified via CT-MRT fused imaging. Intraoperative target finding was supported by micro-electrode recordings as well as clinical testing. Postoperative CT scans were fused with preoperative MRI scans with Boston Sci’s GUIDE DBS visualization system. Postoperative electrode position was visualized. Programming was based on the best calculated volume of electrical tissue activation within this model.
Optimization of transcranial direct current stimulation (tDCS) parameters for lower-extremity pain perception M. Al Sawah a, C. Concerto a, E. Chusid a, M. Bikson b, H. Knotkova c, F. Battaglia d a Department of Pre-clinical Sciences, New York College of Podiatric Medicine, New York, NY b Department of Biomedical Engineering, The City College of New York, New York, NY c MJHS Institute for Innovation in Palliative Care, New York, NY d Seton Hall University, Health and Medical Sciences, South Orange, NJ Aims: TDCS can modulate various functional outcomes, including pain perception. Here we evaluated analgesic effects of anodal tDCS over the leg somatotopic representation as determined by i) focal transcranial magnetic stimulation (TMS) or ii) EEG 10-20 international system (position C1) as compared to pre-stimulation baseline and leg-representation-unrelated area (Oz), and examined the effects of cephalic vs extracephalic position of the complementary electrode (cathode), and two stimulation intensities (1 and 2 mA), on experimentally induced pain in the right anterior tibial area. Methods: Pain was elicited by electrical stimulation in 12 healthy adults (5 F, 7 M), age 30.47.6 years. Pain thresholds were determined in accordance with the guidelines for somatosensory testing. tDCS was delivered by the ActivaDoseÒII device with two salinesoaked sponge electrodes 5x5 cm2 for 5 minutes at 1 or 2 mA, at three cross-over study visits separated by one week. For the TMSguided anode positioning, the stimulus was delivered at 120% of motor threshold. The cathode was placed over the contralateral supraorbital region or on the shoulder (extracephalic montage). A computational modeling was employed to analyze the current flow through cerebral pain-processing network in the parameter-configurations examined in this study. Results: Significant (p<0.03) pain threshold increase were obtained with anodal stimulation of the leg motor area targeted with either the 10-20 EEG system or TMS, as compared to the baseline and to the leg-representation unrelated Oz area. The effects where obtained with both, cephalic and extracephalic cathode electrode positioning (p>0.05) and both 1mA and 2 mA stimulation intensities (p>0.05). No analgesic effects were observed when targeting the leg-representation-unrelated Oz area. Conclusions: The stimulation over C1 at intensity of 1 mA was sufficient to elicit the analgesic effects. The findings encourage explorations of tDCS over C1 in clinical populations of patients with lower-extremity pain.
306 Novel flexible cap with integrated textile electrodes for rapid transcranial electrical stimulation P. Fiedler a,*, A. Hunold a, C. Müller b, G. Rosner b, K. Schellhorn c, J. Haueisen a,d a Technische Universität Ilmenau, Germany b warmX GmbH, Germany c neuroConn GmbH, Germany d Jena University Hospital, Germany
rehabilitation of their motor system. We investigate if transcranial direct current stimulation (tDCS) of the motor cortex elevates the degree and intensity of spontaneous motor imagery in resting states in comparison with a sham-tDCS condition. We report on tDCS-induced motor imagery in waking resting state as well as REM sleep, a state of consciousness that has been associated with motor learning and rehearsal. Our model of motor imagery could be used to design rehabilitation protocols especially for such temporarily immobile clinical patients who cannot perform certain motor imagery tasks, such as dementia patients, patients with psychological disorders, infants with developmental and motor disorders, and coma patients.
405
Results: 10 IPS patients were implanted. They underwent stereotactic DBS electrode insertion into the subthalamic nucleus (STN) using Boston Scientific VerciseÔ system. No intraoperative complications occurred. Conclusions: A visualization system may offer an improvement of programming in respect to symptom reduction as well as reduction of programming time and minimizing electrical consumption and thus increased battery life. Our experience shows this visualization system to be feasible and easy to use. However, its real life significance has to be revealed in clinical studies.
305 302 Transcranial direct current stimulation and cortical indicators of relaxation C. Speth , J. Speth , T. Harley University of Dundee, UK Can we use transcranial direct current stimulation (tDCS) to induce relaxation? Current relaxation techniques are feasible for only a limited group of people, as they require training, rehearsal and are difficult or even contraindicated under several common psychological dispositions (e.g. relaxation induced anxiety). Brain stimulation techniques such as tDCS could be a new approach to relaxation protocols. In an experimental setting with healthy participants, anodal and cathodal transcranial direct current stimulation is used above the C3 scalp position during an EEG controlled relaxation session. We report changes in frequency band power induced by the stimulation condition. The results of this study on healthy participants could lay the groundwork for future studies aiming at viable clinical applications of the technique.
304 Modelling Volume of Tissue Activated for Deep Brain Stimulation Jan Vesper MD, PhD, Gregor Bara MD, Stefan Schu MD, Phillip Slotty MD, Jarek Maciaczyk MD, PhD University Duesseldorf, Duesseldorf, Germany Introduction: DBS technology wise we have encountered the development of traditional constant voltage neurostimulators towards constant current systems with multi independent power sources allowing field shaping. These new stimulators deliver constant current to the brain tissue, irrespective of impedance changes that occur around the electrode, and enable more specific steering of current towards targeted regions of interest. It is thought that therapeutic efficacy elucidated by DBS largely depends on activation of a specific target volume whereas side effects result from activation of surrounding tissue. Therefore DBS surgery requires precise targeting of the electrode in the brain. However, even with the stereotactic based surgical techniques, excessive programming time is needed for an adequate therapeutic effect. Most often this programming practice is based on trial and error and focuses on acute as well as delayed effects. A visualization system for shaping the electric field in an anatomically appropriate manner could improve clinical outcome whilst reducing side effects as well as decreasing programming time and power consumption. Methods: Target areas were identified via CT-MRT fused imaging. Intraoperative target finding was supported by micro-electrode recordings as well as clinical testing. Postoperative CT scans were fused with preoperative MRI scans with Boston Sci’s GUIDE DBS visualization system. Postoperative electrode position was visualized. Programming was based on the best calculated volume of electrical tissue activation within this model.
Optimization of transcranial direct current stimulation (tDCS) parameters for lower-extremity pain perception M. Al Sawah a, C. Concerto a, E. Chusid a, M. Bikson b, H. Knotkova c, F. Battaglia d a Department of Pre-clinical Sciences, New York College of Podiatric Medicine, New York, NY b Department of Biomedical Engineering, The City College of New York, New York, NY c MJHS Institute for Innovation in Palliative Care, New York, NY d Seton Hall University, Health and Medical Sciences, South Orange, NJ Aims: TDCS can modulate various functional outcomes, including pain perception. Here we evaluated analgesic effects of anodal tDCS over the leg somatotopic representation as determined by i) focal transcranial magnetic stimulation (TMS) or ii) EEG 10-20 international system (position C1) as compared to pre-stimulation baseline and leg-representation-unrelated area (Oz), and examined the effects of cephalic vs extracephalic position of the complementary electrode (cathode), and two stimulation intensities (1 and 2 mA), on experimentally induced pain in the right anterior tibial area. Methods: Pain was elicited by electrical stimulation in 12 healthy adults (5 F, 7 M), age 30.47.6 years. Pain thresholds were determined in accordance with the guidelines for somatosensory testing. tDCS was delivered by the ActivaDoseÒII device with two salinesoaked sponge electrodes 5x5 cm2 for 5 minutes at 1 or 2 mA, at three cross-over study visits separated by one week. For the TMSguided anode positioning, the stimulus was delivered at 120% of motor threshold. The cathode was placed over the contralateral supraorbital region or on the shoulder (extracephalic montage). A computational modeling was employed to analyze the current flow through cerebral pain-processing network in the parameter-configurations examined in this study. Results: Significant (p<0.03) pain threshold increase were obtained with anodal stimulation of the leg motor area targeted with either the 10-20 EEG system or TMS, as compared to the baseline and to the leg-representation unrelated Oz area. The effects where obtained with both, cephalic and extracephalic cathode electrode positioning (p>0.05) and both 1mA and 2 mA stimulation intensities (p>0.05). No analgesic effects were observed when targeting the leg-representation-unrelated Oz area. Conclusions: The stimulation over C1 at intensity of 1 mA was sufficient to elicit the analgesic effects. The findings encourage explorations of tDCS over C1 in clinical populations of patients with lower-extremity pain.
306 Novel flexible cap with integrated textile electrodes for rapid transcranial electrical stimulation P. Fiedler a,*, A. Hunold a, C. Müller b, G. Rosner b, K. Schellhorn c, J. Haueisen a,d a Technische Universität Ilmenau, Germany b warmX GmbH, Germany c neuroConn GmbH, Germany d Jena University Hospital, Germany