M. Liu

P247: Brain-machine interface training combined with transcranial direct current stimulation in patients with chronic severe hemiparesis: proof of concept study

Objective: Brain–computer interface technology has been applied to stroke patients to improve their motor function. Event-related desynchronization during motor imagery, which is used as a brain–computer interface trigger, is sometimes difficult to detect in stroke patients. Anodal transcranial direct current stimulation (tDCS) is known to increase event-related desynchronization. This study investigated the adjunctive effect of anodal tDCS for brain–computer interface training in patients with severe hemiparesis. Subjects: Eighteen patients with chronic stroke. Design: A non-randomized controlled study. Methods: Subjects were divided between a brain–computer interface group and a tDCS-brain–computer interface group and participated in a 10-day brain–computer interface training. Event-related desynchronization was detected in the affected hemisphere during motor imagery of the affected fingers. The tDCS-brain–computer interface group received anodal tDCS before brain–computer interface training. Event-related desynchronization was evaluated before and after the intervention. The Fugl-Meyer Assessment upper extremity motor score (FM-U) was assessed before, immediately after, and 3 months after, the intervention. Results: Event-related desynchronization was significantly increased in the tDCS- brain–computer interface group. The FM-U was significantly increased in both groups. The FM-U improvement was maintained at 3 months in the tDCSbrain–computer interface group. Conclusion: Anodal tDCS can be a conditioning tool for brain–computer interface training in patients with severe hemiparetic stroke.

P208 The effects of transcutaneous spinal cord stimulation on spinal reciprocal inhibition in healthy persons

Introduction Transcutaneous spinal cord stimulation (tSCS) is a non-invasive method to stimulate afferent structures of the spinal neural circuits related with lower limb motor control. Its application is known to improve lower limb motor function in individuals with spinal cord injury. However, it remains unknown whether tSCS induces spinal plasticity, which has an essential role in functional recovery of the lower limb after spinal cord injury and stroke. Objectives The purpose of this study was to investigate the effects of tSCS on spinal reciprocal inhibition in healthy individuals. Methods Twelve healthy volunteers participated in this single-masked, sham-controlled crossover study. The following three paradigms were randomly applied to them on three different days: (1) tSCS; (2) sham tSCS; (3) transcutaneous peripheral nerve patterned electrical stimulation (tPES). tSCS and tPES consisted of a train of 10 pulses at 100xa0Hz every 2xa0s for 20xa0min. tSCS was delivered to the thoracic spine level (Th11/12) with the intensity of sensory threshold ×xa02.0 without muscle contraction. tPES was applied to common peroneal nerve using the intensity equal to the motor threshold of tibialis anterior muscle. For sham stimulation, the same procedure was used, but the current was delivered for only 30xa0s.We assessed disynaptic reciprocal inhibition (RI) and presynaptic inhibition (D1) using a soleus H-reflex conditioning-test paradigm. The magnitudes of inhibition was assessed before, immediately after, 15xa0min and 30xa0min after the stimulation. Results tSCS significantly increased the amount of D1 inhibition immediately after and at 15xa0min after when compared with the baseline, and the effects were greater than other conditions immediately after and at 15xa0min after the stimulation. tSCS concurrently increased the amount of RI immediately after. tPES significantly increased the amount of RI until 15xa0min after the stimulation, but did not affect the D1 inhibition. Conclusion The present results provide further evidence that tSCS can induce short-term plastic changes in human spinal reciprocal inhibitory interneuron.

2-A-D-19. Functional navigated tDCS for patients with non-fluent aphasia

Inferior frontal gyrus (IFG) plays an important role for recovery of non-fluent aphasia. It is not, however, clear which side of IFG activation is better for functional recovery of non-fluent aphasia. We applied tDCS over IFG with using MRI guided navigation system and assessed reaction time for naming task. We applied both anodal and cathodal tDCS over left IFG. Electrodes were placed over both IFG. Anode electrode was placed over left IFG and cathode electrode was over right IFG in anodal tDCS. In cathodal tDCS, anode electrode was placed over right IFG and cathode electrode was over left IFG. Stimulus intensity was set at 2xa0mA and tDCS was applied for 10xa0min. Before and after tDCS, we assessed reaction time for naming task with Boston naming test. Anodal tDCS reduced reaction time in one patient (case A) and cathodal tDCS did in the other one patient (case B). We applied 7xa0days tDCS combined with speech therapy. Anodal tDCS in case A and cathodal tDCS in case B combined with speech therapy improved reaction time and correct answer rate. It is supposed that individually-tailored treatment is necessary to apply tDCS for patients with aphasia.

P252: The combined effects of anodal tDCS and patterned electrical stimulation on spinal inhibitory interneurons and motor function among patients with incomplete spinal cord injury

to the tinnitus frequency. One possibility to reverse the effects of this maladaptation is to induce inhibition on neurons corresponding to the tinnitus frequency by auditory stimulation. The aim of this study was to investigate the impact of repetitive stimulation with tailor-made notched music on neural activity in temporal and frontal cortical regions of tinnitus patients. Methods: Ten subjects suffering from chronic tonal tinnitus listened to music passing through a notch-filter centered at the tinnitus frequency (tailor-made notched music) for three hours on each of three consecutive days. Neural activity evoked by either a tone at the tinnitus frequency (tinnitus tone) or by a control tone of 500 Hz was measured by magnetoencephalography (MEG) before and immediately after music exposure. Tinnitus loudness was measured via visual analog scales. A distributed source model was used to investigate the neural activity in auditory as well as in frontal cortical regions in the N1m time window. Results: Neural activity evoked by the tinnitus tone in the temporal lobe decreased significantly after music exposure, whereas neural activity evoked by the control tone remained unaffected. Additionally, tinnitus loudness was rated significantly lower after music exposure. There was a significant correlation between the reduction of neural activity in the temporal lobe evoked by the tinnitus tone and the tinnitus loudness ratings. Furthermore, there was a significant increase of neural activity evoked by the control tone in the frontal lobe after music exposure, which could not be observed in the neural activity evoked by the tinnitus tone. Conclusions: Tailor-made notched music evokes neural plasticity in temporal as well as frontal cortical areas of tinnitus patients. Additionally, there is a clear connection between the reduction of tinnitus loudness and the neural reorganization in the temporal cortex. These effects could be demonstrated after a short period of music exposure, indicating a fast neural reorganization and behavioral adaptation.

P281: Modulation of cortical activity after anodal transcranial direct current stimulation during motor task: an fMRI study

s of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339 S123 pauses) and different c-tDCS durations (22 vs. 9 min), to evaluate if and how these parameters may alter its effects. Methods: 1.5mA c-tDCS was delivered by a battery-driven stimulator through an active electrode applied on primary visual cortex (16 cm2), and a reference electrode on the right arm (60 cm2). 82 subjects executed an orientation discrimination task (ODT) in a between-subjects design. They had to decide whether the presented stimulus was tilted clockwise or counterclockwise relative to the previously presented one. We measured the percentage of accuracy (d’ values). Results: rmANOVAs showed an improvement of the performance when ctDCS was applied before the task whereas with online c-tDCS performance was similar to sham. The presence of pauses during c-tDCS and a different duration of the stimulation did not modify the facilitatory induced effect. Conclusions: We demonstrated that not necessarily c-tDCS induce behavioural inhibition, but the effects should be considered in relation to the timing of application and the executed task. The same protocol of “neuroplasticity induction” can provoke different effects depending on the excitability level of the stimulated neurons. We speculate that offline c-tDCS could induce metaplasticity mechanisms functional to obtain an “optimal” neural activation when consequently the cortical area is involved in a specific task. P280 Effects of different repetitive transcranial magnetic stimulation treatments and the role of attentional bias in complex focal hand dystonia: a case-report A. Salatino1, G. Mazzeo1, M. Nobili2, R. Ricci1 1University of Turin, Department of Psychology, Turin, Italy; 2Koelliker Hospital, Unit of Neurology, Turin, Italy Question: Focal hand dystonia (FHD) is a movement disorder characterized by involuntary muscle contraction, causing abnormal postures. Its symptoms are associated with deficient cortical inhibition. Previous studies suggest that inhibitory low-frequency repetitive Transcranial Magnetic Stimulation (rTMS) over contralateral premotor cortex (PMC) might ameliorate FHD, although no clear evidence of significant improvement has been shown. In this study we investigated the effects of different rTMS protocols on complex FHD of the right hand and associated symptoms in a 41-year-old man. Methods: Two different experiments were conducted. In experiment 1, the patient underwent eight daily sessions of rTMS over left PMC. In experiment 2, in order to investigate the role of rightward attentional bias and the effects of lower doses of stimulation we compared the effectiveness of a weekly three days treatment over PMC with a three days treatment over left PPC (Posterior Parietal Cortex). RTMS over left Occipital cortex and sham stimulation over PPC constituted two control conditions. Clinical and behavioral evaluation comprised the patient’s self-estimation of dystonic symptoms, handwriting, finger tapping, and the use of everyday objects. In experiment 2, a line bisection task was also administered. Results: Taken together the findings of the experiments suggest that: 1) lower doses of rTMS over PMC, more distributed in time, may induce better clinical outcomes than higher doses; 2) the rightward attentional bias played a role in this patient’s FHD and was improved by rTMS over PPC; 3) rTMS over PPC induced longer term beneficial effects than rTMS over PMC. Conclusions: Our findings suggest that both PMC and PPC represent effective sites for rTMS treatment of FDH. Future double-blind placebocontrolled studies on groups of patients are needed to further explore the differential role played by the two sites in the pathophysiology of FHD and optimal doses of stimulation. P281 Modulation of cortical activity after anodal transcranial direct current stimulation during motor task: an fMRI study K. Shindo1,2,3, T. Ono2,4, Y. Kasashima-Shindo1,3, H. Ebata2, M. Liu1 1Keio University School of Medicine, Department of Rehabilitation Medicine, Tokyo, Japan; 2Saiseikai Kanagawa Prefecture Hospital, Department of Rehabilitation Medicine, Yokohama, Japan; 3Danish Research Center for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; 4Keio University Faculty of Science and Technology, Department of Biosciences and Informatics, Yokohama, Japan Question: It is known that offline anodal transcranial direct current stimulation (AtDCS) increases cortical activation by motor task. However, it is still unclear how AtDCS during motor task modulates the brain activity. Methods: AtDCS over the non-dominant hand area of the primary motor cortex was applied in 11 healthy subjects. Each subject participated in 2 experimental sessions (either AtDCS with an intensity of 1mA for 10 minutes or sham tDCS) in pseudo-randomized crossover design with an interval of at least 1 week. Each tDCS was applied while performing finger tapping task using non-dominant hand. Before and 10 minutes after each tDCS, BOLD signals for finger tapping task were recorded in a block design manner. Results: Brain activities in the contralateral primary sensorimotor cortex during the task were reduced after AtDCS. There was no significant change after sham tDCS. Conclusions: This finding supports that AtDCS while performing motor task decreases the motor cortex excitability as measured with transcranial magnetic stimulation (TMS). This study clarified that AtDCS in combination with the motor task induced effects different from AtDCS alone. P282 Effect of coil orientation on strength-duration time constant with controllable pulse parameter transcranial magnetic stimulation K. D’Ostilio1,2, S. Goetz3,4, M. Ciocca1,5, R. Chieffo1,6, J.-C.A. Chen1,7, A.V. Peterchev3, J.C. Rothwell1 1University College London, Sobell Department of Motor Neuroscience and Movement Disorders, London, United Kingdom; 2University of Liege, MoVeRe Group, Cyclotron Research Centre, Liège, Belgium; 3Duke University, Department of Psychiatry and Behavioral Sciences, Durham, United States; 4Technical University Munich, Munich, Germany; 5University of Milan, Department of Neurological Science, Milan, Italy; 6Scientific Institute Hospital San Raffaele, Department of Neurology, Milan, Italy; 7China Medical University Hospital, Department of Neurology, Taiwan, Taiwan Question: Controllable pulse parameter transcranial magnetic stimulation (cTMS) devices are now available. Is it possible to adjust pulse width to more selectively stimulate neuronal populations with different time constants? How does this impact on the evoked EMG responses? Methods: 10 young healthy subjects participated in the experiment (5 men/5 women). Single pulse stimulation over the hand motor area was performed using a cTMS device that generates monophasic pulses with independent control of the pulse width, connected to a figure-of-eight coil. We tested the effect of coil orientations (i.e. posterio-anterior (PA)/anteriorposterior (AP)) with three different pulse widths (30, 60 and 120 μs) on the strength-duration curve, the input-output (IO) curve and the latency of the motor evoked potentials (MEPs) in the first dorsal interosseous muscle. Results: During a weak background contraction, strength-duration time constants were estimated from both motor threshold and IO data for PA and AP orientations. When estimation was based on motor threshold data, the mean strength-duration time constants were 231 and 294 μs (t(9) =3.39; p=0.008) whereas time constants were 252 and 296 μs respectively (t(9) =8.74; p<0.001) for estimation from IO data. Repeated measure ANOVA on MEP latencies to AP and PA stimulation (during active contraction) revealed a significant interaction between pulse width and orientation (F(2,18) =9.97; p=0.001), due mainly to longer onset latencies following AP stimuli of short duration. Conclusion: The data suggests that PA and AP orientation activate neural populations with different time constants. The long time constant element activated by short duration AP pulses has a more indirect connection with the corticospinal output neurones than the PA activated population probably because it tends to recruit later I-waves. P283 Transcranial direct current stimulation (tDCS) in Parkinson’s disease R. Ferrucci1,2, M. Bianchi3, D. Pittera2, F. Cortese2, R. Turrone3, M. Vergari2, T. Bocci2, E. Tomasini2, B. Borroni3, M. Fumagalli2, F. Mameli2, E. Scelzo2, F. Cogiamanian2, G. Ardolino2, A. Di Fonzo2, A. Padovani3, A. Priori1,2 1Università degli Studi di Milano, Milan, Italy; 2Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico di Milano, Università di Milano, Milan, Italy; 3Clinica Neurologica, Spedali Civili di Brescia, Università degli Studi di Brescia,

Poster session 14. NeurorehabilitationP252: The combined effects of anodal tDCS and patterned electrical stimulation on spinal inhibitory interneurons and motor function among patients with incomplete spinal cord injury

s of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339 S115 Abstract P250 – Figure 1. MEP and facilitatory ppTMS pre and post rehabilitation treatment.P250 – Figure 1. MEP and facilitatory ppTMS pre and post rehabilitation treatment. of stroke rehabilitation effects and may contribute to a better understanding of the mechanisms underlying the functional recovery induced by rehabilitation. P251 Central effects of neuromuscular electrical stimulation applied to healthy subjects and stroke patients M. Gobbo1,2, S. Alì1, L. Bissolotti2, C. Orizio1,2, C. Maioli1, L. Falciati1 1University of Brescia, Clinical and Experimental Sciences, Brescia, Italy; 2Fondazione Teresa Camplani Casa di Cura Domus Salutis, Laboratory of Neuromuscular Rehabilitation, Brescia, Italy Modern neurorehabilitation aims at motor recovery by limiting compensatory strategies. For this purpose it is essential to strengthen the muscles involved in daily activities and let the patients relearn motor strategies similar to those of normality. The NeuroMuscular Electrical Stimulation (NMES) is used to regain, maintain or increase muscular strength and function. By applying a paradigm of Transcranial Magnetic Stimulation (TMS) we investigated whether the peripheral electrical stimulation of upper-limb muscles functionally modulates the cortical excitability. The study was first conducted on healthy subjects and, at a later stage, on stroke patients. Single-pulse TMS was applied to the motor cortex and motor evoked potentials (MEPs) were recorded from contralateral upperlimb in extensor carpi radialis (ECR), extensor digitorum (ED) and first dorsal interosseus (FDI) muscles. MEPs were obtained by sequences of 12 TMS pulses delivered within a 1-min time window at 3-min intervals both before the NMES protocol (baseline) and within 15 minutes following it. NMES was applied to extrinsic extensor muscles of the hand for 15 minutes using 30-sec cycles of single pulses and a 2 sec 50 Hz tetanic contraction allowing the extension of wrist and fingers. Results revealed changes on peak-to-peak MEP amplitudes which occurred immediately after NMES, in ED and FDI muscles. This pattern of modulation reached baseline values on mean within 4 minutes following the electrical stimulation protocol. By contrast, no change of MEP amplitude was observed in ECR muscle. Thus, the peripheral electrical stimulation of skeletal muscles induces effects on the excitability of the motor cortex, which, noteworthy, is affected in a specific manner, being the distal muscles controlling hand movements the main target of the observed modulations. This suggests the potential role of NMES in shaping cortical reorganization after stroke. P252 The combined effects of anodal tDCS and patterned electrical stimulation on spinal inhibitory interneurons and motor function among patients with incomplete spinal cord injury T. Yamaguchi1, T. Fujiwara1, Y.-A. Tsai1,2,3, S.-C. Tang2, M. Liu1 1Keio University School of Medicine, Rehabilitation Medicine, Tokyo, Japan; 2Taipei Veterans General Hospital, Center for Neural Regeneration, Taipei, Taiwan; 3National Yang Ming University, Taipei, Taiwan Question: Supraspinal modulation and phase-related sensory input might play an important role for the modulation of spinal reflex and functional recovery of locomotion among patients with incomplete spinal cord injury (SCI). The present study examined the combined effects of anodal transcranial direct current stimulation (tDCS) and patterned electrical stimulation (PES) on the spinal inhibitory interneurons and lower extremity motor function in patients with incomplete SCI. Methods: Eleven patients with incomplete SCI participated in this singlemasked, sham-controlled cross-over study. They randomly participated in the following two sessions: (1) anodal tDCS combined with PES; (2) sham tDCS combined with PES. We applied PES to the common peroneal nerve with a train of 10 pulses at 100 Hz every 2 s for 20 min. Anodal tDCS (1 mA) was simultaneously applied to the primary motor cortex for 20 min. In sham condition, tDCS was delivered for only the first 15 s. We assessed disynaptic reciprocal inhibition (RI) and presynaptic inhibition (D1 and D2) using a soleus H-reflex conditioning-test paradigm. The conditioning-test stimulus interval was set at 2 ms (RI), 20 ms (D1), and 100 ms (D2). The magnitudes of inhibition was assessed before, immediately after, 10 min and 20 min after the stimulation. We measured ankle movement speed before and 20 min after the stimulation. Results: Simultaneous combination of anodal tDCS and PES persistently increased the magnitude of RI and D2 until 20 min after the stimulation, but the D1 inhibition was not changed at each time point. Sham tDCS and PES increased the magnitude of RI immediately after the stimulation. Anodal tDCS and PES significantly increased the number of ankle movement in 10 s. This improvement was significantly correlated with that of the amount of RI and D2. Conclusion: Anodal tDCS combined with PES could modulate reciprocal inhibitory interneurons and improve the ankle movement in patients with incomplete SCI.

P15-21 The effect of handedness on the modulation of mu rhythm desynchronization during motor imagery with transcranial direct current stimulation

patients and between the right GPi and VT in the hemi-dystonia patient during extension of the unaffected right wrist movements but not during attempted extension of the affected left wrist. A ~64 68 Hz gamma coherence was found between the cortex and the contralateral GPi in CD patients and between the cortex, right GPi and VT in the hemi-dystonia patient. The cortico-basal ganglia-thalamo-cortical circuit is active during preparation and execution of voluntary movements. Attenuation of 5 18 Hz coherence in the BG thalamic circuit may be associated with voluntary movements.

P26-9 Effects of transcutaneous electrical stimulation combined with pedaling exercise on spinal interneurons in healthy persons

Y. Kohno1, H. Sekiguchi2, H. Kadota3, S. Takeuchi2,4, T. Ueno1, H. Nagata1, Y. Nakajima4 1Department of Neurology, Ibaraki Prefectural University of Health Sciences Hospital, Ibaraki, Japan, 2Sports Management Program, Faculty of Business and Information Sciences, Jobu University, Japan, 3Graduate School of Education, The University of Tokyo, Japan, 4Department of Rehabilitation for Sensory Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Japan

P20-4 Changes of interhemispheric inhibition and intracortical inhibition induced with bilateral and unilateral finger movement in healthy adults

Methods: Twenty healthy adults participated in this study after giving their informed consents. Each subject was asked to simultaneously gait on a treadmill and perform fingertip precision grip following a visual tracking task (precision task). The precision task was performed in thumb and index finger, this task force output was in the setting of 5% maximum voluntary contraction. We examined the responses of motor evoked potentials (MEPs) elicited from FDI, Thenar, FCR and ECR muscles by TMS. The gait condition was employed from 80%, 50% and 30% of maximum gait speed (gait 80%, gait 50%, gait 30%), i.e., gait 50% condition was almost adapted to be optimal gait speed. Additional studies, each subjects was asked to the optimal gait synchronized with precision task along with optimal gait rhythm (2 Hz Dual motor Task condition) and to the optimal gait desynchronized with precision task (0.7 Hz Dual motor Task condition). Results & Conclusions: The excitability changes of motor cortex by Dual motor Task was strongly dependent on gait speeds. MEP of FDI at the gait 50% condition was significantly the smallest at the gait 30% and gait 80% conditions. Moreover, in the 2 Hz Dual motor Task, MEP of FDI was significantly reduced compared with 0.7 Hz Dual motor Task. Present results suggest that excitability changes in M1 during Dual motor Task was dependent on task properties. That is, the precision task was regulated and affected with alterations in gait speed and rhythmic synchronization.

P26-4 After-effects of active pedaling in patients with spastic hemiparesis

Conclusions: Measurement of clinically significant change following stroke is an important aspect of rehabilitation. Commonly used assessment tools may suffer from ceiling and floor effects, their scoring systems are often based on non-linear nominal scales and they generally require clinical judgement. We have shown that alternative neurophysiological tests which are objective and quantitative may be used to enhance measurement of functional changes post-stroke.