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PTMS21 Cortical excitability changes in high-frequency repetitive transcranial magnetic stimulation for central post-stroke pain
S186 Objectives: To investigate inter-individual variation in the efficiency of BST with regard to the stimulation site. Methods: We studied 31 healthy subjects, using a right hand muscle as a recording site. Three stimulation sites were compared: BST over the inion (inion BST), and BST over the midpoint between the inion and the right (ipsilateral BST) or left (contralateral BST) mastoid process. Five suprathreshold BSTs were performed for each stimulation site using the same stimulation intensity. The mean peak-to-peak amplitudes of MEP were compared. The active motor threshold (AMT) and onset latency for inion BST and ipsilateral BST were also measured and compared. Results: Contralateral BST did not evoke discernible MEPs in most subjects. In 21 subjects (67.7%), ipsilateral BST elicited larger MEPs than inion BST, and AMT for ipsilateral BST was lower than or equal to the AMT for inion BST in all subjects. Ipsilateral BST elicited shorter latency in such subjects, when MEP amplitudes were adjusted. Conclusions: The suitable stimulation site for BST differed among subjects. About two-thirds showed larger MEP to ipsilateral BST. Efficient stimulation site needs to be searched before the main examination. PTMS18 Amyotrophic lateral sclerosis: effects of prolonged motor cortex stimulation L. Florio1 , M. Dileone1 , F. Pilato1 , P. Profice1 , F. Ranieri1 , G. Musumeci1 , B. Cioni2 , M. Meglio2 , F. Papacci2 , M. Sabatelli1 , V. Di Lazzaro1 1 Institute of Neurology, UCSC, Rome, Italy, 2 Institute of Neurosurgery, UCSC, Rome, Italy Introduction: Preliminary studies have proposed motor cortex stimulation for the treatment of amyotrophic lateral sclerosis (ALS): a slight reduction of disease progression has been reported using both invasive and noninvasive repetitive motor cortex stimulation. Objectives: The purpose of this study was to investigate the effect of long-term motor cortex stimulation on ALS progression. Methods: Two ALS patients were treated for a period of about two years, with monthly cycles of repetitive transcranial magnetic stimulation (rTMS) and with chronic epidural motor cortex stimulation respectively. We compared the rate of disease progression before and during the treatment period using the revised ALS functional rating scale (ALSFRS-R). Results: The treatment was well tolerated, without any side effect. Monthly rate of disease progression before treatment was 1.0 point/month in both patients. The patient treated with rTMS showed a slight reduction of deterioration rate, that was 0.2 points/month in the first year and 0.6 points/month in the following 14 months of treatment. Conclusions: This preliminary experience could stimulate possible future studies to investigate the effects of long-term repetitive motor cortex stimulation on a larger group of ALS patients. PTMS19 Representation of cricothyroid muscles at the primary motor cortex (M1) in healthy subjects, using navigated transcranial magnetic stimulation A.L. Jorba1 , V. Deletis2 , J.M. Espadaler1 , M. Rogic3 , C.R. Quijada1 , G. Conesa4 1 Department of Neurology, Hospital del Mar, Barcelona, Spain, 2 Department for Intraoperative Neurophysiology, Roosevelt Hospital, New York, United States, 3 Laboratory for Human and Experimental neurophysiology, School of Medicine, University of Split, Split, Croatia, 4 Department of Neurosurgery, Hospital del Mar, Barcelona, Spain Introduction: Electrical stimulation studies of mapping the human motor cortex showed that vocalization was elicited from rather wide part of primary motor cortex, lateral to the localization for the face and lip muscles. Vocalization like sounds elicited by Penfield during 50 60 Hz stimulation represents tonic activation of laryngeal-pharyngeal and facial muscles. This phenomenon is not identical as simple and isolated contraction of laryngeal muscle. Methodology used in our study is eliciting corticobulbar motor evoked potentials (CoMEPs) from cricothyroid (CTHY) muscles. Objectives: To establish a methodology for mapping of primary motor cortex for cricothyroid muscles in healthy subjects using navigated transcranial magnetic stimulator (nTMS) combined with a 3D MRI images. Method: Ten healthy subjects were included in this study. nTMS was used for stimulation of primary motor cortex (M1) representation for abductor
Poster presentations: TMS meeting poster session pollicis brevis (APB) and CTHY muscles, with recordings of motor evoked potentials (MEPs) from APB and CoMEPs from CTHY muscles. For recording CoMEPs from CTHY muscle, two hook wire electrodes were inserted in the muscle, while surface electrodes were used for recording of MEPs from APB. The location of the stimulating points over M1 for CTHY and APB muscles was determined and superimposed over MRI images, while measure their distance. Results: Cortical location for CTHY and APB muscles was successfully performed in all subjects. Stimulation over the left M1 for the CTHY muscles elicited CoMEPs in the right CTHY muscle with a mean latency of 11.5±0.6 ms. Stimulation over the left M1 for APB muscles elicited MEPs in the right APB muscle with a mean latency of 22.8±0.4 ms. Measurement of distance between cortical representation for APB and CTHY was 26±2.16 mm. Conclusion: This is the first study with the aim to determine the cortical location of CTHY muscle with nTMS, showing that M1 for CTHY muscle is about 3 cm more lateral than M1 for APB muscle. PTMS20 Perturbational approach to sleep deprivation: an EEG TMS study A. Del Felice1 , S. Savazzi1 , A. Fiaschi1 , P. Manganotti1 1 Department of Neurological, Neuropsychological, Morphological and Motor Sciences, University of Verona, Verona, Italy Introduction: Electroencephalography-transcranial magnetic stimulation (EEG-TMS) co-registration is an innovative tecnique to study cortical reactions to external perturbations and their modulation. TMS evoked potentials (TEPs) have been described during both wake and sleep, but the effect of sleep deprivation on TEPs is unknown. Objective: To study vigilance-related modifications of cortical reactivity by measuring variability in TEP. Methods: In twelve healthy subjects, EEG-TMS co-registration was performed with compatible equipment (BrainVision Recording System, 32 electrodes) and the dominant motor area was stimulated in a standard wake condition, after partial sleep deprivation, and during sleep. Of the initial twelve subjects, nine fell asleep during the experiment and qualified for analysis. EEG traces were scored off-line according to Rechschaffen-Kales sleep stages; segments were analysed from 100 ms before to 500 ms after the TMS artifact. Results: TMS induced clear-cut EEG activity lasting up to 300 ms after the TMS artefact and consisting of alternating positive and negative polarity deflections. A statistically significant sleep deprivation-induced increase in amplitude was evident for the late peaks (P100 and N190), as compared to both the wake and sleep conditions, with a global midline distribution for P100 and a more marked posterior distribution for N190. Conclusion: Our results evince increased cortical excitability after global sleep deprivation, with a less evident increase over the anterior cortical regions than over the central and posterior areas. Neurophysiologically, this finding underpins the notion that the frontal-prefrontal areas are more susceptible to the effects of sleep deprivation, as demonstrated by neuropsychology and neuroimaging. Moreover, while no effect of sleep deprivation in healthy subjects has been detected with TMS alone, TMS-EEG co-registration seems to be a more sensitive tool for studying vigilance-induced modulations. PTMS21 Cortical excitability changes in high-frequency repetitive transcranial magnetic stimulation for central post-stroke pain K. Hosomi1 , Y. Saitoh1 , H. Kishima2 , S. Oshino2 , M. Hirata2 , N. Tani2 , T. Maruo2 , T. Yoshimine2 1 Department of Neuromodulation and Neurosurgery, Center for Advanced Science and Innovation, Osaka University, Osaka, Japan, 2 Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan Introduction: Central post-stroke pain (CPSP) is one of the most refractory chronic pain syndromes. We and some researchers have reported that repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex provided moderate pain relief for those pain conditions. However, that mechanism remains unclear. Objectives: The objective of this study was to assess the changes of cortical excitability in patients with intractable CPSP before and after rTMS of the primary motor cortex. Methods: Subjects were comprised of 20 consecutive patients with CPSP of the hand that underwent rTMS or 13 healthy controls. The cortical
14th ECCN / 4th ICTMS/DCS excitability was evaluated before and after navigation-guided 5 Hz-rTMS of the primary motor cortex corresponding to the painful hand. Resting motor threshold, amplitude of motor evoked potential, duration of cortical silent period, short interval intracortical inhibition (SICI) and intracortical facilitation (ICF) were measured as parameters of cortical excitability with single- or paired-pulse TMS methods. Pain reduction of rTMS was assessed with a visual analogue scale (VAS). Results: Eight of 20 patients showed 30% pain reduction in their VAS after rTMS (good responders). SICI in all patients and ICF in good responders were significantly lower than those in the controls at baseline (0.34±0.40 vs. 0.55±0.17, p = 0.045 and 1.10±0.35 vs. 1.71±0.79, p = 0.034, respectively) which were in line with previous reports. The rate of ICF increase in good responders after rTMS was significantly larger than that in the other patients (1.60±0.67 vs. 1.04±0.41, p = 0.042). There were no significant differences or changes in the other parameters. Conclusions: Our findings suggested that restoration of abnormal cortical excitability might be one of the mechanisms underlying pain relief as a result of rTMS in CPSP.
S187 Results: In both relaxed and active DAO, MEP amplitude was decreased (p < 0.001) at 2 3 ms ISIs, and increased (p < 0.001) at 10 15 ms ISIs, after paired pulse TMS. Facial nerve stimulation in the SAI paradigm did not affect MEP amplitude, either in the active or in the relaxed DAO. By contrast it was significantly increased after PAS both in resting (p = 0.047) and active (p = 0.008) conditions. Interestingly, this effect was more prominent after 0 10 min (early plasticity; p = 0.011) in the relaxed DAO and after 20 30 min (late plasticity p = 0.005) in the active DAO. Conclusions: SICI and ICF circuits are active in the facial motor cortex both in resting and active conditions. First evidence of LTP-like plasticity in FM is reported. Further studies are needed to understand how and why PAS works in FM despite the absence of SAI. A second point to be clarified is the different PAS time course in resting and active states. PTMS24 Modulation of sensorimotor cortex by repetitive peripheral magnetic stimulation E. Gallasch1 , M. Christova1 , D. Rafolt2 , A. Kunz3 , S. Golaszewski3 Department of Physiology, Medical University of Graz, Graz, Austria, 2 Center for Medical Physics and Biomedical Engineering, Vienna, Austria, 3 Department of Neurology, Paracelsus Medical University of Salzburg, Salzburg, Austria
1
PTMS22 Motor cortex remodeling in young epileptic cerebral palsy patient F. Pilato1 , F. Capone1 , P. Profice1 , R. Di Iorio1 , M. Dileone1 , D. Battaglia2 , F. Ranieri1 , L. Florio1 , M. Caulo1 , V. Di Lazzaro1 1 Dept. of Neuroscience, Rome, Italy, 2 Istituto di Neuropsichiatria Infantile, Rome, Italy
PTMS23 Intracortical circuits and cortical plasticity in facial muscles
Introduction: Repetitive peripheral magnetic stimulation (rPMS), applied transcutaneously to the muscle, has been developed for treatment of motor deficits after stroke. Objective: The study investigates the cortical neuromodulatory effect of rPMS in healthy subjects using Transcranial Magnetic Stimulation (TMS) and fMRI. Methods: Three groups were investigated: rPMS-25 Hz, rPMS-10 Hz and rPMS-sham. pRMS was delivered on the right forearm (over the flexor carpi radialis muscle) with figure of eight coil with intensity 150% of the individual motor threshold (24 29% of the max output of the stimulator) in a pattern 10 s on 10 s off. The stimulation duration was 20 min. The measured TMS parameters were: recruitment curve (RC), Shortlasting Intracortical inhibition (SICI) and intracortical facilitation (ICF). Five assessments were performed: T0 (pre), T1 (post 0 min), T2 (post 30 min), T3 (post1 h), T4 (post 2 h). MEPs were recorded from flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscle. Additionally the rPMS-25 Hz was examined with fMRI at pre- and post-stimulation on 22 subjects. Results: rPMS-10 Hz did not cause prominent effects in RC. In contrast rPMS-25 Hz induced significant increase lasting up to 30 min post stimulation. The effect is reversible after the first hour. Sham stimulation induced no effect which shows that the changes are specific. No changes were observed at the antagonist ECR. rPMS-25 Hz induced decrease in SICI and a tendency of increased ICF only at the stimulated muscle. Results from fMRI assessments will be further discussed. Conclusions: The post-stimulation effects give evidence for a functional reorganization of the motor cortex after rPMS-25 Hz. The present results are provide important information about proper stimulation set and have the potential to prove the clinical application of rPMS in neurorehabilitation.
G. Pilurzi1 , A. Hasan2 , M. Van den Bos2 , E. Tolu1 , F. Deriu1 , J. Rothwell2 Dept. Biomedical Sciences, University of Sassari, Sassari, Italy, 2 Sobell Dept. of Neuroscience and Movement Disorders, Institute of Neurology, UCL, London, United Kingdom
PTMS25 Long-term effects induced by quadripulse stimulation in Huntington’s disease
Introduction: Here we describe pre- and post-operative neurophysiological and functional Magnetic Resonance Imaging (fMRI) findings in a young epileptic girl with right hemiplegic cerebral palsy. Objectives: Aim of the study was to demonstrate the feasibility of Transcranial magnetic stimulation (TMS) and fMRI for predicting a postsurgical outcome and for evaluating functional cortical reorganization. Methods: We used TMS and fMRI to evaluate the excitability of the human motor cortex and cortical map representation before and after functional hemispherectomy. TMS was performed using single and paired pulse stimulation protocol. Cortical silent periods (CSPs), short interval intracortical inhibition (SICI), volume, area and center of gravity (CoG) of cortical map representation were studied before and after surgery. fMRI was done using the Blood oxygenation level dependent (BOLD) technique with block-designed protocols. Results: After surgery the patient showed an improvement of her clinical status and TMS and fMRI demonstrated a reshaping of cortical representation of motor cortex and a significant reduction of Cortical Silent Periods (CSP). Conclusions: Before surgery, the combination of a clinical, neurophysiological and neuroradiological approach may be predictable of the neurological outcome in epileptic patients. Moreover the patient we describe provides new pieces of information in the mechanisms of plasticity underlying motor recovery after epilepsy surgery.
1
Introduction: The role of intracortical circuits in the modulation of facial muscle (FM) activity is controversial and both sensorimotor integration and LTP-like plasticity, which play an important role in motor learning, have never been investigated in the cranial district. Objectives: To investigate, in FM of normal subjects, short-interval intracortical inhibition (SICI), intracortical facilitation (ICF), shortafferent inhibition (SAI) and effects of paired associative stimulation (PAS). Methods: MEPs were evoked in relaxed and active contralateral depressor angulis oris (DAO) muscle of 9 subjects. SICI and ICF were tested by paired pulse TMS: intestimulus intervals (ISI): 2 3 ms and 10 15 ms. SAI was tested in 5 subjects by pairing (ISIs: 5, 10, 15, 20, 25, 30 ms) the electrical stimulation (ES) of the facial nerve, with TMS of the facial motor cortex. Resting and active MEPs were acquired (n = 20) before and after PAS (200 pairs of ES and TMS; 20 ms ISI, 0.25 Hz, at rest). PAS effects were tested after 0 10 min and 20 30 min. ANOVA and post hoc t-Test were done.
O. Shinya1 , Y. Terao1 , Y. Shirota1 , R. Tsutsumi1 , J. Goto1 , Y. Ichikawa1 , S. Tsuji1 , Y. Ugawa2 , R. Hanajima1 1 Department of Neurology, University of Tokyo, 7 3-1, Hongo, Bunkyo-ku Tokyo, Japan, 2 Department of Neurology, Fukushima Medical University, 1, Hikarigaoka, Fukushima-city, Fukuhima, Japan Introduction: In Huntington’s disease (HD) patients, conventional repetitive transcranial magnetic stimulation (rTMS) did not induce long term potentiation (LTP)-like effects and continuous theta burst stimulation (cTBS) did not long term depression (LTD)-like effects, which indicates abnormal cortical plasticity in HD. Objectives: To see whether a newly developed, powerful quadripulse stimulation (QPS) (Hamada M et al. Clin Neurophysiol 2007; 118: 2672 and J Physiol 2008; 586: 3927) is able to induce some plastic changes in HD. Methods: Five HD patients were recruited. Motor evoked potentials (MEPs) to a single pulse TMS were recorded from the first dorsal interossei (FDI) muscle at more affected side before and after QPS. QPS protocol
Poster presentations: TMS meeting poster session pollicis brevis (APB) and CTHY muscles, with recordings of motor evoked potentials (MEPs) from APB and CoMEPs from CTHY muscles. For recording CoMEPs from CTHY muscle, two hook wire electrodes were inserted in the muscle, while surface electrodes were used for recording of MEPs from APB. The location of the stimulating points over M1 for CTHY and APB muscles was determined and superimposed over MRI images, while measure their distance. Results: Cortical location for CTHY and APB muscles was successfully performed in all subjects. Stimulation over the left M1 for the CTHY muscles elicited CoMEPs in the right CTHY muscle with a mean latency of 11.5±0.6 ms. Stimulation over the left M1 for APB muscles elicited MEPs in the right APB muscle with a mean latency of 22.8±0.4 ms. Measurement of distance between cortical representation for APB and CTHY was 26±2.16 mm. Conclusion: This is the first study with the aim to determine the cortical location of CTHY muscle with nTMS, showing that M1 for CTHY muscle is about 3 cm more lateral than M1 for APB muscle. PTMS20 Perturbational approach to sleep deprivation: an EEG TMS study A. Del Felice1 , S. Savazzi1 , A. Fiaschi1 , P. Manganotti1 1 Department of Neurological, Neuropsychological, Morphological and Motor Sciences, University of Verona, Verona, Italy Introduction: Electroencephalography-transcranial magnetic stimulation (EEG-TMS) co-registration is an innovative tecnique to study cortical reactions to external perturbations and their modulation. TMS evoked potentials (TEPs) have been described during both wake and sleep, but the effect of sleep deprivation on TEPs is unknown. Objective: To study vigilance-related modifications of cortical reactivity by measuring variability in TEP. Methods: In twelve healthy subjects, EEG-TMS co-registration was performed with compatible equipment (BrainVision Recording System, 32 electrodes) and the dominant motor area was stimulated in a standard wake condition, after partial sleep deprivation, and during sleep. Of the initial twelve subjects, nine fell asleep during the experiment and qualified for analysis. EEG traces were scored off-line according to Rechschaffen-Kales sleep stages; segments were analysed from 100 ms before to 500 ms after the TMS artifact. Results: TMS induced clear-cut EEG activity lasting up to 300 ms after the TMS artefact and consisting of alternating positive and negative polarity deflections. A statistically significant sleep deprivation-induced increase in amplitude was evident for the late peaks (P100 and N190), as compared to both the wake and sleep conditions, with a global midline distribution for P100 and a more marked posterior distribution for N190. Conclusion: Our results evince increased cortical excitability after global sleep deprivation, with a less evident increase over the anterior cortical regions than over the central and posterior areas. Neurophysiologically, this finding underpins the notion that the frontal-prefrontal areas are more susceptible to the effects of sleep deprivation, as demonstrated by neuropsychology and neuroimaging. Moreover, while no effect of sleep deprivation in healthy subjects has been detected with TMS alone, TMS-EEG co-registration seems to be a more sensitive tool for studying vigilance-induced modulations. PTMS21 Cortical excitability changes in high-frequency repetitive transcranial magnetic stimulation for central post-stroke pain K. Hosomi1 , Y. Saitoh1 , H. Kishima2 , S. Oshino2 , M. Hirata2 , N. Tani2 , T. Maruo2 , T. Yoshimine2 1 Department of Neuromodulation and Neurosurgery, Center for Advanced Science and Innovation, Osaka University, Osaka, Japan, 2 Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan Introduction: Central post-stroke pain (CPSP) is one of the most refractory chronic pain syndromes. We and some researchers have reported that repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex provided moderate pain relief for those pain conditions. However, that mechanism remains unclear. Objectives: The objective of this study was to assess the changes of cortical excitability in patients with intractable CPSP before and after rTMS of the primary motor cortex. Methods: Subjects were comprised of 20 consecutive patients with CPSP of the hand that underwent rTMS or 13 healthy controls. The cortical
14th ECCN / 4th ICTMS/DCS excitability was evaluated before and after navigation-guided 5 Hz-rTMS of the primary motor cortex corresponding to the painful hand. Resting motor threshold, amplitude of motor evoked potential, duration of cortical silent period, short interval intracortical inhibition (SICI) and intracortical facilitation (ICF) were measured as parameters of cortical excitability with single- or paired-pulse TMS methods. Pain reduction of rTMS was assessed with a visual analogue scale (VAS). Results: Eight of 20 patients showed 30% pain reduction in their VAS after rTMS (good responders). SICI in all patients and ICF in good responders were significantly lower than those in the controls at baseline (0.34±0.40 vs. 0.55±0.17, p = 0.045 and 1.10±0.35 vs. 1.71±0.79, p = 0.034, respectively) which were in line with previous reports. The rate of ICF increase in good responders after rTMS was significantly larger than that in the other patients (1.60±0.67 vs. 1.04±0.41, p = 0.042). There were no significant differences or changes in the other parameters. Conclusions: Our findings suggested that restoration of abnormal cortical excitability might be one of the mechanisms underlying pain relief as a result of rTMS in CPSP.
S187 Results: In both relaxed and active DAO, MEP amplitude was decreased (p < 0.001) at 2 3 ms ISIs, and increased (p < 0.001) at 10 15 ms ISIs, after paired pulse TMS. Facial nerve stimulation in the SAI paradigm did not affect MEP amplitude, either in the active or in the relaxed DAO. By contrast it was significantly increased after PAS both in resting (p = 0.047) and active (p = 0.008) conditions. Interestingly, this effect was more prominent after 0 10 min (early plasticity; p = 0.011) in the relaxed DAO and after 20 30 min (late plasticity p = 0.005) in the active DAO. Conclusions: SICI and ICF circuits are active in the facial motor cortex both in resting and active conditions. First evidence of LTP-like plasticity in FM is reported. Further studies are needed to understand how and why PAS works in FM despite the absence of SAI. A second point to be clarified is the different PAS time course in resting and active states. PTMS24 Modulation of sensorimotor cortex by repetitive peripheral magnetic stimulation E. Gallasch1 , M. Christova1 , D. Rafolt2 , A. Kunz3 , S. Golaszewski3 Department of Physiology, Medical University of Graz, Graz, Austria, 2 Center for Medical Physics and Biomedical Engineering, Vienna, Austria, 3 Department of Neurology, Paracelsus Medical University of Salzburg, Salzburg, Austria
1
PTMS22 Motor cortex remodeling in young epileptic cerebral palsy patient F. Pilato1 , F. Capone1 , P. Profice1 , R. Di Iorio1 , M. Dileone1 , D. Battaglia2 , F. Ranieri1 , L. Florio1 , M. Caulo1 , V. Di Lazzaro1 1 Dept. of Neuroscience, Rome, Italy, 2 Istituto di Neuropsichiatria Infantile, Rome, Italy
PTMS23 Intracortical circuits and cortical plasticity in facial muscles
Introduction: Repetitive peripheral magnetic stimulation (rPMS), applied transcutaneously to the muscle, has been developed for treatment of motor deficits after stroke. Objective: The study investigates the cortical neuromodulatory effect of rPMS in healthy subjects using Transcranial Magnetic Stimulation (TMS) and fMRI. Methods: Three groups were investigated: rPMS-25 Hz, rPMS-10 Hz and rPMS-sham. pRMS was delivered on the right forearm (over the flexor carpi radialis muscle) with figure of eight coil with intensity 150% of the individual motor threshold (24 29% of the max output of the stimulator) in a pattern 10 s on 10 s off. The stimulation duration was 20 min. The measured TMS parameters were: recruitment curve (RC), Shortlasting Intracortical inhibition (SICI) and intracortical facilitation (ICF). Five assessments were performed: T0 (pre), T1 (post 0 min), T2 (post 30 min), T3 (post1 h), T4 (post 2 h). MEPs were recorded from flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscle. Additionally the rPMS-25 Hz was examined with fMRI at pre- and post-stimulation on 22 subjects. Results: rPMS-10 Hz did not cause prominent effects in RC. In contrast rPMS-25 Hz induced significant increase lasting up to 30 min post stimulation. The effect is reversible after the first hour. Sham stimulation induced no effect which shows that the changes are specific. No changes were observed at the antagonist ECR. rPMS-25 Hz induced decrease in SICI and a tendency of increased ICF only at the stimulated muscle. Results from fMRI assessments will be further discussed. Conclusions: The post-stimulation effects give evidence for a functional reorganization of the motor cortex after rPMS-25 Hz. The present results are provide important information about proper stimulation set and have the potential to prove the clinical application of rPMS in neurorehabilitation.
G. Pilurzi1 , A. Hasan2 , M. Van den Bos2 , E. Tolu1 , F. Deriu1 , J. Rothwell2 Dept. Biomedical Sciences, University of Sassari, Sassari, Italy, 2 Sobell Dept. of Neuroscience and Movement Disorders, Institute of Neurology, UCL, London, United Kingdom
PTMS25 Long-term effects induced by quadripulse stimulation in Huntington’s disease
Introduction: Here we describe pre- and post-operative neurophysiological and functional Magnetic Resonance Imaging (fMRI) findings in a young epileptic girl with right hemiplegic cerebral palsy. Objectives: Aim of the study was to demonstrate the feasibility of Transcranial magnetic stimulation (TMS) and fMRI for predicting a postsurgical outcome and for evaluating functional cortical reorganization. Methods: We used TMS and fMRI to evaluate the excitability of the human motor cortex and cortical map representation before and after functional hemispherectomy. TMS was performed using single and paired pulse stimulation protocol. Cortical silent periods (CSPs), short interval intracortical inhibition (SICI), volume, area and center of gravity (CoG) of cortical map representation were studied before and after surgery. fMRI was done using the Blood oxygenation level dependent (BOLD) technique with block-designed protocols. Results: After surgery the patient showed an improvement of her clinical status and TMS and fMRI demonstrated a reshaping of cortical representation of motor cortex and a significant reduction of Cortical Silent Periods (CSP). Conclusions: Before surgery, the combination of a clinical, neurophysiological and neuroradiological approach may be predictable of the neurological outcome in epileptic patients. Moreover the patient we describe provides new pieces of information in the mechanisms of plasticity underlying motor recovery after epilepsy surgery.
1
Introduction: The role of intracortical circuits in the modulation of facial muscle (FM) activity is controversial and both sensorimotor integration and LTP-like plasticity, which play an important role in motor learning, have never been investigated in the cranial district. Objectives: To investigate, in FM of normal subjects, short-interval intracortical inhibition (SICI), intracortical facilitation (ICF), shortafferent inhibition (SAI) and effects of paired associative stimulation (PAS). Methods: MEPs were evoked in relaxed and active contralateral depressor angulis oris (DAO) muscle of 9 subjects. SICI and ICF were tested by paired pulse TMS: intestimulus intervals (ISI): 2 3 ms and 10 15 ms. SAI was tested in 5 subjects by pairing (ISIs: 5, 10, 15, 20, 25, 30 ms) the electrical stimulation (ES) of the facial nerve, with TMS of the facial motor cortex. Resting and active MEPs were acquired (n = 20) before and after PAS (200 pairs of ES and TMS; 20 ms ISI, 0.25 Hz, at rest). PAS effects were tested after 0 10 min and 20 30 min. ANOVA and post hoc t-Test were done.
O. Shinya1 , Y. Terao1 , Y. Shirota1 , R. Tsutsumi1 , J. Goto1 , Y. Ichikawa1 , S. Tsuji1 , Y. Ugawa2 , R. Hanajima1 1 Department of Neurology, University of Tokyo, 7 3-1, Hongo, Bunkyo-ku Tokyo, Japan, 2 Department of Neurology, Fukushima Medical University, 1, Hikarigaoka, Fukushima-city, Fukuhima, Japan Introduction: In Huntington’s disease (HD) patients, conventional repetitive transcranial magnetic stimulation (rTMS) did not induce long term potentiation (LTP)-like effects and continuous theta burst stimulation (cTBS) did not long term depression (LTD)-like effects, which indicates abnormal cortical plasticity in HD. Objectives: To see whether a newly developed, powerful quadripulse stimulation (QPS) (Hamada M et al. Clin Neurophysiol 2007; 118: 2672 and J Physiol 2008; 586: 3927) is able to induce some plastic changes in HD. Methods: Five HD patients were recruited. Motor evoked potentials (MEPs) to a single pulse TMS were recorded from the first dorsal interossei (FDI) muscle at more affected side before and after QPS. QPS protocol