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P14.19 Effects of transcutaneous spinal cord direct current stimulation (ts-DCS) on the lower limb nociceptive flexion reflex in humans
S126
Poster presentations: Poster session 15. Autonomic system
P14.19 Effects of transcutaneous spinal cord direct current stimulation (tsDCS) on the lower limb nociceptive flexion reflex in humans
ipsilateral hand and support the role of cerebellum in temporal discrimination in the millisecond range.
F. Cogiamanian1 , M. Vergari2 , G. Ardolino2 , E. Scelzo2 , M. Ciocca2 , S. Barbieri2 , A. Priori3 1 Centro Clinico per la Neurostimolazione, le Neurotecnologie ed i Disordini del Movimento, UO Neurofisiopatologia, Fondazione IRCCS Ospedale Maggiore Policlinico, Milan, Italy, 2 UO Neurofisiopatologia, IRCCS Fondazione C` a Granda Ospedale Maggiore Policlinico, Milan, Italy, 3 Centro Clinico per la Neurostimolazione, le Neurotecnologie ed i Disordini del Movimento, IRCCS Fondazione C` a Granda Ospedale Maggiore Policlinico, Universit` a di Milano, Dipartimento di Scienze Neurologiche, Milan, Italy
P14.21 Frequency-dependent tuning of human motor system induced by transcranial oscillatory potentials
Introduction: Aiming at developing a new, non invasive, approach to spinal cord neuromodulation we recently assessed the after-effects of thoracic transcutaneous spinal direct current stimulation (tsDCS) on somatosensory potentials (SEPs) evoked in healthy subjects by posterior tibial nerve (PTN) stimulation. Our findings showed that thoracic anodal tsDCS depresses the cervico-medullary PTN-SEP component (P30) without eliciting adverse effects (Cogiamanian et al. 2008). To date no studies have evaluated whether tsDCS can modulate central nociceptive signal transmission in humans, an essential requirement to hypothesize the application of this non-invasive neuromodulatory technique as a new therapeutic approach for pain. Objective: To evaluate whether tsDCS affects the central nociceptive signal transmission in humans. Methods: A double-blind crossover design was used to investigate the effects of anodal direct current (2 mA, 15 min) applied on the skin overlying the thoracic spinal cord on the lower-limb flexion reflex in a group of 11 healthy volunteers. Results: In our healthy subjects anodal thoracic tsDCS reduced the total lower-limb flexion reflex area by 40.25% immediately after stimulation (T0) and by 46.9% 30 minutes after stimulation offset (T30). When we analyzed the two lower-limb flexion reflex components (RII tactile and RIII nociceptive) separately we found that anodal tsDCS induced a significant reduction in RIII area with a slight but not significant effect on RII area. After anodal tsDCS the RIII area decreased by 27% at T0 and by 28% at T30. None of our subjects reported adverse effects after active stimulation. Conclusions: In our healthy subjects, thoracic anodal tsDCS elicited long-lasting after-effects on central nociceptive signal transmission. Our results suggest that tsDCS holds promise as a novel clinical tool that can be complementary or alternative to drugs and invasive SCS in managing chronic pain. P14.20 Theta burst stimulation of cerebellum interferes with somatosensory temporal discrimination
M. Feurra1 , G. Bianco2 , M. Del Testa2 , E. Santarnecchi1 , A. Rossi1 , S. Rossi1 1 Dipartimento di Neuroscienze, Sezione Neurologia & Neurofisiologia Clinica, Brain Stimulation & Evoked Potentials Lab, Policlinico le Scotte, Siena, Italy, 2 Dipartimento di Neuroscienze, Sezione Neurologia & Neurofisiologia Clinica, Policlinico le Scotte, Siena, Italy Background: Oscillatory currents delivered through the scalp by Transcranial Alternate Current Stimulation (tACS) at different frequencies seem able to entrain specific electroencephalographic (EEG) brain activities, thereby reinforcing physiological phenomena specifically related to the frequency bands of the stimulated brain region. Causal relationships between the oscillatory activity of the motor areas with the human corticospinal output still need to be elucidated. Objective: Here we used a novel approach which combines on-line simultaneous single-pulse Transcranial Magnetic Stimulation (TMS) with tACS at different frequencies (5 to 40 Hz), in order to investigate if the corticospinal output measured by Motor Evoked Potentials (MEPs) of the left primary motor cortex (M1) may be modulated by frequencydependent tACS. Methods: Twelve right-handed subjects underwent to seven random and counterbalanced conditions: two basal sessions (no-tACS), tACS of the left M1 at 5 Hz (theta), 10 Hz (alpha), 20 Hz (beta), 40 Hz (gamma), as well as 20 Hz of the right parietal cortex (control site). Each session of stimulation lasted 1.5 2 minutes. TMS was applied over the sponge electrode used for tACS overlying the left M1. MEPs were recorded from the right First Dorsal Interosseus, during online neuronavigation. In order to control any effect due to biophysical interactions of the tACS and TMS electric fields, the experiment was then repeated by applying the same protocol (5 and 20 Hz) on the ulnar nerve. Results: ANOVA showed that the corticospinal output resulted in a better reactivity when tACS was applied on the left M1 at 20 Hz. This was reflected by a significant enhancement of the MEPs size obtained during tACS at 20 Hz with respect to all the other conditions. Peripheral tACS was uneffective. Conclusions: Results originally provides causal evidence that 20 Hz rhythm of the motor cortex plays a specific role in corticospinal facilitation by showing a better reactivity with a robust enhancement of the MEPs size with respect to all the other conditions when tACS was applied on the left M1.
F. Manganelli1 , C. Pisciotta1 , R. Dubbioso1 , R. Iodice1 , M. Esposito1 , L. Ruggiero1 , L. Santoro1 1 Department of Neurological Sciences, University Federico II of Naples, Naples, Italy
Poster session 15. Autonomic system
Introduction: Time processing is important in several cognitive and motor functions. Processing of time in millisecond seems to depend on cerebellar influence and repetitive transcranial magnetic stimulation (TMS) of cerebellum has been shown to interfere with temporal discrimination. In this study we applied over the lateral cerebellum the continuous theta burst stimulation (cTBS) protocol. Objective: To investigate the effect of cerebellar cTBS on a somatosensory temporal-discrimination task. Methods: Eight healthy subjects underwent somatosensory temporaldiscrimination (STD) test performed by delivering paired stimuli starting with an intestimulus interval (ISI) of 0 ms followed by progressively increasing ISI (in 10 ms steps) applied on the right index finger. The ISI at which the subjects were able to discriminate the pair of stimuli as separate in time was considered the STD threshold. STD threshold was evaluated before (basal) and for up to 90 minutes (post 0, post 15 , post 30 , post 60 , post 90 ) after cTBS applied on the right cerebellar hemisphere. Results: We found that cTBS induced a significant increase of STD threshold with respect to basal value lasting up to 30 minutes after cerebellar repetitive TMS. Discussion: Our findings show that cerebellar cTBS worsens temporal discrimination of paired somatosensory electrical stimuli on the
V. Donadio1 , G. Plazzi1 , S. Vandi1 , M. Elam2 , M.P. Giannoccaro1 , T. Karlsson2 , C. Franceschini1 , R. Liguori1 1 Department Neurological Sciences, Bologna, Italy, 2 Department of Clinical Neurophysiology, Inst of Neuroscience and Physiology, G¨ oteborg, Sweden
P15.1 Sympathetic activity during SOREMP in narcoleptic patients
Objective: Narcolepsy is a CNS hypersomnia characterized by the presence of sleep-onset REM periods (SOREMP) and is considered a REM sleep disorder. In normal subjects REM sleep is characterized by specific autonomic changes with marked sympathetic increase. Autonomic changes during SOREMP were not previously reported. The aim of this study is to describe sympathetic activity and cardiovascular changes during SOREMP to clarify the specific role of REM sleep for narcoleptic pathogenesis. Methods: We studied 5 medication free patients (37±5 years, 2 males) with polysomnographic confirmed narcolepsy. Patients were selected because of recordable muscle sympathetic nerve activity (MSNA) and no major motor movements during sleep. They underwent to a complete polysomnography with simultaneous recording of muscle sympathetic nerve activity (MSNA), from peroneal nerve, heart rate (HR), respiratory movements, arterial finger blood pressure (BP), EEG, electro-oculogram, and superficial electromyogram.
Poster presentations: Poster session 15. Autonomic system
P14.19 Effects of transcutaneous spinal cord direct current stimulation (tsDCS) on the lower limb nociceptive flexion reflex in humans
ipsilateral hand and support the role of cerebellum in temporal discrimination in the millisecond range.
F. Cogiamanian1 , M. Vergari2 , G. Ardolino2 , E. Scelzo2 , M. Ciocca2 , S. Barbieri2 , A. Priori3 1 Centro Clinico per la Neurostimolazione, le Neurotecnologie ed i Disordini del Movimento, UO Neurofisiopatologia, Fondazione IRCCS Ospedale Maggiore Policlinico, Milan, Italy, 2 UO Neurofisiopatologia, IRCCS Fondazione C` a Granda Ospedale Maggiore Policlinico, Milan, Italy, 3 Centro Clinico per la Neurostimolazione, le Neurotecnologie ed i Disordini del Movimento, IRCCS Fondazione C` a Granda Ospedale Maggiore Policlinico, Universit` a di Milano, Dipartimento di Scienze Neurologiche, Milan, Italy
P14.21 Frequency-dependent tuning of human motor system induced by transcranial oscillatory potentials
Introduction: Aiming at developing a new, non invasive, approach to spinal cord neuromodulation we recently assessed the after-effects of thoracic transcutaneous spinal direct current stimulation (tsDCS) on somatosensory potentials (SEPs) evoked in healthy subjects by posterior tibial nerve (PTN) stimulation. Our findings showed that thoracic anodal tsDCS depresses the cervico-medullary PTN-SEP component (P30) without eliciting adverse effects (Cogiamanian et al. 2008). To date no studies have evaluated whether tsDCS can modulate central nociceptive signal transmission in humans, an essential requirement to hypothesize the application of this non-invasive neuromodulatory technique as a new therapeutic approach for pain. Objective: To evaluate whether tsDCS affects the central nociceptive signal transmission in humans. Methods: A double-blind crossover design was used to investigate the effects of anodal direct current (2 mA, 15 min) applied on the skin overlying the thoracic spinal cord on the lower-limb flexion reflex in a group of 11 healthy volunteers. Results: In our healthy subjects anodal thoracic tsDCS reduced the total lower-limb flexion reflex area by 40.25% immediately after stimulation (T0) and by 46.9% 30 minutes after stimulation offset (T30). When we analyzed the two lower-limb flexion reflex components (RII tactile and RIII nociceptive) separately we found that anodal tsDCS induced a significant reduction in RIII area with a slight but not significant effect on RII area. After anodal tsDCS the RIII area decreased by 27% at T0 and by 28% at T30. None of our subjects reported adverse effects after active stimulation. Conclusions: In our healthy subjects, thoracic anodal tsDCS elicited long-lasting after-effects on central nociceptive signal transmission. Our results suggest that tsDCS holds promise as a novel clinical tool that can be complementary or alternative to drugs and invasive SCS in managing chronic pain. P14.20 Theta burst stimulation of cerebellum interferes with somatosensory temporal discrimination
M. Feurra1 , G. Bianco2 , M. Del Testa2 , E. Santarnecchi1 , A. Rossi1 , S. Rossi1 1 Dipartimento di Neuroscienze, Sezione Neurologia & Neurofisiologia Clinica, Brain Stimulation & Evoked Potentials Lab, Policlinico le Scotte, Siena, Italy, 2 Dipartimento di Neuroscienze, Sezione Neurologia & Neurofisiologia Clinica, Policlinico le Scotte, Siena, Italy Background: Oscillatory currents delivered through the scalp by Transcranial Alternate Current Stimulation (tACS) at different frequencies seem able to entrain specific electroencephalographic (EEG) brain activities, thereby reinforcing physiological phenomena specifically related to the frequency bands of the stimulated brain region. Causal relationships between the oscillatory activity of the motor areas with the human corticospinal output still need to be elucidated. Objective: Here we used a novel approach which combines on-line simultaneous single-pulse Transcranial Magnetic Stimulation (TMS) with tACS at different frequencies (5 to 40 Hz), in order to investigate if the corticospinal output measured by Motor Evoked Potentials (MEPs) of the left primary motor cortex (M1) may be modulated by frequencydependent tACS. Methods: Twelve right-handed subjects underwent to seven random and counterbalanced conditions: two basal sessions (no-tACS), tACS of the left M1 at 5 Hz (theta), 10 Hz (alpha), 20 Hz (beta), 40 Hz (gamma), as well as 20 Hz of the right parietal cortex (control site). Each session of stimulation lasted 1.5 2 minutes. TMS was applied over the sponge electrode used for tACS overlying the left M1. MEPs were recorded from the right First Dorsal Interosseus, during online neuronavigation. In order to control any effect due to biophysical interactions of the tACS and TMS electric fields, the experiment was then repeated by applying the same protocol (5 and 20 Hz) on the ulnar nerve. Results: ANOVA showed that the corticospinal output resulted in a better reactivity when tACS was applied on the left M1 at 20 Hz. This was reflected by a significant enhancement of the MEPs size obtained during tACS at 20 Hz with respect to all the other conditions. Peripheral tACS was uneffective. Conclusions: Results originally provides causal evidence that 20 Hz rhythm of the motor cortex plays a specific role in corticospinal facilitation by showing a better reactivity with a robust enhancement of the MEPs size with respect to all the other conditions when tACS was applied on the left M1.
F. Manganelli1 , C. Pisciotta1 , R. Dubbioso1 , R. Iodice1 , M. Esposito1 , L. Ruggiero1 , L. Santoro1 1 Department of Neurological Sciences, University Federico II of Naples, Naples, Italy
Poster session 15. Autonomic system
Introduction: Time processing is important in several cognitive and motor functions. Processing of time in millisecond seems to depend on cerebellar influence and repetitive transcranial magnetic stimulation (TMS) of cerebellum has been shown to interfere with temporal discrimination. In this study we applied over the lateral cerebellum the continuous theta burst stimulation (cTBS) protocol. Objective: To investigate the effect of cerebellar cTBS on a somatosensory temporal-discrimination task. Methods: Eight healthy subjects underwent somatosensory temporaldiscrimination (STD) test performed by delivering paired stimuli starting with an intestimulus interval (ISI) of 0 ms followed by progressively increasing ISI (in 10 ms steps) applied on the right index finger. The ISI at which the subjects were able to discriminate the pair of stimuli as separate in time was considered the STD threshold. STD threshold was evaluated before (basal) and for up to 90 minutes (post 0, post 15 , post 30 , post 60 , post 90 ) after cTBS applied on the right cerebellar hemisphere. Results: We found that cTBS induced a significant increase of STD threshold with respect to basal value lasting up to 30 minutes after cerebellar repetitive TMS. Discussion: Our findings show that cerebellar cTBS worsens temporal discrimination of paired somatosensory electrical stimuli on the
V. Donadio1 , G. Plazzi1 , S. Vandi1 , M. Elam2 , M.P. Giannoccaro1 , T. Karlsson2 , C. Franceschini1 , R. Liguori1 1 Department Neurological Sciences, Bologna, Italy, 2 Department of Clinical Neurophysiology, Inst of Neuroscience and Physiology, G¨ oteborg, Sweden
P15.1 Sympathetic activity during SOREMP in narcoleptic patients
Objective: Narcolepsy is a CNS hypersomnia characterized by the presence of sleep-onset REM periods (SOREMP) and is considered a REM sleep disorder. In normal subjects REM sleep is characterized by specific autonomic changes with marked sympathetic increase. Autonomic changes during SOREMP were not previously reported. The aim of this study is to describe sympathetic activity and cardiovascular changes during SOREMP to clarify the specific role of REM sleep for narcoleptic pathogenesis. Methods: We studied 5 medication free patients (37±5 years, 2 males) with polysomnographic confirmed narcolepsy. Patients were selected because of recordable muscle sympathetic nerve activity (MSNA) and no major motor movements during sleep. They underwent to a complete polysomnography with simultaneous recording of muscle sympathetic nerve activity (MSNA), from peroneal nerve, heart rate (HR), respiratory movements, arterial finger blood pressure (BP), EEG, electro-oculogram, and superficial electromyogram.