- Email: [email protected]
Pharyngeal Dystonia
Abstracts / Brain Stimulation 10 (2017) e1–e19
7 NONINVASIVE STIMULATION OF PREFRONTAL CORTEX STRENGTHENS EXISTING EPISODIC MEMORIES AND REDUCES FORGETTING IN THE ELDERLY Marco Sandrini a,b,*, Michela Brambilla c, Rosa Manenti c, Sandra Rosini c, Leonardo G. Cohen a, Maria Cotelli c. a Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, USA; b Center for Neuroscience and Regenerative Medicine, Uniformed Services University of Health Sciences, Bethesda, USA; c Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy * Corresponding author. Memory for unique personal experiences (episodic memory) is critical to daily life functioning. This form of long-term memory also displays the largest degree of age-related decline. Since this condition is accelerated in Alzheimer’s disease (AD), the development of effective therapeutic interventions to prevent or delay AD is an urgent priority. Accumulating evidence shows that reactivation of consolidated memories by a reminder triggers reconsolidation, a time-limited state of plasticity during which existing memories can be modified (i.e. weakened or strengthened). A recent study showed that the dorsolateral prefrontal cortex (DLPFC) plays a causal role in strengthening of verbal episodic memories through reconsolidation in young adults (Sandrini, Censor, Mishoe, and Cohen, Current Biology 2013). Here, we investigated whether anodal tDCS over the left DLPFC would strengthen verbal episodic memories through reconsolidation in healthy older adults. On Day 1, subjects learned a list of words. On Day 2 (24 h later), they received a reminder or not, and then tDCS was applied over the left DLPFC (15 min, 1.5 mA, cathode over the contralateral supraorbital area). Memory recall was tested on Day 3 (48 h later) and Day 30 (1 month later). Anodal tDCS over the left DLPFC (i.e. with or without the reminder) strengthened existing verbal episodic memories and reduced forgetting compared to sham stimulation. These results provide a framework for testing the hypothesis that tDCS of left DLPFC might strengthen existing episodic memories through reconsolidation in older adults with amnestic mild cognitive impairment, which is often the precursor for emerging AD. Acknowledgements: This work was partially supported by funding from US Department of Defense in the Center for Neuroscience and Regenerative Medicine (CNRM) to Marco Sandrini.
8 TIME DEPENDENT EFFECTS OF TRANSCRANIAL DIRECT CURRENT STIMULATION AND CAFFEINE ON VIGILANCE PERFORMANCE DURING EXTENDED WAKEFULNESS R. Andy McKinley a , Lindsey K. McIntire b , Ryan Schilling c , Chuck Goodyear b, Justin Nelson b. a Applied Neuroscience Branch, Air Force Research Laboratory, Wright-Patterson AFB, OH, USA; b Infoscitex Inc., Dayton, OH, USA; c Oak Ridge Institute for Science and Education (ORISE), Dayton, OH, USA Background: Previously, we found that transcranial direct current stimulation (tDCS) preserved vigilance performance twice as well and three times as long as caffeine during a period of extended wakefulness. Vigilance performance often declines linearly over time, but in our previous study the performance trends over the period of watch were not analyzed. Hence, it was not known whether the intervention reduced the vigilance decrement, or simply shifted the performance to a higher mean value while maintaining a similar slope. Objective: Our objective was to evaluate the time-dependent of anodal transcranial direct current stimulation (tDCS) applied to the
e3
pre-frontal cortex at 2 mA for 30 minutes. We then compared these results to those of caffeine as well as the effects of both interventions on arousal. Methods: The period of watch was segregated into equal time segments and target identification accuracy was averaged across subjects in each group. These values were used in an analysis of covariance (separately for ]sessions) as the dependent variable. Factors were group and subject nested in group. Results: The results indicated there is not a significant difference in slope (i.e. vigilance decrement) between the treatment conditions (tDCS, caffeine, and sham) within each period of watch. However, as reported previously, there was a significant difference in mean change from baseline between treatment conditions. Conclusion: Our data suggests that tDCS does not prevent the vigilance decrement within the period of watch. Rather, it shifts performance to higher mean values by a scalar multiple while maintaining a similar slope. Acknowledgements: We’d like to thank the Air Force Office of Scientific research for their continued support and financial contributions.
9 BRAINKIT: A PLATFORM FOR SMALL-SCALE RATIONAL DESIGN OF tDCS MONTAGES Nathan Whitmore. Independent Researcher A major obstacle to using tDCS for therapy and cognitive enhancement is the problem of selecting parameters like electrode position which are likely to achieve particular goals for an individual person. tDCS parameters which create significant effects at a group level are often unreliable at an individual level, and in many cases there is little a priori evidence for which regions should be targeted to achieve an effect (especially in the case of complex cognitive functions). A potential way to address these issues is combining tDCS with individual-level neurophysiological data. BrainKit is an opensource tDCS stimulator integrated with tools for automatically predicting effective tDCS parameters based on brain dynamics measurement. Covariance of physiological and behavioral variables is exploited to identify brain variables which predict behavioral variables of interest, and a tDCS model is applied to generate predicted parameters for driving these variables in a desired direction. BrainKit uses a novel current regulator, which allows scalp capacitance measurement (recently developed as a low-resolution neuroimaging technique) to be integrated and used as a source of neurophysiological data. Preliminary data suggest that capacitive measurements reflect natural and tDCS-induced brain activity changes, and are valuable for generating tDCS “targets”. BrainKit therefore offers a simple, integrated platform for rational design and optimization of tDCS montages and delivery of stimulation which may improve the effectiveness and applicability of tDCS in clinical and cognitiveenhancement settings.
10 MOTOR ENHANCEMENT WITH SPEECH THERAPY PRIMED BY RTMS: A CASE REPORT OF ORAL/PHARYNGEAL DYSTONIA Susan Wortman-Jutt a, *, Dylan J. Edwards b,c,d , Douglas Labar b,c , Matthew Fink b. a Burke Rehabilitation Hospital, White Plains, NY, USA; b Non-invasive Brain Stimulation and Human Motor Control Laboratory, Burke Medical Research Institute, White Plains, NY, USA; c Neurology Department, Weill Medical College of Cornell University, New York, USA; d Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA * Corresponding author.
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Abstracts / Brain Stimulation 10 (2017) e1–e19
Purpose: The authors report a case of chronic oral-pharyngeal dystonia, and a resultant profound dysarthria, in a post-encephalitic young woman who demonstrated quantitative improvement during a two-week combined course of priming repetitive transcranial magnetic stimulation (rTMS) and speech therapy. Method: An oral-motor examination and assessment of intelligibility and language skills were customized by the speech-language pathologist (SLP). A personalized speech-language assessment was required due to the level of severity, which was profound. Single pulse TMS mapping was used to locate the left hemisphere motor cortex for the orbicularis oris muscle, to serve as a therapeutic rTMS stimulation site. For 10 consecutive weekdays, 30-minute rTMS sessions were given, immediately followed by 45 minutes of individualized speech therapy. Pre-, mid- and post-treatment videos were taken and presented randomly to a blinded group of 6 SLPs, each having no less than 5 years experience in the assessment and treatment of dysarthria. Each SLP was asked to rate levels of severity for all tasks in each video and judge which video was pre- or post-treatment. Additionally, an objective measurement was taken for the timing of lip closure during verbal production of the phoneme /m/. Results: 5 of the 6 SLPs accurately judged which video was post-treatment. The timing of the patient’s lip closure for /m/ improved, from 61 seconds pre-treatment to 12 seconds post-treatment. Conclusion: This case provides preliminary support for tolerability and efficacy using non-invasive brain stimulation priming for the therapeutic retraining of oro-motor control in acquired dystonia.
11 OPEN EPHYS ELECTROENCEPHALOGRAPHY: A NOVEL METHOD FOR REAL-TIME RECORDING DURING TRANSCRANIAL ALTERNATING CURRENT STIMULATION Chris J. Black a,b,*, Jakob Voigts a,c, Chris I. Moore a, Stephanie R. Jones a. a Department of Neuroscience, Brown University, Providence, RI, USA; b Department of Biomedical Engineering, Brown University, Providence, RI, USA; c Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA * Corresponding author. Transcranial alternating current stimulation (tACS) is a frequency dependent, non-invasive stimulation technique used to treat an array of neurological disorders. While the therapeutic effects of tACS are clear the mechanism of action is poorly understood. Electroencephalography (EEG), a neural recording technique with high temporal resolution, offers a non-invasive method to study the effects of tACS on neural activity. Currently, stimulation from tACS obscures EEG signals and produces irregularities in bio amplifier operations, hindering the ability to simultaneously stimulate and record. Post-processing techniques can extract signals from noisy recordings but also results in data loss. Alternatively, EEG can be done post-stimulation but powering up electronics causes delays for signal acquisition. We have addressed these issues by developing EEG compatibility on the open-electrophysiology platform, Open Ephys. By recording EEG on the Open Ephys platform we can reduce the time lag in data acquisition. Open ephys employs an Intan Technologies RHD2000 amplifier chip that provides an amplifier fast settle function. Amplifier output can be set and held at zero, and then reset to normal operation within 200 microseconds. Implementing this low-latency, fast settle function during tACS inhibits amplifier saturation from high voltage inputs allowing for reliable EEG recording immediately following stimulation. Monitoring this resulting neural activity
has strong implications in optimizing stimulation based therapies and neural-interface technologies. We are currently applying this system to study the impact of tACS on somatosensation and pain. Acknowledgements: We thank Reid Harrison of Intan Technologies, everyone who has contributed to Open Ephys, and the Rhode Island NASA Space Grant Consortium for their support.
12 RANDOM NOISE STIMULATION OF THE CORTEX: STOCHASTIC RESONANCE ENHANCES CENTRAL MECHANISMS OF PERCEPTION Onno van der Groen *, Nicole Wenderoth. Neural Control of Movement Lab, Department of Health Sciences and Technology, ETH Zurich, Switzerland * Corresponding author. It has been demonstrated that detection thresholds decrease by adding random noise to the peripheral nervous system (Simonotto et al., 1996, Collins et al., 1996) in accordance to a stochastic resonance (SR) phenomenon. Psychophysical experiments in humans suggest that SR in the visual system can occur in the primary visual cortex (Aihara et al., 2008). In an EEG (electroencephalography) study in humans, it was shown that when a small amount of tactile random noise was applied to a tactile signal on the fingertip signal-to-noise ratio of the EEG signals decreased for the optimal level of peripheral noise, which is a characteristic of SR (Manjarrez et al., 2003). In previous work, signal and noise were always applied to the peripheral nervous system and not directly to the central nervous system. The question arises as to whether SR-like behavior occurs if noise is added to cortical areas. Here subjects performed a visual perception task while different levels of noise were added either to the peripheral or central nervous system. Peripheral noise was zero-mean Gaussian noise represented on the screen. Central noise was applied via transcranial random noise stimulation (tRNS, 100-640 Hz, intensity varying between 0 and 1.5 mA) with one electrode overlying the visual cortex. Our results indicate that a small amount of peripheral as well as central noise induces a SR effect for sub-threshold stimuli, i.e. the detection threshold is reduced for optimal noise levels. Increasing the noise beyond the optimal amount does not benefit perception.
13 EFFECTS OF TDCS ON STEPPING REACTION IN HEALTHY ADULTS AND INDIVIDUALS WITH CHRONIC STROKE Shuo-Hsiu Chang a,*, Joshua Choi b, Shih-Chiao Tseng c. a Department of Physical Medicine and Rehabilitation, UT Health, Houston, TX, USA; b Department of Bioengineering, Rice University, Houston, TX, USA; c School of Physical Therapy, Texas Women’s University, Houston, TX, USA * Corresponding author. Stepping is an important protective reaction to prevent falls and fall related injuries and this ability is usually impaired in elderly and individuals with stroke. This impaired stepping reaction is characterized by prolong reaction time and decrease neuromuscular control. Transcranial direct current stimulation (tDCS) has been applied in human to enhance cortical excitability and in turn
7 NONINVASIVE STIMULATION OF PREFRONTAL CORTEX STRENGTHENS EXISTING EPISODIC MEMORIES AND REDUCES FORGETTING IN THE ELDERLY Marco Sandrini a,b,*, Michela Brambilla c, Rosa Manenti c, Sandra Rosini c, Leonardo G. Cohen a, Maria Cotelli c. a Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, USA; b Center for Neuroscience and Regenerative Medicine, Uniformed Services University of Health Sciences, Bethesda, USA; c Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy * Corresponding author. Memory for unique personal experiences (episodic memory) is critical to daily life functioning. This form of long-term memory also displays the largest degree of age-related decline. Since this condition is accelerated in Alzheimer’s disease (AD), the development of effective therapeutic interventions to prevent or delay AD is an urgent priority. Accumulating evidence shows that reactivation of consolidated memories by a reminder triggers reconsolidation, a time-limited state of plasticity during which existing memories can be modified (i.e. weakened or strengthened). A recent study showed that the dorsolateral prefrontal cortex (DLPFC) plays a causal role in strengthening of verbal episodic memories through reconsolidation in young adults (Sandrini, Censor, Mishoe, and Cohen, Current Biology 2013). Here, we investigated whether anodal tDCS over the left DLPFC would strengthen verbal episodic memories through reconsolidation in healthy older adults. On Day 1, subjects learned a list of words. On Day 2 (24 h later), they received a reminder or not, and then tDCS was applied over the left DLPFC (15 min, 1.5 mA, cathode over the contralateral supraorbital area). Memory recall was tested on Day 3 (48 h later) and Day 30 (1 month later). Anodal tDCS over the left DLPFC (i.e. with or without the reminder) strengthened existing verbal episodic memories and reduced forgetting compared to sham stimulation. These results provide a framework for testing the hypothesis that tDCS of left DLPFC might strengthen existing episodic memories through reconsolidation in older adults with amnestic mild cognitive impairment, which is often the precursor for emerging AD. Acknowledgements: This work was partially supported by funding from US Department of Defense in the Center for Neuroscience and Regenerative Medicine (CNRM) to Marco Sandrini.
8 TIME DEPENDENT EFFECTS OF TRANSCRANIAL DIRECT CURRENT STIMULATION AND CAFFEINE ON VIGILANCE PERFORMANCE DURING EXTENDED WAKEFULNESS R. Andy McKinley a , Lindsey K. McIntire b , Ryan Schilling c , Chuck Goodyear b, Justin Nelson b. a Applied Neuroscience Branch, Air Force Research Laboratory, Wright-Patterson AFB, OH, USA; b Infoscitex Inc., Dayton, OH, USA; c Oak Ridge Institute for Science and Education (ORISE), Dayton, OH, USA Background: Previously, we found that transcranial direct current stimulation (tDCS) preserved vigilance performance twice as well and three times as long as caffeine during a period of extended wakefulness. Vigilance performance often declines linearly over time, but in our previous study the performance trends over the period of watch were not analyzed. Hence, it was not known whether the intervention reduced the vigilance decrement, or simply shifted the performance to a higher mean value while maintaining a similar slope. Objective: Our objective was to evaluate the time-dependent of anodal transcranial direct current stimulation (tDCS) applied to the
e3
pre-frontal cortex at 2 mA for 30 minutes. We then compared these results to those of caffeine as well as the effects of both interventions on arousal. Methods: The period of watch was segregated into equal time segments and target identification accuracy was averaged across subjects in each group. These values were used in an analysis of covariance (separately for ]sessions) as the dependent variable. Factors were group and subject nested in group. Results: The results indicated there is not a significant difference in slope (i.e. vigilance decrement) between the treatment conditions (tDCS, caffeine, and sham) within each period of watch. However, as reported previously, there was a significant difference in mean change from baseline between treatment conditions. Conclusion: Our data suggests that tDCS does not prevent the vigilance decrement within the period of watch. Rather, it shifts performance to higher mean values by a scalar multiple while maintaining a similar slope. Acknowledgements: We’d like to thank the Air Force Office of Scientific research for their continued support and financial contributions.
9 BRAINKIT: A PLATFORM FOR SMALL-SCALE RATIONAL DESIGN OF tDCS MONTAGES Nathan Whitmore. Independent Researcher A major obstacle to using tDCS for therapy and cognitive enhancement is the problem of selecting parameters like electrode position which are likely to achieve particular goals for an individual person. tDCS parameters which create significant effects at a group level are often unreliable at an individual level, and in many cases there is little a priori evidence for which regions should be targeted to achieve an effect (especially in the case of complex cognitive functions). A potential way to address these issues is combining tDCS with individual-level neurophysiological data. BrainKit is an opensource tDCS stimulator integrated with tools for automatically predicting effective tDCS parameters based on brain dynamics measurement. Covariance of physiological and behavioral variables is exploited to identify brain variables which predict behavioral variables of interest, and a tDCS model is applied to generate predicted parameters for driving these variables in a desired direction. BrainKit uses a novel current regulator, which allows scalp capacitance measurement (recently developed as a low-resolution neuroimaging technique) to be integrated and used as a source of neurophysiological data. Preliminary data suggest that capacitive measurements reflect natural and tDCS-induced brain activity changes, and are valuable for generating tDCS “targets”. BrainKit therefore offers a simple, integrated platform for rational design and optimization of tDCS montages and delivery of stimulation which may improve the effectiveness and applicability of tDCS in clinical and cognitiveenhancement settings.
10 MOTOR ENHANCEMENT WITH SPEECH THERAPY PRIMED BY RTMS: A CASE REPORT OF ORAL/PHARYNGEAL DYSTONIA Susan Wortman-Jutt a, *, Dylan J. Edwards b,c,d , Douglas Labar b,c , Matthew Fink b. a Burke Rehabilitation Hospital, White Plains, NY, USA; b Non-invasive Brain Stimulation and Human Motor Control Laboratory, Burke Medical Research Institute, White Plains, NY, USA; c Neurology Department, Weill Medical College of Cornell University, New York, USA; d Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA * Corresponding author.
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Abstracts / Brain Stimulation 10 (2017) e1–e19
Purpose: The authors report a case of chronic oral-pharyngeal dystonia, and a resultant profound dysarthria, in a post-encephalitic young woman who demonstrated quantitative improvement during a two-week combined course of priming repetitive transcranial magnetic stimulation (rTMS) and speech therapy. Method: An oral-motor examination and assessment of intelligibility and language skills were customized by the speech-language pathologist (SLP). A personalized speech-language assessment was required due to the level of severity, which was profound. Single pulse TMS mapping was used to locate the left hemisphere motor cortex for the orbicularis oris muscle, to serve as a therapeutic rTMS stimulation site. For 10 consecutive weekdays, 30-minute rTMS sessions were given, immediately followed by 45 minutes of individualized speech therapy. Pre-, mid- and post-treatment videos were taken and presented randomly to a blinded group of 6 SLPs, each having no less than 5 years experience in the assessment and treatment of dysarthria. Each SLP was asked to rate levels of severity for all tasks in each video and judge which video was pre- or post-treatment. Additionally, an objective measurement was taken for the timing of lip closure during verbal production of the phoneme /m/. Results: 5 of the 6 SLPs accurately judged which video was post-treatment. The timing of the patient’s lip closure for /m/ improved, from 61 seconds pre-treatment to 12 seconds post-treatment. Conclusion: This case provides preliminary support for tolerability and efficacy using non-invasive brain stimulation priming for the therapeutic retraining of oro-motor control in acquired dystonia.
11 OPEN EPHYS ELECTROENCEPHALOGRAPHY: A NOVEL METHOD FOR REAL-TIME RECORDING DURING TRANSCRANIAL ALTERNATING CURRENT STIMULATION Chris J. Black a,b,*, Jakob Voigts a,c, Chris I. Moore a, Stephanie R. Jones a. a Department of Neuroscience, Brown University, Providence, RI, USA; b Department of Biomedical Engineering, Brown University, Providence, RI, USA; c Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA * Corresponding author. Transcranial alternating current stimulation (tACS) is a frequency dependent, non-invasive stimulation technique used to treat an array of neurological disorders. While the therapeutic effects of tACS are clear the mechanism of action is poorly understood. Electroencephalography (EEG), a neural recording technique with high temporal resolution, offers a non-invasive method to study the effects of tACS on neural activity. Currently, stimulation from tACS obscures EEG signals and produces irregularities in bio amplifier operations, hindering the ability to simultaneously stimulate and record. Post-processing techniques can extract signals from noisy recordings but also results in data loss. Alternatively, EEG can be done post-stimulation but powering up electronics causes delays for signal acquisition. We have addressed these issues by developing EEG compatibility on the open-electrophysiology platform, Open Ephys. By recording EEG on the Open Ephys platform we can reduce the time lag in data acquisition. Open ephys employs an Intan Technologies RHD2000 amplifier chip that provides an amplifier fast settle function. Amplifier output can be set and held at zero, and then reset to normal operation within 200 microseconds. Implementing this low-latency, fast settle function during tACS inhibits amplifier saturation from high voltage inputs allowing for reliable EEG recording immediately following stimulation. Monitoring this resulting neural activity
has strong implications in optimizing stimulation based therapies and neural-interface technologies. We are currently applying this system to study the impact of tACS on somatosensation and pain. Acknowledgements: We thank Reid Harrison of Intan Technologies, everyone who has contributed to Open Ephys, and the Rhode Island NASA Space Grant Consortium for their support.
12 RANDOM NOISE STIMULATION OF THE CORTEX: STOCHASTIC RESONANCE ENHANCES CENTRAL MECHANISMS OF PERCEPTION Onno van der Groen *, Nicole Wenderoth. Neural Control of Movement Lab, Department of Health Sciences and Technology, ETH Zurich, Switzerland * Corresponding author. It has been demonstrated that detection thresholds decrease by adding random noise to the peripheral nervous system (Simonotto et al., 1996, Collins et al., 1996) in accordance to a stochastic resonance (SR) phenomenon. Psychophysical experiments in humans suggest that SR in the visual system can occur in the primary visual cortex (Aihara et al., 2008). In an EEG (electroencephalography) study in humans, it was shown that when a small amount of tactile random noise was applied to a tactile signal on the fingertip signal-to-noise ratio of the EEG signals decreased for the optimal level of peripheral noise, which is a characteristic of SR (Manjarrez et al., 2003). In previous work, signal and noise were always applied to the peripheral nervous system and not directly to the central nervous system. The question arises as to whether SR-like behavior occurs if noise is added to cortical areas. Here subjects performed a visual perception task while different levels of noise were added either to the peripheral or central nervous system. Peripheral noise was zero-mean Gaussian noise represented on the screen. Central noise was applied via transcranial random noise stimulation (tRNS, 100-640 Hz, intensity varying between 0 and 1.5 mA) with one electrode overlying the visual cortex. Our results indicate that a small amount of peripheral as well as central noise induces a SR effect for sub-threshold stimuli, i.e. the detection threshold is reduced for optimal noise levels. Increasing the noise beyond the optimal amount does not benefit perception.
13 EFFECTS OF TDCS ON STEPPING REACTION IN HEALTHY ADULTS AND INDIVIDUALS WITH CHRONIC STROKE Shuo-Hsiu Chang a,*, Joshua Choi b, Shih-Chiao Tseng c. a Department of Physical Medicine and Rehabilitation, UT Health, Houston, TX, USA; b Department of Bioengineering, Rice University, Houston, TX, USA; c School of Physical Therapy, Texas Women’s University, Houston, TX, USA * Corresponding author. Stepping is an important protective reaction to prevent falls and fall related injuries and this ability is usually impaired in elderly and individuals with stroke. This impaired stepping reaction is characterized by prolong reaction time and decrease neuromuscular control. Transcranial direct current stimulation (tDCS) has been applied in human to enhance cortical excitability and in turn