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Xu B, Ma W, Li H, Li S. Improvements in Nerve Dissection Surgery Methodology for Spasmodic Torticollis Treatment. World Neurosurg 2021; 156:33-42. [PMID: 34464776 DOI: 10.1016/j.wneu.2021.08.094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 11/15/2022]
Abstract
Spasmodic torticollis is the most common focal dystonia and is characterized by aberrant involuntary contraction of muscles of the neck and shoulders, which greatly affects patients' quality of life. Consequently, patients with this condition often desire treatment to alleviate their symptoms. The common clinical treatments for spasmodic torticollis include interventions such as drug therapy, botulinum toxin injections, and surgery. Surgical treatment is feasible for patients who do not respond well to other treatments or who are resistant to drugs. The gradual improvement of surgeons' understanding of anatomy and the ongoing developments in surgical techniques since their advent in the 1640s have resulted in many innovative surgical approaches that have led to improvements in the treatment of spasmodic torticollis. Previously used surgical treatments that result in uncertain outcomes, various postoperative complications, and serious damage to motor functions of the head and neck have gradually been discontinued. Nerve dissection surgery is the most common surgical treatment for spasmodic torticollis. This article reviews existing research on nerve dissection surgery for the treatment of spasmodic torticollis and the history of its development, along with the advantages and disadvantages of various surgical improvements. This article aims to provide clinicians with practical advice.
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Affiliation(s)
- Baoxin Xu
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Weining Ma
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Han Li
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Shaoyi Li
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China.
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Kaňovský P, Rosales R, Otruba P, Nevrlý M, Hvizdošová L, Opavský R, Kaiserová M, Hok P, Menšíková K, Hluštík P, Bareš M. Contemporary clinical neurophysiology applications in dystonia. J Neural Transm (Vienna) 2021; 128:509-519. [PMID: 33591454 DOI: 10.1007/s00702-021-02310-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 01/18/2021] [Indexed: 12/25/2022]
Abstract
The complex phenomenological understanding of dystonia has transcended from the clinics to genetics, imaging and neurophysiology. One way in which electrophysiology will impact into the clinics are cases wherein a dystonic clinical presentation may not be typical or a "forme fruste" of the disorder. Indeed, the physiological imprints of dystonia are present regardless of its clinical manifestation. Underpinnings in the understanding of dystonia span from the peripheral, segmental and suprasegmental levels to the cortex, and various electrophysiological tests have been applied in the course of time to elucidate the origin of dystonia pathophysiology. While loss of inhibition remains to be the key finding in this regard, intricacies and variabilities exist, thus leading to a notion that perhaps dystonia should best be gleaned as network disorder. Interestingly, the complex process has now spanned towards the understanding in terms of networks related to the cerebellar circuitry and the neuroplasticity. What is evolving towards a better and cohesive view will be neurophysiology attributes combined with structural dynamic imaging. Such a sound approach will significantly lead to better therapeutic modalities in the future.
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Affiliation(s)
- Petr Kaňovský
- Department of Neurology, Faculty of Medicine and Dentistry, University Hospital, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic.
| | - Raymond Rosales
- Department of Neurology, Faculty of Medicine and Dentistry, University Hospital, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic.,Department of Neurology and Psychiatry, The Neuroscience Institute, University of Santo Tomás Hospital, Manila, Philippines
| | - Pavel Otruba
- Department of Neurology, Faculty of Medicine and Dentistry, University Hospital, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Martin Nevrlý
- Department of Neurology, Faculty of Medicine and Dentistry, University Hospital, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Lenka Hvizdošová
- Department of Neurology, Faculty of Medicine and Dentistry, University Hospital, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Robert Opavský
- Department of Neurology, Faculty of Medicine and Dentistry, University Hospital, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Michaela Kaiserová
- Department of Neurology, Faculty of Medicine and Dentistry, University Hospital, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Pavel Hok
- Department of Neurology, Faculty of Medicine and Dentistry, University Hospital, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Kateřina Menšíková
- Department of Neurology, Faculty of Medicine and Dentistry, University Hospital, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Petr Hluštík
- Department of Neurology, Faculty of Medicine and Dentistry, University Hospital, Palacky University, I. P. Pavlova 6, 775 20, Olomouc, Czech Republic
| | - Martin Bareš
- 1st Department of Neurology, Masaryk University Medical School and St. Anne University Hospital, Brno, Czech Republic
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McCambridge AB, Bradnam LV. Cortical neurophysiology of primary isolated dystonia and non-dystonic adults: A meta-analysis. Eur J Neurosci 2020; 53:1300-1323. [PMID: 32991762 DOI: 10.1111/ejn.14987] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 11/30/2022]
Abstract
Transcranial magnetic stimulation (TMS) is a non-invasive method to assess neurophysiology of the primary motor cortex in humans. Dystonia is a poorly understood neurological movement disorder, often presenting in an idiopathic, isolated form across different parts of the body. The neurophysiological profile of isolated dystonia compared to healthy adults remains unclear. We conducted a systematic review with meta-analysis of neurophysiologic TMS measures in people with isolated dystonia to provide a synthesized understanding of cortical neurophysiology associated with isolated dystonia. We performed a systematic database search and data were extracted independently by the two authors. Separate meta-analyses were performed for TMS measures of: motor threshold, corticomotor excitability, short interval intracortical inhibition, cortical silent period, intracortical facilitation and afferent-induced inhibition. Standardized mean differences were calculated using a random effects model to determine overall effect sizes and confidence intervals. Heterogeneity was explored using dystonia type subgroup analysis. The search resulted in 78 studies meeting inclusion criteria, of these 57 studies reported data in participants with focal hand dystonia, cervical dystonia, blepharospasm or spasmodic dysphonia, and were included in at least one meta-analysis. The cortical silent period, short-interval intracortical inhibition and afferent-induced inhibition was found to be reduced in isolated dystonia compared to controls. Reduced GABAergic-mediated inhibition in the primary motor cortex in idiopathic isolated dystonia's suggest interventions targeted to aberrant cortical disinhibition could provide a novel treatment. Future meta-analyses require neurophysiology studies to use homogeneous cohorts of isolated dystonia participants, publish raw data values, and record electromyographic responses from dystonic musculature where possible.
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Affiliation(s)
- Alana B McCambridge
- Graduate School of Health, Discipline of Physiotherapy, University of Technology Sydney, Sydney, NSW, Australia
| | - Lynley V Bradnam
- Department of Exercise Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand
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Chen M, Summers RLS, Prudente CN, Goding GS, Samargia-Grivette S, Ludlow CL, Kimberley TJ. Transcranial magnetic stimulation and functional magnet resonance imaging evaluation of adductor spasmodic dysphonia during phonation. Brain Stimul 2020; 13:908-915. [PMID: 32289724 PMCID: PMC7213049 DOI: 10.1016/j.brs.2020.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 03/04/2020] [Accepted: 03/06/2020] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Reduced intracortical inhibition is a neurophysiologic finding in focal dystonia that suggests a broader problem of impaired cortical excitability within the brain. A robust understanding of the neurophysiology in dystonia is essential to elucidate the pathophysiology of the disorder and develop new treatments. The cortical silent period (cSP) is a reliable, non-invasive method to measure intracortical inhibition in the primary motor cortex associated with a muscle of interest. In adductor spasmodic dysphonia (AdSD), cSP of the laryngeal motor cortex (LMC) which directly corresponds to the affected musculature, the thyroarytenoid (TA), has not been examined. OBJECTIVE This work evaluated the cSP of the LMC and the relationship between cSP and functional magnetic resonance imaging (fMRI) blood-oxygen-level dependent (BOLD) activation in people with AdSD (n = 12) compared to healthy controls (CTL, n = 14). RESULTS Shortened LMC cSP were observed bilaterally in people with AdSD vs CTL (F(1, 99) = 19.5226, p < 0.0001), with a large effect size (η2 = 0.1834). Between-group fMRI analysis revealed greater activation in bilateral LMC in the AdSD > CTL contrast as compared to CTL > AdSD contrast. Correlation analysis showed that people with AdSD have positive correlation of left LMC BOLD activation and the cSP. Further, the right LMC cSP lacks either positive or negative associations with BOLD activation. CTL individuals displayed both positive and negative correlations between cSP and BOLD activation in the left LMC. In CTL, the LMC cSP and BOLD activation showed exclusively negative correlations in both hemispheres. CONCLUSION In AdSD, the cortical activation during phonation may not be efficiently or effectively associated with inhibitory processes, leading to muscular dysfunction. These findings may give insight into the maladaptive cortical control during phonation in people with AdSD.
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Affiliation(s)
- Mo Chen
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota. 426 Church St. SE, Minneapolis, MN, 55455, USA; Non-invasive Neuromodulation Laboratory, MnDRIVE Initiative, University of Minnesota. 247, 717 Delaware St. SE, Minneapolis, MN, 55414, USA
| | - Rebekah L S Summers
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota. 426 Church St. SE, Minneapolis, MN, 55455, USA; Department of Neurology, School of Medicine, University of Minnesota, 717 Delaware St., SE. Minneapolis, MN, 55414, USA
| | - Cecília N Prudente
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota. 426 Church St. SE, Minneapolis, MN, 55455, USA
| | - George S Goding
- Department of Otolaryngology-Head and Neck Surgery, University of Minnesota, Phillips Wangensteen Building, 516 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Sharyl Samargia-Grivette
- Department of Communication Sciences and Disorders, University of Wisconsin River Falls Campus. 220 Wyman Teacher Education Bldg, 410 South Third Street, River Falls, WI, 54022, USA
| | - Christy L Ludlow
- Department of Communication Sciences and Disorders, James Madison University, MSC 4304, MLK Drive, Harrisonburg, VA, 22807, USA
| | - Teresa J Kimberley
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota. 426 Church St. SE, Minneapolis, MN, 55455, USA; School of Health and Rehabilitation Sciences, Department of Physical Therapy, Massachusetts General Hospital, Institute of Health Professions, 36 First Ave, Boston, MA, 02129, USA.
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Summers RLS, Chen M, MacKinnon CD, Kimberley TJ. Evidence for normal intracortical inhibitory recruitment properties in cervical dystonia. Clin Neurophysiol 2020; 131:1272-1279. [PMID: 32304844 DOI: 10.1016/j.clinph.2020.03.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/17/2020] [Accepted: 03/22/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Dystonia is associated with reduced intracortical inhibition as measured by the cortical silent period (cSP); however, this may be due to abnormal cSP threshold or input-output properties. This study evaluated cSP recruitment properties in people with cervical dystonia (CD). METHODS Bilateral electromyographic recordings were collected in the upper trapezius muscle in response to transcranial magnetic stimulation of the left and right primary motor cortex in a group with CD (n = 19) and controls (n = 21). cSP threshold, cSP input-output properties at stimulation intensities from 1 to 1.4x the cSP threshold, ipsilateral silent period duration (iSP) and timing and magnitude of the contralateral and ipsilateral motor evoked potential (MEP) were assessed. RESULTS The cSP threshold, input-output properties, and contralateral MEP magnitude were not significantly different between groups (all p > 0.07). Hemispheric symmetry was present in the control group while the CD group had reduced iSP (p < 0.01) and a trend for reduced ipsilateral MEP response (p = 0.053) in the left hemisphere. CONCLUSIONS Recruitment properties of intracortical inhibition are similar between control and CD groups. Transcallosal inhibition is asymmetric between hemispheres in people with CD. SIGNIFICANCE Evidence of normal intracortical inhibition recruitment properties challenge the commonly held view that cortical inhibition is reduced in dystonia.
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Affiliation(s)
- Rebekah L S Summers
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota, 426 Church St. SE, Minneapolis, MN 55455, USA; Department of Neurology, School of Medicine, University of Minnesota, 717 Delaware St. SE, Minneapolis, MN 55414, USA.
| | - Mo Chen
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota, 426 Church St. SE, Minneapolis, MN 55455, USA; Non-invasive Neuromodulation Laboratory, MnDRIVE Initiative, University of Minnesota, 247, 717 Delaware St. SE, Minneapolis, MN 55414, USA
| | - Colum D MacKinnon
- Department of Neurology, School of Medicine, University of Minnesota, 717 Delaware St. SE, Minneapolis, MN 55414, USA
| | - Teresa J Kimberley
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota, 426 Church St. SE, Minneapolis, MN 55455, USA; School of Health and Rehabilitation Sciences, Department of Physical Therapy, Massachusetts General Hospital, Institute of Health Professions, 36 First Ave, Boston, MA 02129, USA
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Odorfer TM, Homola GA, Reich MM, Volkmann J, Zeller D. Increased Finger-Tapping Related Cerebellar Activation in Cervical Dystonia, Enhanced by Transcranial Stimulation: An Indicator of Compensation? Front Neurol 2019; 10:231. [PMID: 30930842 PMCID: PMC6428698 DOI: 10.3389/fneur.2019.00231] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Accepted: 02/22/2019] [Indexed: 01/09/2023] Open
Abstract
Background: Cervical dystonia is a movement disorder causing abnormal postures and movements of the head. While the exact pathophysiology of cervical dystonia has not yet been fully elucidated, a growing body of evidence points to the cerebellum as an important node. Methods: Here, we examined the impact of cerebellar interference by transcranial magnetic stimulation on finger-tapping related brain activation and neurophysiological measures of cortical excitability and inhibition in cervical dystonia and controls. Bilateral continuous theta-burst stimulation was used to modulate cerebellar cortical excitability in 16 patients and matched healthy controls. In a functional magnetic resonance imaging arm, data were acquired during simple finger tapping before and after cerebellar stimulation. In a neurophysiological arm, assessment comprised motor-evoked potentials amplitude and cortical silent period duration. Theta-burst stimulation over the dorsal premotor cortex and sham stimulation (neurophysiological arm only) served as control conditions. Results: At baseline, finger tapping was associated with increased activation in the ipsilateral cerebellum in patients compared to controls. Following cerebellar theta-burst stimulation, this pattern was even more pronounced, along with an additional movement-related activation in the contralateral somatosensory region and angular gyrus. Baseline motor-evoked potential amplitudes were higher and cortical silent period duration shorter in patients compared to controls. After cerebellar theta-burst stimulation, cortical silent period duration increased significantly in dystonia patients. Conclusion: We conclude that in cervical dystonia, finger movements—though clinically non-dystonic—are associated with increased activation of the lateral cerebellum, possibly pointing to general motor disorganization, which remains subclinical in most body regions. Enhancement of this activation together with an increase of silent period duration by cerebellar continuous theta-burst stimulation may indicate predominant disinhibitory effects on Purkinje cells, eventually resulting in an inhibition of cerebello-thalamocortical circuits.
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Affiliation(s)
| | - György A Homola
- Department of Neuroradiology, University of Würzburg, Würzburg, Germany
| | - Martin M Reich
- Department of Neurology, University of Würzburg, Würzburg, Germany
| | - Jens Volkmann
- Department of Neurology, University of Würzburg, Würzburg, Germany
| | - Daniel Zeller
- Department of Neurology, University of Würzburg, Würzburg, Germany
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Abstract
Dystonia can be seen in a number of different phenotypes that may arise from different etiologies. The pathophysiological substrate of dystonia is related to three lines of research. The first postulate a loss of inhibition which may account for the excess of movement and for the overflow phenomena. A second abnormality is sensory dysfunction which is related to the mild sensory complaints in patients with focal dystonias and may be responsible for some of the motor dysfunction. Finally, there are strong pieces of evidence from animal and human studies suggesting that alterations of synaptic plasticity characterized by a disruption of homeostatic plasticity, with a prevailing facilitation of synaptic potentiation may play a pivotal role in primary dystonia. These working hypotheses have been generalized in all form of dystonia. On the other hand, several pieces of evidence now suggest that the pathophysiology may be slightly different in the different types of dystonia. Therefore, in the present review, we would like to discuss the neural mechanisms underlying the different forms of dystonia to disentangle the different weight and role of environmental and predisposing factors.
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Affiliation(s)
- Angelo Quartarone
- Department of Biomedical, Dental Sciences and Morphological and Functional Images, University of Messina, Messina, Italy.,IRCCS Centro Neurolesi "Bonino Pulejo", Messina, Italy
| | - Diane Ruge
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Dortmund, Germany
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Forbes PA, de Bruijn E, Nijmeijer SWR, Koelman JHTM, van der Helm FCT, Schouten AC, Tijssen MAJ, Happee R. Dynamic head-neck stabilization in cervical dystonia. Clin Biomech (Bristol, Avon) 2017; 42:120-127. [PMID: 28157620 DOI: 10.1016/j.clinbiomech.2017.01.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 01/11/2017] [Accepted: 01/15/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Effective sensorimotor integration is essential to modulate (adapt) neck stabilization strategies in response to varying tasks and disturbances. This study evaluates the hypothesis that relative to healthy controls cervical dystonia patients have an impaired ability to modulate afferent feedback for neck stabilization with changes in the frequency content of mechanical perturbations. METHODS We applied anterior-posterior displacement perturbations (110s) on the torso of seated subjects, while recording head-neck kinematics and muscular activity. We compared low bandwidth (0.2-1.2Hz) and high bandwidth (0.2-8Hz) perturbations where our previous research showed a profound modulation of stabilization strategies in healthy subjects. Cervical dystonia patients and age matched controls performed two tasks: (1) maintain head forward posture and (2) allow dystonia to dictate head posture. FINDINGS Patients and controls demonstrated similar kinematic and muscular responses. Patient modulation was similar to that of healthy controls (P>0.05); neck stiffness and afferent feedback decreased with high bandwidth perturbations. During the head forward task patients had an increased neck stiffness relative to controls (P<0.05), due to increased afferent feedback. INTERPRETATION The unaffected modulation of head-neck stabilization (both kinematic and muscular) in patients with cervical dystonia does not support the hypothesis of impaired afferent feedback modulation for neck stabilization.
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Affiliation(s)
- Patrick A Forbes
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands; Department of Neuroscience, Erasmus University Medical Centre, Rotterdam, The Netherlands.
| | - Edo de Bruijn
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands
| | - Sebastiaan W R Nijmeijer
- Department of Neurology and Clinical Neurophysiology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Johannes H T M Koelman
- Department of Neurology and Clinical Neurophysiology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Frans C T van der Helm
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands; Laboratory of Biomechanical Engineering, Institute for Biomedical Technology and Technical Medicine (MIRA), University of Twente, Enschede, The Netherlands
| | - Alfred C Schouten
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands; Laboratory of Biomechanical Engineering, Institute for Biomedical Technology and Technical Medicine (MIRA), University of Twente, Enschede, The Netherlands
| | - Marina A J Tijssen
- Department of Neurology and Clinical Neurophysiology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands; Department of Neurology, University Medical Centre Groningen (UMCG), University of Groningen, Groningen, The Netherlands
| | - Riender Happee
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands
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Boček V, Štětkářová I, Fečíková A, Čejka V, Urgošík D, Jech R. Pallidal stimulation in dystonia affects cortical but not spinal inhibitory mechanisms. J Neurol Sci 2016; 369:19-26. [DOI: 10.1016/j.jns.2016.07.053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 06/30/2016] [Accepted: 07/22/2016] [Indexed: 12/14/2022]
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Samargia S, Schmidt R, Kimberley TJ. Cortical Silent Period Reveals Differences Between Adductor Spasmodic Dysphonia and Muscle Tension Dysphonia. Neurorehabil Neural Repair 2015; 30:221-32. [PMID: 26089309 DOI: 10.1177/1545968315591705] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The pathophysiology of adductor spasmodic dysphonia (AdSD), like other focal dystonias, is largely unknown. OBJECTIVE The purposes of this study were to determine (a) cortical excitability differences between AdSD, muscle tension dysphonia (MTD), and healthy controls; (b) distribution of potential differences in cranial or skeletal muscle; and (c) if cortical excitability measures assist in the differential diagnosis of AdSD and MTD. METHODS Ten participants with adductor spasmodic dysphonia, 8 with muscle tension dysphonia, and 10 healthy controls received single and paired pulse transcranial magnetic stimulation (TMS) to the primary motor cortex contralateral to tested muscles, first dorsal interosseus (FDI), and masseter. We tested the hypothesis that cortical excitability measures in AdSD would be significantly different from those in MTD and healthy controls. In addition, we hypothesized that there would be a correlation between cortical excitability measures and clinical voice severity in AdSD. RESULTS Cortical silent period duration in masseter and FDI was significantly shorter in AdSD than MTD and healthy controls. Other measures failed to demonstrate differences. CONCLUSION There are differences in cortical excitability between AdSD, MTD, and healthy controls. These differences in the cortical measure of both the FDI and masseter muscles in AdSD suggest widespread dysfunction of the GABAB mechanism may be a pathophysiologic feature of AdSD, similar to other forms of focal dystonia. Further exploration of the use of TMS to assist in the differential diagnosis of AdSD and MTD is warranted.
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Affiliation(s)
- Sharyl Samargia
- University of Minnesota, Minneapolis, MN, USA University of Wisconsin, River Falls, WI, USA
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Shortened cortical silent period in adductor spasmodic dysphonia: evidence for widespread cortical excitability. Neurosci Lett 2013; 560:12-5. [PMID: 24333913 DOI: 10.1016/j.neulet.2013.12.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 11/27/2013] [Accepted: 12/04/2013] [Indexed: 11/20/2022]
Abstract
The purpose of this study was to compare cortical inhibition in the hand region of the primary motor cortex between subjects with focal hand dystonia (FHD), adductor spasmodic dysphonia (AdSD), and healthy controls. Data from 28 subjects were analyzed (FHD n=11, 53.25 ± 8.74 y; AdSD: n=8, 56.38 ± 7.5 y; and healthy controls: n=941.67 ± 10.85 y). All subjects received single pulse TMS to the left motor cortex to measure cortical silent period (CSP) in the right first dorsal interosseus (FDI) muscle. Duration of the CSP was measured and compared across groups. A one-way ANCOVA with age as a covariate revealed a significant group effect (p<0.001). Post hoc analysis revealed significantly longer CSP duration in the healthy group vs. AdSD group (p<0.001) and FHD group (p<0.001). These results suggest impaired intracortical inhibition is a neurophysiologic characteristic of FHD and AdSD. In addition, the shortened CSP in AdSD provides evidence to support a widespread decrease in cortical inhibition in areas of the motor cortex that represent an asymptomatic region of the body. These findings may inform future investigations of differential diagnosis as well as alternative treatments for focal dystonias.
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Colosimo C, Suppa A, Fabbrini G, Bologna M, Berardelli A. Craniocervical dystonia: clinical and pathophysiological features. Eur J Neurol 2010; 17 Suppl 1:15-21. [PMID: 20590803 DOI: 10.1111/j.1468-1331.2010.03045.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Blepharospasm, oromandibular, lingual, laryngeal and cervical dystonia are common forms of adult-onset dystonia. Each condition may appear in isolation or manifest along with other forms of craniocervical dystonia. Although the various craniocervical dystonias typically present with involuntary muscle spasms causing abnormal postures, they differ for some clinical features. Neurophysiologic and neuroimaging studies have shown a number of motor and sensory abnormalities at cortical and subcortical levels, probably reflecting a dysfunction in the basal ganglia-thalamo-cortical circuits. The best treatment for craniocervical dystonia is botulinum toxin injected into the overactive muscles.
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Affiliation(s)
- C Colosimo
- Department of Neurological Sciences, Sapienza University of Rome, Rome, Italy
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Tinazzi M, Squintani G, Berardelli A. Does neurophysiological testing provide the information we need to improve the clinical management of primary dystonia? Clin Neurophysiol 2009; 120:1424-32. [DOI: 10.1016/j.clinph.2009.06.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Revised: 05/20/2009] [Accepted: 06/20/2009] [Indexed: 11/17/2022]
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Wit HP, Kingma CM. A simple model for the generation of the vestibular evoked myogenic potential (VEMP). Clin Neurophysiol 2006; 117:1354-8. [PMID: 16678484 DOI: 10.1016/j.clinph.2006.03.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2005] [Revised: 02/23/2006] [Accepted: 03/05/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To describe the mechanism by which the vestibular evoked myogenic potential is generated. METHODS Vestibular evoked myogenic potential generation is modeled by adding a large number of muscle motor unit action potentials. These action potentials occur randomly in time along a 100 ms long time axis. But because between approximately 15 and 20 ms after a loud short sound stimulus (almost) no action potentials are generated during VEMP measurements in human subjects, no action potentials are present in the model during this time. RESULTS The evoked potential is the result of the lack of amplitude cancellation in the averaged surface electromyogram at the edges of this 5 ms long time interval. CONCLUSIONS The relatively simple model describes generation and some properties of the vestibular evoked myogenic potential very well. SIGNIFICANCE It is shown that, in contrast with other evoked potentials (BAEPs, VERs), the vestibular evoked myogenic potential is the result of an interruption of activity and not that of summed synchronized neural action potentials.
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Affiliation(s)
- Hero P Wit
- Department of Otorhinolaryngology, University Medical Center Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.
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Liepert J, Restemeyer C, Münchau A, Weiller C. Motor cortex excitability after thalamic infarction. Clin Neurophysiol 2005; 116:1621-7. [PMID: 15907397 DOI: 10.1016/j.clinph.2005.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Revised: 02/16/2005] [Accepted: 03/11/2005] [Indexed: 11/30/2022]
Abstract
OBJECTIVE We examined 8 patients with hemihypesthesia due to an ischemic thalamic lesion to explore the effects of a central sensory dysfunction on motor cortex excitability. METHODS Motor excitability was assessed using transcranial magnetic stimulation techniques and electrical peripheral nerve stimulation. Motor function was evaluated by the Nine-Hole-Peg Test and measurement of hand grip strength. The affected side was compared with the non-lesioned side and with an age-matched control group. RESULTS Patients had a loss of inhibition and an increase of facilitation in the motor cortex of the affected side. The silent period was prolonged and motor function was impaired on the affected side. CONCLUSIONS A thalamic lesion can modulate motor cortical excitability. SIGNIFICANCE This study suggests that, under normal conditions, somatosensory afferents influence inhibitory and excitatory properties in the motor cortex.
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Affiliation(s)
- J Liepert
- Department of Neurology, University Hospital Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany.
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Lefaucheur JP. Stimulation du cortex moteur, Parkinson et dystonie : que nous enseigne la stimulation magnétique transcrânienne? revue de la littérature. Rev Neurol (Paris) 2005; 161:27-41. [PMID: 15677999 DOI: 10.1016/s0035-3787(05)84971-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Over the last few years, deep brain stimulation techniques, with targets such as the subthalamic nucleus or the pallidum, have bee found to be beneficial in the treatment of Parkinson's disease and dystonia. Conversely, therapeutic strategies of cortical stimulation have not yet been validated in these diseases, although they are known to be associated with various cortical dysfunctions. Transcranial magnetic stimulation (TMS) is a valuable tool for non-invasive study of the role played by the motor cortex in the pathophysiology of movement disorders, in particular by assessing various cortical excitability determinants using single or paired pulse paradigms. In addition, repetitive TMS (rTMS) trains can be used to study the effects of transient activity changes of a targeted cortical area. BACKGROUND Studies with TMS revealed significant motor cortex excitability changes, particularly regarding intracortical inhibitory pathways, both in Parkinson's disease and in dystonia, and these changes can be distinguished owing to the resting state or to the phases of movement preparation or execution. However, more specific correlation between electrophysiological features and clinical symptoms remains to be established. In addition, the stimulation of various cortical targets by rTMS protocols applied at low or high frequencies have induced some clear clinical effects. PERSPECTIVES The TMS effects are and will remain applied in movement disorders to better understand the role played by the motor cortex, to assess various types of treatment and appraise the therapeutic potential of cortical stimulation. CONCLUSION TMS provides evidence for motor cortex dysfunction in Parkinson's disease or dystonia. Moreover, rTMS results have opened new perspectives for therapeutic strategies of implanted cortical stimulation. By these both aspects, TMS techniques show their usefulness in the assessment of movement disorders.
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Affiliation(s)
- J-P Lefaucheur
- Service de Physiologie, Explorations Fonctionnelles, Hôpital Henri Mondor, Créteil.
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18
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Abstract
Noninvasive electrical stimulation of the human brain first was attempted in the 1950s. In the early 1980s, the first clinical application method of transcranial electrical stimulation was developed. Investigators in the mid-1980s showed that it was possible to stimulate the nerve and the brain using external magnetic stimulation (transcranial magnetic stimulation [TMS]), with little or no pain. TMS now is used commonly in clinical neurology to study central motor conduction time. Depending on the stimulation techniques and parameters, TMS can excite or inhibit brain activity, allowing functional mapping of cortical regions and creation of transient functional lesions. It now is used widely as a research tool to study aspects of human brain physiology, including motor function and the pathophysiology of various brain disorders.
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Affiliation(s)
- Young H Sohn
- Department of Neurology and Brain Research Institute, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-752, Korea.
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Bogey RA, Elovic EP, Bryant PR, Geis CC, Moroz A, O'Neill BJ. Rehabilitation of movement disorders11A commercial party with a direct financial interest in the results of the research supporting this article has conferred or will confer a financial benefit upon the author or one or more of the authors. Elovic is on the advisory board and speaker’s bureau of Allergan. Arch Phys Med Rehabil 2004; 85:S41-5. [PMID: 15034854 DOI: 10.1053/j.apmr.2003.11.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
UNLABELLED This self-directed learning module highlights several movement disorders. These include dystonia, chorea, tremors, and myoclonus. A description of the clinical presentation and associated disease processes is presented. Although the discussion on treatment focuses on pharmacologic intervention, surgical options are presented when appropriate. Other movement disorders (ie, parkinsonism) are discussed elsewhere in the Study Guide. OVERALL ARTICLE OBJECTIVES (a) To define the various symptoms and etiologies of dystonia; (b) to define chorea and its treatment; (c) to define tremors, including associated neurologic disorders, plus pharmacologic and potential surgical interventions; and (d) to describe the symptoms, classification, and treatment of primary and secondary myoclonus.
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Affiliation(s)
- Ross A Bogey
- Department of Physical Medicine and Rehabilitation, Rehabilitation Institute of Chicago, IL 60611, USA.
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Liepert J, Gorsler A, van Eimeren T, Münchau A, Weiller C. Motor excitability in a patient with a somatosensory cortex lesion. Clin Neurophysiol 2003; 114:1003-8. [PMID: 12804668 DOI: 10.1016/s1388-2457(03)00062-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE We report a patient with an ischemic lesion in right somatosensory cortex who developed dystonic posturing and pseudo-athetotic involuntary left-sided finger movements during voluntary muscle contractions. METHODS Motor excitability was assessed using transcranial magnetic stimulation techniques and electrical peripheral nerve stimulation. Results obtained from abductor digiti minimi muscles of both hands were compared. RESULTS On the affected side, silent period duration and intracortical inhibition were reduced, indicating a loss of inhibitory properties. Intracortical facilitation was enhanced. Stimulus-response curves showed a smaller increase of motor evoked potential amplitudes when recorded during muscle relaxation, but not during voluntary muscle activation. CONCLUSIONS The results suggest that, under normal conditions, somatosensory cortex modifies inhibitory as well as excitatory properties in the motor system.
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Affiliation(s)
- Joachim Liepert
- Department of Neurology, University of Hamburg, University Hospital Eppendorf, Martinistrasse 52, D-20246, Hamburg, Germany.
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Chapter 8 Transcranial magnetic stimulation. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1567-4231(09)70156-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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22
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Abstract
The author reviews the applications of transcranial magnetic stimulation (TMS) in a series of movement disorders--namely, Parkinson's disease, corticobasal degeneration, multiple system atrophy, progressive supranuclear palsy, essential tremor, dystonia, Huntington's chorea, myoclonus, the ataxias, Tourette's syndrome, restless legs syndrome, Wilson's disease, Rett syndrome, and stiff-person syndrome. Single- and paired-pulse TMS studies have been done mainly for pathophysiologic purposes. Repetitive TMS has been used largely for therapy. Many TMS abnormalities are seen in the different diseases. They concur to show that motor cortical areas and their projections are the main target of the basal ganglia dysfunction typical of movement disorders. Interpretation has not always been clear, and sometimes there were discrepancies and contradictions. Largely, this may be the result of the extreme heterogeneity of the methods used and of the patients studied. It is premature to give repetitive TMS a role in treatment. Overall, however, TMS gives rise to a new, outstanding enthusiasm in the neurophysiology of movement disorders. There is reason to predict that TMS, with its continuous technical refinement, will prove even more helpful in the near future. Then, research achievements are reasonably expected to spill over into clinical practice.
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Affiliation(s)
- Roberto Cantello
- Department of Medical Sciences, Section of Neurology, School of Medicine, Amedeo Avogadro University, Novara, Italy.
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Abstract
Dystonia has commonly been thought to represent a disorder of basal ganglia function. Although long considered a hyperkinetic movement disorder, the evidence to support such a classification was based on the presence of excessive involuntary movement, not on physiological data. Only recently, with the return of surgical procedures using microelectrode guidance for the treatment of dystonia, has electrophysiological data demonstrated an alteration in mean discharge rate, somatosensory responsiveness and the pattern of neuronal activity in the basal ganglia thalamocortical motor circuit. Previous models of dystonia suggested that reduced mean discharge rates in the globus pallidus internus (GPi) led to unopposed increases in activity in the thalamocortical circuit that precipitated the development of involuntary movement associated with dystonia. This model has subsequently been modified given the clear improvement in dystonic symptoms following lesions in the GPi, a procedure that is associated with a further reduction in pallidal output. The improvement in dystonia following pallidal lesions is difficult to reconcile with the "rate" hypothesis for hypokinetic and hyperkinetic movement disorders and has led to the development of alternative models that, in addition to rate, incorporate changes in pattern, somatosensory responsiveness and degree of synchronization of neuronal activity. Present models of dystonia, however, must not only take these changes into account but must reconcile these changes with the reported changes in cortical excitability reported with transcranial magnetic stimulation, the changes in metabolic activity in cortical and subcortical structures documented by positron emission tomography (PET), and the alterations in spinal and brainstem reflexes. A model incorporating these changes together with the reported changes in neuronal activity in the basal ganglia and thalamus is presented.
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Affiliation(s)
- Jerrold L Vitek
- Department of Neurology, Emory University School of Medicine, Woodruff Memorial Research Building, Atlanta, Georgia 30322, USA.
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Abstract
Dystonia is a syndrome of sustained involuntary muscle contractions, frequently causing twisting and repetitive movements or abnormal posturing. Cervical dystonia (CD) is a form of dystonia that involves neck muscles. However, CD is not the only cause of neck rotation. Torticollis may be caused by orthopaedic, musculofibrotic, infectious and other neurological conditions that affect the anatomy of the neck, and structural causes. It is estimated that there are between 60,000 and 90,000 patients with CD in the US. The majority of the patients present with a combination of neck rotation (rotatory torticollis or rotatocollis), flexion (anterocollis), extension (retrocollis), head tilt (laterocollis) or a lateral or sagittal shift. Neck posturing may be either tonic, clonic or tremulous, and may result in permanent and fixed contractures. Sensory tricks ('geste antagonistique') often temporarily ameliorate dystonic movements and postures. Commonly used sensory tricks by patients with CD include touching the chin, back of the head or top of the head. Patients with CD are classified according to aetiology into two groups: primary CD (idiopathic--may be genetic or sporadic) or secondary CD (symptomatic). Patients with primary CD have no evidence by history, physical examination or laboratory studies (except primary dystonia gene) of any secondary cause for the dystonic symptoms. CD is a part of either generalised or focal dystonic syndrome which may have a genetic basis, with an identifiable genetic association. Secondary or symptomatic CD may be caused by central or peripheral trauma, exposure to dopamine receptor antagonists (tardive), neurodegenerative disease, and other conditions associated with abnormal functioning of the basal ganglia. In the majority of patients with CD, the aetiology is not identifiable and the disorder is often classified as primary. Unless the aetiological investigation reveals a specific therapeutic intervention, therapy for CD is symptomatic. It includes supportive therapy and counselling, physical therapy, pharmacotherapy, chemodenervation [botulinum toxin (BTX), phenol, alcohol], and central and peripheral surgical therapy. The most widely used and accepted therapy for CD is local intramuscular injections of BTX-type A. Currently, both BTX type A and type B are commercially available, and type F has undergone testing. Pharmacotherapy, including anticholinergics, dopaminergic depleting and blocking agents, and other muscle relaxants can be used alone or in combination with other therapeutic interventions. Surgery is usually reserved for patients with CD in whom other forms of treatment have failed.
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Affiliation(s)
- M Velickovic
- Department of Neurology, The Mount Sinai Medical Center, New York, New York, 10029, USA.
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Abstract
Since 1985, when the technique of transcranial magnetic stimulation (TMS) was first developed, a wide range of applications in healthy and diseased subjects has been described. Comprehension of the physiological basis of motor control and cortical function has been improved. Modifications of the basic technique of measuring central motor conduction time (CMCT) have included measurement of the cortical silent period, paired stimulation in a conditioning test paradigm, repetitive transcranial magnetic stimulation (rTMS), and peristimulus time histograms (PSTH). These methods allow dissection of central motor excitatory versus inhibitory interplay on the cortical motor neuron and its presynaptic connections at the spinal cord, and have proven to be powerful investigational techniques. TMS can be used to assess upper and lower motor neuron dysfunction, monitor the effects of many pharmacological agents, predict stroke outcome, document the plasticity of the motor system, and assess its maturation and the effects of aging, as well as perform intraoperative monitoring. The recent use of rTMS in the treatment of depression and movement disorders is novel, and opens the way for other potential therapeutic applications.
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Affiliation(s)
- Markus Weber
- Department of Neurology, Kantonsspital, CH-9007 St. Gallen, Switzerland
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