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Shin-Yi Lin C, Howells J, Rutkove S, Nandedkar S, Neuwirth C, Noto YI, Shahrizaila N, Whittaker RG, Bostock H, Burke D, Tankisi H. Neurophysiological and imaging biomarkers of lower motor neuron dysfunction in motor neuron diseases/amyotrophic lateral sclerosis: IFCN handbook chapter. Clin Neurophysiol 2024; 162:91-120. [PMID: 38603949 DOI: 10.1016/j.clinph.2024.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 02/07/2024] [Accepted: 03/12/2024] [Indexed: 04/13/2024]
Abstract
This chapter discusses comprehensive neurophysiological biomarkers utilised in motor neuron disease (MND) and, in particular, its commonest form, amyotrophic lateral sclerosis (ALS). These encompass the conventional techniques including nerve conduction studies (NCS), needle and high-density surface electromyography (EMG) and H-reflex studies as well as novel techniques. In the last two decades, new methods of assessing the loss of motor units in a muscle have been developed, that are more convenient than earlier methods of motor unit number estimation (MUNE),and may use either electrical stimulation (e.g. MScanFit MUNE) or voluntary activation (MUNIX). Electrical impedance myography (EIM) is another novel approach for the evaluation that relies upon the application and measurement of high-frequency, low-intensity electrical current. Nerve excitability techniques (NET) also provide insights into the function of an axon and reflect the changes in resting membrane potential, ion channel dysfunction and the structural integrity of the axon and myelin sheath. Furthermore, imaging ultrasound techniques as well as magnetic resonance imaging are capable of detecting the constituents of morphological changes in the nerve and muscle. The chapter provides a critical description of the ability of each technique to provide neurophysiological insight into the complex pathophysiology of MND/ALS. However, it is important to recognise the strengths and limitations of each approach in order to clarify utility. These neurophysiological biomarkers have demonstrated reliability, specificity and provide additional information to validate and assess lower motor neuron dysfunction. Their use has expanded the knowledge about MND/ALS and enhanced our understanding of the relationship between motor units, axons, reflexes and other neural circuits in relation to clinical features of patients with MND/ALS at different stages of the disease. Taken together, the ultimate goal is to aid early diagnosis, distinguish potential disease mimics, monitor and stage disease progression, quantify response to treatment and develop potential therapeutic interventions.
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Affiliation(s)
- Cindy Shin-Yi Lin
- Faculty of Medicine and Health, Central Clinical School, Brain and Mind Centre, University of Sydney, Sydney 2006, Australia.
| | - James Howells
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Seward Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Sanjeev Nandedkar
- Natus Medical Inc, Middleton, Wisconsin, USA and Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christoph Neuwirth
- Neuromuscular Diseases Unit/ALS Clinic, Kantonsspital, St. Gallen, Switzerland
| | - Yu-Ichi Noto
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Nortina Shahrizaila
- Division of Neurology, Department of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Roger G Whittaker
- Newcastle University Translational and Clinical Research Institute (NUTCRI), Newcastle University., Newcastle Upon Tyne, United Kingdom
| | - Hugh Bostock
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, WC1N 3BG, London, United Kingdom
| | - David Burke
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital and Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
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Lugg A, Schindle M, Sivak A, Tankisi H, Jones KE. Nerve excitability measured with the TROND protocol in amyotrophic lateral sclerosis: a systematic review and meta-analysis. J Neurophysiol 2023; 130:1480-1491. [PMID: 37910562 DOI: 10.1152/jn.00174.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 10/30/2023] [Accepted: 10/31/2023] [Indexed: 11/03/2023] Open
Abstract
This meta-analysis assessed the 30+ nerve excitability indices generated by the TROND protocol to identify potential biomarkers for amyotrophic lateral sclerosis (ALS). A comprehensive search was conducted in multiple databases to identify human studies that tested median motor axons. Forest plot analyses were performed using a random-effects model to determine the pooled effect (Z-score), heterogeneity (I2), and Cohen's d for potential biomarker identification. Out of 2,866 studies, 23 studies met the inclusion criteria, incorporating data from 719 controls and 942 patients with ALS. Seven indices emerged as potential biomarkers: depolarizing threshold electrotonus (TEd) 90-100 ms, strength-duration time constant (SDTC), superexcitability, TEd 40-60 ms, resting I/V slope, 50% depolarizing I/V, and subexcitability (ranked by the magnitude of the difference between patients and controls from largest to smallest). In a sensitivity analysis focusing on patients with larger compound muscle action potentials (CMAPs), only four indices were potential biomarkers: TEd 10-20 ms, TEd 90-100 ms, superexcitability, and SDTC. Among the extensive range of 30+ excitability indices generated by the TROND protocol, we have identified seven indices that effectively differentiate patients with ALS from healthy controls. Furthermore, a smaller subset of four indices shows promise as potential biomarkers when the CMAP remains relatively large. However, most studies were considered to be at moderate risk of bias due to case-control designs and absence of sensitivity and specificity calculations, underscoring the need for more prospective diagnostic test-accuracy studies with appropriate disease controls.NEW & NOTEWORTHY This meta-analysis uncovers seven potential axonal excitability biomarkers for lower motor neuron pathology in ALS, shedding light on ion channel dysfunction. The identified dysfunction aligns with the primary pathology-protein homeostasis disruption. These biomarkers could fill a gap to detect presymptomatic spread of the disease in the spinal cord and monitor treatments targeting protein homeostasis and limiting spread, toward enhancing patient care.
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Affiliation(s)
- Anna Lugg
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Mason Schindle
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Allison Sivak
- University of Alberta Library, Edmonton, Alberta, Canada
| | - Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
| | - Kelvin E Jones
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, Edmonton, Alberta, Canada
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3
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Jazaeri SZ, Taghizadeh G, Babaei JF, Goudarzi S, Saadatmand P, Joghataei MT, Khanahmadi Z. Aquaporin 4 beyond a water channel; participation in motor, sensory, cognitive and psychological performances, a comprehensive review. Physiol Behav 2023; 271:114353. [PMID: 37714320 DOI: 10.1016/j.physbeh.2023.114353] [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: 06/05/2023] [Revised: 08/15/2023] [Accepted: 09/13/2023] [Indexed: 09/17/2023]
Abstract
Aquaporin 4 (AQP4) is a protein highly expressed in the central nervous system (CNS) and peripheral nervous system (PNS) as well as various other organs, whose different sites of action indicate its importance in various functions. AQP4 has a variety of essential roles beyond water homeostasis. In this article, we have for the first time summarized different roles of AQP4 in motor and sensory functions, besides cognitive and psychological performances, and most importantly, possible physiological mechanisms by which AQP4 can exert its effects. Furthermore, we demonstrated that AQP4 participates in pathology of different neurological disorders, various effects depending on the disease type. Since neurological diseases involve a spectrum of dysfunctions and due to the difficulty of obtaining a treatment that can simultaneously affect these deficits, it is therefore suggested that future studies consider the role of this protein in different functional impairments related to neurological disorders simultaneously or separately by targeting AQP4 expression and/or polarity modulation.
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Affiliation(s)
- Seyede Zohreh Jazaeri
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran; Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Ghorban Taghizadeh
- Department of Occupational Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
| | - Javad Fahanik Babaei
- Electrophysiology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Sepideh Goudarzi
- Experimental Medicine Research Center, Tehran University of medical Sciences, Tehran, Iran
| | - Pegah Saadatmand
- Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Taghi Joghataei
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran; Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Anatomy, School of Medicine, Iran University of Medical Sciences, Tehran, Iran; Department of Innovation in Medical Education, Faculty of Medicine, Ottawa University, Ottawa, Canada.
| | - Zohreh Khanahmadi
- Department of Occupational Therapy, School of Rehabilitation Services, Isfahan University of Medical Sciences, Isfahan, Iran
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4
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Lum JS, Yerbury JJ. Misfolding at the synapse: A role in amyotrophic lateral sclerosis pathogenesis? Front Mol Neurosci 2022; 15:997661. [PMID: 36157072 PMCID: PMC9500160 DOI: 10.3389/fnmol.2022.997661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
A growing wave of evidence has placed the concept of protein homeostasis at the center of the pathogenesis of amyotrophic lateral sclerosis (ALS). This is due primarily to the presence of pathological transactive response DNA-binding protein (TDP-43), fused in sarcoma (FUS) or superoxide dismutase-1 (SOD1) inclusions within motor neurons of ALS postmortem tissue. However, the earliest pathological alterations associated with ALS occur to the structure and function of the synapse, prior to motor neuron loss. Recent evidence demonstrates the pathological accumulation of ALS-associated proteins (TDP-43, FUS, C9orf72-associated di-peptide repeats and SOD1) within the axo-synaptic compartment of motor neurons. In this review, we discuss this recent evidence and how axo-synaptic proteome dyshomeostasis may contribute to synaptic dysfunction in ALS.
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Affiliation(s)
- Jeremy S. Lum
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - Justin J. Yerbury
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
- *Correspondence: Justin J. Yerbury, ; orcid.org/0000-0003-2528-7039
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5
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Lambert-Smith IA, Saunders DN, Yerbury JJ. Progress in biophysics and molecular biology proteostasis impairment and ALS. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 174:3-27. [PMID: 35716729 DOI: 10.1016/j.pbiomolbio.2022.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 05/19/2022] [Accepted: 06/09/2022] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and fatal neurodegenerative disease that results from the loss of both upper and lower motor neurons. It is the most common motor neuron disease and currently has no effective treatment. There is mounting evidence to suggest that disturbances in proteostasis play a significant role in ALS pathogenesis. Proteostasis is the maintenance of the proteome at the right level, conformation and location to allow a cell to perform its intended function. In this review, we present a thorough synthesis of the literature that provides evidence that genetic mutations associated with ALS cause imbalance to a proteome that is vulnerable to such pressure due to its metastable nature. We propose that the mechanism underlying motor neuron death caused by defects in mRNA metabolism and protein degradation pathways converges on proteostasis dysfunction. We propose that the proteostasis network may provide an effective target for therapeutic development in ALS.
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Affiliation(s)
- Isabella A Lambert-Smith
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - Darren N Saunders
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Justin J Yerbury
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.
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6
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Lum JS, Berg T, Chisholm CG, Vendruscolo M, Yerbury JJ. Vulnerability of the spinal motor neuron presynaptic terminal sub-proteome in ALS. Neurosci Lett 2022; 778:136614. [PMID: 35367314 DOI: 10.1016/j.neulet.2022.136614] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 03/29/2022] [Indexed: 12/13/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder, characterised by the loss of motor neurons and subsequent paralysis. Evidence indicates that synaptic alterations are associated with the early stages of ALS pathogenesis. A hallmark of ALS postmortem tissue is the presence of proteinaceous inclusions, indicative of disturbed protein homeostasis, particularly in spinal cord motor neurons. We recently demonstrated that spinal cord motor neurons contain a supersaturated proteome, as they possess proteins at concentrations that exceed their solubility limits, resulting in a metastable proteome conducive to protein misfolding and aggregation. Recent evidence indicates metastable sub-proteomes within neuronal compartments, such as the synapse, may be particularly vulnerable and underlie their involvement in the initial stages of neurodegenerative diseases. To investigate if the motor neuron presynaptic terminal possesses a metastable sub-proteome, we used human and mouse spinal cord motor neuron expression data to calculate supersaturation scores. Here, we found that both the human and mouse presynaptic terminal sub-proteomes have higher supersaturation scores than the entire motor neuron proteome. In addition, we observed that proteins down-regulated in ALS were over-represented in the synapse. These results provide support for the notion that the metastability of the sub-proteome within the motor neuron presynaptic terminal may be particularly susceptible to protein homeostasis disturbances in ALS, and may contribute to explaining the observed synaptic dysfunction in ALS.
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Affiliation(s)
- Jeremy S Lum
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - Tracey Berg
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - Christen G Chisholm
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
| | - Michele Vendruscolo
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Justin J Yerbury
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.
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7
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Fralish Z, Lotz EM, Chavez T, Khodabukus A, Bursac N. Neuromuscular Development and Disease: Learning From in vitro and in vivo Models. Front Cell Dev Biol 2021; 9:764732. [PMID: 34778273 PMCID: PMC8579029 DOI: 10.3389/fcell.2021.764732] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/06/2021] [Indexed: 01/02/2023] Open
Abstract
The neuromuscular junction (NMJ) is a specialized cholinergic synaptic interface between a motor neuron and a skeletal muscle fiber that translates presynaptic electrical impulses into motor function. NMJ formation and maintenance require tightly regulated signaling and cellular communication among motor neurons, myogenic cells, and Schwann cells. Neuromuscular diseases (NMDs) can result in loss of NMJ function and motor input leading to paralysis or even death. Although small animal models have been instrumental in advancing our understanding of the NMJ structure and function, the complexities of studying this multi-tissue system in vivo and poor clinical outcomes of candidate therapies developed in small animal models has driven the need for in vitro models of functional human NMJ to complement animal studies. In this review, we discuss prevailing models of NMDs and highlight the current progress and ongoing challenges in developing human iPSC-derived (hiPSC) 3D cell culture models of functional NMJs. We first review in vivo development of motor neurons, skeletal muscle, Schwann cells, and the NMJ alongside current methods for directing the differentiation of relevant cell types from hiPSCs. We further compare the efficacy of modeling NMDs in animals and human cell culture systems in the context of five NMDs: amyotrophic lateral sclerosis, myasthenia gravis, Duchenne muscular dystrophy, myotonic dystrophy, and Pompe disease. Finally, we discuss further work necessary for hiPSC-derived NMJ models to function as effective personalized NMD platforms.
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Affiliation(s)
- Zachary Fralish
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Ethan M Lotz
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Taylor Chavez
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Alastair Khodabukus
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Nenad Bursac
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
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8
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Huang X, Roet KCD, Zhang L, Brault A, Berg AP, Jefferson AB, Klug-McLeod J, Leach KL, Vincent F, Yang H, Coyle AJ, Jones LH, Frost D, Wiskow O, Chen K, Maeda R, Grantham A, Dornon MK, Klim JR, Siekmann MT, Zhao D, Lee S, Eggan K, Woolf CJ. Human amyotrophic lateral sclerosis excitability phenotype screen: Target discovery and validation. Cell Rep 2021; 35:109224. [PMID: 34107252 PMCID: PMC8209673 DOI: 10.1016/j.celrep.2021.109224] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 10/14/2020] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
Drug development is hampered by poor target selection. Phenotypic screens using neurons differentiated from patient stem cells offer the possibility to validate known and discover novel disease targets in an unbiased fashion. To identify targets for managing hyperexcitability, a pathological feature of amyotrophic lateral sclerosis (ALS), we design a multi-step screening funnel using patient-derived motor neurons. High-content live cell imaging is used to evaluate neuronal excitability, and from a screen against a chemogenomic library of 2,899 target-annotated compounds, 67 reduce the hyperexcitability of ALS motor neurons carrying the SOD1(A4V) mutation, without cytotoxicity. Bioinformatic deconvolution identifies 13 targets that modulate motor neuron excitability, including two known ALS excitability modulators, AMPA receptors and Kv7.2/3 ion channels, constituting target validation. We also identify D2 dopamine receptors as modulators of ALS motor neuron excitability. This screen demonstrates the power of human disease cell-based phenotypic screens for identifying clinically relevant targets for neurological disorders. Motor neuron hyperexcitability is observed in both ALS patients and their iPSC-derived neurons. Combining a high-content live imaging excitability phenotypic assay, high-throughput screening against a cross-annotated chemogenomic library, and bioinformatic enrichment analysis, Huang et al. identify targets modulating the hyperexcitability of ALS patient-derived motor neurons in an unbiased manner.
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Affiliation(s)
- Xuan Huang
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Kasper C D Roet
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Liying Zhang
- Medicine Design, Pfizer, Cambridge, MA 02139, USA
| | - Amy Brault
- Medicine Design, Pfizer, Groton, CT 06340, USA
| | - Allison P Berg
- Rare Disease Research Unit, Pfizer, Cambridge, MA 02139, USA
| | - Anne B Jefferson
- Pfizer Centers for Therapeutic Innovation (CTI), San Francisco, CA 94080, USA
| | | | - Karen L Leach
- Pfizer Centers for Therapeutic Innovation (CTI), Cambridge, MA 02139, USA
| | | | - Hongying Yang
- Pfizer Centers for Therapeutic Innovation (CTI), Cambridge, MA 02139, USA
| | - Anthony J Coyle
- Pfizer Centers for Therapeutic Innovation (CTI), Cambridge, MA 02139, USA
| | - Lyn H Jones
- Medicine Design, Pfizer, Cambridge, MA 02139, USA
| | - Devlin Frost
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Ole Wiskow
- Department of Stem Cell and Regenerative Biology, Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Kuchuan Chen
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Rie Maeda
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Alyssa Grantham
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Mary K Dornon
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Joseph R Klim
- Department of Stem Cell and Regenerative Biology, Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Marco T Siekmann
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Dongyi Zhao
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Seungkyu Lee
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Kevin Eggan
- Department of Stem Cell and Regenerative Biology, Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
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9
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Demystifying the spontaneous phenomena of motor hyperexcitability. Clin Neurophysiol 2021; 132:1830-1844. [PMID: 34130251 DOI: 10.1016/j.clinph.2021.03.053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/18/2021] [Accepted: 03/29/2021] [Indexed: 10/21/2022]
Abstract
Possessing a discrete functional repertoire, the anterior horn cell can be in one of two electrophysiological states: on or off. Usually under tight regulatory control by the central nervous system, a hierarchical network of these specialist neurons ensures muscular strength is coordinated, gradated and adaptable. However, spontaneous activation of these cells and their axons can result in abnormal muscular twitching. The muscular twitch is the common building block of several distinct clinical patterns, namely fasciculation, myokymia and neuromyotonia. When attempting to distinguish these entities electromyographically, their unique temporal and morphological profiles must be appreciated. Detection and quantification of burst duration, firing frequency, multiplet patterns and amplitude are informative. A common feature is their persistence during sleep. In this review, we explain the accepted terminology used to describe the spontaneous phenomena of motor hyperexcitability, highlighting potential pitfalls amidst a bemusing and complex collection of overlapping terms. We outline the relevance of these findings within the context of disease, principally amyotrophic lateral sclerosis, Isaacs syndrome and Morvan syndrome. In addition, we highlight the use of high-density surface electromyography, suggesting that more widespread use of this non-invasive technique is likely to provide an enhanced understanding of these motor hyperexcitability syndromes.
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10
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de Jongh R, Spijkers XM, Pasteuning-Vuhman S, Vulto P, Pasterkamp RJ. Neuromuscular junction-on-a-chip: ALS disease modeling and read-out development in microfluidic devices. J Neurochem 2021; 157:393-412. [PMID: 33382092 DOI: 10.1111/jnc.15289] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 12/24/2020] [Accepted: 12/28/2020] [Indexed: 12/21/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal and progressive neurodegenerative disease affecting upper and lower motor neurons with no cure available. Clinical and animal studies reveal that the neuromuscular junction (NMJ), a synaptic connection between motor neurons and skeletal muscle fibers, is highly vulnerable in ALS and suggest that NMJ defects may occur at the early stages of the disease. However, mechanistic insight into how NMJ dysfunction relates to the onset and progression of ALS is incomplete, which hampers therapy development. This is, in part, caused by a lack of robust in vitro models. The ability to combine microfluidic and induced pluripotent stem cell (iPSC) technologies has opened up new avenues for studying molecular and cellular ALS phenotypes in vitro. Microfluidic devices offer several advantages over traditional culture approaches when modeling the NMJ, such as the spatial separation of different cell types and increased control over the cellular microenvironment. Moreover, they are compatible with 3D cell culture, which enhances NMJ functionality and maturity. Here, we review how microfluidic technology is currently being employed to develop more reliable in vitro NMJ models. To validate and phenotype such models, various morphological and functional read-outs have been developed. We describe and discuss the relevance of these read-outs and specifically illustrate how these read-outs have enhanced our understanding of NMJ pathology in ALS. Finally, we share our view on potential future directions and challenges.
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Affiliation(s)
- Rianne de Jongh
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Xandor M Spijkers
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands.,Mimetas B.V., Organ-on-a-chip Company, Leiden, The Netherlands
| | - Svetlana Pasteuning-Vuhman
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Paul Vulto
- Mimetas B.V., Organ-on-a-chip Company, Leiden, The Netherlands
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
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11
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Jørgensen HS, Jensen DB, Dimintiyanova KP, Bonnevie VS, Hedegaard A, Lehnhoff J, Moldovan M, Grondahl L, Meehan CF. Increased Axon Initial Segment Length Results in Increased Na + Currents in Spinal Motoneurones at Symptom Onset in the G127X SOD1 Mouse Model of Amyotrophic Lateral Sclerosis. Neuroscience 2020; 468:247-264. [PMID: 33246068 DOI: 10.1016/j.neuroscience.2020.11.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 10/22/2020] [Accepted: 11/10/2020] [Indexed: 12/13/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease preferentially affecting motoneurones. Transgenic mouse models have been used to investigate the role of abnormal motoneurone excitability in this disease. Whilst an increased excitability has repeatedly been demonstrated in vitro in neonatal and embryonic preparations from SOD1 mouse models, the results from the only studies to record in vivo from spinal motoneurones in adult SOD1 models have produced conflicting findings. Deficits in repetitive firing have been reported in G93A SOD1(high copy number) mice but not in presymptomatic G127X SOD1 mice despite shorter motoneurone axon initial segments (AISs) in these mice. These discrepancies may be due to the earlier disease onset and prolonged disease progression in G93A SOD1 mice with recordings potentially performed at a later sub-clinical stage of the disease in this mouse. To test this, and to explore how the evolution of excitability changes with symptom onset we performed in vivo intracellular recording and AIS labelling in G127X SOD1 mice immediately after symptom onset. No reductions in repetitive firing were observed showing that this is not a common feature across all ALS models. Immunohistochemistry for the Na+ channel Nav1.6 showed that motoneurone AISs increase in length in G127X SOD1 mice at symptom onset. Consistent with this, the rate of rise of AIS components of antidromic action potentials were significantly faster confirming that this increase in length represents an increase in AIS Na+ channels occurring at symptom onset in this model.
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Affiliation(s)
- H S Jørgensen
- Department of Neuroscience, University of Copenhagen, Denmark
| | - D B Jensen
- Department of Neuroscience, University of Copenhagen, Denmark
| | | | - V S Bonnevie
- Department of Neuroscience, University of Copenhagen, Denmark
| | - A Hedegaard
- Department of Neuroscience, University of Copenhagen, Denmark
| | - J Lehnhoff
- Department of Neuroscience, University of Copenhagen, Denmark
| | - M Moldovan
- Department of Neuroscience, University of Copenhagen, Denmark
| | - L Grondahl
- Department of Neuroscience, University of Copenhagen, Denmark
| | - C F Meehan
- Department of Neuroscience, University of Copenhagen, Denmark.
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12
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Sato M, Nakamura T, Nagashima K, Fujita Y, Ikeda Y. Prolonged distal latency of the median motor nerve is associated with poor prognosis in amyotrophic lateral sclerosis. Neurol Res 2020; 43:191-198. [PMID: 33054692 DOI: 10.1080/01616412.2020.1834291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A nerve conduction study (NCS) is routinely undertaken for the differential diagnosis of amyotrophic lateral sclerosis (ALS). Prolonged median motor distal latency (MMDL) has been reported in a subset of patients with ALS. This study aimed to investigate the clinical importance of NCS characteristics in patients with ALS. A total of 75 patients who underwent NCS were enrolled in this study. The frequency of ALS patients with prolonged motor DL was higher in the median than ulnar NCS. The multivariate analysis revealed that shorter diagnostic latency, prolonged MMDL, and higher disease progression rate were significantly associated with poor prognosis. When ALS patients were divided into two groups according to the cut-off value (4.2 ms) of the MMDL, the group with prolonged MMDL had lower ALS functional rating scale and frontal assessment battery scores, upper limbs subscore, and shorter survival time than the group with shorter MMDL. In conclusion, patients with ALS that have prolonged MMDL may have upper limb dysfunction and shorter survival. MMDL can be a useful prognostic marker for patients with ALS. Abbreviations: ADM = abductor digiti minimi; APB = abductor pollicis brevis; ALS = amyotrophic lateral sclerosis; ALSFRS-R = revised ALS Functional Rating Scale; CI = confidence interval; CMAP = compound muscle action potential; CTS = carpal tunnel syndrome; DL = distal latency; ΔFS = disease progression rate; FAB = frontal assessment battery; FVC = forced vital capacity; HR = hazard ratio; MCV = motor nerve conduction velocity; MMDL = median motor distal latency; MMSE = mini-mental state examination; NCS = nerve conduction study; PaCO2 = partial pressure of arterial carbon dioxide; SBMA = spinal and bulbar muscular atrophy; SCV = sensory nerve conduction velocity; SD = standard deviation; SMA = spinal muscular atrophy; SNAP = sensory nerve action potential; SOD1 = superoxide dismutase 1; UMDL = ulnar motor distal latency.
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Affiliation(s)
- Masayuki Sato
- Department of Neurology, Gunma University Graduate School of Medicine , Maebashi, Japan
| | - Takumi Nakamura
- Department of Neurology, Gunma University Graduate School of Medicine , Maebashi, Japan
| | - Kazuaki Nagashima
- Department of Neurology, Gunma University Graduate School of Medicine , Maebashi, Japan
| | - Yukio Fujita
- Department of Neurology, Gunma University Graduate School of Medicine , Maebashi, Japan
| | - Yoshio Ikeda
- Department of Neurology, Gunma University Graduate School of Medicine , Maebashi, Japan
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13
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Excitability Properties of Distal Motor Axons in the Human Ulnar Nerve. NEUROPHYSIOLOGY+ 2020. [DOI: 10.1007/s11062-020-09862-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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Gunes ZI, Kan VWY, Ye X, Liebscher S. Exciting Complexity: The Role of Motor Circuit Elements in ALS Pathophysiology. Front Neurosci 2020; 14:573. [PMID: 32625051 PMCID: PMC7311855 DOI: 10.3389/fnins.2020.00573] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 05/11/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal disease, characterized by the degeneration of both upper and lower motor neurons. Despite decades of research, we still to date lack a cure or disease modifying treatment, emphasizing the need for a much-improved insight into disease mechanisms and cell type vulnerability. Altered neuronal excitability is a common phenomenon reported in ALS patients, as well as in animal models of the disease, but the cellular and circuit processes involved, as well as the causal relevance of those observations to molecular alterations and final cell death, remain poorly understood. Here, we review evidence from clinical studies, cell type-specific electrophysiology, genetic manipulations and molecular characterizations in animal models and culture experiments, which argue for a causal involvement of complex alterations of structure, function and connectivity of different neuronal subtypes within the cortical and spinal cord motor circuitries. We also summarize the current knowledge regarding the detrimental role of astrocytes and reassess the frequently proposed hypothesis of glutamate-mediated excitotoxicity with respect to changes in neuronal excitability. Together, these findings suggest multifaceted cell type-, brain area- and disease stage- specific disturbances of the excitation/inhibition balance as a cardinal aspect of ALS pathophysiology.
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Affiliation(s)
- Zeynep I Gunes
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - Vanessa W Y Kan
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - XiaoQian Ye
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - Sabine Liebscher
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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15
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Liu W, Venugopal S, Majid S, Ahn IS, Diamante G, Hong J, Yang X, Chandler SH. Single-cell RNA-seq analysis of the brainstem of mutant SOD1 mice reveals perturbed cell types and pathways of amyotrophic lateral sclerosis. Neurobiol Dis 2020; 141:104877. [PMID: 32360664 PMCID: PMC7519882 DOI: 10.1016/j.nbd.2020.104877] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/13/2020] [Accepted: 04/22/2020] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which motor neurons throughout the brain and spinal cord progressively degenerate resulting in muscle atrophy, paralysis and death. Recent studies using animal models of ALS implicate multiple cell-types (e.g., astrocytes and microglia) in ALS pathogenesis in the spinal motor systems. To ascertain cellular vulnerability and cell-type specific mechanisms of ALS in the brainstem that orchestrates oral-motor functions, we conducted parallel single cell RNA sequencing (scRNA-seq) analysis using the high-throughput Drop-seq method. We isolated 1894 and 3199 cells from the brainstem of wildtype and mutant SOD1 symptomatic mice respectively, at postnatal day 100. We recovered major known cell types and neuronal subpopulations, such as interneurons and motor neurons, and trigeminal ganglion (TG) peripheral sensory neurons, as well as, previously uncharacterized interneuron subtypes. We found that the majority of the cell types displayed transcriptomic alterations in ALS mice. Differentially expressed genes (DEGs) of individual cell populations revealed cell-type specific alterations in numerous pathways, including previously known ALS pathways such as inflammation (in microglia), stress response (ependymal and an uncharacterized cell population), neurogenesis (astrocytes, oligodendrocytes, neurons), synapse organization and transmission (microglia, oligodendrocyte precursor cells, and neuronal subtypes), and mitochondrial function (uncharacterized cell populations). Other cell-type specific processes altered in SOD1 mutant brainstem include those from motor neurons (axon regeneration, voltage-gated sodium and potassium channels underlying excitability, potassium ion transport), trigeminal sensory neurons (detection of temperature stimulus involved in sensory perception), and cellular response to toxic substances (uncharacterized cell populations). DEGs consistently altered across cell types (e.g., Malat1), as well as cell-type specific DEGs, were identified. Importantly, DEGs from various cell types overlapped with known ALS genes from the literature and with top hits from an existing human ALS genome-wide association study (GWAS), implicating the potential cell types in which the ALS genes function with ALS pathogenesis. Our molecular investigation at single cell resolution provides comprehensive insights into the cell types, genes and pathways altered in the brainstem in a widely used ALS mouse model.
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Affiliation(s)
- Wenting Liu
- Department of Integrative Biology & Physiology, University of California, 2024 Terasaki Bld, 610 Charles E. Young Dr. East, Los Angeles, USA
| | - Sharmila Venugopal
- Department of Integrative Biology & Physiology, University of California, 2024 Terasaki Bld, 610 Charles E. Young Dr. East, Los Angeles, USA
| | - Sana Majid
- Department of Integrative Biology & Physiology, University of California, 2024 Terasaki Bld, 610 Charles E. Young Dr. East, Los Angeles, USA
| | - In Sook Ahn
- Department of Integrative Biology & Physiology, University of California, 2024 Terasaki Bld, 610 Charles E. Young Dr. East, Los Angeles, USA
| | - Graciel Diamante
- Department of Integrative Biology & Physiology, University of California, 2024 Terasaki Bld, 610 Charles E. Young Dr. East, Los Angeles, USA
| | - Jason Hong
- Department of Integrative Biology & Physiology, University of California, 2024 Terasaki Bld, 610 Charles E. Young Dr. East, Los Angeles, USA
| | - Xia Yang
- Department of Integrative Biology & Physiology, University of California, 2024 Terasaki Bld, 610 Charles E. Young Dr. East, Los Angeles, USA; Brain Research Institute, University of California, Los Angeles, USA; Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, USA.
| | - Scott H Chandler
- Department of Integrative Biology & Physiology, University of California, 2024 Terasaki Bld, 610 Charles E. Young Dr. East, Los Angeles, USA; Brain Research Institute, University of California, Los Angeles, USA.
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16
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Bonnevie VS, Dimintiyanova KP, Hedegaard A, Lehnhoff J, Grøndahl L, Moldovan M, Meehan CF. Shorter axon initial segments do not cause repetitive firing impairments in the adult presymptomatic G127X SOD-1 Amyotrophic Lateral Sclerosis mouse. Sci Rep 2020; 10:1280. [PMID: 31992746 PMCID: PMC6987224 DOI: 10.1038/s41598-019-57314-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 12/19/2019] [Indexed: 12/13/2022] Open
Abstract
Increases in axonal sodium currents in peripheral nerves are some of the earliest excitability changes observed in Amyotrophic Lateral Sclerosis (ALS) patients. Nothing is known, however, about axonal sodium channels more proximally, particularly at the action potential initiating region - the axon initial segment (AIS). Immunohistochemistry for Nav1.6 sodium channels was used to investigate parameters of AISs of spinal motoneurones in the G127X SOD1 mouse model of ALS in adult mice at presymptomatic time points (~190 days old). In vivo intracellular recordings from lumbar spinal motoneurones were used to determine the consequences of any AIS changes. AISs of both alpha and gamma motoneurones were found to be significantly shorter (by 6.6% and 11.8% respectively) in G127X mice as well as being wider by 9.8% (alpha motoneurones). Measurements from 20–23 day old mice confirmed that this represented a change during adulthood. Intracellular recordings from motoneurones in presymptomatic adult mice, however, revealed no differences in individual action potentials or the cells ability to initiate repetitive action potentials. To conclude, despite changes in AIS geometry, no evidence was found for reduced excitability within the functional working range of firing frequencies of motoneurones in this model of ALS.
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Affiliation(s)
- V S Bonnevie
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - K P Dimintiyanova
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - A Hedegaard
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - J Lehnhoff
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - L Grøndahl
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - M Moldovan
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - C F Meehan
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark.
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17
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Amino H, Shibuya K, Misawa S, Sekiguchi Y, Beppu M, Suichi T, Suzuki YI, Tsuneyama A, Kuwabara S. Membrane property changes in most distal motor axons in chronic inflammatory demyelinating polyneuropathy. Muscle Nerve 2019; 61:238-242. [PMID: 31650564 DOI: 10.1002/mus.26744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 10/16/2019] [Accepted: 10/18/2019] [Indexed: 11/11/2022]
Abstract
INTRODUCTION Distal nerve terminals, where the blood-nerve barrier is anatomically deficient, are preferentially affected in immune-mediated neuropathies. Excitability alterations near the motor nerve terminals may be more prominent than the nerve trunk in typical chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS In 20 patients with typical CIDP, motor nerve excitability testing was performed at the motor point and wrist of the ulnar nerve, and results were compared with those in 20 healthy persons. RESULTS Chronic inflammatory demyelinating polyneuropathy patients showed greater threshold changes in hyperpolarizing threshold electrotonus at the motor point (P < .05) but not at the wrist. Strength-duration time constant did not show significant differences between CIDP and controls at both sites. DISCUSSION Axonal property changes in CIDP are more prominent in distal portions of axons compared with the nerve trunk, presumably due to salient demyelination near the distal nerve terminals. Motor point excitability measurements could elucidate underlying pathophysiology in immune-mediated neuropathies.
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Affiliation(s)
- Hiroshi Amino
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Kazumoto Shibuya
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Sonoko Misawa
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yukari Sekiguchi
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Minako Beppu
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Tomoki Suichi
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yo-Ichi Suzuki
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Atsuko Tsuneyama
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Satoshi Kuwabara
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
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18
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Abraham MJ, Fleming KL, Raymond S, Wong AYC, Bergeron R. The sigma-1 receptor behaves as an atypical auxiliary subunit to modulate the functional characteristics of Kv1.2 channels expressed in HEK293 cells. Physiol Rep 2019; 7:e14147. [PMID: 31222975 PMCID: PMC6586770 DOI: 10.14814/phy2.14147] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/17/2019] [Accepted: 05/25/2019] [Indexed: 12/11/2022] Open
Abstract
Expression of Kv1.2 within Kv1.x potassium channel complexes is critical in maintaining appropriate neuronal excitability and determining the threshold for action potential firing. This is attributed to the interaction of Kv1.2 with a hitherto unidentified protein that confers bimodal channel activation gating, allowing neurons to adapt to repetitive trains of stimulation and protecting against hyperexcitability. One potential protein candidate is the sigma-1 receptor (Sig-1R), which regulates other members of the Kv1.x channel family; however, the biophysical nature of the interaction between Sig-1R and Kv1.2 has not been elucidated. We hypothesized that Sig-1R may regulate Kv1.2 and may further act as the unidentified modulator of Kv1.2 activation. In transiently transfected HEK293 cells, we found that ligand activation of the Sig-1R modulates Kv1.2 current amplitude. More importantly, Sig-1R interacts with Kv1.2 in baseline conditions to influence bimodal activation gating. These effects are abolished in the presence of the auxiliary subunit Kvβ2 and when the Sig-1R mutation underlying ALS16 (Sig-1R-E102Q), is expressed. These data suggest that Kvβ2 occludes the interaction of Sig-1R with Kv1.2, and that E102 may be a residue critical for Sig-1R modulation of Kv1.2. The results of this investigation describe an important new role for Sig-1R in the regulation of neuronal excitability and introduce a novel mechanism of pathophysiology in Sig-1R dysfunction.
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Affiliation(s)
- Madelyn J. Abraham
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioCanada
| | - Kayla L. Fleming
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioCanada
| | - Sophie Raymond
- NeuroscienceOttawa Hospital Research InstituteOttawaOntarioCanada
| | | | - Richard Bergeron
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioCanada
- NeuroscienceOttawa Hospital Research InstituteOttawaOntarioCanada
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19
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Yerbury JJ, Ooi L, Blair IP, Ciryam P, Dobson CM, Vendruscolo M. The metastability of the proteome of spinal motor neurons underlies their selective vulnerability in ALS. Neurosci Lett 2019; 704:89-94. [DOI: 10.1016/j.neulet.2019.04.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 03/29/2019] [Accepted: 04/01/2019] [Indexed: 12/13/2022]
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20
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The potential roles of aquaporin 4 in amyotrophic lateral sclerosis. Neurol Sci 2019; 40:1541-1549. [PMID: 30980198 DOI: 10.1007/s10072-019-03877-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/28/2019] [Indexed: 12/13/2022]
Abstract
Aquaporin 4 (AQP4) is a primary water channel found on astrocytes in the central nervous system (CNS). Besides its function in water and ion homeostasis, AQP4 has also been documented to be involved in a myriad of acute and chronic cerebral pathologies, including autoimmune neurodegenerative diseases. AQP4 has been postulated to be associated with the incidence of a progressive neurodegenerative disorder known as amyotrophic lateral sclerosis (ALS), a disease that targets the motor neurons, causing muscle weakness and eventually paralysis. Raised AQP4 levels were noted in association with vessels surrounded with swollen astrocytic processes as well as in the brainstem, cortex, and gray matter in patients with terminal ALS. AQP4 depolarization may lead to motor neuron degeneration in ALS via GLT-1. Besides, alterations in AQP4 expression in ALS may result in the loss of blood-brain barrier (BBB) integrity. Changes in AQP4 function may also disrupt K+ homeostasis and cause connexin dysregulation, the latter of which is associated to ALS disease progression. Furthermore, AQP4 suppression augments recovery in motor function in ALS, a phenomenon thought to be associated to NGF. No therapeutic drug targeting AQP4 has been developed to date. Nevertheless, the plethora of suggestive experimental results underscores the significance of further exploration into this area.
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21
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Franssen H. Normal sensory membrane properties in amyotrophic lateral sclerosis. Clin Neurophysiol 2018; 129:1453-1454. [PMID: 29728299 DOI: 10.1016/j.clinph.2018.04.606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 04/07/2018] [Indexed: 10/17/2022]
Affiliation(s)
- Hessel Franssen
- Brain Center Rudolf Magnus, Section Neuromuscular Disorders, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, The Netherlands.
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22
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Stephanova DI, Kossev A. Temperature effects on accommodative processes in simulated amyotrophic lateral sclerosis in the physiological range. J Integr Neurosci 2017; 16:319-333. [PMID: 28891518 DOI: 10.3233/jin-170022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The present study investigates the temperature dependence of electrotonic potentials in mathematically-simulated myelinated axons with one of three increasingly-severe type of amyotrophic lateral sclerosis (ALS) pathology, termed as ALS1, ALS2 and ALS3, respectively, in the physiological range (30-37∘C). These potentials were elicited by long-lasting (100 ms) subthreshold polarizing current stimuli (±40% of the threshold). Numerical solutions were computed using our temperature-dependent multi-layered model. The results showed the following trends: (i) in ALS1, polarizing electrotonic potentials were normal; (ii) in ALS2 and ALS3, action potentials were elicited in the early parts of the depolarizing electrotonic potentials, and (iii) in ALS3, spontaneous discharges were elicited after the termination of applied hyperpolarizing stimuli (i.e., post-anodal excitation). The ionic currents underlying electrotonic potentials in the ALS1 case were attributable to the activation of potassium fast (Kf+) and slow (Ks+) channels in the nodal and internodal axolemma beneath the myelin sheath. By contrast, in ALS2 and ALS3, the depolarizing stimuli activated the classical "transient" Na+ channels in the nodal and internodal axolemma beneath the myelin sheath eliciting action potential generation. These results obtained were closer to those observed in hypothermia (⩽25∘C) than in hyperthermia (⩾40∘C).
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Affiliation(s)
- D I Stephanova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. Bl 21, Sofia 1113, Bulgaria
| | - A Kossev
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. Bl 21, Sofia 1113, Bulgaria
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23
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Maglemose R, Hedegaard A, Lehnhoff J, Dimintiyanova KP, Moldovan M, Grøndahl L, Meehan CF. Potassium channel abnormalities are consistent with early axon degeneration of motor axons in the G127X SOD1 mouse model of amyotrophic lateral sclerosis. Exp Neurol 2017; 292:154-167. [PMID: 28322742 DOI: 10.1016/j.expneurol.2017.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 02/21/2017] [Accepted: 03/14/2017] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a lethal neurodegenerative disease, which selectively affects upper and lower motoneurones. The underlying pathophysiology of the disease is complex but electrophysiological studies of peripheral nerves in ALS patients as well as human autopsy studies indicate that a potassium channel dysfunction/loss is present early in the symptomatic phase. It remains unclear to what extent potassium channel abnormalities reflect a specific pathogenic mechanism in ALS. The aim of this study was therefore to investigate the temporal changes in the expression and/or function of potassium channels in motoneurones in the adult G127X SOD1 mouse model of ALS, a model which has a very long presymptomatic phase. Evidence from animal models indicates that the early progressive motoneurone dysfunction and degeneration can be largely compensated by motor unit remodeling, delaying the clinical symptom onset. Experiments were therefore performed both before and after symptom onset. Immunohistochemistry of motor axons in the ventral roots of G127X SOD1 mice, was used to investigate juxta-paranodal Kv1.2 potassium channels along with nodal Nav1.6 and the paranodal scaffolding protein Caspr. This allowed an investigation of changes in the distribution of Kv1.2 relative to the general structure of the nodal-paranodal-juxta-paranodal complex. This revealed that the motor axons in the ventral roots of presymptomatic G127X SOD1 mice, already show a disruption in juxta-paranodal Kv1.2 potassium channels. The axonal Kv1.2 disruption was preceded by abnormalities in the distribution of the paranodal scaffolding protein Caspr with the nodal arrangement of Nav1.6 appearing relatively preserved even in symptomatic mice. These changes were accompanied by axon swelling and a slowing of conduction in the peripheral motor axons in symptomatic mice. In vivo electrophysiological intracellular recordings of individual spinal motoneurones revealed that central potassium channel function was preserved or even enhanced with higher amplitude and longer duration after-hyperpolarisations in the G127X SOD1 mice. Our data suggest that the potassium channel abnormalities observed in presymptomatic G127X, rather than representing a specific pathophysiological mechanism targeting potassium channels, most likely reflect early axonal degenerative changes, consistent with the "dying-back" phenomenon observed in other ALS models.
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Affiliation(s)
- Rikke Maglemose
- Centre for Neuroscience, Copenhagen University, Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Anne Hedegaard
- Centre for Neuroscience, Copenhagen University, Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Janna Lehnhoff
- Centre for Neuroscience, Copenhagen University, Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | | | - Mihai Moldovan
- Centre for Neuroscience, Copenhagen University, Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Lillian Grøndahl
- Centre for Neuroscience, Copenhagen University, Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Claire Francesca Meehan
- Centre for Neuroscience, Copenhagen University, Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
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24
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Babu S, Pioro EP, Li J, Li Y. Optimizing muscle selection for electromyography in amyotrophic lateral sclerosis. Muscle Nerve 2017; 56:36-44. [DOI: 10.1002/mus.25444] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 10/12/2016] [Accepted: 10/18/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Suma Babu
- Neuromuscular Center Desk S90, Department of Neurology; Cleveland Clinic; 9500 Euclid Avenue Cleveland Ohio 44195 USA
| | - Erik P Pioro
- Neuromuscular Center Desk S90, Department of Neurology; Cleveland Clinic; 9500 Euclid Avenue Cleveland Ohio 44195 USA
| | - Jianbo Li
- Department of Quantitative Health Sciences; Learner Research Institute, Cleveland Clinic Foundation; Cleveland Ohio USA
| | - Yuebing Li
- Neuromuscular Center Desk S90, Department of Neurology; Cleveland Clinic; 9500 Euclid Avenue Cleveland Ohio 44195 USA
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Stephanova DI, Kossev A. Theoretical predication of temperature effects on accommodative processes in simulated amyotrophic lateral sclerosis during hypothermia and hyperthermia. J Integr Neurosci 2017; 15:553-569. [PMID: 28100104 DOI: 10.1142/s0219635216500308] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Electrotonic potentials allow the accommodative processes to long-lasting subthreshold polarizing stimuli to be assessed. The present study investigates such potentials in previously simulated cases of amyotrophic lateral sclerosis, termed as ALS1, ALS2 and ALS3, respectively, when the temperature is changed during hypothermia ([Formula: see text]C) and hyperthermia ([Formula: see text]C). The ALS cases are modeled as three progressively severe uniform axonal dysfunctions along the human motor nerve fiber which is simulated by our temperature-dependent multi-layered numerical model. The results show that the polarizing electrotonic potentials in the ALS1 case are quite similar to those in the normal case during hypothermia. Their defining currents are caused by the activation of potassium fast (K[Formula: see text]) and slow (K[Formula: see text]) channels in the nodal and internodal axolemma beneath the myelin sheath. Except in the ALS3 case at 20[Formula: see text]C, where the accommodative processes are blocked by depolarizing stimuli, in the ALS2 and ALS3 cases during hypothermia these stimuli activate the classical "transient" Na[Formula: see text] channels in the nodal and internodal axolemma beneath the myelin sheath. And this leads to action potential generations during the early parts of electrotonic responses in all compartments along the fiber length. Only in the ALS3 case after the termination of long-lasting subthreshold hyperpolarizing stimuli, action potential generations are obtained in the late parts of electrotonic potentials along the fiber length. In comparison to the normal case, in the gradually severe ALS cases, the depolarizing electrotonic potentials gradually increase, while the hyperpolarizing electrotonic potentials gradually decrease during hyperthermia. However, the repetitive firings are not obtained in these polarizing electrotonic potentials. The results show that the accommodative processes to depolarizing stimuli in the ALS3 case are more likely to be blocked during hypothermia than hyperthermia. The results also show that the polarizing electrotonic potentials in the three simulated ALS cases are specific indicators for the motor nerve disease ALS during hypothermia and hyperthermia.
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Affiliation(s)
- D I Stephanova
- 1 Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. Bl 21, Sofia 1113, Bulgaria
| | - A Kossev
- 1 Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. Bl 21, Sofia 1113, Bulgaria
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Park SB, Kiernan MC, Vucic S. Axonal Excitability in Amyotrophic Lateral Sclerosis : Axonal Excitability in ALS. Neurotherapeutics 2017; 14:78-90. [PMID: 27878516 PMCID: PMC5233634 DOI: 10.1007/s13311-016-0492-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Axonal excitability testing provides in vivo assessment of axonal ion channel function and membrane potential. Excitability techniques have provided insights into the pathophysiological mechanisms underlying the development of neurodegeneration and clinical features of amyotrophic lateral sclerosis (ALS) and related neuromuscular disorders. Specifically, abnormalities of Na+ and K+ conductances contribute to development of membrane hyperexcitability in ALS, thereby leading to symptom generation of muscle cramps and fasciculations, in addition to promoting a neurodegenerative cascade via Ca2+-mediated processes. Modulation of axonal ion channel function in ALS has resulted in significant symptomatic improvement that has been accompanied by stabilization of axonal excitability parameters. Separately, axonal ion channel dysfunction evolves with disease progression and correlates with survival, thereby serving as a potential therapeutic biomarker in ALS. The present review provides an overview of axonal excitability techniques and the physiological mechanisms underlying membrane excitability, with a focus on the role of axonal ion channel dysfunction in motor neuron disease and related neuromuscular diseases.
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Affiliation(s)
- Susanna B Park
- Brain and Mind Centre, University of Sydney, Sydney, Australia
| | | | - Steve Vucic
- Westmead Clinical School, University of Sydney, Sydney, Australia.
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Isak B, Tankisi H, Johnsen B, Pugdahl K, Torvin MØLler A, Finnerup NB, Christensen PB, Fuglsang-Frederiksen A. Involvement of distal sensory nerves in amyotrophic lateral sclerosis. Muscle Nerve 2016; 54:1086-1092. [DOI: 10.1002/mus.25157] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Baris Isak
- Department of Clinical Neurophysiology; Aarhus University Hospital; Nørrebrogade 44, Building 10 DK-8000 Aarhus C Denmark
| | - Hatice Tankisi
- Department of Clinical Neurophysiology; Aarhus University Hospital; Nørrebrogade 44, Building 10 DK-8000 Aarhus C Denmark
| | - Birger Johnsen
- Department of Clinical Neurophysiology; Aarhus University Hospital; Nørrebrogade 44, Building 10 DK-8000 Aarhus C Denmark
| | - Kirsten Pugdahl
- Department of Clinical Neurophysiology; Aarhus University Hospital; Nørrebrogade 44, Building 10 DK-8000 Aarhus C Denmark
| | | | - Nanna Brix Finnerup
- Danish Pain Research Centre, Department of Clinical Medicine; Aarhus University; Aarhus Denmark
| | | | - Anders Fuglsang-Frederiksen
- Department of Clinical Neurophysiology; Aarhus University Hospital; Nørrebrogade 44, Building 10 DK-8000 Aarhus C Denmark
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Noto YI, Shibuya K, Vucic S, Kiernan MC. Novel therapies in development that inhibit motor neuron hyperexcitability in amyotrophic lateral sclerosis. Expert Rev Neurother 2016; 16:1147-54. [DOI: 10.1080/14737175.2016.1197774] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Weiss MD, Macklin EA, Simmons Z, Knox AS, Greenblatt DJ, Atassi N, Graves M, Parziale N, Salameh JS, Quinn C, Brown RH, Distad JB, Trivedi J, Shefner JM, Barohn RJ, Pestronk A, Swenson A, Cudkowicz ME. A randomized trial of mexiletine in ALS: Safety and effects on muscle cramps and progression. Neurology 2016; 86:1474-81. [PMID: 26911633 DOI: 10.1212/wnl.0000000000002507] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 10/26/2015] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine the safety and tolerability of mexiletine in a phase II double-blind randomized controlled trial of sporadic amyotrophic lateral sclerosis (SALS). METHODS Sixty participants with SALS from 10 centers were randomized 1:1:1 to placebo, mexiletine 300 mg/d, or mexiletine 900 mg/d and followed for 12 weeks. The primary endpoints were safety and tolerability. Secondary endpoints were pharmacokinetic study from plasma and CSF, ALS Functional Rating Scale-Revised (ALSFRS-R) score, slow vital capacity (SVC), and muscle cramp frequency and severity. RESULTS The only serious adverse event among active arm participants was one episode of imbalance. Thirty-two percent of participants receiving 900 mg of mexiletine discontinued study drug vs 5% on placebo (p = 0.026). Pharmacokinetic study demonstrated a peak plasma concentration 2 hours postdose and strong correlation between plasma and CSF (p < 0.001). Rates of decline of ALSFRS-R and SVC did not differ from placebo. Analysis of all randomized patients demonstrated significant reductions of muscle cramp frequency (300 mg: rate = 31% of placebo, p = 0.047; 900 mg: 16% of placebo, p = 0.002) and cramp intensity (300 mg: mean = 45% of placebo, p = 0.08; 900 mg: 25% of placebo, p = 0.005). CONCLUSIONS Mexiletine was safe at both doses and well-tolerated at 300 mg/d but adverse effects at 900 mg/d led to a high rate of discontinuation. Mexiletine treatment resulted in large dose-dependent reductions in muscle cramp frequency and severity. No effect on rate of progression was detected, but clinically important differences could not be excluded in this small and short-duration study. CLASSIFICATION OF EVIDENCE This study provides Class I evidence that mexiletine is safe when given daily to patients with amyotrophic lateral sclerosis at 300 and 900 mg and well-tolerated at the lower dose.
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Affiliation(s)
- Michael D Weiss
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City.
| | - Eric A Macklin
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Zachary Simmons
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Angela S Knox
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - David J Greenblatt
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Nazem Atassi
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Michael Graves
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Nicholas Parziale
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Johnny S Salameh
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Colin Quinn
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Robert H Brown
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Jane B Distad
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Jaya Trivedi
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Jeremy M Shefner
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Richard J Barohn
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Alan Pestronk
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Andrea Swenson
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
| | - Merit E Cudkowicz
- From the Department of Neurology (M.D.W., J.B.D.), University of Washington Medical Center, Seattle; Biostatistics Center (E.A.M.), Massachusetts General Hospital and Harvard Medical School, Boston; Department of Neurology (Z.S.), Penn State Hershey Medical Center, Hershey, PA; Department of Neurology (A.S.K., N.A., M.E.C.), Neurological Clinical Research Institute, Massachusetts General Hospital, Boston; Program in Pharmacology and Experimental Therapeutics (D.J.G.), Tufts University School of Medicine, Boston, MA; Department of Neurology (M.G., N.P.), UCLA Medical Center, Los Angeles, CA; Department of Neurology (J.S.S., C.Q., R.H.B.), University of Massachusetts Memorial Medical Center, Worcester; Department of Neurology (J.T.), University of Texas Southwestern Medical Center, Dallas; Department of Neurology (J.M.S.), Barrow Neurological Institute, Phoenix, AZ; Department of Neurology (R.J.B.), University of Kansas Medical Center, Kansas City; Department of Neurology (A.P.), Washington University Medical Center, St. Louis, MO; and Department of Neurology (A.S.), University of Iowa Hospitals and Clinics, Iowa City
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King AE, Woodhouse A, Kirkcaldie MT, Vickers JC. Excitotoxicity in ALS: Overstimulation, or overreaction? Exp Neurol 2016; 275 Pt 1:162-71. [DOI: 10.1016/j.expneurol.2015.09.019] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 08/30/2015] [Accepted: 09/28/2015] [Indexed: 12/14/2022]
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Sleutjes BTHM, Maathuis EM, van Doorn PA, Blok JH, Visser GH. Electrically evoked multiplet discharges are associated with more marked clinical deterioration in motor neuron disease. Muscle Nerve 2015; 53:222-6. [PMID: 25960042 DOI: 10.1002/mus.24700] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2015] [Indexed: 12/12/2022]
Abstract
INTRODUCTION The aim of this study was to determine whether electrically evoked multiplet discharges (MDs) are related to severity of clinical deterioration in motor neuron disease (MND). METHODS Stimulated high-density surface electromyographic (HDsEMG) recordings were performed in thenar muscles. Data were collected from 31 MND patients. MDs from the HDsEMG recordings were determined at baseline. ALSFRS-R scores were obtained at baseline and at a maximum of 16 weeks follow-up. RESULTS The presence of MDs was associated with progressive deterioration of ALSFRS-R score (P = 0.02) and fine motor function (FMF) (P < 0.001). Patients who had a higher number of motor units that generated MDs (r = 0.61, P < 0.001) and patients who had a higher number of MDs (as percentage of applied stimuli) (r = 0.59, P = 0.001) had a more severe decline in FMF. CONCLUSIONS Electrically evoked MDs are associated with more marked clinical deterioration in patients with MND.
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Affiliation(s)
- Boudewijn T H M Sleutjes
- Department of Clinical Neurophysiology, University Medical Centre Rotterdam, P.O. Box 2040, 3000, CA Rotterdam, The Netherlands
| | - Ellen M Maathuis
- Department of Clinical Neurophysiology, University Medical Centre Rotterdam, P.O. Box 2040, 3000, CA Rotterdam, The Netherlands
| | - Pieter A van Doorn
- Department of Neurology, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Joleen H Blok
- Department of Clinical Neurophysiology, University Medical Centre Rotterdam, P.O. Box 2040, 3000, CA Rotterdam, The Netherlands.,Department of Clinical Physics, Máxima Medical Centre Veldhoven, Veldhoven, The Netherlands
| | - Gerhard H Visser
- Department of Clinical Neurophysiology, University Medical Centre Rotterdam, P.O. Box 2040, 3000, CA Rotterdam, The Netherlands.,Department of Clinical Neurophysiology, SEIN Heemstede, Heemstede, The Netherlands
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Sleutjes BTHM, Montfoort I, van Doorn PA, Visser GH, Blok JH. Diagnostic accuracy of electrically elicited multiplet discharges in patients with motor neuron disease. J Neurol Neurosurg Psychiatry 2015; 86:1234-9. [PMID: 25540246 DOI: 10.1136/jnnp-2014-308589] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 12/03/2014] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To determine and compare the diagnostic accuracy of electrically elicited multiplet discharges (MDs) and fasciculation potentials (FPs) in motor neuron disease (MND). METHODS Patients were eligible when they had MND in their differential diagnosis and were referred for electromyogram (EMG). Stimulated high-density surface EMG of the thenar muscles was performed on the same day as standard EMG examination. High-density recordings were analysed for presence of MDs and needle EMG of any muscle investigated in the cervical region for presence of FPs. RESULTS Of the 61 patients enrolled in this diagnostic study, 24 patients were clinically diagnosed with amyotrophic lateral sclerosis (ALS) and 11 patients with progressive muscular atrophy (PMA). Another diagnosis was made in 26 patients. Sixteen patients in whom MDs were detected were diagnosed with either ALS (n = 11) or PMA (n = 5; sensitivity = 47.1%, PPV = 94.1%). MDs were detected in only one patient initially diagnosed with PMA, but in whom later on, multifocal motor neuropathy could not be excluded (specificity = 96.2%). Electrically elicited MDs had a higher specificity than FPs (96.2% vs 53.9%, p < 0.001, n = 26) and lower sensitivity (47.1% vs 85.3%, p = 0.002, n = 34). When considering presence of MDs in MND as neurogenic EMG abnormality, lower motor neuron involvement of ≥ 1 EMG region increased from 50% to 73.5% (p = 0.008, n = 34). CONCLUSIONS Electrically evoked MDs are highly specific for ALS and PMA and are an early sign of lower motor neuron dysfunction.
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Affiliation(s)
- Boudewijn T H M Sleutjes
- Department of Clinical Neurophysiology, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Inger Montfoort
- Department of Clinical Neurophysiology, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Pieter A van Doorn
- Department of Neurology, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Gerhard H Visser
- Department of Clinical Neurophysiology, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands Department of Clinical Neurophysiology, SEIN Heemstede, Heemstede, The Netherlands
| | - Joleen H Blok
- Department of Clinical Neurophysiology, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands Department of Clinical Physics, Máxima Medical Centre, Veldhoven, The Netherlands
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The interplay between metabolic homeostasis and neurodegeneration: insights into the neurometabolic nature of amyotrophic lateral sclerosis. CELL REGENERATION 2015; 4:5. [PMID: 26322226 PMCID: PMC4551561 DOI: 10.1186/s13619-015-0019-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 07/23/2015] [Indexed: 02/06/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disease that is characterized by the selective degeneration of upper motor neurons and lower spinal motor neurons, resulting in the progressive paralysis of all voluntary muscles. Approximately 10 % of ALS cases are linked to known genetic mutations, with the remaining 90 % of cases being sporadic. While the primary pathology in ALS is the selective death of upper and lower motor neurons, numerous studies indicate that an imbalance in whole body and/or cellular metabolism influences the rate of progression of disease. This review summarizes current research surrounding the impact of impaired metabolic physiology in ALS. We extend ideas to consider prospects that lie ahead in terms of how metabolic alterations may impact the selective degeneration of neurons in ALS and how targeting of adenosine triphosphate-sensitive potassium (KATP) channels may represent a promising approach for obtaining neuroprotection in ALS.
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Sleutjes BTHM, Montfoort I, van Doorn PA, Visser GH, Blok JH. Increased supernormality in patients with multiplet discharges: Evidence for a common pathophysiological mechanism behind multiplets and fasciculations. Clin Neurophysiol 2014; 126:1440-5. [PMID: 25468238 DOI: 10.1016/j.clinph.2014.10.145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 10/16/2014] [Accepted: 10/21/2014] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To determine whether there is a relation between electrically evoked multiplet discharges (MDs) and motor axonal excitability properties. We hypothesized that electrically evoked MDs share their underlying pathophysiological mechanism with fasciculations. METHODS High-density surface EMG and motor nerve excitability recordings of the thenar muscles were performed in 22 patients with motor neuron disease (MND) in their differential diagnosis and who were referred for EMG examination. RESULTS Supernormality (hyperexcitable phase following the refractory period) was significantly increased in patients with MDs (n=10) compared to patients without MDs (n=12) (25.5% vs 17.0%; p=0.02). Depolarizing threshold electrotonus differed significantly between both groups as well (TEdpeak, 76.6% vs 66.6%, p<0.01; TEd90-100ms, 51.7% vs 44.3%, p<0.01) CONCLUSIONS: Our findings imply that the same pathophysiological excitability changes are involved in generating MDs and fasciculations. Yet, MDs may be quantified more easily, and may be more specific for abnormal distal excitability than fasciculations, because fasciculations may originate along the motor axon as well as in the neuron cell body. SIGNIFICANCE MDs are potentially useful as objective measure of increased distal axonal excitability at individual motor unit level and might complement clinical studies in MND.
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Affiliation(s)
| | | | - Pieter A van Doorn
- Department of Neurology, Erasmus MC, University Medical Centre Rotterdam, The Netherlands
| | - Gerhard H Visser
- Department of Clinical Neurophysiology, The Netherlands; Department of Clinical Neurophysiology, SEIN Heemstede, The Netherlands
| | - Joleen H Blok
- Department of Clinical Neurophysiology, The Netherlands; Department of Clinical Physics, Reinier de Graaf Hospital Delft, The Netherlands
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Moloney EB, de Winter F, Verhaagen J. ALS as a distal axonopathy: molecular mechanisms affecting neuromuscular junction stability in the presymptomatic stages of the disease. Front Neurosci 2014; 8:252. [PMID: 25177267 PMCID: PMC4132373 DOI: 10.3389/fnins.2014.00252] [Citation(s) in RCA: 217] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 07/29/2014] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is being redefined as a distal axonopathy, in that many molecular changes influencing motor neuron degeneration occur at the neuromuscular junction (NMJ) at very early stages of the disease prior to symptom onset. A huge variety of genetic and environmental causes have been associated with ALS, and interestingly, although the cause of the disease can differ, both sporadic and familial forms of ALS show a remarkable similarity in terms of disease progression and clinical manifestation. The NMJ is a highly specialized synapse, allowing for controlled signaling between muscle and nerve necessary for skeletal muscle function. In this review we will evaluate the clinical, animal experimental and cellular/molecular evidence that supports the idea of ALS as a distal axonopathy. We will discuss the early molecular mechanisms that occur at the NMJ, which alter the functional abilities of the NMJ. Specifically, we focus on the role of axon guidance molecules on the stability of the cytoskeleton and how these molecules may directly influence the cells of the NMJ in a way that may initiate or facilitate the dismantling of the neuromuscular synapse in the presymptomatic stages of ALS.
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Affiliation(s)
- Elizabeth B. Moloney
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and ScienceAmsterdam, Netherlands
| | - Fred de Winter
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and ScienceAmsterdam, Netherlands
- Department of Neurosurgery, Leiden University Medical CentreLeiden, Netherlands
| | - Joost Verhaagen
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and ScienceAmsterdam, Netherlands
- Centre for Neurogenomics and Cognitive Research, Vrije Universiteit AmsterdamAmsterdam, Netherlands
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Sato A, Sakai N, Shinbo J, Hashidate H, Igarashi S, Kakita A, Yamazaki M. [An autopsy case of amyotrophic lateral sclerosis with prominent muscle cramps, fasciculation, and high titer of anti-voltage gated potassium channel (VGKC) complex antibody]. Rinsho Shinkeigaku 2014; 54:32-7. [PMID: 24429646 DOI: 10.5692/clinicalneurol.54.32] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The patient was a 55-year-old male who had prominent fasciculation and muscle cramps. Muscle weakness and atrophy of the trunk, respiratory system, and extremities gradually progressed. On the basis of these features, we diagnosed this patient as having amyotrophic lateral sclerosis (ALS), however, the upper motor neuron signs were not significant. Following the detection of the anti-voltage gated potassium channel (VGKC) complex antibody at 907.5 pM (normal < 100 pM) and repetitive discharge in a nerve conduction study, immunotherapy with intravenous immunoglobulin, methylprednisolone (mPSL), double filtration plasmapheresis (DFPP), ciclosporin, and rituximab was introduced. mPSL and DFPP showed only tentative effectiveness for fasciculation and muscle cramps, respectively. Thereafter, muscle weakness progressed. The patient died of type II respiratory failure at the age of 57 years, about 2 years after the onset of the disease. At autopsy, a histopathological diagnosis of ALS with lower-motor-predominant degeneration was made. Characteristic cellular features, including Bunina bodies in the remaining lower motor neurons and phosphorylated TAR DNA-binding protein 43-kDa (pTDP-43)-immunopositive inclusions in both upper and lower motor neuron systems, were evident. At present, an immunological role of the anti-VGKC complex antibody in the development of cramp-fasciculation syndrome has been speculated. In this ALS patient, the antibodies might be associated with pathomechanisms underlying the characteristic symptoms.
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Affiliation(s)
- Aki Sato
- Department of Neurology, Niigata City General Hospital
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Intrinsic membrane hyperexcitability of amyotrophic lateral sclerosis patient-derived motor neurons. Cell Rep 2014; 7:1-11. [PMID: 24703839 DOI: 10.1016/j.celrep.2014.03.019] [Citation(s) in RCA: 463] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 02/17/2014] [Accepted: 03/10/2014] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of the motor nervous system. We show using multielectrode array and patch-clamp recordings that hyperexcitability detected by clinical neurophysiological studies of ALS patients is recapitulated in induced pluripotent stem cell-derived motor neurons from ALS patients harboring superoxide dismutase 1 (SOD1), C9orf72, and fused-in-sarcoma mutations. Motor neurons produced from a genetically corrected but otherwise isogenic SOD1(+/+) stem cell line do not display the hyperexcitability phenotype. SOD1(A4V/+) ALS patient-derived motor neurons have reduced delayed-rectifier potassium current amplitudes relative to control-derived motor neurons, a deficit that may underlie their hyperexcitability. The Kv7 channel activator retigabine both blocks the hyperexcitability and improves motor neuron survival in vitro when tested in SOD1 mutant ALS cases. Therefore, electrophysiological characterization of human stem cell-derived neurons can reveal disease-related mechanisms and identify therapeutic candidates.
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Axonal degeneration in the peripheral nervous system: Implications for the pathogenesis of amyotrophic lateral sclerosis. Exp Neurol 2013; 246:6-13. [DOI: 10.1016/j.expneurol.2013.05.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 04/22/2013] [Accepted: 05/02/2013] [Indexed: 12/13/2022]
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Bae JS, Simon NG, Menon P, Vucic S, Kiernan MC. The puzzling case of hyperexcitability in amyotrophic lateral sclerosis. J Clin Neurol 2013; 9:65-74. [PMID: 23626643 PMCID: PMC3633193 DOI: 10.3988/jcn.2013.9.2.65] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 08/24/2012] [Accepted: 08/24/2012] [Indexed: 12/11/2022] Open
Abstract
The development of hyperexcitability in amyotrophic lateral sclerosis (ALS) is a well-known phenomenon. Despite controversy as to the underlying mechanisms, cortical hyperexcitability appears to be closely related to the interplay between excitatory corticomotoneurons and inhibitory interneurons. Hyperexcitability is not a static phenomenon but rather shows a pattern of progression in a spatiotemporal aspect. Cortical hyperexcitability may serve as a trigger to the development of anterior horn cell degeneration through a 'dying forward' process. Hyperexcitability appears to develop during the early disease stages and gradually disappears in the advanced stages of the disease, linked to the destruction of corticomotorneuronal pathways. As such, a more precise interpretation of these unique processes may provide new insight regarding the pathophysiology of ALS and its clinical features. Recently developed technologies such as threshold tracking transcranial magnetic stimulation and automated nerve excitability tests have provided some clues about underlying pathophysiological processes linked to hyperexcitability. Additionally, these novel techniques have enabled clinicians to use the specific finding of hyperexcitability as a useful diagnostic biomarker, enabling clarification of various ALS-mimic syndromes, and the prediction of disease development in pre-symptomatic carriers of familial ALS. In terms of nerve excitability tests for peripheral nerves, an increase in persistent Na+ conductances has been identified as a major determinant of peripheral hyperexcitability in ALS, inversely correlated with the survival in ALS. As such, the present Review will focus primarily on the puzzling theory of hyperexcitability in ALS and summarize clinical and pathophysiological implications for current and future ALS research.
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Affiliation(s)
- Jong Seok Bae
- Department of Neurology, College of Medicine, Inje University, Busan, Korea. ; Neuroscience Research Australia, Sydney, Australia
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Piotrkiewicz M, Hausmanowa-Petrusewicz I. Amyotrophic lateral sclerosis: a dying motor unit? Front Aging Neurosci 2013; 5:7. [PMID: 23533375 PMCID: PMC3607785 DOI: 10.3389/fnagi.2013.00007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 02/26/2013] [Indexed: 12/11/2022] Open
Affiliation(s)
- Maria Piotrkiewicz
- Department of Engineering of Nervous and Muscular System, Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences Warsaw, Poland
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Joyce NC, Carter GT. Electrodiagnosis in persons with amyotrophic lateral sclerosis. PM R 2013; 5:S89-95. [PMID: 23523708 DOI: 10.1016/j.pmrj.2013.03.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 03/15/2013] [Indexed: 12/12/2022]
Abstract
Electrophysiology remains an important tool in the evaluation of patients presenting with signs and symptoms of motor neuron disease. The electrodiagnostic study should include peripheral nerve conduction studies and needle electromyography to both exclude treatable disease and gather evidence regarding a diagnosis of amyotrophic lateral sclerosis (ALS). The recent changes in the revised El Escorial criteria, recommended by the Awaji-shima consensus group, have increased the diagnostic significance of fasciculation potentials to equal that of fibrillation and positive sharp-wave potentials in the needle electromyography examination of patients suspected of having ALS. In addition, electrophysiologic evidence is now considered equivalent to clinical signs and symptoms in reaching a diagnostic certainty of ALS. These changes, strategies for the design, and implementation of an effective electrodiagnostic evaluation, in addition to electrophysiologic techniques and their relationship to the evaluation of a patient with ALS, are reviewed and discussed.
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Affiliation(s)
- Nanette C Joyce
- Department of Physical Medicine and Rehabilitation, University of California, Davis School of Medicine, 4860 Y St, Suite 3850, Sacramento, CA 95817, USA.
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Maathuis EM, Drenthen J, van Doorn PA, Visser GH, Blok JH. Multiplet discharges after electrical stimulation: New evidence for distal excitability changes in motor neuron disease. ACTA ACUST UNITED AC 2012; 13:514-20. [DOI: 10.3109/17482968.2012.669386] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Carvalho MD, Swash M. Fasciculation potentials: Still mysterious. Clin Neurophysiol 2012; 123:227-8. [DOI: 10.1016/j.clinph.2011.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Revised: 07/02/2011] [Accepted: 07/04/2011] [Indexed: 12/13/2022]
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Bowser R, Turner MR, Shefner J. Biomarkers in amyotrophic lateral sclerosis: opportunities and limitations. Nat Rev Neurol 2011; 7:631-8. [DOI: 10.1038/nrneurol.2011.151] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Noto YI, Kanai K, Misawa S, Shibuya K, Isose S, Nasu S, Sekiguchi Y, Fujimaki Y, Nakagawa M, Kuwabara S. Distal motor axonal dysfunction in amyotrophic lateral sclerosis. J Neurol Sci 2010; 302:58-62. [PMID: 21195434 DOI: 10.1016/j.jns.2010.11.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 10/16/2010] [Accepted: 11/30/2010] [Indexed: 10/18/2022]
Abstract
Nerve conduction slowing in amyotrophic lateral sclerosis (ALS) is usually caused by loss of fast motor axons. We studied the frequency, extent, and distribution of prominently prolonged distal motor latencies in ALS. We reviewed results of median, ulnar, and tibial nerve conduction studies in 91 patients with ALS, 24 with lower motor neuron disorders, and 36 with axonal neuropathy. Coincidental carpal tunnel syndrome was found for 4 (4.4%) of the ALS patients who were excluded from analyses. Markedly prolonged distal latencies (>125% of the upper limit of normal) were found only in the median nerve of ALS patients (9%), and in none of the disease controls. Excitability studies suggested membrane depolarization in some ALS patients. Our results show that approximately 10% of ALS patients shows prominently prolonged median distal latency, which cannot be explained by axonal loss and carpal tunnel lesion. The distal nerve conduction slowing may partly be caused by membrane depolarization possibly due to motor neuronal degeneration in ALS. We suggest that recognition of the pattern of distal motor axonal dysfunction predominant in the median nerve is clinically important, and could provide additional insights into the pathophysiology of ALS.
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Affiliation(s)
- Yu-ichi Noto
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan.
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Meehan CF, Moldovan M, Marklund SL, Graffmo KS, Nielsen JB, Hultborn H. Intrinsic properties of lumbar motor neurones in the adult G127insTGGG superoxide dismutase-1 mutant mouse in vivo: evidence for increased persistent inward currents. Acta Physiol (Oxf) 2010; 200:361-76. [PMID: 20874803 DOI: 10.1111/j.1748-1716.2010.02188.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
AIM Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by a preferential loss of motor neurones. Previous publications using in vitro neonatal preparations suggest an increased excitability of motor neurones in various superoxide dismutase-1 (SOD1) mutant mice models of ALS which may contribute to excitotoxicity of the motor neurones. METHODS Using intracellular recording, we tested this hypothesis in vivo in the adult presymptomatic G127insTGGG (G127X) SOD1 mutant mouse model of ALS. RESULTS At resting membrane potentials the basic intrinsic properties of lumbar motor neurones in the adult presymptomatic G127X mutant are not significantly different from those of wild type. However, at more depolarized membrane potentials, motor neurones in the G127X SOD1 mutants can sustain higher frequency firing, showing less spike frequency adaption (SFA) and with persistent inward currents (PICs) being activated at lower firing frequencies and being more pronounced. CONCLUSION We demonstrated that, in vivo, at resting membrane potential, spinal motor neurones of the adult G127X mice do not show an increased excitability. However, when depolarized they show evidence of an increased PIC and less SFA which may contribute to excitotoxicity of these neurones as the disease progresses.
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Affiliation(s)
- C F Meehan
- Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Denmark.
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Mills KR. Characteristics of fasciculations in amyotrophic lateral sclerosis and the benign fasciculation syndrome. Brain 2010; 133:3458-69. [DOI: 10.1093/brain/awq290] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Visser GH, Blok JH. The CMAP scan. MOTOR UNIT NUMBER ESTIMATION (MUNE) AND QUANTITATIVE EMG - SELECTED PRESENTATIONS FROM THE SECOND INTERNATIONAL SYMPOSIUM ON MUNE AND QEMG, SNOWBIRD, UTAH, USA, 18–20 AUGUST 2006 2009; 60:65-77. [DOI: 10.1016/s1567-424x(08)00006-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Affiliation(s)
- Martin R Turner
- Department of Clinical Neurology, University of Oxford, Oxford, UK.
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Protein Misfolding and Axonal Protection in Neurodegenerative Diseases. PROTEIN FOLDING AND MISFOLDING: NEURODEGENERATIVE DISEASES 2008. [DOI: 10.1007/978-1-4020-9434-7_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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