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Bilgin Topçuoğlu Ö, Çetintaş Afşar G, Alibaş H, Uluç K. Impact of obstructive sleep apnea on neuromuscular transmission- a descriptive study. Cranio 2024; 42:292-297. [PMID: 34228607 DOI: 10.1080/08869634.2021.1952016] [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] [Indexed: 10/20/2022]
Abstract
Objective: Obstructive sleep apnea (OSA) is a sleep disorder accompanied by intermittent hypoxia. Neuromuscular transmission (NT) is known to be disturbed under chronic hypoxia. In this descriptive study, it has been aimed to test NT under intermittent hypoxia in OSA. Methods: Thirty-nine newly diagnosed OSA patients without any comorbidities or conditions that alter NT were included in the study. Jitter analysis was performed using a concentric needle electrode. Results: The mean jitter value of 39 OSA patients was 25.9 ± 3.7 μs. When compared to the mean reference jitter values, patients in the present study had significantly higher jitter (p < 0.001). Seven (17.9%) patients met the electrophysiological criteria for NT failure. Conclusion: The authors propose that intermittent hypoxia can be the trigger for NT failure in OSA. The interaction between increased oxidative stress and disturbed mitochondrial functions may also contribute.
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Affiliation(s)
| | - Gülgün Çetintaş Afşar
- Department of Chest Diseases, Sureyyapasa Chest Diseases and Thorax Surgery Training and Research Hospital, Istanbul, Turkey
| | - Hande Alibaş
- Department of Neurology, Marmara University, Medical School, Istanbul, Turkey
| | - Kayıhan Uluç
- Department of Neurology, Marmara University, Medical School, Istanbul, Turkey
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2
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Kouyoumdjian JA, Estephan EDP. Electrophysiological evaluation of the neuromuscular junction: a brief review. ARQUIVOS DE NEURO-PSIQUIATRIA 2023; 81:1040-1052. [PMID: 38157872 PMCID: PMC10756823 DOI: 10.1055/s-0043-1777749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/17/2023] [Indexed: 01/03/2024]
Abstract
The nerve terminal and muscle membrane compose the neuromuscular junction. After opening the voltage-gated calcium channels, action potentials from the motor axons provoke a cascade for the acetylcholine release from synaptic vesicles to the synaptic cleft, where it binds to its receptor at the muscle membrane for depolarization. Low amplitude compound muscle action potential typically presents in presynaptic disorders, increasing by more than 100% after a 10-second effort in the Lambert-Eaton myasthenic syndrome and less in botulism. Needle electromyography may show myopathic motor unit action potentials and morphological instability ("jiggle") due to impulse blocking. Low-frequency repetitive nerve stimulation (RNS) is helpful in postsynaptic disorders, such as myasthenia gravis and most congenital myasthenic syndromes, where the number of functioning acetylcholine receptors is reduced. Low-frequency RNS with a decrement >10% is abnormal when comparing the 4th to the first compound muscle action potential amplitude. High-frequency RNS is helpful in presynaptic disorders like Lambert-Eaton myasthenic syndrome, botulism, and some rare congenital myasthenic syndromes. The high-frequency RNS releases more calcium, increasing the acetylcholine with a compound muscle action potential increment. Concentric needle records apparent single-fiber action potentials (spikes). A voluntary activation measures the jitter between spikes from two endplates. An electrical activation measures the jitter of one spike (one endplate). The jitter is the most sensitive test for detecting a neuromuscular junction dysfunction. Most neuromuscular junction disorders are responsive to treatment.
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Affiliation(s)
- João Aris Kouyoumdjian
- Faculdade de Medicina de São José do Rio Preto, Departamento de Ciências Neurológicas, Psiquiatria e Psicologia Médica, São José do Rio Preto SP, Brazil.
| | - Eduardo de Paula Estephan
- Faculdade de Medicina de São José do Rio Preto, Departamento de Ciências Neurológicas, Psiquiatria e Psicologia Médica, São José do Rio Preto SP, Brazil.
- Universidade de São Paulo, Departamento de Neurologia, São Paulo SP, Brazil.
- Faculdade de Medicina Santa Marcelina, São Paulo SP, Brazil.
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3
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Tilki HE. Some reasons for frowning upon the effects of botulinum toxin injections in facial muscles. Clin Neurophysiol Pract 2023; 8:174-176. [PMID: 37681119 PMCID: PMC10480585 DOI: 10.1016/j.cnp.2023.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/30/2023] [Accepted: 08/01/2023] [Indexed: 09/09/2023] Open
Affiliation(s)
- Hacer Erdem Tilki
- Ondokuz Mayıs University, Medical Faculty, Departments of Neurology and Clinical Neurophysiology, Samsun, Turkey
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Malanda A, Stashuk DW, Navallas J, Rodríguez-Falces J, Rodríguez-Carreño I, Valle C, Garnés-Camarena O. Automatic jitter measurement in needle-detected motor unit potential trains. Comput Biol Med 2022; 149:105973. [DOI: 10.1016/j.compbiomed.2022.105973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 07/28/2022] [Accepted: 08/13/2022] [Indexed: 11/03/2022]
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5
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Kouyoumdjian JA, Graca CR. Concentric needle jitter: Reference values in stimulated Tibialis Anterior muscle. Front Neurol 2022; 13:957174. [PMID: 35937059 PMCID: PMC9355656 DOI: 10.3389/fneur.2022.957174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 06/23/2022] [Indexed: 12/04/2022] Open
Abstract
Calculating the reference values for jitter parameters utilizing a disposable concentric needle have been already done for the most often tested muscles. Jitter, expressed as the mean consecutive difference (MCD), was measured in the Tibialis Anterior (TA), not routinely tested muscle. Jitter measurement was taken using the intramuscular microaxonal stimulation technique in 32 healthy subjects. The mean MCD and the mean MCD of the 27th value from the 32 subjects had a normal distribution and were 19.79 ± 2.72 μs and 26.88 ± 3.56 μs, respectively. The suggested limit for the mean MCD is ≥ 26 μs and for the individual values is > 34 μs.
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Affiliation(s)
- João Aris Kouyoumdjian
- Neuromuscular Investigation Laboratory, Department of Neurological Sciences, Psychiatry and Medical Psychology, State Medical School (FAMERP), São Paulo, Brazil
| | - Carla Renata Graca
- Neuromuscular Investigation Laboratory, Department of Neurological Sciences, Psychiatry and Medical Psychology, State Medical School (FAMERP), São Paulo, Brazil
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6
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Sanders DB, Kouyoumdjian JA, Stålberg EV. Single fiber electromyography and measuring jitter with concentric needle electrodes. Muscle Nerve 2022; 66:118-130. [PMID: 35694863 DOI: 10.1002/mus.27573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 05/06/2022] [Indexed: 11/07/2022]
Abstract
This monograph contains descriptions of the single fiber electromyography (SFEMG) method and of the more recently implemented method of recording jitter with concentric needle electrodes (CNEs). SFEMG records action potentials from single muscle fibers (SFAPs), which permits measuring fiber density (FD), a sensitive measure of reinnervation, and jitter, a sensitive measure of abnormal neuromuscular transmission (NMT). With voluntary activation, jitter is measured between two SFAPs with acceptable amplitude and rise time. With activation by axon stimulation, jitter is measured between the stimulus and individual SFAPs. Pitfalls due to unstable triggers and inconstant firing rates during voluntary activation and subliminal stimulation during axon stimulation should be identified and avoided. In CNE recordings, spikes with shoulders or rising phases that are not parallel are produced by summation of SFAPS; these should be excluded and reference values for CNE jitter should be used. CNE and SFEMG have similar and very high sensitivity in detecting increased jitter, as in myasthenia gravis and other myasthenic conditions. However, jitter is also seen in ongoing reinnervation and some myopathic conditions. With SFEMG, these can be identified by increased FD; however, FD cannot be measured with CNE, and conventional electromyography should be performed in muscles with increased jitter to detect neurogenic or myogenic abnormalities. Jitter is abnormal after injections of botulinum toxin, even in muscles remote from the injection site, and can persist for 6 mo or more. This can complicate the detection or exclusion of abnormal NMT.
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Affiliation(s)
- Donald B Sanders
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - João A Kouyoumdjian
- Department of Neurological Sciences, State Medical School (FAMERP), São Paulo, Brazil
| | - Erik V Stålberg
- Department of Clinical Neurophysiology, Academic Hospital, Uppsala, Sweden
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7
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Sanders DB, Kouyoumdjian JA, Stålberg EV. Single fiber EMG and measuring jitter with concentric needle electrodes. Muscle Nerve 2022. [PMID: 35652573 DOI: 10.1002/mus.27572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 05/05/2022] [Indexed: 11/08/2022]
Abstract
This monograph contains descriptions of the single-fiber electromyography (SFEMG) method and of the more recently implemented method of recording jitter with concentric needle electrodes (CNE). SFEMG records action potentials from single muscle fibers (SFAPs), which permits measuring fiber density (FD), a sensitive measure of reinnervation, and jitter, a sensitive measure of abnormal neuromuscular transmission (NMT). With voluntary activation, jitter is measured between two SFAPs with acceptable amplitude and rise time. With activation by axon stimulation, jitter is measured between the stimulus and individual SFAPs. Pitfalls due to unstable triggers and inconstant firing rates during voluntary activation and subliminal stimulation during axon stimulation should be identified and avoided. In CNE recordings, spikes with shoulders or rising phases that are not parallel are produced by summation of SFAPS; these should be excluded and reference values for CNE jitter should be used. CNE and SFEMG have similar and very high sensitivity in detecting increased jitter, as in myasthenia gravis and other myasthenic conditions. However, jitter is also seen in ongoing reinnervation and some myopathic conditions. With SFEMG, these can be identified by increased FD; however, FD cannot be measured with CNE, and conventional EMG should be performed in muscles with increased jitter to detect neurogenic or myogenic abnormalities. Jitter is abnormal after injections of botulinum toxin, even in muscles remote from the injection site, and can persist for 6 mo or more. This can complicate the detection or exclusion of abnormal NMT.
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Affiliation(s)
- Donald B Sanders
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - João A Kouyoumdjian
- Department of Neurological Sciences, State Medical School (FAMERP), São Paulo, Brazil
| | - Erik V Stålberg
- Department of Clinical Neurophysiology, Academic Hospital, Uppsala, Sweden
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8
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Zalewska E. Influence of time shifting of single muscle fiber potentials (SFPs) on jitter values measured using concentric needle electrode - a simulation study. Neurophysiol Clin 2022; 52:252-258. [PMID: 35660332 DOI: 10.1016/j.neucli.2022.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 03/25/2022] [Accepted: 03/25/2022] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES The aim of this simulation study was to evaluate the resulting value of jitter measured from a simulated examination recording and to analyze its dependence on both the number of SFPs contributing either to the triggering peak or the non-triggered peak, and time shifting (delays of triggering at the end-plate) of individual SFPs in these paired potentials. METHODS We simulated potentials recorded using a concentric needle electrode with two well separated peaks, and performed a simulated examination (consisting of 50 trains of 100 discharges) with an assumed number of fibers forming peaks. For each train, fiber diameters were chosen at random within the allowed ranges. For each discharge the delay of triggering for each fiber at the end-plate was selected at random from an assumed range. The mean jitter values were calculated, together with the median and 95% quantile. RESULTS The results suggest that jitter is related to the mean of the individual SFP shifts. CONCLUSION These findings extend the understanding of reduced jitter measurements using a concentric needle electrode. If more than one fiber forms the peak, then jitter decreases due to averaging of individual time shifts of potentials constituting the peak, rather than due to detection of the SFP with the earliest peak.
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Affiliation(s)
- Ewa Zalewska
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4 str., Warsaw 02-109, Poland.
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9
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Bedside and laboratory diagnostic testing in myasthenia. J Neurol 2022; 269:3372-3384. [PMID: 35142871 PMCID: PMC9119875 DOI: 10.1007/s00415-022-10986-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 11/02/2022]
Abstract
Myasthenia gravis (MG) and congenital myasthenic syndromes (CMS) are a group of disorders with a well characterised autoimmune or genetic and neurophysiological basis. We reviewed the literature from the last 20 years assessing the utility of various neurophysiological, immunological, provocative and genetic tests in MG and CMS. Diagnostic sensitivity of repetitive nerve stimulation test ranges between 14 and 94% and specificity between 73 and 100%; sensitivity of single-fibre EMG (SFEMG) test ranges between 64 and 100% and specificity between 22 and 100%; anti-acetylcholine receptor (AChR) antibody sensitivity ranges from 13 to 97% and specificity ranges from 95 to 100%. Overall, SFEMG has the highest sensitivity while positive anti-AChR antibodies have the highest specificity. Newer testing strategies that have been investigated over the last couple of decades include ocular vestibular-evoked myogenic potentials, otoacoustic emissions and disease-specific circulating miRNAs in serum for autoimmune myasthenia, as well as next-generation sequencing for genetic testing of CMS. While there has been significant progress in developing newer testing strategies for diagnosing MG and CMS over the last couple of decades, more research is needed to assess the utility of these newer tools regarding their sensitivity and specificity.
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10
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Smith VM, Nguyen H, Rumsey JW, Long CJ, Shuler ML, Hickman JJ. A Functional Human-on-a-Chip Autoimmune Disease Model of Myasthenia Gravis for Development of Therapeutics. Front Cell Dev Biol 2021; 9:745897. [PMID: 34881241 PMCID: PMC8645836 DOI: 10.3389/fcell.2021.745897] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/14/2021] [Indexed: 11/13/2022] Open
Abstract
Myasthenia gravis (MG) is a chronic and progressive neuromuscular disease where autoantibodies target essential proteins such as the nicotinic acetylcholine receptor (nAChR) at the neuromuscular junction (NMJ) causing muscle fatigue and weakness. Autoantibodies directed against nAChRs are proposed to work by three main pathological mechanisms of receptor disruption: blocking, receptor internalization, and downregulation. Current in vivo models using experimental autoimmune animal models fail to recapitulate the disease pathology and are limited in clinical translatability due to disproportionate disease severity and high animal death rates. The development of a highly sensitive antibody assay that mimics human disease pathology is desirable for clinical advancement and therapeutic development. To address this lack of relevant models, an NMJ platform derived from human iPSC differentiated motoneurons and primary skeletal muscle was used to investigate the ability of an anti-nAChR antibody to induce clinically relevant MG pathology in the serum-free, spatially organized, functionally mature NMJ platform. Treatment of the NMJ model with the anti-nAChR antibody revealed decreasing NMJ stability as measured by the number of NMJs before and after the synchrony stimulation protocol. This decrease in NMJ stability was dose-dependent over a concentration range of 0.01-20 μg/mL. Immunocytochemical (ICC) analysis was used to distinguish between pathological mechanisms of antibody-mediated receptor disruption including blocking, receptor internalization and downregulation. Antibody treatment also activated the complement cascade as indicated by complement protein 3 deposition near the nAChRs. Additionally, complement cascade activation significantly altered other readouts of NMJ function including the NMJ fidelity parameter as measured by the number of muscle contractions missed in response to increasing motoneuron stimulation frequencies. This synchrony readout mimics the clinical phenotype of neurological blocking that results in failure of muscle contractions despite motoneuron stimulations. Taken together, these data indicate the establishment of a relevant disease model of MG that mimics reduction of functional nAChRs at the NMJ, decreased NMJ stability, complement activation and blocking of neuromuscular transmission. This system is the first functional human in vitro model of MG to be used to simulate three potential disease mechanisms as well as to establish a preclinical platform for evaluation of disease modifying treatments (etiology).
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Affiliation(s)
- Virginia M. Smith
- Hybrid Systems Lab, NanoScience Technology Center, University of Central Florida, Orlando, FL, United States
- Hesperos, Inc., Orlando, FL, United States
| | - Huan Nguyen
- Hybrid Systems Lab, NanoScience Technology Center, University of Central Florida, Orlando, FL, United States
| | | | | | | | - James J. Hickman
- Hybrid Systems Lab, NanoScience Technology Center, University of Central Florida, Orlando, FL, United States
- Hesperos, Inc., Orlando, FL, United States
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11
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Gilhus NE, Verschuuren JJGM, Hovland SIB, Simmonds H, Groot F, Palace J. Myasthenia gravis: do not forget the patient perspective. Neuromuscul Disord 2021; 31:S0960-8966(21)00583-6. [PMID: 34635387 DOI: 10.1016/j.nmd.2021.07.396] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/09/2021] [Accepted: 07/20/2021] [Indexed: 12/19/2022]
Affiliation(s)
- Nils Erik Gilhus
- Department of Clinical Medicine, University of Bergen, Norway; Department of Neurology, Haukeland University Hospital, Bergen, Norway.
| | | | | | - Huw Simmonds
- Myaware, College Business Centre, Derby, England
| | - Floor Groot
- Dutch Neuromuscular disease Association, Baarn, The Netherlands
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, University of Oxford, Hospitals Trust, Oxford, England
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12
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Katzberg HD, Abraham A. Electrodiagnostic Assessment of Neuromuscular Junction Disorders. Neurol Clin 2021; 39:1051-1070. [PMID: 34602214 DOI: 10.1016/j.ncl.2021.06.013] [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: 10/20/2022]
Abstract
Please verify edits, "These techniques", or specify. This article reviews advanced electrodiagnostic techniques used to assess for neuromuscular junction disorders, including repetitive nerve stimulation, conventional or concentric-needle single-fiber electromyography (SFEMG), and stimulated SFEMG. These techniques have high sensitivity but limited specificity. Novel methods currently under investigation are discussed, including vestibular ocular myogenic potential and oculography analysis.
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Affiliation(s)
- Hans D Katzberg
- Division of Neurology, University Health Network, Toronto General Hospital, 200 Elizabeth Street, 5ES-306, Toronto, Ontario M5G 2C4, Canada.
| | - Alon Abraham
- Neuromuscular Diseases Unit, Department of Neurology, Tel Aviv Sourasky Medical Center, 6 Weizmann Street, Tel Aviv 6423906, Israel
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13
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Allen MD, Dalton BH, Gilmore KJ, McNeil CJ, Doherty TJ, Rice CL, Power GA. Neuroprotective effects of exercise on the aging human neuromuscular system. Exp Gerontol 2021; 152:111465. [PMID: 34224847 DOI: 10.1016/j.exger.2021.111465] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 05/31/2021] [Accepted: 06/30/2021] [Indexed: 12/23/2022]
Abstract
Human biological aging from maturity to senescence is associated with a gradual loss of muscle mass and neuromuscular function. It is not until very old age (>80 years) however, that these changes often manifest into functional impairments. A driving factor underlying the age-related loss of muscle mass and function is the reduction in the number and quality of motor units (MUs). A MU consists of a single motoneuron, located either in the spinal cord or the brain stem, and all of the muscle fibres it innervates via its peripheral axon. Throughout the adult lifespan, MUs are slowly, but progressively lost. The compensatory process of collateral reinnervation attempts to recapture orphaned muscle fibres following the death of a motoneuron. Whereas this process helps mitigate loss of muscle mass during the latter decades of adult aging, the neuromuscular system has fewer and larger MUs, which have lower quality connections between the axon terminal and innervated muscle fibres. Whether this process of MU death and degradation can be attenuated with habitual physical activity has been a challenging question of great interest. This review focuses on age-related alterations of the human neuromuscular system, with an emphasis on the MU, and presents findings on the potential protective effects of lifelong physical activity. Although there is some discrepancy across studies of masters athletes, if one considers all experimental limitations as well as the available literature in animals, there is compelling evidence of a protective effect of chronic physical training on human MUs. Our tenet is that high-levels of physical activity can mitigate the natural trajectory of loss of quantity and quality of MUs in old age.
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Affiliation(s)
- Matti D Allen
- Department of Physical Medicine and Rehabilitation, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON K7L 4X3, Canada; School of Kinesiology and Health Studies, Faculty of Arts and Sciences, Queen's University, Kingston, ON K7L 4X3, Canada
| | - Brian H Dalton
- School of Health and Exercise Science, University of British Columbia, Kelowna, BC V1V 1V7, Canada
| | - Kevin J Gilmore
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Chris J McNeil
- School of Health and Exercise Science, University of British Columbia, Kelowna, BC V1V 1V7, Canada
| | - Timothy J Doherty
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada; Department of Physical Medicine and Rehabilitation, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada
| | - Charles L Rice
- School of Kinesiology, The University of Western Ontario, London, ON, Canada; Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.
| | - Geoffrey A Power
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
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Zalewska E, Gawel M. Differentiation between single fiber potentials from one muscle fiber or contaminated by other fibers using discriminating function. Neurophysiol Clin 2021; 51:466-479. [PMID: 33962869 DOI: 10.1016/j.neucli.2020.12.001] [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: 09/02/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES The aim was to improve the identification of potentials recorded using single fiber electromyography (SFEMG) contaminated by potentials from other muscle fibers, which might affect measured jitter value, by defining more selective criteria of single fiber potential (SFP) discrimination. We were looking for solutions suitable for automatization. METHODS Standard parameters characterizing SFP and their combinations were analyzed to define an analytical discriminating function able to verify if potentials recorded using SFEMG are due to single fiber or due to two (or more) fibers. RESULTS The discriminating function is based on combination of standard SFP parameters. The procedure was tested on a set of simulated i.e., known data and on samples of clinical data. The tests on simulated data confirmed assumed properties of discriminating function. Preliminary results of pilot studies using patient data suggest its ability for differentiation between potentials of one fiber and contaminated ones. The procedure is suitable for automatization. CONCLUSION Results suggest that proposed discriminating function when supplementing standard criteria would help to promote SFP recordings and enable to improve relevancy of jitter measurements and of jitter value norms.
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Affiliation(s)
- Ewa Zalewska
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4 Str., 02-109 Warsaw, Poland.
| | - Malgorzata Gawel
- Department of Neurology, Medical University of Warsaw, Banacha 1A Str., 02-097 Warsaw, Poland
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15
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Kouyoumdjian JA, Paiva GP, Stålberg E. Concentric Needle Jitter in 97 Myasthenia Gravis Patients. Front Neurol 2020; 11:600680. [PMID: 33281737 PMCID: PMC7691317 DOI: 10.3389/fneur.2020.600680] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/13/2020] [Indexed: 11/24/2022] Open
Abstract
Objectives: To estimate the jitter parameters (single-fiber electromyography) in myasthenia gravis patients mostly by electrical activation in Frontalis, Orbicularis Oculi, and Extensor Digitorum muscles using a concentric needle electrode. Methods: Between 2009 and 2019, a total of 97 myasthenia gravis patients, 52 male, and mean age 54 years were included. Results: Any abnormal jitter parameter in individual muscles was 90.5% (Frontalis), 88.5% (Orbicularis Oculi), and 86.6% (Extensor Digitorum). Any jitter parameter combining Orbicularis Oculi and Frontalis muscle was abnormal in 100% for the ocular, and in 92.9% for the generalized myasthenia gravis. The most abnormal muscle was Orbicularis Oculi for the generalized, and Frontalis for the ocular myasthenia gravis. The decrement was abnormal in 78.4%, 85.9% for the generalized, and 25% for the ocular myasthenia gravis. The mean jitter ranged from 14.2 to 86 μs (mean 33.3 μs) for the ocular myasthenia gravis and from 14.4 to 220.4 μs (mean 66.3 μs) for the generalized myasthenia gravis. The antibody titers tested positive in 86.6%, 91.8% for the generalized, and 50% for the ocular myasthenia gravis. Thymectomy was done in 48.5%, thymoma was found in 19.6%, and myasthenic crisis occurred by 21.6%. Conclusion: The jitter parameters achieved a 100% abnormality in ocular myasthenia gravis if both the Orbicularis Oculi and Frontalis muscles were tested. There was a high jitter abnormality in generalized myasthenia gravis cases with one muscle tested, with about a 2% increase in sensitivity when a second is added. Concentric needle electrode jitter had high sensitivity similar to the single fiber electrode (93.8%), followed by antibody titers (86.6%), and abnormal decrement (78.4%).
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Affiliation(s)
- João Aris Kouyoumdjian
- Laboratório Investigação Neuromuscular, Faculdade Estadual Medicina São José do Rio Preto, São Paulo, Brazil
| | - Gabriel Pina Paiva
- Laboratório Investigação Neuromuscular, Faculdade Estadual Medicina São José do Rio Preto, São Paulo, Brazil
| | - Erik Stålberg
- Department of Clinical Neurophysiology, Institute of Neurosciences, Uppsala University, Uppsala, Sweden
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16
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Caldas VM, Heise CO, Kouyoumdjian JA, Zambon AA, Silva AMS, Estephan EDP, Zanoteli E. Electrophysiological study of neuromuscular junction in congenital myasthenic syndromes, congenital myopathies, and chronic progressive external ophthalmoplegia. Neuromuscul Disord 2020; 30:897-903. [PMID: 33121830 DOI: 10.1016/j.nmd.2020.10.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 11/19/2022]
Abstract
This study was designed to analyze the sensitivity, specificity, and accuracy of jitter parameters combined with repetitive nerve stimulation (RNS) in congenital myasthenic syndrome (CMS), chronic progressive external ophthalmoplegia (CPEO), and congenital myopathies (CM). Jitter was obtained with a concentric needle electrode during voluntary activation of the Orbicularis Oculi muscle in CMS (n = 21), CPEO (n = 20), and CM (n = 18) patients and in controls (n = 14). RNS (3 Hz) was performed in six different muscles for all patients (Abductor Digiti Minimi, Tibialis Anterior, upper Trapezius, Deltoideus, Orbicularis Oculi, and Nasalis). RNS was abnormal in 90.5% of CMS patients and in only one CM patient. Jitter was abnormal in 95.2% of CMS, 20% of CPEO, and 11.1% of CM patients. No patient with CPEO or CM presented a mean jitter higher than 53.6 µs or more than 30% abnormal individual jitter (> 45 µs). No patient with CPEO or CM and mild abnormal jitter values presented an abnormal decrement. Jitter and RNS assessment are valuable tools for diagnosing neuromuscular transmission abnormalities in CMS patients. A mean jitter value above 53.6 µs or the presence of more than 30% abnormal individual jitter (> 45 µs) strongly suggests CMS compared with CPEO and CM.
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Affiliation(s)
- Vitor Marques Caldas
- Department of Neurology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Dr. Enéas Carvalho Aguiar 255, 05403-900 São Paulo SP, Brazil
| | - Carlos Otto Heise
- Department of Neurology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Dr. Enéas Carvalho Aguiar 255, 05403-900 São Paulo SP, Brazil
| | - João Aris Kouyoumdjian
- Laboratório de Investigação Neuromuscular, Faculdade Estadual de Medicina de São Jose do Rio Preto (FAMERP), São Jose do Rio Preto, SP, Brazil
| | - Antônio Alberto Zambon
- Department of Neurology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Dr. Enéas Carvalho Aguiar 255, 05403-900 São Paulo SP, Brazil
| | - André Macedo Serafim Silva
- Department of Neurology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Dr. Enéas Carvalho Aguiar 255, 05403-900 São Paulo SP, Brazil
| | - Eduardo de Paula Estephan
- Department of Neurology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Dr. Enéas Carvalho Aguiar 255, 05403-900 São Paulo SP, Brazil; Department of Medicine, Faculdade Santa Marcelina, São Paulo, Brazil
| | - Edmar Zanoteli
- Department of Neurology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Dr. Enéas Carvalho Aguiar 255, 05403-900 São Paulo SP, Brazil.
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Doughty CT, Guidon AC. Diagnostic testing for ocular myasthenia gravis: Stronger together. Neurology 2020; 95:563-564. [PMID: 32788244 DOI: 10.1212/wnl.0000000000010616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Christopher T Doughty
- From Brigham and Women's Hospital (C.T.D.); Harvard Medical School (C.T.D., A.C.G.); and Massachusetts General Hospital (A.C.G.), Boston.
| | - Amanda C Guidon
- From Brigham and Women's Hospital (C.T.D.); Harvard Medical School (C.T.D., A.C.G.); and Massachusetts General Hospital (A.C.G.), Boston
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Kouyoumdjian JA, Ronchi LG, de Faria FO. Jitter evaluation in denervation and reinnervation in 32 cases of chronic radiculopathy. Clin Neurophysiol Pract 2020; 5:165-172. [PMID: 32939421 PMCID: PMC7479254 DOI: 10.1016/j.cnp.2020.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/09/2020] [Accepted: 07/26/2020] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVE To measure the jitter parameters in muscles with denervation/reinnervation in 32 chronic radiculopathy cases. METHODS Measurements were done in chronic denervated muscles by voluntary and electrical activation using a concentric needle electrode. RESULTS Mean jitter was abnormal in 87.5% (mean 49.2 µs) and 81.25% (mean 36.8 µs), for voluntary and electrical activation. In muscles with fibrillation potentials (FPs), the mean jitter was abnormal in all cases, and impulse blocking was frequent (53.4-92.3%). In muscles without FPs, the mean jitter was abnormal in 78.9% for voluntary activation and 68.4% for electrical activation. No correlation was found between jitter and motor unit action potential amplitude. CONCLUSION The muscles with FPs were associated with the immature spread of acetylcholine receptors (AChRs) throughout the muscle membrane. Conversely, the neuromuscular junctions (NMJs) assemble may be repressed by the already reinnervated muscles. For those, higher jitter may be due to the persistence of atrophic fibers expressing neonatal myosin heavy chain (MHC) and immaturity of NMJ composting instead of the overspread of immature AChRs. SIGNIFICANCE Jitter measurement must be avoided in chronic denervated muscles, regardless of FPs' presence. The activity of reinnervated muscle could maintain neonatal MHC and repress new NMJs development.
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Affiliation(s)
- Joao Aris Kouyoumdjian
- Faculdade Estadual Medicina Sao Jose do Rio Preto (FAMERP), Laboratorio Investigacao Neuromuscular (LIN), Associate-Professor of Neurology, 15090-000 Sao Jose do Rio Preto, Sao Paulo, Brazil
| | - Luis Guilherme Ronchi
- Fellows in Neuromuscular Diseases and Eletrectromyography, Faculdade Estadual Medicina Sao Jose do Rio Preto (FAMERP), 15090-000 Sao Jose do Rio Preto, Sao Paulo, Brazil
| | - Felipe Oliveira de Faria
- Fellows in Neuromuscular Diseases and Eletrectromyography, Faculdade Estadual Medicina Sao Jose do Rio Preto (FAMERP), 15090-000 Sao Jose do Rio Preto, Sao Paulo, Brazil
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Dede HÖ, Sirin NG, Kocasoy-Orhan E, Idrisoglu HA, Baslo MB. Changes in motor unit bioelectrical activity recorded at two different sites in a muscle. Neurophysiol Clin 2020; 50:113-118. [PMID: 32171639 DOI: 10.1016/j.neucli.2020.02.001] [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: 07/02/2019] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 12/29/2022] Open
Abstract
INTRODUCTION The objective of this study was to compare the properties of bioelectrical signals of motor units recorded at different sites in the muscles of controls, patients with myopathy and patients with motor neuron disease (MND). METHODS Five controls, 10 patients with myopathy and 11 patients with MND were included. Electrophysiologic tests were performed in the biceps brachii (BB) muscle from two recording sites. Site 1 was near the belly of the muscle and Site 2 was 5cm distal from Site 1, near the tendon. Multi-motor unit potential (MUP) analysis, jitter analysis, and peak number count were calculated from the signals recorded using a concentric needle electrode (CN). RESULTS At Site 2, duration was longer, number of phases was higher and amplitudes were smaller in MUPs compared with those recorded at Site 1. This significant difference between recording site and patient groups was related to neurogenic muscles. Jitter analysis showed no significant difference except an intergroup difference between the patient groups and controls. The peak number calculated using the CN was greater when recorded from Site 1 in concordance with MUP analysis. CONCLUSION Duration of MUP was longer and amplitude was smaller when the recording electrode was placed distally along the muscle near the tendon in neurogenic muscles, probably related to increased temporal dispersion. However, changing the position of the needle did not provide further information in distinguishing myogenic muscles.
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Affiliation(s)
- Hava Özlem Dede
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, 34100 Istanbul Capa, Fatih Turkey.
| | - Nermin Gorkem Sirin
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, 34100 Istanbul Capa, Fatih Turkey
| | - Elif Kocasoy-Orhan
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, 34100 Istanbul Capa, Fatih Turkey
| | - Halil Atilla Idrisoglu
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, 34100 Istanbul Capa, Fatih Turkey
| | - Mehmet Baris Baslo
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, 34100 Istanbul Capa, Fatih Turkey
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Zalewska E, Gawel M. Evolution of single fiber potential (SFP) criteria towards improving jitter measurement. Neurophysiol Clin 2019; 49:205-207. [DOI: 10.1016/j.neucli.2019.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/01/2019] [Accepted: 04/04/2019] [Indexed: 11/25/2022] Open
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Abstract
Myasthenia gravis (MG) is an autoimmune disease caused by antibodies against the acetylcholine receptor (AChR), muscle-specific kinase (MuSK) or other AChR-related proteins in the postsynaptic muscle membrane. Localized or general muscle weakness is the predominant symptom and is induced by the antibodies. Patients are grouped according to the presence of antibodies, symptoms, age at onset and thymus pathology. Diagnosis is straightforward in most patients with typical symptoms and a positive antibody test, although a detailed clinical and neurophysiological examination is important in antibody-negative patients. MG therapy should be ambitious and aim for clinical remission or only mild symptoms with near-normal function and quality of life. Treatment should be based on MG subgroup and includes symptomatic treatment using acetylcholinesterase inhibitors, thymectomy and immunotherapy. Intravenous immunoglobulin and plasma exchange are fast-acting treatments used for disease exacerbations, and intensive care is necessary during exacerbations with respiratory failure. Comorbidity is frequent, particularly in elderly patients. Active physical training should be encouraged.
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Sanders DB, Arimura K, Cui L, Ertaş M, Farrugia ME, Gilchrist J, Kouyoumdjian JA, Padua L, Pitt M, Stålberg E. Guidelines for single fiber EMG. Clin Neurophysiol 2019; 130:1417-1439. [PMID: 31080019 DOI: 10.1016/j.clinph.2019.04.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/30/2019] [Accepted: 04/06/2019] [Indexed: 12/13/2022]
Abstract
This document is the consensus of international experts on the current status of Single Fiber EMG (SFEMG) and the measurement of neuromuscular jitter with concentric needle electrodes (CNE - CN-jitter). The panel of authors was chosen based on their particular interests and previous publications within a specific area of SFEMG or CN-jitter. Each member of the panel was asked to submit a section on their particular area of interest and these submissions were circulated among the panel members for edits and comments. This process continued until a consensus was reached. Donald Sanders and Erik Stålberg then edited the final document.
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Affiliation(s)
| | - Kimiyoshi Arimura
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
| | - LiYing Cui
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
| | | | | | - James Gilchrist
- Southern Illinois University School of Medicine, Springfield, IL USA.
| | | | - Luca Padua
- Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Department of Geriatrics, Neurosciences and Orthopaedics, Università Cattolica del Sacro Cuore, Rome, Italy.
| | - Matthew Pitt
- Department of Clinical Neurophysiology, Great Ormond Street Hospital, London, UK.
| | - Erik Stålberg
- Department of Clinical Neurophysiology, Uppsala University, Uppsala, Sweden.
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Zalewska E, Gawel M. Identification of components from distant fibers in a recorded single muscle fiber potential (SFP) – a new approach to the SFP criteria. Neurophysiol Clin 2019; 49:69-80. [DOI: 10.1016/j.neucli.2018.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 09/24/2018] [Accepted: 09/27/2018] [Indexed: 10/28/2022] Open
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24
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Sirin NG, Kocasoy Orhan E, Durmus H, Deymeer F, Baslo MB. Repetitive nerve stimulation and jitter measurement with disposable concentric needle electrode in newly diagnosed myasthenia gravis patients. Neurophysiol Clin 2018; 48:261-267. [DOI: 10.1016/j.neucli.2018.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/13/2018] [Accepted: 01/19/2018] [Indexed: 10/17/2022] Open
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Wang S, Breskovska I, Gandhy S, Punga AR, Guptill JT, Kaminski HJ. Advances in autoimmune myasthenia gravis management. Expert Rev Neurother 2018; 18:573-588. [PMID: 29932785 PMCID: PMC6289049 DOI: 10.1080/14737175.2018.1491310] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Myasthenia gravis (MG) is an autoimmune neuromuscular disorder with no cure and conventional treatments limited by significant adverse effects and variable benefit. In the last decade, therapeutic development has expanded based on improved understanding of autoimmunity and financial incentives for drug development in rare disease. Clinical subtypes exist based on age, gender, thymic pathology, autoantibody profile, and other poorly defined factors, such as genetics, complicate development of specific therapies. Areas covered: Clinical presentation and pathology vary considerably among patients with some having weakness limited to the ocular muscles and others having profound generalized weakness leading to respiratory insufficiency. MG is an antibody-mediated disorder dependent on autoreactive B cells which require T-cell support. Treatments focus on elimination of circulating autoantibodies or inhibition of effector mechanisms by a broad spectrum of approaches from plasmapheresis to B-cell elimination to complement inhibition. Expert commentary: Standard therapies and those under development are disease modifying and not curative. As a rare disease, clinical trials are challenged in patient recruitment. The great interest in development of treatments specific for MG is welcome, but decisions will need to be made to focus on those that offer significant benefits to patients.
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Affiliation(s)
- Shuhui Wang
- Department of Neurology, George Washington University, Washington DC 20008
| | - Iva Breskovska
- Department of Neurology, George Washington University, Washington DC 20008
| | - Shreya Gandhy
- Department of Neurology, George Washington University, Washington DC 20008
| | - Anna Rostedt Punga
- Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala, Sweden
| | - Jeffery T. Guptill
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - Henry J. Kaminski
- Department of Neurology, George Washington University, Washington DC 20008
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