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Lu M, Reisch J, Iannaccone S, Batley K. Juvenile Myasthenia Gravis in North Texas: Clinical Features, Treatment Response, and Outcomes. Pediatr Neurol 2024; 156:10-14. [PMID: 38688232 DOI: 10.1016/j.pediatrneurol.2024.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 03/08/2024] [Accepted: 03/19/2024] [Indexed: 05/02/2024]
Abstract
BACKGROUND Juvenile myasthenia gravis (JMG) is a rare autoimmune disease that causes fatigable muscle weakness in children aged <18 years. There is currently no curative treatment or internationally accepted standard of care for JMG. The objective is to investigate relationships between clinical presentation, antibody status, severity of disease onset, electrodiagnostic evaluation, and response to therapy in JMG. METHODS This study was a retrospective chart review. Congenital myasthenic syndromes were excluded. Data on demographics, treatments, and outcomes were collected. Disease severity was evaluated using Myasthenia Gravis Foundation of America (MGFA) clinical classifications. RESULTS We identified 84 patients with JMG at Children's Medical Center Dallas between January 2014 and February 2022. It was found that 52% of patients presented with ocular JMG (median onset age 4.5 years) and 48% with generalized JMG (median onset age 11.5 years); 81% tested positive for acetylcholine receptor antibodies. Patients were 17% non-Hispanic white, 29% Hispanic, 39% black, and 12% Asian. There was a significant difference in average MGFA scores between ethnicities (P = 0.047) and age groups (P = 0.004), with postpubertal patients having higher average MGFA scores than prepubertal patients. Seventy-one percent of patients who underwent thymectomy experienced a decrease in MGFA scores postprocedure. CONCLUSIONS Our study showed that there were significant differences in disease severity between ethnicities and age groups and that most patients who underwent thymectomy showed clinical improvement. These outcomes highlight the need for additional therapies in the treatment of JMG and the importance of extending clinical trials to the pediatric population.
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Affiliation(s)
- Marilyn Lu
- Pediatric Neuromuscular Division, Departments of Pediatrics and Neurology, The University of Texas Southwestern Medical Center, Dallas, Texas.
| | - Joan Reisch
- Department of Population and Data Sciences, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Susan Iannaccone
- Pediatric Neuromuscular Division, Departments of Pediatrics and Neurology, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Kaitlin Batley
- Pediatric Neuromuscular Division, Departments of Pediatrics and Neurology, The University of Texas Southwestern Medical Center, Dallas, Texas
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2
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Perrino M, Voulaz E, Balin S, Cazzato G, Fontana E, Franzese S, Defendi M, De Vincenzo F, Cordua N, Tamma R, Borea F, Aliprandi M, Airoldi M, Cecchi LG, Fazio R, Alloisio M, Marulli G, Santoro A, Di Tommaso L, Ingravallo G, Russo L, Da Rin G, Villa A, Della Bella S, Zucali PA, Mavilio D. Autoimmunity in thymic epithelial tumors: a not yet clarified pathologic paradigm associated with several unmet clinical needs. Front Immunol 2024; 15:1288045. [PMID: 38629065 PMCID: PMC11018877 DOI: 10.3389/fimmu.2024.1288045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 01/29/2024] [Indexed: 04/19/2024] Open
Abstract
Thymic epithelial tumors (TETs) are rare mediastinal cancers originating from the thymus, classified in two main histotypes: thymoma and thymic carcinoma (TC). TETs affect a primary lymphoid organ playing a critical role in keeping T-cell homeostasis and ensuring an adequate immunological tolerance against "self". In particular, thymomas and not TC are frequently associated with autoimmune diseases (ADs), with Myasthenia Gravis being the most common AD present in 30% of patients with thymoma. This comorbidity, in addition to negatively affecting the quality and duration of patients' life, reduces the spectrum of the available therapeutic options. Indeed, the presence of autoimmunity represents an exclusion criteria for the administration of the newest immunotherapeutic treatments with checkpoint inhibitors. The pathophysiological correlation between TETs and autoimmunity remains a mystery. Several studies have demonstrated the presence of a residual and active thymopoiesis in adult patients affected by thymomas, especially in mixed and lymphocytic-rich thymomas, currently known as type AB and B thymomas. The aim of this review is to provide the state of art in regard to the histological features of the different TET histotype, to the role of the different immune cells infiltrating tumor microenvironments and their impact in the break of central immunologic thymic tolerance in thymomas. We discuss here both cellular and molecular immunologic mechanisms inducing the onset of autoimmunity in TETs, limiting the portfolio of therapeutic strategies against TETs and greatly impacting the prognosis of associated autoimmune diseases.
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Affiliation(s)
- Matteo Perrino
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Emanuele Voulaz
- Division of Thoracic Surgery, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Simone Balin
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
| | - Gerardo Cazzato
- Section of Pathology, Department of Precision and Regenerative Medicine and Ionian Area (DiMePRe-J), University of Bari “Aldo Moro”, Bari, Italy
| | - Elena Fontana
- Istituto di Ricerca Genetica e Biomedica (IRGB), National Research Council (CNR), Milan, Italy
- Human Genome and Biomedical Technologies Unit, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Sara Franzese
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
- Unit of Clinical and Experimental Immunology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Martina Defendi
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
- Unit of Clinical and Experimental Immunology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Fabio De Vincenzo
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Nadia Cordua
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Roberto Tamma
- Section of Human Anatomy and Histology, Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari “Aldo Moro”, Bari, Italy
| | - Federica Borea
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Marta Aliprandi
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Marco Airoldi
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Luigi Giovanni Cecchi
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Roberta Fazio
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Marco Alloisio
- Division of Thoracic Surgery, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Giuseppe Marulli
- Division of Thoracic Surgery, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Armando Santoro
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Luca Di Tommaso
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- Department of Pathology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Giuseppe Ingravallo
- Section of Pathology, Department of Precision and Regenerative Medicine and Ionian Area (DiMePRe-J), University of Bari “Aldo Moro”, Bari, Italy
| | - Laura Russo
- Clinical Laboratory, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Giorgio Da Rin
- Clinical Laboratory, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Anna Villa
- Istituto di Ricerca Genetica e Biomedica (IRGB), National Research Council (CNR), Milan, Italy
- San Raffaele Telethon Institute for Gene Therapy (SR-TIGET), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Silvia Della Bella
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
- Unit of Clinical and Experimental Immunology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Paolo Andrea Zucali
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Domenico Mavilio
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
- Unit of Clinical and Experimental Immunology, IRCCS Humanitas Research Hospital, Milan, Italy
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Winther JB, Morgen JJ, Skov M, Broch-Lips MG, Nielsen OB, Overgaard K, Pedersen TH. Role of recovery of acetylcholine release in compromised neuromuscular junction function. Neuromuscul Disord 2024; 36:48-59. [PMID: 38359767 DOI: 10.1016/j.nmd.2024.01.007] [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: 09/25/2023] [Revised: 12/17/2023] [Accepted: 01/22/2024] [Indexed: 02/17/2024]
Abstract
Everyday physical activities, such as walking, are enabled by repeated skeletal muscle contractions and require a well-functioning neuromuscular transmission. In myasthenic disorders, activities of daily living are debilitated by a compromised neuromuscular transmission leading to muscle weakness and fatiguability in patients. To enable physical activity, acetylcholine (ACh) is released repeatedly from the motor nerve, however, the role of the nerve terminals' capacity to sustain ACh release to support repetitive contractions under compromised neuromuscular transmission remains unclear. To explore this, we studied synaptic and contractile function during repeated contractions in healthy rat skeletal muscles under conditions of pharmacological induced compromised neuromuscular transmission. Using recordings of endplate potentials, compound muscle action potential (CMAP) and force production in isolated skeletal muscles and living, anesthetized animals, we found that force and CMAP were markedly reduced by even very light activity performed up to 5 s prior to contraction showing that recovery of ACh release was insufficient to maintain synaptic transmission strength. Our results suggest that the timing of depletion and restoration of ACh release may impact clinical signs of weakness and fatigability in patients with impaired neuromuscular transmission and affect the sensitivity of electromyographic recordings in the clinic.
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Affiliation(s)
| | | | - Martin Skov
- NMD Pharma A/S, Palle Juul-Jensens Blvd. 82, 8200 Aarhus N, Denmark
| | | | - Ole Bækgaard Nielsen
- Department of Public Health, Aarhus University, Bartholins Allé 2, 8000 Aarhus C, Denmark
| | - Kristian Overgaard
- Department of Public Health, Aarhus University, Bartholins Allé 2, 8000 Aarhus C, Denmark
| | - Thomas Holm Pedersen
- NMD Pharma A/S, Palle Juul-Jensens Blvd. 82, 8200 Aarhus N, Denmark; Department of Biomedicine, Aarhus University, Ole Worms Allé 4, 8000 Aarhus C, Denmark.
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4
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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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Andrapalliyal N, Claytor B, Li Y. Incidence and causes of overdiagnosis of myasthenia gravis. Muscle Nerve 2022; 67:464-468. [PMID: 36533968 DOI: 10.1002/mus.27774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 12/06/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022]
Abstract
INTRODUCTION/AIMS We have encountered non-myasthenic patients being given a diagnosis of myasthenia gravis (MG). This study aims to investigate the frequency of, and factors contributing to, overdiagnosis of MG. METHODS This is a retrospective analysis of patients referred to our tertiary neuromuscular center for evaluation due to a previously suspected/confirmed MG diagnosis during a 6-year span. RESULTS A total of 531 patients sought a second opinion regarding their MG diagnosis, and 77 (14.5%) were found to have non-myasthenic conditions. A total of 11 patients tested positive for acetylcholine receptor (AChR) antibodies. Repeated AChR antibodies became negative in five patients while in four patients, AChR binding antibody titers were persistently low. In seven patients, striational antibody was the only positive antibody identified. In 25 patients, a prior electrodiagnostic (EDX) study was deemed positive, including 14 patients with abnormal repetitive nerve stimulation (RNS) and 12 with abnormal single fiber electromyography (SFEMG). Technical issues were noted on prior RNS studies in 8 patients, and repeat RNS was negative in 10 patients. In eight patients with previously abnormal SFEMG, results showed minimal or equivocal abnormalities. In two patients, a repeat SFEMG was normal. Further analysis revealed atypical clinical presentation, deceptively positive ice pack test, clinically insignificant antibody result and misleading EDX finding as main contributors to MG overdiagnosis. DISCUSSION Overdiagnosis of MG is not uncommon, and occurs more frequently in seronegative patients. To make an accurate diagnosis of MG, there is a need to recognize atypical presentations, and avoid overreliance on minor or non-specific serological and electrodiagnostic findings.
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Affiliation(s)
- Nirmal Andrapalliyal
- Department of Neurology, Neurological Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Benjamin Claytor
- Department of Neurology, Neurological Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Yuebing Li
- Department of Neurology, Neurological Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
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6
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Monte G, Evoli A, Sanders DB, Modoni A. Neurophysiological challenges in myasthenia gravis associated with MuSK antibodies: a case report. Neurol Sci 2022; 43:4591-4593. [DOI: 10.1007/s10072-022-06013-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 03/13/2022] [Indexed: 11/29/2022]
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7
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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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8
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Huang K, Duan HQ, Li QX, Luo YB, Bi FF, Yang H. Clinicopathological-genetic features of congenital myasthenic syndrome from a Chinese neuromuscular centre. J Cell Mol Med 2022; 26:3828-3836. [PMID: 35670010 PMCID: PMC9279597 DOI: 10.1111/jcmm.17417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 05/13/2022] [Accepted: 05/20/2022] [Indexed: 12/28/2022] Open
Abstract
Congenital myasthenic syndrome (CMS) encompasses a heterogeneous group of inherited disorders affecting nerve transmission across the neuromuscular junction. The aim of this study was to characterize the clinical, physiological, pathohistological and genetic features of nine unrelated Chinese patients with CMS from a single neuromuscular centre. A total of nine patients aged from neonates to 34 years were enrolled who exhibited initial symptoms. Physical examinations revealed that all patients exhibited muscle weakness. Muscle biopsies demonstrated multiple myopathological changes, including increased fibre size variation, myofibrillar network disarray, necrosis, myofiber grouping, regeneration, fibre atrophy and angular fibres. Genetic testing revealed six different mutated genes, including AGRN (2/9), CHRNE (1/9), GFPT1 (1/9), GMPPB (1/9), PLEC (3/9) and SCN4A (1/9). In addition, patients exhibited differential responses to pharmacological treatment. Prompt utilization of genetic testing will identify novel variants and expand our understanding of the phenotype of this rare syndrome. Our findings contribute to the clinical, pathohistological and genetic spectrum of congenital myasthenic syndrome in China.
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Affiliation(s)
- Kun Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Institute of Molecular Precision Medicine and Hunan Key Laboratory of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Hui-Qian Duan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Qiu-Xiang Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yue-Bei Luo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Fang-Fang Bi
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
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9
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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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10
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Fatema K, Rahman M. Fast channel congenital myesthenic syndrome: Reporting two cases with mutation of CHRNE gene and short review. J Pediatr Neurosci 2022. [DOI: 10.4103/jpn.jpn_124_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Abstract
Neuroelectrophysiology is an old science, dating to the 18th century when electrical activity in nerves was discovered. Such discoveries have led to a variety of neurophysiological techniques, ranging from basic neuroscience to clinical applications. These clinical applications allow assessment of complex neurological functions such as (but not limited to) sensory perception (vision, hearing, somatosensory function), and muscle function. The ability to use similar techniques in both humans and animal models increases the ability to perform mechanistic research to investigate neurological problems. Good animal to human homology of many neurophysiological systems facilitates interpretation of data to provide cause-effect linkages to epidemiological findings. Mechanistic cellular research to screen for toxicity often includes gaps between cellular and whole animal/person neurophysiological changes, preventing understanding of the complete function of the nervous system. Building Adverse Outcome Pathways (AOPs) will allow us to begin to identify brain regions, timelines, neurotransmitters, etc. that may be Key Events (KE) in the Adverse Outcomes (AO). This requires an integrated strategy, from in vitro to in vivo (and hypothesis generation, testing, revision). Scientists need to determine intermediate levels of nervous system organization that are related to an AO and work both upstream and downstream using mechanistic approaches. Possibly more than any other organ, the brain will require networks of pathways/AOPs to allow sufficient predictive accuracy. Advancements in neurobiological techniques should be incorporated into these AOP-base neurotoxicological assessments, including interactions between many regions of the brain simultaneously. Coupled with advancements in optogenetic manipulation, complex functions of the nervous system (such as acquisition, attention, sensory perception, etc.) can be examined in real time. The integration of neurophysiological changes with changes in gene/protein expression can begin to provide the mechanistic underpinnings for biological changes. Establishment of linkages between changes in cellular physiology and those at the level of the AO will allow construction of biological pathways (AOPs) and allow development of higher throughput assays to test for changes to critical physiological circuits. To allow mechanistic/predictive toxicology of the nervous system to be protective of human populations, neuroelectrophysiology has a critical role in our future.
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Affiliation(s)
- David W Herr
- Neurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, CPHEA/ORD, U.S. Environmental Protection Agency, Washington, NC, United States
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12
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Pike-Lee T, Higginbotham D, Li Y. Direct comparison of median and ulnar repetitive nerve stimulation in generalized myasthenia gravis. Muscle Nerve 2021; 64:490-493. [PMID: 34196418 DOI: 10.1002/mus.27366] [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: 03/29/2021] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 11/11/2022]
Abstract
INTRODUCTION/AIMS Ulnar nerve repetitive nerve stimulation (RNS) has been traditionally used in the electrophysiological evaluation of myasthenia gravis (MG). However, its low diagnostic sensitivity remains a limitation. Existing data may suggest that median nerve RNS outperforms that of the ulnar nerve, but a direct comparison is currently lacking. The aim of this study was to directly compare the diagnostic yields between median and ulnar nerve RNS in patients with generalized MG. METHODS We performed a retrospective analysis of patients with MG who underwent median and ulnar nerve RNS at a single tertiary center. RESULTS RNS studies of median nerve recording from the abductor pollicis brevis and ulnar nerve recording from the adductor digiti minimi were completed in 28 patients with generalized MG. Abnormal RNS was more frequently observed in the median compared with the ulnar nerve (60.7% vs 35.7%, P = .046). The average magnitude of decrement was higher in the median nerve compared with the ulnar nerve (17.3% vs 9.6%, P = .017). Differences between the median and ulnar nerve RNS studies were restricted to patients with mild manifestations (Myasthenia Gravis Foundation of America class II). DISCUSSION Median nerve RNS has superior diagnostic sensitivity as compared with ulnar nerve RNS in the assessment of mild generalized MG.
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Affiliation(s)
- Tiffany Pike-Lee
- Neuromuscular Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Department of Neurology, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Dana Higginbotham
- Neuromuscular Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Yuebing Li
- Neuromuscular Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
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Padilla CJ, Harrigan ME, Harris H, Schwab JM, Rutkove SB, Rich MM, Clark BC, Arnold WD. Profiling age-related muscle weakness and wasting: neuromuscular junction transmission as a driver of age-related physical decline. GeroScience 2021; 43:1265-1281. [PMID: 33895959 PMCID: PMC8190265 DOI: 10.1007/s11357-021-00369-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/19/2021] [Indexed: 12/22/2022] Open
Abstract
Pathological age-related loss of skeletal muscle strength and mass contribute to impaired physical function in older adults. Factors that promote the development of these conditions remain incompletely understood, impeding development of effective and specific diagnostic and therapeutic approaches. Inconclusive evidence across species suggests disruption of action potential signal transmission at the neuromuscular junction (NMJ), the crucial connection between the nervous and muscular systems, as a possible contributor to age-related muscle dysfunction. Here we investigated age-related loss of NMJ function using clinically relevant, electrophysiological measures (single-fiber electromyography (SFEMG) and repetitive nerve stimulation (RNS)) in aged (26 months) versus young (6 months) F344 rats. Measures of muscle function (e.g., grip strength, peak plantarflexion contractility torque) and mass were assessed for correlations with physiological measures (e.g., indices of NMJ transmission). Other outcomes also included plantarflexion muscle contractility tetanic torque fade during 1-s trains of stimulation as well as gastrocnemius motor unit size and number. Profiling NMJ function in aged rats identified significant declines in NMJ transmission stability and reliability. Further, NMJ deficits were tightly correlated with hindlimb grip strength, gastrocnemius muscle weight, loss of peak contractility torque, degree of tetanic fade, and motor unit loss. Thus, these findings provide direct evidence for NMJ dysfunction as a potential mechanism of age-related muscle dysfunction pathogenesis and severity. These findings also suggest that NMJ transmission modulation may serve as a target for therapeutic development for age-related loss of physical function.
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Affiliation(s)
- Carlos J Padilla
- Division of Neuromuscular Diseases, Department of Neurology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Room 207, Columbus, OH, 43210, USA
| | - Markus E Harrigan
- Division of Neuromuscular Diseases, Department of Neurology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Room 207, Columbus, OH, 43210, USA
| | - Hallie Harris
- Division of Neuromuscular Diseases, Department of Neurology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Room 207, Columbus, OH, 43210, USA
| | - Jan M Schwab
- Division of Neuromuscular Diseases, Department of Neurology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Room 207, Columbus, OH, 43210, USA
- Belford Center for Spinal Cord Injury, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Physical Medicine and Rehabilitation, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Center for Brain and Spinal Cord Repair, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- The Neurological Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Seward B Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Mark M Rich
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH, 45435, USA
| | - Brian C Clark
- Department of Biomedical Sciences, Ohio Musculoskeletal and Neurological Institute, Athens, OH, 45701, USA
| | - W David Arnold
- Division of Neuromuscular Diseases, Department of Neurology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Room 207, Columbus, OH, 43210, USA.
- Department of Physical Medicine and Rehabilitation, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
- The Neurological Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
- Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
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14
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Evoli A, Iorio R. Controversies in Ocular Myasthenia Gravis. Front Neurol 2020; 11:605902. [PMID: 33329368 PMCID: PMC7734350 DOI: 10.3389/fneur.2020.605902] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 10/26/2020] [Indexed: 12/12/2022] Open
Abstract
Myasthenia gravis (MG) with symptoms limited to eye muscles [ocular MG (OMG)] is a rare disease. OMG incidence varies according to ethnicity and age of onset. In recent years, both an increase in incidence rate, particularly in the elderly, and a lower risk for secondary generalization may have contributed to the growing disease prevalence in Western countries. OMG should be considered in patients with painless ptosis and extrinsic ophthalmoparesis. Though asymmetric muscle involvement and symptom fluctuations are typical, in some cases, OMG can mimic isolated cranial nerve paresis, internuclear ophthalmoplegia, and conjugate gaze palsy. Diagnostic confirmation can be challenging in patients negative for anti-acetylcholine receptor and anti-muscle-specific tyrosine kinase antibodies on standard radioimmunoassay. Early treatment is aimed at relieving symptoms and at preventing disease progression to generalized MG. Despite the absence of high-level evidence, there is general agreement on the efficacy of steroids at low to moderate dosage; immunosuppressants are considered when steroid high maintenance doses are required. The role of thymectomy in non-thymoma patients is controversial. Prolonged exposure to immunosuppressive therapy has a negative impact on the health-related quality of life in a proportion of these patients. OMG is currently excluded from most of the treatments recently developed in generalized MG.
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Affiliation(s)
- Amelia Evoli
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Raffaele Iorio
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
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15
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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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16
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Shelly S, Paul P, Bi H, Dubey D, Milone M, Sorenson EJ, Crum BA, Laughlin RS, Liewluck T, Mandrekar J, Pittock SJ, Zekeridou A, McKeon A, Harper MC, Mills JR, Klein CJ. Improving accuracy of myasthenia gravis autoantibody testing by reflex algorithm. Neurology 2020; 95:e3002-e3011. [PMID: 32938782 DOI: 10.1212/wnl.0000000000010910] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 07/22/2020] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE To improve myasthenia gravis (MG) autoantibody testing. METHODS MG serologic tests with confirmatory or refuting clinical-electrodiagnostic (EDX) testing and cancer evaluations were reviewed over 4 years (2012-2015). All patients had acetylcholine receptor-binding (AChR-Bi), modulating (AChR-Mo), and striational (STR) autoantibody testing, and negatives reflexed to muscle-specific kinase (MuSK). Thymoma and cancer occurrences were correlated with STR and reflexed glutamic acid decarboxylase 65 (GAD65), ganglionic acetylcholine receptor (α3), collapsin response mediating protein-5, and voltage-gated potassium channel complex autoantibodies. RESULTS Of 433 samples tested, 133 (31%) met clinical-EDX criteria for MG. Best sensitivity (90%) occurred at AChR-Bi >0.02 nmol/L, leaving 14 negative (6 ocular MG, 7 generalized MG, 1 MuSK MG) with specificity 90% (31 false-positives). Using AChR-Mo antibodies (>20% loss), specificity was better (92%, 24 false-positives), but sensitivity dropped (85%). Specificity improved (95%) by testing AChR-Mo when AChR-Bi are positive, resulting in 45% reduction of false-positives (31-17), maintaining AChR-Bi 90% sensitivity. Cutoff values recommended by area under the curve analysis did not outperform this approach. AChR-Bi and AChR-Mo values were significantly higher in true-positives. CT evaluations in 121 MG samples revealed 16 thymomas. Historical or subsequent cancers occurred in 22. STR and reflexed autoantibodies were not more common in MG with thymoma or other cancers. Full-body CT (n = 34) was performed in those with STR and reflex autoantibody positivity, but without additional cancers found. CONCLUSION Accuracy of MG serologic testing is improved by reflexing AChR-Bi-positive cases to AChR-Mo. STR and other reflexed cancer evaluation autoantibodies did not provide value beyond standard CT chest imaging at the time of MG diagnosis. Diagnostic certainty is informed by AChR-Bi and AChR-Mo with higher values increasing specificity.
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Affiliation(s)
- Shahar Shelly
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Pritikanta Paul
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Hongyan Bi
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Divyanshu Dubey
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Margherita Milone
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Eric J Sorenson
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Brian A Crum
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Ruple S Laughlin
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Teerin Liewluck
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Jay Mandrekar
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Sean J Pittock
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Anastasia Zekeridou
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Andrew McKeon
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Michael C Harper
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - John R Mills
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN
| | - Christopher J Klein
- From the Departments of Neurology (S.S., P.P., H.B., D.D., M.M., E.J.S., B.A.C., R.S.L., T.L., S.J.P., A.Z., A.M., M.C.H., C.J.K.), Laboratory Medicine and Pathology (D.D., S.J.P., A.Z., A.M., J.R.M., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic Foundation, Rochester, MN.
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Abstract
PURPOSE OF REVIEW "Double vision" is a commonly encountered concern in neurologic practice; the experience of diplopia is always sudden and is frequently a cause of great apprehension and potential disability for patients. Moreover, while some causes of diplopia are benign, others require immediate recognition, a focused diagnostic evaluation, and appropriate treatment to prevent vision- and life-threatening outcomes. A logical, easy-to-follow approach to the clinical evaluation of patients with diplopia is helpful in ensuring accurate localization, a comprehensive differential diagnosis, and optimal patient care. This article provides a foundation for formulating an approach to the patient with diplopia and includes practical examples of developing the differential diagnosis, effectively using confirmatory examination techniques, determining an appropriate diagnostic strategy, and (where applicable) providing effective treatment. RECENT FINDINGS Recent population-based analyses have determined that diplopia is a common presentation in both ambulatory and emergency department settings, with 850,000 such visits occurring annually. For patients presenting to an outpatient facility, diagnoses are rarely serious. However, potentially life-threatening causes (predominantly stroke or transient ischemic attack) can be encountered. In patients presenting with diplopia related to isolated cranial nerve palsy, immediate neuroimaging can often be avoided if an appropriate history and examination are used to exclude worrisome etiologies. SUMMARY Binocular diplopia is most often due to a neurologic cause. The onset of true "double vision" is debilitating for most patients and commonly prompts immediate access to health care services as a consequence of functional impairment and concern for worrisome underlying causes. Although patients may seek initial evaluation through the emergency department or from their primary care/ophthalmic provider, elimination of an ocular cause will not infrequently result in the patient being referred for neurologic consultation. A logical, localization-driven, and evidence-based approach is the most effective way to arrive at the correct diagnosis and provide the best outcome for the patient.
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18
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Consideration of repetitive nerve stimulation of the median nerve in patients being evaluated for myasthenia gravis. Muscle Nerve 2019; 60:658-661. [DOI: 10.1002/mus.26713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 11/07/2022]
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19
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Timmermans G, Depierreux F, Wang F, Hansen I, Maquet P. Cosmetic Injection of Botulinum Toxin Unmasking Subclinical Myasthenia Gravis: A Case Report and Literature Review. Case Rep Neurol 2019; 11:244-251. [PMID: 31572161 PMCID: PMC6751432 DOI: 10.1159/000502350] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 07/26/2019] [Indexed: 11/19/2022] Open
Abstract
Cosmetic or therapeutic use of botulinum toxin type A (BoNT-A) is usually safe but can rarely cause iatrogenic botulism. Iatrogenic botulism and myasthenia gravis (MG) share similar clinical features, because both BoNT-A and anti-acetylcholine receptorantibodies impair neuromuscular transmission. We report a patient who underwent cosmetic BoNT-A injection and later developed serious local and systemic adverse reactions. The peculiarity of this case is that a latent seropositive MG was eventually discovered, suggesting that both iatrogenic botulism and MG contributed to the clinical picture. This patient is one of the less than 10 reported cases worldwide in whom MG was unmasked by BoNT-A injection. He is the first to be assessed in detail by single-fiber electromyography. This case emphasizes the risk associated with BoNT-A injection in patients with subclinical impairment of neuromuscular transmission and prompts the search for MG in case of exaggerated response.
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Affiliation(s)
- Grégory Timmermans
- Department of Neurology, University of Liège, CHU Sart-Tilman, Liège, Belgium
| | | | - François Wang
- Department of Neurophysiology, University of Liège, CHU Sart-Tilman, Liège, Belgium
| | - Isabelle Hansen
- Department of Neurology, University of Liège, CHU Sart-Tilman, Liège, Belgium
| | - Pierre Maquet
- Department of Neurology, University of Liège, CHU Sart-Tilman, Liège, Belgium
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20
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Italian recommendations for the diagnosis and treatment of myasthenia gravis. Neurol Sci 2019; 40:1111-1124. [PMID: 30778878 DOI: 10.1007/s10072-019-03746-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/31/2019] [Indexed: 12/30/2022]
Abstract
Myasthenia gravis is a well-treatable disease, in which a prompt diagnosis and an adequate management can achieve satisfactory control of symptoms in the great majority of patients. Improved knowledge of the disease pathogenesis has led to recognition of patient subgroups, according to associated antibodies, age at onset and thymus pathology, and to a more personalized treatment. When myasthenia gravis is suspected on clinical grounds, diagnostic confirmation relies mainly on the detection of specific antibodies. Neurophysiological studies and, to a lesser extent, clinical response to cholinesterase inhibitors support the diagnosis in seronegative patients. In these cases, the differentiation from congenital myasthenia can be challenging. Treatment planning must consider weakness extension and severity, disease subtype, thymus pathology, together with patient characteristics and comorbidities. Since most subjects with myasthenia gravis require long-term immunosuppressive therapy, surveillance of expected and potential adverse events is critical. For patients refractory to conventional immunosuppression, the use of biologic agents is highly promising. These recommendations are addressed to non-experts on neuromuscular transmission disorders. The diagnostic procedures and therapeutic approaches hereafter described are largely accessible in Italy.
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21
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Italian recommendations for diagnosis and management of congenital myasthenic syndromes. Neurol Sci 2018; 40:457-468. [PMID: 30554356 DOI: 10.1007/s10072-018-3682-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/10/2018] [Indexed: 12/11/2022]
Abstract
Congenital myasthenic syndromes (CMS) are genetic disorders due to mutations in genes encoding proteins involved in the neuromuscular junction structure and function. CMS usually present in young children, but perinatal and adult onset has been reported. Clinical presentation is highly heterogeneous, ranging from mild symptoms to severe manifestations, sometimes with life-threatening respiratory episodes, especially in the first decade of life. Although considered rare, CMS are probably underestimated due to diagnostic difficulties. Because of the several therapeutic opportunities, CMS should be always considered in the differential diagnosis of neuromuscular disorders. The Italian Network on CMS proposes here recommendations for proper CMS diagnosis and management, aiming to guide clinicians in their practical approach to CMS patients.
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22
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Zouari S, Kacem HH, Gheriani A, Farhat N, Hdiji O, Sakka S, Damak M, Mhiri C. Electromyography: Beyond positive diagnosis of myastenic syndrome. Neurophysiol Clin 2018. [DOI: 10.1016/j.neucli.2018.05.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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23
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French DM, Bridges EP, Hoskins MC, Andrews CM, Nelson CH. Myasthenic Crisis In Pregnancy. Clin Pract Cases Emerg Med 2017; 1:291-294. [PMID: 29849328 PMCID: PMC5965196 DOI: 10.5811/cpcem.2017.5.33404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/30/2017] [Accepted: 05/11/2017] [Indexed: 12/28/2022] Open
Abstract
This case reviews the management of a 27-year-old pregnant female in myasthenic crisis. She presented to the emergency department in respiratory distress refractory to standard therapy, necessitating airway and ventilatory support and treatment with plasmapheresis. Myasthenic crisis in the setting of pregnancy is rare and presents unique management challenges for emergency physicians.
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Affiliation(s)
- David M French
- Medical University of South Carolina, Emergency Medicine, Charleston, South Carolina
| | - E Page Bridges
- Greenville Health System, Emergency Medicine, Greenville, South Carolina
| | - Matthew C Hoskins
- Medical University of South Carolina, Emergency Medicine, Charleston, South Carolina
| | - Charles M Andrews
- Medical University of South Carolina, Emergency Medicine, Charleston, South Carolina.,Medical University of South Carolina, Neurocritical Care, Charleston, South Carolina
| | - Cecil H Nelson
- Medical University of South Carolina, Department of Obstetrics and Gynecology, Charleston, South Carolina
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Wang Y, Xiao Z, Chu H, Liang J, Wu X, Dong H, Yan Y, Lu Z. Correlations between slow-rate repetitive nerve stimulation and characteristics associated with amyotrophic lateral sclerosis in Chinese patients. J Phys Ther Sci 2017; 29:737-743. [PMID: 28533621 PMCID: PMC5430284 DOI: 10.1589/jpts.29.737] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Accepted: 01/17/2017] [Indexed: 11/24/2022] Open
Abstract
[Purpose] To clarify the features associated with decrements in compound muscle action
potentials (CMAP) during slow-rate repetitive nerve stimulation (RNS) of muscles involved
in amyotrophic lateral sclerosis (ALS) in mainland China. [Subjects and Methods] A
retrospective study of decremental responses to slow-rate RNS was performed to compare
patients with ALS to those with myasthenia gravis (MG). [Results] A significant decrement
(>5%) was observed in at least one muscle in 54% of ALS patients. The trapezius muscle
was the most commonly affected (67%). In the ALS group, the CMAP amplitude evoked by the
first stimulus was negatively correlated with the CMAP decrement in ulnar but not
accessory nerves. Additionally, a positive decrement was associated with disease
progression but not gender, age at onset, disease duration, region of onset, ALSFRS-R
scores, or ALS diagnostic subgroup in ALS. Furthermore, the incidence of positive
decrements and the decremental percentages were significantly higher in myasthenia gravis
(MG) than in ALS. [Conclusions] The lower CMAP amplitude by the first RNS stimulus was
more likely to induce a positive decrement in the ulnar nerve in ALS patients. The
positive decremental responses to RNS observed in ALS indicate the faster progress of the
disease, which is helpful for evaluating prognoses.
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Affiliation(s)
- Yan Wang
- Department of Neurology, Institution of Neuropsychiatry Research, Renmin Hospital of Wuhan University, China
| | - Zheman Xiao
- Department of Neurology, Institution of Neuropsychiatry Research, Renmin Hospital of Wuhan University, China
| | - Hong Chu
- Department of Neurology, Institution of Neuropsychiatry Research, Renmin Hospital of Wuhan University, China
| | - Jingjing Liang
- Department of Neurology, Institution of Neuropsychiatry Research, Renmin Hospital of Wuhan University, China
| | - Xu Wu
- Department of Neurology, Institution of Neuropsychiatry Research, Renmin Hospital of Wuhan University, China
| | - Hongjuan Dong
- Department of Neurology, Institution of Neuropsychiatry Research, Renmin Hospital of Wuhan University, China
| | - Yang Yan
- Department of Neurology, Renhe Hospital of Three Gorges University, China
| | - Zuneng Lu
- Department of Neurology, Institution of Neuropsychiatry Research, Renmin Hospital of Wuhan University, China
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Rigoni M, Montecucco C. Animal models for studying motor axon terminal paralysis and recovery. J Neurochem 2017; 142 Suppl 2:122-129. [PMID: 28326543 DOI: 10.1111/jnc.13956] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 12/16/2022]
Abstract
An extraordinary property of the peripheral nervous system is that nerve terminals can regenerate after damage caused by different physical, chemical, or biological pathogens. Regeneration is the result of a complex and ill-known interplay among the nerve, the glia, the muscle, the basal lamina and, in some cases, the immune system. This phenomenon has been studied using different injury models mainly in rodents, particularly in mice, where a lesion can be produced in a chosen anatomical area. These approaches differ significantly among them for the nature of the lesion and the final outcomes. We have reviewed here the most common experimental models employed to induce motor axon injury, the relative advantages and drawbacks, and the principal read-outs used to monitor the regenerative process. Recently introduced tools for inducing reversible damage to the motor axon terminal that overcome some of the drawbacks of the more classical approaches are also discussed. Animal models have provided precious information about the cellular components involved in the regenerative process and on its electrophysiological features. Methods and tools made available recently allow one to identify and study molecules that are involved in the crosstalk among the components of the endplate. The time-course of the intercellular signaling and of the intracellular pathways activated will draw a picture of the entire process of regeneration as seen from a privileged anatomical site of observation. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
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Affiliation(s)
- Michela Rigoni
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,CNR Institute of Neuroscience, Padua, Italy
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26
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van der Pijl EM, van Putten M, Niks EH, Verschuuren JJGM, Aartsma-Rus A, Plomp JJ. Characterization of neuromuscular synapse function abnormalities in multiple Duchenne muscular dystrophy mouse models. Eur J Neurosci 2016; 43:1623-35. [PMID: 27037492 DOI: 10.1111/ejn.13249] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 03/22/2016] [Accepted: 03/23/2016] [Indexed: 11/30/2022]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked myopathy caused by dystrophin deficiency. Dystrophin is present intracellularly at the sarcolemma, connecting actin to the dystrophin-associated glycoprotein complex. Interestingly, it is enriched postsynaptically at the neuromuscular junction (NMJ), but its synaptic function is largely unknown. Utrophin, a dystrophin homologue, is also concentrated at the NMJ, and upregulated in DMD. It is possible that the absence of dystrophin at NMJs in DMD causes neuromuscular transmission defects that aggravate muscle weakness. We studied NMJ function in mdx mice (lacking dystrophin) and wild type mice. In addition, mdx/utrn(+/-) and mdx/utrn(-/-) mice (lacking utrophin) were used to investigate influences of utrophin levels. The three Duchenne mouse models showed muscle weakness when comparatively tested in vivo, with mdx/utrn(-/-) mice being weakest. Ex vivo muscle contraction and electrophysiological studies showed a reduced safety factor of neuromuscular transmission in all models. NMJs had ~ 40% smaller miniature endplate potential amplitudes compared with wild type, indicating postsynaptic sensitivity loss for the neurotransmitter acetylcholine. However, nerve stimulation-evoked endplate potential amplitudes were unchanged. Consequently, quantal content (i.e. the number of acetylcholine quanta released per nerve impulse) was considerably increased. Such a homeostatic compensatory increase in neurotransmitter release is also found at NMJs in myasthenia gravis, where autoantibodies reduce acetylcholine receptors. However, high-rate nerve stimulation induced exaggerated endplate potential rundown. Study of NMJ morphology showed that fragmentation of acetylcholine receptor clusters occurred in all models, being most severe in mdx/utrn(-/-) mice. Overall, we showed mild 'myasthenia-like' neuromuscular synaptic dysfunction in several Duchenne mouse models, which possibly affects muscle weakness and degeneration.
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Affiliation(s)
- Elizabeth M van der Pijl
- Department of Neurology, Leiden University Medical Centre, Research Building S5-P, P.O. Box 9600 2300 RC, Leiden, The Netherlands
| | - Maaike van Putten
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Erik H Niks
- Department of Neurology, Leiden University Medical Centre, Research Building S5-P, P.O. Box 9600 2300 RC, Leiden, The Netherlands
| | - Jan J G M Verschuuren
- Department of Neurology, Leiden University Medical Centre, Research Building S5-P, P.O. Box 9600 2300 RC, Leiden, The Netherlands
| | - Annemieke Aartsma-Rus
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Jaap J Plomp
- Department of Neurology, Leiden University Medical Centre, Research Building S5-P, P.O. Box 9600 2300 RC, Leiden, The Netherlands
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27
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Evoli A, Iorio R, Bartoccioni E. Overcoming challenges in the diagnosis and treatment of myasthenia gravis. Expert Rev Clin Immunol 2015; 12:157-68. [PMID: 26675896 DOI: 10.1586/1744666x.2016.1110487] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In recent years, the discovery of new autoantigens and the use of sensitive assays have expanded the clinical spectrum of myasthenia gravis (MG). In particular, antibodies binding to clustered acetylcholine receptors and to the low-density lipoprotein receptor-related protein 4 have not only bridged a significant gap in diagnosis but also have relevant clinical implications. MG management includes different therapeutic options, from symptomatic agents as the only therapy in mildly affected cases to combined long-term immunosuppression and thymectomy in patients with severe disabling disease. MG biological diversity can influence the response to therapies and should be taken into account when planning treatment. Biologic agents are promising, though their use is currently limited to patients with refractory disease.
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Affiliation(s)
- Amelia Evoli
- a Institute of Neurology , Catholic University , Roma , Italy
| | - Raffaele Iorio
- a Institute of Neurology , Catholic University , Roma , Italy.,b Don Gnocchi ONLUS Foundation , Milan , Italy
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28
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Myasthenia gravis with presynaptic neurophysiological signs: Two case reports and literature review. Neuromuscul Disord 2015; 25:646-50. [DOI: 10.1016/j.nmd.2015.04.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/15/2015] [Accepted: 04/29/2015] [Indexed: 11/23/2022]
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29
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Abstract
Thymic malignancy is often associated with paraneoplastic neurological diseases (PNDs) and recognition of these disorders is important for physicians who treat these patients. The most common thymoma-associated PNDs are myasthenia gravis (MG), acquired neuromyotonia (Isaacs' syndrome), encephalitis, Morvan's syndrome, and myositis. Diagnosis of these disorders is complex but often aided by testing for specific autoantibodies, including those to the acetylcholine receptor for MG and to contactin-associated protein-like 2, protein of the voltage-gated potassium channel complex, in patients with acquired neuromyotonia, Morvan's syndrome, or encephalitis. Patients who manifest these disorders should be screened for thymoma at diagnosis, and worsening of these PNDs may be associated with recurrent thymoma. These disorders can cause profound disability but usually respond to immunotherapy, and often improve with thymoma treatment. Close cooperation among a team of specialists is required to take proper care of these patients.
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Abstract
PURPOSE OF REVIEW Infections are important, potentially treatable causes of peripheral nervous system disease. This article reviews the clinical presentation and management of several common peripheral nervous system diseases due to viral, bacterial, spirochetal, and parasitic infections. RECENT FINDINGS The clinical presentation and evaluation of infectious peripheral nervous system diseases are well established. Advances in the treatment and, in some cases, the prevention of these diseases are still evolving. SUMMARY A diverse range of peripheral nervous system diseases, including peripheral neuropathy, radiculopathy, radiculomyelopathy, cranial neuropathy, and motor neuropathy, are caused by numerous infectious agents. In some patients, peripheral neuropathy may be a side effect of anti-infectious drugs. Infectious neuropathies are important to recognize as they are potentially treatable. This article discusses the clinical presentation, evaluation, and treatment of several common peripheral nervous system diseases caused by viral, bacterial, spirochetal, and parasitic infections, as well as some peripheral nerve disorders caused by adverse effects of the treatments of these infectious diseases.
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Plomp JJ, Morsch M, Phillips WD, Verschuuren JJGM. Electrophysiological analysis of neuromuscular synaptic function in myasthenia gravis patients and animal models. Exp Neurol 2015; 270:41-54. [PMID: 25620417 DOI: 10.1016/j.expneurol.2015.01.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 01/07/2015] [Accepted: 01/16/2015] [Indexed: 12/21/2022]
Abstract
Study of the electrophysiological function of the neuromuscular junction (NMJ) is instrumental in the understanding of the symptoms and pathophysiology of myasthenia gravis (MG), an autoimmune disorder characterized by fluctuating and fatigable muscle weakness. Most patients have autoantibodies to the acetylcholine receptor at the NMJ. However, in recent years autoantibodies to other crucial postsynaptic membrane proteins have been found in previously 'seronegative' MG patients. Electromyographical recording of compound and single-fibre muscle action potentials provides a crucial in vivo method to determine neuromuscular transmission failure while ex vivo (miniature) endplate potential recordings can reveal the precise synaptic impairment. Here we will review these electrophysiological methods used to assess NMJ function and discuss their application and typical results found in the diagnostic and experimental study of patients and animal models of the several forms of MG.
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Affiliation(s)
- Jaap J Plomp
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands.
| | - Marco Morsch
- Motor Neuron Disease Research Group, Macquarie University, Sydney, Australia
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Tamburrini A, Tacconi F, Barlattani A, C. Mineo T. An update on myasthenia gravis, challenging disease for the dental profession. J Oral Sci 2015; 57:161-8. [DOI: 10.2334/josnusd.57.161] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Alessandro Tamburrini
- Thoracic Surgery Division, Multidisciplinary Myasthenia Gravis Unit, Tor Vergata University
| | - Federico Tacconi
- Thoracic Surgery Division, Multidisciplinary Myasthenia Gravis Unit, Tor Vergata University
| | | | - Tommaso C. Mineo
- Thoracic Surgery Division, Multidisciplinary Myasthenia Gravis Unit, Tor Vergata University
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