scholarly journals Classification of myasthenia gravis and congenital myasthenic syndromes in dogs and cats

2020 ◽  
Vol 34 (5) ◽  
pp. 1707-1717
Author(s):  
Thomas Mignan ◽  
Mike Targett ◽  
Mark Lowrie
Keyword(s):  
Myasthenia Gravis ◽  
Congenital Myasthenic Syndromes ◽  
Myasthenic Syndromes

Congenital myasthenic syndromes: spotlight on genetic defects of neuromuscular transmission

2007 ◽  
Vol 9 (22) ◽  
pp. 1-20 ◽  
Author(s):  
Juliane S Müller ◽  
Violeta Mihaylova ◽  
Angela Abicht ◽  
Hanns Lochmüller
Keyword(s):  
Neuromuscular Transmission ◽  
Complex Structure ◽  
Molecular Classification ◽  
Synaptic Proteins ◽  
Congenital Myasthenic Syndromes ◽  
Different Types ◽  
Genes Encoding ◽  
Hereditary Disorders ◽  
Myasthenic Syndromes

AbstractThe neuromuscular junction (NMJ) is a complex structure that efficiently communicates the electrical impulse from the motor neuron to the skeletal muscle to induce muscle contraction. Genetic and autoimmune disorders known to compromise neuromuscular transmission are providing further insights into the complexities of NMJ function. Congenital myasthenic syndromes (CMSs) are a genetically and phenotypically heterogeneous group of rare hereditary disorders affecting neuromuscular transmission. The understanding of the molecular basis of the different types of CMSs has evolved rapidly in recent years. Mutations were first identified in the subunits of the nicotinic acetylcholine receptor (AChR), but now mutations in ten different genes – encoding post-, pre- or synaptic proteins – are known to cause CMSs. Pathogenic mechanisms leading to an impaired neuromuscular transmission modify AChRs or endplate structure or lead to decreased acetylcholine synthesis and release. However, the genetic background of many CMS forms is still unresolved. A precise molecular classification of CMS type is of paramount importance for the diagnosis, counselling and therapy of a patient, as different drugs may be beneficial or deleterious depending on the molecular background of the particular CMS.

scholarly journals Congenital myasthenic syndromes in adult neurology clinic

Neurology ◽  
2018 ◽  
Vol 91 (19) ◽  
pp. e1770-e1777 ◽  
Author(s):  
Justin C. Kao ◽  
Margherita Milone ◽  
Duygu Selcen ◽  
Xin-Ming Shen ◽  
Andrew G. Engel ◽  
...  
Keyword(s):  
Myasthenia Gravis ◽  
Clinical Laboratory ◽  
Age At Onset ◽  
Diagnostic Delay ◽  
Repetitive Nerve Stimulation ◽  
Congenital Myasthenic Syndromes ◽  
Muscle Diseases ◽  
Seronegative Myasthenia Gravis ◽  
Neurology Clinic ◽  
Myasthenic Syndromes

ObjectiveTo investigate the diagnostic challenges of congenital myasthenic syndromes (CMS) in adult neuromuscular practice.MethodsWe searched the Mayo Clinic database for patients with CMS diagnosed in adulthood in the neuromuscular clinic between 2000 and 2016. Clinical, laboratory, and electrodiagnostic data were reviewed.ResultsWe identified 34 patients with CMS, 30 of whom had a molecular diagnosis (14 DOK7, 6 RAPSN, 2 LRP4, 2 COLQ, 2 slow-channel syndrome, 1 primary acetylcholine receptor deficiency, 1 AGRN, 1 GFPT1, and 1 SCN4A). Ophthalmoparesis was often mild and present in 13 patients. Predominant limb-girdle weakness occurred in 19 patients. Two patients had only ptosis. Age at onset ranged from birth to 39 years (median 5 years). The median time from onset to diagnosis was 26 years (range 4–56 years). Thirteen patients had affected family members. Fatigable weakness was present when examined. Creatine kinase was elevated in 4 of 23 patients (range 1.2–4.2 times the upper limit of normal). Repetitive nerve stimulation revealed a decrement in 30 patients. Thirty-two patients were previously misdiagnosed with seronegative myasthenia gravis (n = 16), muscle diseases (n = 15), weakness of undetermined cause (n = 8), and others (n = 4). Fifteen patients received immunotherapy or thymectomy without benefits. Fourteen of the 25 patients receiving pyridostigmine did not improve or worsen.ConclusionMisdiagnosis occurred in 94% of the adult patients with CMS and causes a median diagnostic delay of nearly 3 decades from symptom onset. Seronegative myasthenia gravis and muscle diseases were the 2 most common misdiagnoses, which led to treatment delay and unnecessary exposure to immunotherapy, thymectomy, or muscle biopsy.

Neuromuscular Junction Disorders

2015 ◽  
Author(s):  
Anthony A Amato ◽  
Mohammad Kian Salajegheh
Keyword(s):  
Neuromuscular Junction ◽  
Myasthenia Gravis ◽  
Motor Nerve ◽  
Neuromuscular Disorders ◽  
Synaptic Cleft ◽  
Organophosphate Poisoning ◽  
Electric Currents ◽  
Repetitive Nerve Stimulation ◽  
Congenital Myasthenic Syndromes ◽  
Myasthenic Syndromes

The three main components of the neuromuscular junction (NMJ) include the presynaptic region, the synaptic cleft, and the postsynaptic region. The NMJ acts as an interface between the motor nerve and muscle by converting the motor nerve electric currents into chemical signals and then back into electric currents in the muscle. This chapter reviews electrodiagnostic testing in NMJ disorders, including repetitive nerve stimulation and single-fiber electromyography. Myasthenia gravis, congenital myasthenic syndromes, Lambert-Eaton myasthenic syndrome, botulism, and organophosphate poisoning and other toxins are discussed, including epidemiology, etiology/genetics, pathogenesis, diagnosis, differential diagnosis, management, complications, and prognosis. Tables include an overview of neuromuscular disorders, drugs with adverse effects on the NMJ, common immunomodulatory agents used for treatment of myasthenia gravis, congenital myasthenic syndromes, and toxins and venoms. Figures illustrate the NMJ structure and function, structure of the presynaptic and postsynaptic regions, electrodiagnostic studies in NMJ disorders, and dysfunction of the NMJ in acetylcholine receptor myasthenia gravis. This chapter contains 5 highly rendered figures, 5 tables, 65 references, and 5 MCQs.

scholarly journals Ephedrine for myasthenia gravis, neonatal myasthenia and the congenital myasthenic syndromes

2014 ◽  
Author(s):  
Charlotte Vrinten ◽  
Angeli M van der Zwaag ◽  
Stephanie S Weinreich ◽  
Rob JPM Scholten ◽  
Jan JGM Verschuuren
Keyword(s):  
Myasthenia Gravis ◽  
Congenital Myasthenic Syndromes ◽  
Myasthenic Syndromes

Neuromuscular Junction Disorders

2015 ◽  
Author(s):  
Anthony A Amato ◽  
Mohammad Kian Salajegheh
Keyword(s):  
Neuromuscular Junction ◽  
Myasthenia Gravis ◽  
Motor Nerve ◽  
Neuromuscular Disorders ◽  
Synaptic Cleft ◽  
Organophosphate Poisoning ◽  
Electric Currents ◽  
Repetitive Nerve Stimulation ◽  
Congenital Myasthenic Syndromes ◽  
Myasthenic Syndromes

The three main components of the neuromuscular junction (NMJ) include the presynaptic region, the synaptic cleft, and the postsynaptic region. The NMJ acts as an interface between the motor nerve and muscle by converting the motor nerve electric currents into chemical signals and then back into electric currents in the muscle. This chapter reviews electrodiagnostic testing in NMJ disorders, including repetitive nerve stimulation and single-fiber electromyography. Myasthenia gravis, congenital myasthenic syndromes, Lambert-Eaton myasthenic syndrome, botulism, and organophosphate poisoning and other toxins are discussed, including epidemiology, etiology/genetics, pathogenesis, diagnosis, differential diagnosis, management, complications, and prognosis. Tables include an overview of neuromuscular disorders, drugs with adverse effects on the NMJ, common immunomodulatory agents used for treatment of myasthenia gravis, congenital myasthenic syndromes, and toxins and venoms. Figures illustrate the NMJ structure and function, structure of the presynaptic and postsynaptic regions, electrodiagnostic studies in NMJ disorders, and dysfunction of the NMJ in acetylcholine receptor myasthenia gravis. This review contains 5 highly rendered figures, 5 tables, and 65 references.

Neuromuscular Junction Disorders

2015 ◽  
Author(s):  
Anthony A Amato ◽  
Mohammad Kian Salajegheh
Keyword(s):  
Neuromuscular Junction ◽  
Myasthenia Gravis ◽  
Motor Nerve ◽  
Neuromuscular Disorders ◽  
Synaptic Cleft ◽  
Organophosphate Poisoning ◽  
Electric Currents ◽  
Repetitive Nerve Stimulation ◽  
Congenital Myasthenic Syndromes ◽  
Myasthenic Syndromes

The three main components of the neuromuscular junction (NMJ) include the presynaptic region, the synaptic cleft, and the postsynaptic region. The NMJ acts as an interface between the motor nerve and muscle by converting the motor nerve electric currents into chemical signals and then back into electric currents in the muscle. This chapter reviews electrodiagnostic testing in NMJ disorders, including repetitive nerve stimulation and single-fiber electromyography. Myasthenia gravis, congenital myasthenic syndromes, Lambert-Eaton myasthenic syndrome, botulism, and organophosphate poisoning and other toxins are discussed, including epidemiology, etiology/genetics, pathogenesis, diagnosis, differential diagnosis, management, complications, and prognosis. Tables include an overview of neuromuscular disorders, drugs with adverse effects on the NMJ, common immunomodulatory agents used for treatment of myasthenia gravis, congenital myasthenic syndromes, and toxins and venoms. Figures illustrate the NMJ structure and function, structure of the presynaptic and postsynaptic regions, electrodiagnostic studies in NMJ disorders, and dysfunction of the NMJ in acetylcholine receptor myasthenia gravis. This review contains 5 highly rendered figures, 5 tables, and 65 references.

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