Muscle-Specific Tyrosine Kinase-Associated Myasthenia Gravis: A Neuromuscular Surprise

Myasthenia gravis is a neuromuscular autoimmune disease that results in skeletal muscle weakness that worsens after periods of activity and improves after rest. Myasthenia gravis means “grave (serious), muscle weakness.” Although not completely curable, it can be managed well with a relatively high quality of life and expectancy. In myasthenia gravis, antibodies against the acetylcholine receptors at the neuromuscular junction interfere with regular muscular contraction. Although most commonly caused by antibodies to the acetylcholine receptor, antibodies against MuSK (muscle-specific kinase) protein can also weaken transmission at the neuromuscular junction. Muscle-specific tyrosine kinase myasthenia gravis (MuSK-Ab MG) is a rare subtype of myasthenia gravis with distinct pathogenesis and unique clinical features. Diagnosis can be challenging due to its atypical presentation as compared to seropositive myasthenia gravis. It responds inconsistently to steroids, but plasma exchange and immunosuppressive therapies have shown promising results. We report a case of a 49-year-old female who presented with acute hypoxic respiratory failure. Our patient experienced progressive, undiagnosed MuSK-Ab MG for years without a diagnosis.

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Spinal Surgery- Use of Dexmedetomidine for Myasthenia Grvis - A Case Report

Liaquat National Journal of Primary Care ◽

10.37184/lnjpc.2707-3521.1.19 ◽

2020 ◽

Keyword(s):

Neuromuscular Junction ◽

Myasthenia Gravis ◽

General Anesthesia ◽

Muscle Weakness ◽

Spinal Surgery ◽

Acetylcholine Receptors ◽

Spinal Fixation ◽

Serum Autoantibody ◽

Upper And Lower Extremities ◽

Chronic Autoimmune Disease

Myasthenia gravis (MG) is a chronic autoimmune disease in which autoantibodies destroy acetylcholine receptors at motor end plat of neuromuscular junction which prevent skeletal muscle depolarization and contraction, causes muscle weakness and tiredness upon exertion with a tendency to be subsided after taking some rest or after taking anticholinesterase medication. Symptoms of progression of MG include the involvement of upper and lower extremities and muscle weakness that leads to inability in doing basic motor functions. The diagnosis of myasthenia gravis includes sign and symptoms, clinical examination and laboratory investigation of serum autoantibody (AChR autoantibodies) implicated in the disease pathology. Surgical procedures under general anesthesia in a patient with MG could be very challenging for an anesthetist because of pathophysiological manifestations of the disease. We report a case of a patient undergoing 4 level spinal fixation with coexistent myasthenia gravis (according to Osserman II B), requiring general anesthesia for spinal surgery in prone position. Myasthenia gravis affects the neuromuscular junction that is why it has a great significance of interest for the anesthetist.

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Myasthenia Gravis Patient Presenting for Ureteroscopy

Anesthesiology: A Problem-Based Learning Approach ◽

10.1093/med/9780190850692.003.0033 ◽

2018 ◽

pp. 287-294

Author(s):

Theresa J. Barnes ◽

Amanda Moraska Benson ◽

Ashish K. Khanna

Keyword(s):

Myasthenia Gravis ◽

Muscle Weakness ◽

Respiratory Insufficiency ◽

Nicotinic Acetylcholine Receptors ◽

Acetylcholine Receptors ◽

Neuromuscular Blocking ◽

Myasthenic Crisis ◽

Respiratory Impairment ◽

Skeletal Muscle Weakness ◽

Autoimmune Condition

Myasthenia gravis (MG) is an autoimmune condition, most commonly affecting middle-aged women and older males, caused by antibody-mediated attack of the postsynaptic nicotinic acetylcholine receptors at the neuromuscular junction. The resulting skeletal muscle weakness can be highly variable, ranging from fatigue of ocular muscles only to significant respiratory impairment with peripheral muscle weakness. MG has multiple important implications for anesthesiologists. This surgical case explores the pathophysiology of MG, common treatments, preoperative anesthetic assessment, intraoperative considerations, implications for anesthetic drug interactions, predictors of postoperative respiratory insufficiency, and a review of postoperative concerns and complications. Topics covered include myasthenic crisis, postoperative respiratory insufficiency, anticholinesterase, neuromuscular blocking drugs, thymectomy, and extubation criteria.

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MYASTHENIA GRAVIS: A SERUM FACTOR BLOCKING ACETYLCHOLINE RECEPTORS OF THE HUMAN NEUROMUSCULAR JUNCTION

The Lancet ◽

10.1016/s0140-6736(75)91886-3 ◽

1975 ◽

Vol 305 (7907) ◽

pp. 607-609 ◽

Cited By ~ 123

Author(s):

AdamN Bender ◽

W King Engel ◽

StevenP Ringel ◽

MathewP Daniels ◽

Zvi Vogel

Keyword(s):

Neuromuscular Junction ◽

Myasthenia Gravis ◽

Acetylcholine Receptors ◽

Serum Factor

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Neuromuscular Junction in Myasthenia Gravis: Decreased Acetylcholine Receptors

Science ◽

10.1126/science.182.4109.293 ◽

1973 ◽

Vol 182 (4109) ◽

pp. 293-295 ◽

Cited By ~ 449

Author(s):

D. M. Fambrough ◽

D. B. Drachman ◽

S. Satyamurti

Keyword(s):

Neuromuscular Junction ◽

Myasthenia Gravis ◽

Acetylcholine Receptors

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Other Proven and Putative Autoimmune Disorders of the Peripheral Nervous System

10.1093/med/9780199937837.003.0098 ◽

2017 ◽

Author(s):

Doris G. Leung

Keyword(s):

Neuromuscular Junction ◽

Myasthenia Gravis ◽

Nicotinic Acetylcholine Receptors ◽

Acetylcholine Receptors ◽

Autoimmune Disorder ◽

Synaptic Proteins ◽

Disease Treatment ◽

Nicotinic Acetylcholine ◽

System P ◽

Presynaptic Calcium

Myasthenia gravis is in most cases an autoimmune disorder of the neuromuscular junction in which antibodies are directed at nicotinic acetylcholine receptors or other synaptic proteins, such as the MusK protein that is involved in the formation of the formation and maturation of the motor endplate. Less commonly, myasthenia gravis can result from antibodies directed to presynaptic calcium channels as a side effect of paraneoplastic antibodies (Lambert-Eaton syndrome) or from a developmental paucity of acetylcholine receptors in the neonatal form of the disease. Treatment is usually a combination of aceetylcoholinesterase inhibitors such as pyridostigmine to prolong the life of acetylcholine released at the neuromuscular junction and/or drugs such as corticosteroids aimed at reducing inflammation.

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Auto-antibodies to the receptor tyrosine kinase MuSK in patients with myasthenia gravis without acetylcholine receptor antibodies

Nature Medicine ◽

10.1038/85520 ◽

2001 ◽

Vol 7 (3) ◽

pp. 365-368 ◽

Cited By ~ 721

Author(s):

Werner Hoch ◽

John McConville ◽

Sigrun Helms ◽

John Newsom-Davis ◽

Arthur Melms ◽

...

Keyword(s):

Tyrosine Kinase ◽

Myasthenia Gravis ◽

Acetylcholine Receptor ◽

Receptor Tyrosine Kinase ◽

Receptor Antibodies

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EFFECT OF PANCHKARMA IN MYASTHENIA GRAVIS: A CASE REPORT

November 2020 - International Ayurvedic Medical Journal ◽

10.46607/iamj0807302020 ◽

2020 ◽

Vol 8 (7) ◽

pp. 4003-4008

Author(s):

Atul Joshi ◽

Amit Awadhiya ◽

Neha Keshari ◽

Anup Thakar

Keyword(s):

Skeletal Muscle ◽

Case Report ◽

Side Effects ◽

Myasthenia Gravis ◽

Neuromuscular Disease ◽

Acetylcholine Receptors ◽

Present Observation ◽

Autoimmune Attack ◽

Skeletal Muscle Weakness

Myasthenia Gravis (MG) is a long-term neuromuscular disease that leads to varying degrees of skeletal muscle weakness. The condition is caused by breakdown in communication between nerves and muscles. The underlying defect is a decrease in the number of available acetylcholine receptors (AChRs) at neuro-muscular junctions due to an antibody mediated autoimmune attack.1 The most commonly affected mus-cles are those of the eyes, face and swallowing. The cause of this disease can be understood in view of Dhatavgnimaandhya, Vyana Vayu Vikriti. The present observation was conducted with an objective to find out the efficacy of Ayurvedic management in Myasthenia Gravis. Here is a case of 60 years old Hindu male who was diagnosed as Myasthenia Gravis (MG) reported with complaint of slurred speech, low pitch of voice, difficulty to open the mouth and to swallow food and difficulty in elevating right eyebrow since 6 months was registered in OPD of Panchakarma, IPGT & RA, Jamnagar. Considering the signs and symp-toms patient was treated on the line of Aavrita Vata Chikitsa, Sthanika Abhyanga with Bala Taila, Nasya with Anu Taila, Jihwa Pratisarana with Vacha Churna and Ghritapana before meal with Go Ghrita was administered. Treatment shows significant improvement in the symptoms without any side effects.

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Two patients with a neuroendocrine tumour of the small intestine and paraneoplastic myasthenia gravis

Endocrinology Diabetes and Metabolism Case Reports ◽

10.1530/edm-14-0013 ◽

2014 ◽

Vol 2014 ◽

Author(s):

M A W Hermans ◽

B M L Stelten ◽

H R Haak ◽

W W de Herder ◽

M W Dercksen

Keyword(s):

Small Intestine ◽

Myasthenia Gravis ◽

Acetylcholine Receptor ◽

Muscle Weakness ◽

Neuroendocrine Tumour ◽

Stage Iv ◽

List Type ◽

Bulbar Symptoms ◽

Receptor Antibodies ◽

Learning Points

Summary This paper reports on two patients with a long-standing diagnosis of an ENETS stage IV neuroendocrine tumour (NET) of the small intestine who developed neurological symptoms. The first patient only had bulbar symptoms and tested positive for acetylcholine receptor antibodies. The second patient had more classical symptoms of fatigable diplopia and muscle weakness of the legs, but no detectable antibodies. The diagnosis of paraneoplastical myasthenia gravis (MG) was postulated. Both patients were treated with pyridostigmine for MG and octreotide for the NETs. Interestingly, treatment of the NETs resulted in improvement of myasthenic symptoms. Paraneoplastic MG has been described to occur with certain malignancies, mainly thymoma. Herein, we prove that the association with gastrointestinal NETs, however, rare, is also one to be considered by clinicians dealing with either of these diseases. The pathogenesis has yet to be elucidated. Learning points NETs are rare malignancies with a wide variety of symptoms. Paraneoplastic MG can occur with various types of malignancies. Herein, we provide evidence of paraneoplastic MG in association with a grade IV NET of the small intestine. Treatment of the NETs resulted in remission of myasthenic symptoms in one patient.

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