Sign In

Myasthenia Gravis: Overview and Treatment

Myasthenia gravis is a neuromuscular transmission disorder characterized by weakness and increased fatigability of skeletal muscles. It is an autoimmune disease affecting approximately one in 2000 people, where antibodies against the α1 subunit of nicotinic acetylcholine receptors are produced.

These antibodies interfere with the function of the nicotinic receptors in three ways: by binding to the receptor and disrupting acetylcholine binding; by causing cross-linking of receptors which leads to their internalization and degradation; and by inducing the breakdown of the postsynaptic muscle membrane. This results in impaired neurotransmission, leading to drooping eyelids, double vision, difficulty swallowing (dysphagia), and speech difficulties (dysarthria). In severe cases, respiratory and limb muscles may also be affected.

The primary drugs used to manage the symptoms of myasthenia gravis are acetylcholinesterase (AChE) inhibitors. These include neostigmine, pyridostigmine, and ambenonium. These medications help increase the accumulation of acetylcholine in the synaptic cleft, which assists in depolarizing the endplate and improving muscle function. Thymectomy, the surgical removal of the thymus gland, is often recommended due to its potential role in the disease's development and the frequent presence of thymus gland tumors. Thymectomy can gradually improve motor symptoms and sometimes lead to complete remission. In severe cases, plasmapheresis may be necessary to remove circulating antibodies. Immunosuppressant medications such as azathioprine, cyclosporine, and glucocorticoids are used to target T-cells and reduce the production of anti-receptor antibodies, providing clinical benefits.

Tags
Myasthenia GravisNeuromuscular Transmission DisorderAutoimmune DiseaseAcetylcholine ReceptorsAntibodiesNeurotransmission ImpairmentDrooping EyelidsDouble VisionDysphagiaDysarthriaAcetylcholinesterase InhibitorsNeostigminePyridostigmineAmbenoniumThymectomyPlasmapheresisImmunosuppressants

From Chapter undefined:

article

Now Playing

Myasthenia Gravis: Overview and Treatment

Related Videos

596 Views

article

Autonomic Nervous System: Overview

Related Videos

1.7K Views

article

Neurochemical Transmission: Sites of Drug Action

Related Videos

1.3K Views

article

Classification of Neurotransmitters

Related Videos

1.7K Views

article

Cholinergic Neurons: Neurotransmission

Related Videos

974 Views

article

Cholinergic Receptors: Muscarinic

Related Videos

819 Views

article

Cholinergic Receptors: Nicotinic

Related Videos

1.2K Views

article

Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship

Related Videos

372 Views

article

Direct-Acting Cholinergic Agonists: Pharmacokinetics

Related Videos

690 Views

article

Direct-Acting Cholinergic Agonists: Pharmacological Actions

Related Videos

681 Views

article

Direct-Acting Cholinergic Agonists: Therapeutic Uses

Related Videos

317 Views

article

Cholinesterases: Distribution and Function

Related Videos

183 Views

article

Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship

Related Videos

245 Views

article

Indirect-Acting Cholinergic Agonists: Mechanism of Action

Related Videos

1.0K Views

article

Indirect-Acting Cholinergic Agonists: Pharmacokinetics

Related Videos

543 Views

See More

JoVE Logo

Privacy

Terms of Use

Policies

Research

Education

ABOUT JoVE

Copyright © 2024 MyJoVE Corporation. All rights reserved