NCLEX Review & Nursing School

Myasthenia Gravis

– a neuromuscular disease characterized by a considerable weakness and fatigue of the voluntary muscles.

• There is a decrease and insufficient amount of acetycholine, while an excessive release of cholinesterase.

– The body inappropriately produces antibodies against acetylcholine nicotinic receptors, and thus inhibits proper acetylcholine signal transmission.

1. In the peripheral nervous system, acetylcholine activates muscles, and is a major neurotransmitter in the autonomic nervous system.
2. In the central nervous system, ACh has a variety of effects as a neuromodulator upon plasticity, it has an important role in the enhancement of sensory perceptions when we wake up and in sustaining attention.

Assessment:

• Weakness and Fatigue
• Dysphagia (difficulty swallowing)
• Respiratory paralysis (failure)

Medications includes:

• Neostigmine Bromide (Prostigmin)
• Pyridostigmine Bromide (Mestinon)
• Corticosteroids such as Prednisone

Surgical Interventions can include the removal of the thymus (Thymectomy)

* It is important to monitor respiratory status.

Damage to the cholinergic (acetylcholine-producing) system in the brain has been shown to be plausibly associated with with Alzheimer’s disease.

The Tensilon Test

– it is used to diagnose myasthenia gravis & is used to differentiate between myasthenia gravis and cholinergic crisis.

– Edrophonium (Tensilon) is first injected into client.

• On this test, the client is at risk for ventricular fibrillation and cardiac arrest, so it is important to prepare for this possibility.

Results:

Positive Sign for Myasthenia Gravis:

• Client Shows improvement, right after the administration of Tensilon

Negative Sign

• Patient shows no improvement after administration, and patient’s condition may be even worse.

Differentiate between Myasthenia gravis and Cholinergic Crisis:

• Myasthenia gravis- When Tensilon is administered, client’s condition improves.
• Cholinergic Crisis- When Tensilon is administered, client’s weaknes deteriorates and becomes more severe.

If accidentally over medicated the patient with Tensilon, administer “Atropine Sulfate” as antidote.

 

• ♣It is very important to have a proper respiratory management for the client ** since the weakness within the larynx can lead to aspiration and choking.