What is cholinergic crisis in myasthenia gravis?
Cholinergic crisis is secondary to excess cholinesterase inhibitor medication. In these cases, excessive Ach stimulation of striated muscles at the neuromuscular junction produces flaccid muscle paralysis that can be clinically indistinguishable from weakness due to myasthenia crisis.
What is the difference between myasthenic crisis and cholinergic crisis?
Cholinergic crisis is when there is no improvement or worsening of weakness when edrophonium is administered. Myasthenic crisis is when there is improvement with a small dose of edrophonium.
Which characteristic is common to both myasthenic and cholinergic crises?
Both myasthenic crisis and cholinergic crisis may cause bronchospasm with wheezing, bronchorrhea, respiratory failure, diaphoresis, and cyanosis.
How do you manage a cholinergic crisis?
A cholinergic crisis should be treated by withdrawing all anticholinesterase medication, mechanical ventilation if required, and atropine i.v. for muscarinic effects of the overdose. The neuromuscular block is a nicotinic effect and will be unchanged by atropine.
How does Edrophonium differentiate myasthenia gravis from cholinergic crisis?
Edrophonium (by the so-called Tensilon test) is used to differentiate myasthenia gravis from cholinergic crisis and Lambert-Eaton. In myasthenia gravis, the body produces autoantibodies which block, inhibit or destroy nicotinic acetylcholine receptors in the neuromuscular junction.
What triggers myasthenic crisis?
Myasthenia crisis may be caused by a lack of medicine or by other factors, such as a respiratory infection, emotional stress, surgery, or some other type of stress. In severe crisis, a person may have to be placed on a ventilator to help with breathing until muscle strength returns with treatment.
What happens during a cholinergic crisis?
Excessive accumulation of acetylcholine (ACh) at the neuromuscular junctions and synapses causes symptoms of both muscarinic and nicotinic toxicity. These include cramps, increased salivation, lacrimation, muscular weakness, paralysis, muscular fasciculation, diarrhea, and blurry vision.
What is edrophonium?
EDROPHONIUM (ed ruh FOH nee uhm) works on the nervous system of the body. It is used to test for muscle response and to diagnose myasthenia gravis. It is also used to check for a response to drug therapy in patients with myasthenia gravis.
What are the side effects of cholinergic agents?
WHAT ARE SIDE EFFECTS OF CHOLINERGIC AGONISTS?
- Bone marrow suppression.
- Sore throat.
- Blurred vision.
- Increased sweating and salivation.
- Increased urinary frequency.
- Rash.
- Fever.
- Dry mouth.
What is an example of cholinergic?
Examples of direct-acting cholinergic agents include choline esters (acetylcholine, methacholine, carbachol, bethanechol) and alkaloids (muscarine, pilocarpine, cevimeline).
What is a cholinergic crisis?
Cholinergic crisis is a clinical condition that develops as a result of overstimulation of nicotinic and muscarinic receptors at the neuromuscular junctions and synapses.