A cholinergic crisis is a serious condition associated with myasthenia gravis (MG). As its name suggests, in a cholinergic crisis there is too much acetylcholine at the meeting point between the nerves and the muscles, also known as the neuromuscular junction.
This creates a medical emergency that can potentially be life-threatening. People with MG should know the signs of a cholinergic crisis, so they can get care as soon as possible.
Understanding the role of acetylcholine
Acetylcholine is a neurotransmitter, a chemical that the nerves send to the muscles to signal for the muscles to contract. This transfer of signals takes place across the neuromuscular junction.
In MG, the body’s immune system creates antibodies that attack the acetylcholine receptors on the muscles. As such, the muscles cannot readily receive instructions from the nerves. It is this breakdown in nerve-muscle communication that causes muscle weakness in MG.
Read more about MG testing and diagnosis
To remedy this problem, doctors often prescribe a class of medications known as cholinesterase inhibitors. Cholinesterase breaks down acetylcholine at the neuromuscular junction. Inhibiting its action means higher levels of acetylcholine at the neuromuscular junction, which helps improve communication between nerves and muscles.
When cholinesterase inhibition goes overboard
Treatment in MG is all about finding the right balance.
There needs to be enough acetylcholine at the neuromuscular junction for effective communication between the nerves and the muscles. However, if there’s too much cholinesterase inhibition, the levels of acetylcholine can get too high. This creates a cholinergic crisis.
When this occurs, patience may experience a number of key symptoms:
- Muscle weakness with fasciculations (twitching).
- Bronchospasms, contractions of the airway muscles that leads to difficulty breathing.
- Excessive tearing of the eyes.
- Pinpoint pupils.
- Blurred vision.
- Drooling.
- Vomiting.
- Diarrhea.
- Abdominal cramping.
- Need for frequent urination.
The symptoms of a cholinergic crisis overlap with those of a myasthenic crisis, which can make it difficult to identify and treat the condition.
What to do next
If you think you are experiencing a cholinergic crisis, the most important thing to do is to seek emergency care. Let them know about your medical history and the medications that you are on.
If a cholinergic crisis is confirmed, doctors can administer therapies, such as atropine, that reverses many of the symptoms. At the hospital, they will additionally be able to monitor your vital signs closely to ensure that you’re clinically stable before discharge.
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