It refers to a sudden worsening of myasthenia symptoms, with progressive weakness or paralysis of the respiratory and swallowing muscles, which can be life-threatening.

bubble_chart Clinical Manifestations

According to the different disease causes that induce the crisis, it is divided into:

1. Myasthenic crisis:

Also known as the neostigmine deficiency crisis, often caused by infection, trauma, or dosage reduction. Respiratory muscle paralysis, weak coughing and swallowing, which can be life-threatening.

2. Cholinergic crisis:

Also known as the neostigmine overdose crisis. In addition to the symptoms of myasthenic crisis mentioned above, there are also symptoms of excessive acetylcholine accumulation:

① Muscarinic poisoning: nausea, vomiting, diarrhea, abdominal pain, small pupils, profuse sweating, salivation, excessive tracheal secretions, slow heart rate;

② Nicotinic poisoning symptoms: muscle tremor, spasms, tightness;

③ Central nervous system symptoms: anxiety, insomnia, mental confusion, spasm, etc.

3. Refractory crisis:

A crisis whose nature is difficult to distinguish and cannot be improved by stopping or increasing the drug dose, often occurring after long-term high-dose treatment.

bubble_chart Treatment Measures

Myasthenic crisis:

Neostigmine methylsulfate 1-2mg intramuscular injection or 0.5-1mg IV, total daily dose 6mg.

Cholinergic crisis:

Immediately discontinue anticholinesterase drugs, atropine 0.5-2mg IV or intramuscular injection, repeat every 15-30 minutes until muscarinic symptoms are relieved or disappear. To counteract nicotinic symptoms, pralidoxime 400-500mg in 5% glucose or normal saline IV drip until muscle relaxation is achieved.

Discontinue all anticholinesterase drugs for at least 3 days, then restart at half the original dose, while switching to or combining with corticosteroids.