Diagnosis of Myasthenia Gravis in Children

Myasthenia gravis in children is an extremely harmful disease. The occurrence of myasthenia gravis in children will not only affect the patient's daily activities but also cause the patient to lose his ability to work. In order for children to grow up healthily, we must pay enough attention to myasthenia gravis in children. We not only need to understand the symptoms of myasthenia gravis in children, but also need to know the prevention and treatment methods of myasthenia gravis in children. In addition, the diagnosis method of myasthenia gravis in children is also knowledge we need to know.

It has typical clinical features: fatigability and weakness of the affected skeletal muscles, which are relieved or disappear after rest or use of cholesterase inhibitors.

The diagnosis can only be confirmed if one of the following conditions is met:

1) Neostigmine methylsulfate drug test positive: 0.04 mg/kg each time, intramuscular injection. The dose for newborns is 0.1-0.15 mg, the common dose for children is 0.25-0.50 mg, the maximum dose is ≤1.00 mg, and improvement in muscle strength after 30 minutes is considered positive. Tensilon 0.2 mg/kg can also be injected intramuscularly, which can improve muscle strength within 1 minute and the effect lasts less than 5 minutes. However, due to the short duration of action of this drug and the difficulty in observing crying children, it is not suitable for infants and young children, but is suitable for children with severe MG or myasthenic crisis. During drug trials, if severe parasympathetic stimulation symptoms (intestinal colic, diarrhoea, bradycardia, etc.) occur, atropine sulfate 0.01 mg/kg can be used by intramuscular injection.

2) Repetitive nerve stimulation (RNS) positive: Use electromyograph to detect the facial, ulnar and median nerves. The stimulation frequencies were 1, 2, 3, 10 and 20 Hz and the duration was 3 s. The result was judged as positive if the attenuation of the amplitude of the fifth wave compared with the first wave was greater than or equal to 10%.

3) AchR-Ab test is positive. AchR-Ab positivity is important for the diagnosis of MG, but a negative result cannot rule out the disease. The AchR-Ab positivity rate in JMG children was 33%, which may be related to the fact that most children have the ocular muscle type and mild symptoms.

In the above article, we introduced what myasthenia gravis is in children. We know that myasthenia gravis in children is a very harmful disease. Parents should help their children prevent myasthenia gravis in daily life. The above article introduces the diagnosis method of myasthenia gravis in children in detail.