Myasthenia Gravis in Children

Also known as: grave muscle weakness, MG.

What is myasthenia gravis?

Myasthenia gravis is an uncommon chronic autoimmune neuromuscular disease in children of all ages, ethnicities and genders. MG is characterized by muscle weakness of varying degree in many different areas of the body, it commonly affects the eyes, mouth, throat, arms and legs. MG tends to get worse during activity and improves after rest. There are 3 types of myasthenia gravis in children:

1. Transient Neonatal MG, a temporary form of MG that occurs in babies born to mothers with MG.
2. Juvenile MG, a lifelong autoimmune disorder that frequently occurs in white teenage girls.
3. Congenital MG, a very rare form which starts at birth, is lifelong, is not an autoimmune disease but is inherited from an abnormal gene received from each parent.

What causes myasthenia gravis?

What causes the autoimmune disorder to occur, is unknown.

What are the symptoms of myasthenia gravis?

1. In Transient Neonatal MG, babies have muscle weakness, difficulty sucking, or breathing which may require artificial mechanical breathing help. Transient Neonatal MG tends to improve over weeks to months as the mother's antibodies disappear normally over time.
2. Juvenile MG tends to start slowly over weeks. Typical signs include infants becoming tired after very little activity, or having difficulty chewing or swallowing. Droopy eyelids may be noted and all symptoms tend to be less in the morning and get worse as the day wears on.
3. Congenital MG presents with muscle weakness usually noted at or soon after birth, with delays in sitting, crawling or walking. There may be difficulty with swallowing and/or breathing with poor head control and droopy eyelids.

What are the treatment options for Myasthenia Gravis?

Transient Neonatal MG will improve over time and may or may not (depending on severity of symptoms) require treatment.

While no cure exists for the other forms of MG, the following are available to optimize your child’s health:

• Breathing support (assisted ventilation)
• Nutritional help
• Medications (acetylcholine esterase inhibitors-pyridostigmine)
• Intravenous high-dose immune globulin and/or steroids
• Plasmapharesis (to remove the abnormal antibodies from the blood)
• Thymectomy (surgical removal of the thymus gland) 

Reviewed by: Jack Wolfsdorf, MD, FAAP

This page was last updated on: November 06, 2023 04:05 PM