Myasthenia gravis in children symptoms causes and treatment

Myasthenia Gravis (MG) in children is a rare condition that causes muscle weakness, making it difficult for the child to move or control facial and eye muscles. The disease can appear at any age and usually requires close monitoring by a pediatric neurologist.In this Medical Guide, we will cover the causes of Myasthenia Gravis in children, its symptoms, types, stages of progression, risks, diagnostic methods, and the latest treatments including medications, surgery, and laser therapy. We will also provide important tips for parents to help manage their child’s condition and protect their overall health.If you notice any signs of muscle weakness in your child, this article will help you understand the disease quickly and guide you on when to consult your doctor.

Myasthenia Gravis in Children

Myasthenia Gravis (MG) in children is a rare disease that affects muscle strength, causing muscles to weaken quickly after activity, but improving with rest. The problem occurs due to a breakdown in communication between nerves and muscles, which makes muscles respond poorly to nerve signals.

Which Children Are at Risk?

A child is more likely to develop MG if:

The mother has Myasthenia Gravis.
There is a genetic predisposition or specific genetic changes in the parents.

Causes of Myasthenia Gravis in Children

1️⃣ Congenital or Genetic Causes

Some children are born with problems in muscle receptors for nerves (AChR).
This form is rare and usually appears at birth or during the first few months of life.

2️⃣ Autoimmune Causes (Acquired)

The immune system attacks muscle receptors or associated proteins (like MuSK).
This leads to weak and easily fatigued muscles.

3️⃣ Thymus Gland Problems

Some children have tumors or abnormalities in the thymus gland, which can trigger abnormal immune activity against muscles.

4️⃣ External Triggers

Viral or bacterial infections may trigger symptoms in children with a genetic predisposition.
Persistent fatigue can also reveal muscle weakness quickly.

Symptoms of Myasthenia Gravis in Children

1️⃣ Eye Symptoms (Ocular)

Ptosis (drooping eyelids): Most common symptom.
Diplopia (double vision): Seeing double after play or fatigue.
Difficulty moving the eyes in certain directions.

2️⃣ Face and Mouth Symptoms

Weak facial muscles: difficulty smiling or controlling facial expressions.
Dysphagia: Difficulty chewing or swallowing.
Dysarthria: Changes in voice tone or clarity.

3️⃣ Body and Neck Symptoms

Muscle weakness after activity, improving with rest.
Difficulty raising the head or arms.
Quick fatigue with simple movements.

4️⃣ General and Severe Symptoms

Breathing difficulties due to weak chest muscles.
General body weakness even after routine daily activities.

Types of Myasthenia Gravis in Children

1️⃣ Ocular Myasthenia Gravis

Affected muscles: Eyes and eyelids only.
Symptoms: Ptosis, diplopia.
Features: Other muscles usually remain normal. Symptoms may fluctuate with activity.
Note: Early diagnosis is important to prevent spread to other muscles.

2️⃣ Generalized Myasthenia Gravis

Affected muscles: Face, mouth, throat, neck, limbs, sometimes respiratory muscles.
Symptoms: Difficulty swallowing, facial weakness, arm and leg weakness, rapid fatigue, occasional breathing problems.
Risk: Higher than ocular type, requires close monitoring and prompt treatment.

3️⃣ Neonatal Myasthenia Gravis

Occurs in: Newborns due to antibodies transferred from an affected mother via the placenta.
Symptoms: Muscle weakness, difficulty feeding, ptosis, occasional breathing issues.
Features: Usually temporary, disappearing within weeks, but requires careful monitoring.

4️⃣ Congenital Myasthenic Syndromes

Cause: Genetic mutations affecting nerve-to-muscle signal transmission.
Symptoms: From birth or infancy, continuous muscle weakness, feeding and breathing difficulties, sometimes ongoing motor challenges.
Difference from autoimmune type: Not caused by antibodies, but by genetic defects in muscles or nerves.

Risks of Myasthenia Gravis in Children

1️⃣ Muscle weakness affecting daily life

Difficulty raising head or controlling arms and legs.
Rapid fatigue during daily activities.
Facial muscle weakness affecting expressions or smiling.

2️⃣ Eye problems

Ptosis may obstruct vision.
Diplopia affects focus and school performance.
Persistent eye fatigue may reduce concentration.

3️⃣ Swallowing and speech difficulties

Weak mouth and throat muscles cause trouble eating and swallowing.
May affect speech in younger children.
Severe cases risk choking during meals.

4️⃣ Breathing problems (most serious complication)

Weak chest and diaphragm muscles cause difficulty breathing.
May lead to a myasthenic respiratory crisis.

5️⃣ Psychological and social impact

Ongoing fatigue reduces activity and school participation.
Muscle weakness or appearance changes may cause embarrassment or social anxiety.

6️⃣ Treatment complications or delayed diagnosis

Some children require long-term immunosuppressive medications with potential side effects.
Delayed diagnosis increases symptom severity and risk of respiratory or swallowing complications.

Diagnosis of Myasthenia Gravis in Children

1️⃣ Medical History and Clinical Examination

Ask parents about onset, severity, and progression of symptoms.
Observe signs like ptosis, diplopia, and muscle weakness, especially after fatigue.
Test ability to raise head, use arms and legs, and overall movement.
Evaluate facial and oral functions: swallowing, speech, and smiling.

2️⃣ Blood Tests

AChR antibodies: Usually positive in most affected children.
Sometimes test for other antibodies like MuSK or muscle proteins as needed.

Diagnosis of Myasthenia Gravis in Children

3️⃣ Electrophysiological Tests

Electromyography (EMG): Measures how well muscles respond to nerve signals.
Repetitive Nerve Stimulation (RNS): Detects repeated muscle weakness during stimulation.

4️⃣ Drug Response Test

Edrophonium (Tensilon) Test: A short-acting drug that temporarily strengthens muscles.
Used under medical supervision to help confirm the diagnosis in certain cases.

5️⃣ Imaging

MRI or CT scans: To check for enlargement of the thymus gland or tumors associated with the disease.

6️⃣ Functional Assessment

Monitor swallowing, breathing, and speech to determine disease severity.
Assess the impact of the disease on the child’s daily life.

Treatment of Myasthenia Gravis in Children

1️⃣ Acetylcholinesterase Inhibitors

Example: Pyridostigmine.
Function: Increases acetylcholine at the neuromuscular junction, temporarily strengthening muscles.
Dosage: Adjusted according to the child’s weight and condition, under careful medical supervision.
Note: May cause increased saliva, nausea, or abdominal cramps.

2️⃣ Immunosuppressive Medications

Examples: Prednisone, Azathioprine (for severe cases).
Function: Reduce immune system activity attacking the muscles.
Typically used if symptoms persist despite acetylcholinesterase inhibitors.
Note: Close monitoring is necessary to prevent side effects from steroids or immune suppression.

3️⃣ Crisis Management

For a myasthenic crisis:
- The child may require IVIG (Intravenous Immunoglobulin) or Plasmapheresis temporarily.
- Goal: Temporarily reduce antibodies and protect breathing and swallowing.

4️⃣ Supportive Medications

Additional medications may be prescribed to treat inflammation or manage side effects depending on the child’s condition.

⚠️ Important Tips:

All medications must be supervised by a pediatric neurologist specialized in Myasthenia Gravis.
Continuous monitoring of muscles, breathing, swallowing, and growth is essential.
Dosages should be adjusted based on symptom severity and response to treatment.

Surgery and Laser Therapy for Myasthenia Gravis

In most cases, surgery or laser therapy is reserved for very specific cases, especially if there are thymus gland issues or to reduce neuromuscular complications.

1️⃣ Surgery

A. Thymectomy (Thymus Removal)

Indications: Children with antibodies against acetylcholine receptors, especially if the thymus is enlarged or has a benign tumor (Thymoma).
Goal: Remove the thymus to reduce antibody production attacking muscles and improve long-term symptoms.
Surgical methods:
- Traditional chest surgery (Median Sternotomy).
- Minimally invasive or robotic surgery (Minimally Invasive/Robotic) – less pain, faster recovery.
Notes: Results may take months to appear and are often better in younger children.

B. Correction of Musculoskeletal Complications

In rare cases, if MG causes neck or spine deformities due to continuous muscle weakness, surgical intervention may be needed to correct alignment.

2️⃣ Laser Therapy

Laser does not treat the underlying cause of MG (neuromuscular problem).
Sometimes used for:
- Skin complications, like pressure sores from supportive devices.
- Reducing scarring after thymus surgery.

⚠️ Post-Surgery Tips:

Continuous follow-up with a pediatric neurologist and thoracic surgeon.
Closely monitor breathing and muscle function.
Continue acetylcholinesterase inhibitors as recommended.
Protect the child from infections during recovery.

3️⃣ Surgical Failure

What is surgical failure?

No improvement in MG symptoms after surgery.
Persistent muscle weakness or rapid fatigue.
Ongoing breathing or swallowing problems.
Post-surgical complications making the condition unstable.

Causes of surgical failure:

Incomplete thymus removal → continued antibody production.
Late diagnosis or advanced disease → longer recovery or additional treatment needed.
Highly active antibodies → strong immune response may not respond easily to surgery.
Postoperative complications → infection, bleeding, poor wound healing.
Pre-existing muscle or nerve weakness → may persist and require additional treatment.

Signs of surgical failure:

Continued muscle weakness or rapid fatigue.
Breathing or swallowing difficulties after recovery.
Ongoing need for MG medications.
Symptoms do not improve or return shortly after surgery.

Managing surgical failure:

Close follow-up with a pediatric neurologist.
Evaluate muscle and respiratory function.
Additional medications: acetylcholinesterase inhibitors or corticosteroids as needed.
Re-evaluate the thymus: sometimes residual tissue needs removal later.
Physical therapy and muscle strengthening to improve movement and reduce fatigue.

Tips for Parents: Managing Myasthenia Gravis in Children

1️⃣ Continuous Medical Follow-Up

Child should be monitored by a pediatric neurologist specialized in MG.
Regular check-ups to track disease progression and treatment response.
Contact the doctor immediately if there are sudden changes in muscle strength or breathing.

2️⃣ Medication Adherence

Give medications exactly as prescribed without skipping doses.
Do not stop treatment without consulting the doctor, even if symptoms improve.
Monitor side effects and report any issues to the doctor.

3️⃣ Proper Nutrition

Meals rich in protein and vitamins to support muscle strength.
Avoid foods that strain digestion if the child has swallowing difficulties.
Divide meals into small, frequent portions to make swallowing and digestion easier.

4️⃣ Appropriate Physical Activity

Light exercises according to the child’s ability, avoiding overexertion.
Physical therapy is important to strengthen muscles and improve coordination.
Avoid strenuous activities or contact sports that may cause rapid muscle fatigue.

5️⃣ Rest and Adequate Sleep

Ensure sufficient and regular sleep to reduce muscle fatigue.
Schedule rest periods during the day, especially after activities or schoolwork.

6️⃣ Infection Prevention

Children with MG are more susceptible to infections that worsen muscle weakness.
Wash hands regularly and avoid contact with sick children.
Keep vaccinations up-to-date as recommended by the doctor.

7️⃣ Managing Respiratory Symptoms

Monitor for any breathing or swallowing difficulties as these are serious signs.
Learn basic respiratory first aid as instructed by the doctor.
Go to the emergency room immediately if sudden breathing difficulty or severe muscle weakness occurs.