Myasthenia Gravis

What Is Myasthenia Gravis?

Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disease that causes weakness in skeletal muscles. The immune system produces antibodies that block or destroy acetylcholine receptors at the neuromuscular junction, disrupting the signal between nerves and muscles.¹

Symptoms²

Ocular Symptoms

Ptosis (drooping eyelids)
Diplopia (double vision)
Often the first symptoms
May remain only ocular in some

Generalized Symptoms

Facial muscle weakness
Difficulty chewing and swallowing
Slurred speech
Limb weakness (arms often before legs)
Breathing difficulties (in severe cases)

Key Characteristic

Weakness worsens with activity
Improves with rest
Fluctuates throughout day
Worse in evening or after exertion

Diagnosis

Acetylcholine receptor antibody test
MuSK antibody test
Edrophonium (Tensilon) test
Nerve conduction studies
CT or MRI of chest (thymus evaluation)

Treatment³

Medications

Cholinesterase inhibitors (pyridostigmine)
Corticosteroids
Immunosuppressants (azathioprine, mycophenolate)
Newer biologics available

Other Treatments

Thymectomy (thymus removal)
Plasmapheresis (plasma exchange)
Intravenous immunoglobulin (IVIG)

Myasthenic Crisis

Life-threatening breathing weakness
Requires immediate medical attention
May need ventilator support
Often triggered by infection or medication changes

Living with MG

Plan activities for times of peak strength
Take rest breaks throughout day
Avoid extreme temperatures
Be aware of medications that worsen MG
Wear medical alert identification
Regular follow-up with neurologist

References

Gilhus NE, Tzartos S, Evoli A, et al. Myasthenia gravis. Nat Rev Dis Primers. 2019;5(1):30.
Meriggioli MN, Sanders DB. Autoimmune myasthenia gravis: emerging clinical and biological heterogeneity. Lancet Neurol. 2009;8(5):475-490.
Sanders DB, Wolfe GI, Benatar M, et al. International consensus guidance for management of myasthenia gravis. Neurology. 2016;87(4):419-425.