Myasthenia Gravis

What is Myasthenia Gravis?

Myasthenia Gravis is a chronic autoimmune neuromuscular disorder that causes weakness of voluntary muscles, which are responsible for actions such as talking, chewing, breathing, and walking. The hallmark feature of this condition is muscle weakness that worsens with activity and improves with rest.

Causes

Myasthenia Gravis occurs when the body’s immune system produces antibodies that block or destroy acetylcholine receptors at the neuromuscular junction—the site where nerves communicate with muscles. This disruption prevents proper signal transmission, resulting in weak muscle contractions.

Common Symptoms

Symptoms may vary in severity but commonly include:

• Drooping eyelids (ptosis)
• Double vision (diplopia)
• Difficulty swallowing or speaking
• Facial muscle weakness
• Fatigue affecting the arms, legs, or neck
• Shortness of breath, especially after physical exertion

Symptoms often worsen as the day progresses or with repeated muscle use and improve after rest. In severe cases, weakness of the respiratory muscles can lead to a myasthenic crisis, which is a medical emergency requiring immediate treatment.

Who is Affected?

Myasthenia Gravis can affect individuals of any age but is more commonly seen in:

• Women under 40 years of age
• Men over 60 years of age
• Individuals with a history of autoimmune disorders such as thyroid disease or rheumatoid arthritis

Diagnosis

Diagnosis of Myasthenia Gravis is based on the following investigations:

• Blood tests to detect antibodies such as anti-AChR or anti-MuSK
• Repetitive nerve stimulation studies
• CT scan or MRI of the chest to evaluate the thymus gland

Treatment

• Medications such as cholinesterase inhibitors and immunosuppressants
• Plasma exchange or intravenous immunoglobulin (IVIG), usually used in severe cases
• Thymectomy (surgical removal of the thymus), particularly when a thymoma is present

Prognosis

With appropriate treatment and lifestyle modifications, many individuals with Myasthenia Gravis are able to live full and active lives. Avoiding stress, infections, and excessive physical exertion can help reduce symptom flare-ups. Regular follow-up with a neurologist is essential to monitor disease progression and optimize treatment.