Myasthenia Gravis
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Myasthenia gravis is a chronic autoimmune disorder that results in weak voluntary muscles, particularly in the face, throat, diaphragm, and bones. It can cause eye/eyelid and facial weakness, and in more extreme cases can even lead to difficulty swallowing and breathing. Although the cause is unknown, myasthenia gravis is thought to be a result of both genetic and environmental factors. It is a treatable condition.
Clinical features
Muscle fatigueness is the key feature of myasthenia gravis. This condition is usually chronic as the muscles become weaker over time. Ocular myasthenia occurs when the eyes/eyelids are impacted. This condition can be unilateral or bilateral and can result in droopy lids and sometimes double vision. Beyond the eyes, symptoms can include difficulty in speech, walking, and in the arms and legs weakness. In more severe cases, patients can have difficulty swallowing and breathing.
Pathophysiology
The primary cause of myasthenia gravis is an autoimmune weakness where antibodies act against proteins. At the neuromuscular junction involving the nerves and the muscles, receptors typically conduct electrical impulses from the nerves to the muscle. Under the condition of myasthenia gravis, these receptors are blocked, resulting in muscle weakness and tiredness. A genetic abnormality within the thymus gland is also thought to result in this condition.
Diagnosis
In Idaho Eyelid and Facial Plastic Surgery, ocular myasthenia gravis is diagnosed through understanding a patient’s clinical history and conducting a physical examination. A relatively simple exam is conducted at the office, and involves patients focusing upwards by exclusively elevating their eyes but fixing the position while keeping their head still. Within a short timeframe, their eyelid muscles weaken and the condition of ptosis becomes apparent. Other tests to identify myasthenia gravis include blood panels to detect antibodies, electromyography tests to assess nerve impulses, and edrophonium tests. The latter utilizes an injection of edrophonium chloride to temporarily reverse ptosis in myasthenia gravis patients.
Treatment
Myasthenia gravis is managed thought treatment and many patients can go on to live normal and active lives. At Idaho Eyelid and Facial Plastic Surgery, treatment includes medication and/or surgery. Medication options include small doses of acetylcholinesterase inhibitors/immunosuppressants to manage muscle weakness (neostigmine and pyridostigmine). Steroids, such as mycophenolate mofetil and azathioprine, can also be beneficial. For ocular myasthenia gravis, ptosis surgery to tighten eyelids may be performed. Removal of the thymus gland (thymectomy) can also be considered at other practices. In addition, plasmapheresis, a procedure that helps remove antibodies from the blood, and lifestyle modifications, reduce stress and increase rest, can have some benefit.
Conclusion
Myasthenia gravis is a condition that results in muscle weakness, and ocular myasthenia gravis results in eyelid weakness and droopiness. Diagnosis at Idaho Eyelid and Facial Plastic Surgery is straightforward, and treatment options are available.
