Introduction
It is a chronic autoimmune, neuromuscular disorder. The autoimmune condition, Myasthenia Gravis, impacts the neuromuscular junction. The symptoms include a generalised muscle weakness that might affect the breathing muscles and cause a myasthenic crisis, a severe medical emergency.
Symptoms of Myasthenia Gravis
Myasthenia gravis is characterised by fluctuating weakness of the skeletal muscle groups.
Below are the symptoms of Myasthenia gravis.
- Eye muscles weakness (Ocular myasthenia),
- One or both eyelids drooping (ptosis),
- Double vision or blurred vision (diplopia),
- A change in facial features,
- Difficulty in walking, chewing & swallowing.
- Shortness of breath
- Slurred speech (dysarthria)
Types of Myasthenia Gravis
The basic types of Myasthenia gravis include
- Ocular Myasthenia gravis - Patients with this type of MG, known as ocular MG, frequently experience double vision and eyelid droopiness as their eyes and eyelid muscles gradually weaken.
- Generalised Myasthenia gravis - This type of MG is characterised by generalised muscle weakness and fatigue that are not limited to the muscles of the eye and eyelids or any other particular muscle groups. Skeletal muscles & voluntary muscle weakness are noticeable, especially the muscles which involve eye movements, mouth, throat and limbs, which end up in whole body muscle weakness.
- Congenital Myasthenia gravis - According to estimates, 2–12 persons per million develop congenital MG, which is often inherited rather than brought on by an immune system problem in the body. Genetic defects in the genes involved in nerve-muscle communication, usually inherited from both parents, cause congenital MG.
Medications for Myasthenia Gravis
Following are the medications commonly prescribed for patients with Myasthenia gravis.
- Cholinesterase inhibitors (anticholinesterase - pyridostigmine and neostigmine) improve muscle strength.
- Immunosuppressants such as corticosteroids (Ex: prednisone) decrease inflammation.
- Monoclonal antibodies: Intravenous (IV) infusions of biologically engineered proteins – eculizumab, suppress an overactive immune system.
- IV immunoglobulin (IVIG)
- Plasma exchange (plasmapheresis)
Surgery for Myasthenia Gravis
Thymectomy can be recommended for all patients with thymomas (thymus tumour) and for patients with mild to moderate muscle weakness due to Myasthenia gravis.
Prevention of Myasthenia Gravis
To prevent Myasthenia gravis, people at risk for the disease and patients who receive immunosuppressive therapy are recommended to get a seasonal influenza vaccination. Studies show that people who received the influenza vaccine had a lower incidence of symptom aggravation than those with an influenza-like illness.
Conclusion
Myasthenia gravis (MG) is an uncommon autoimmune condition. Muscle weakness is the predominant symptom of MG.
The progression is variable, although three years after the initial onset of symptoms, the majority of patients with initial ocular weakness also have bulbar or limb weakness.
Due to advancements in diagnostic procedures, immunotherapy and intensive care, the prognosis today is good, with less than 5% mortality and with normal life expectancy.
Early detection, regular exercise, physiotherapy & prior vaccination will help better manage MG.
