MYASTHENIA GRAVIS (MG) is an autoimmune neuromuscular transmission disorder where well-defined autoantibodies against muscle and muscle cell membrane molecules are directly pathogenetic. Myasthenia gravis is characterized by weakness and rapid fatigue of any of the muscles under voluntary control.
1. Antibodies – Myasthenia gravis, the immune system produces antibodies that block or destroy many muscle receptor sites for a neurotransmitter called acetylcholine. With fewer receptor sites available, muscles receive fewer nerve signals, resulting in weakness. Antibodies can also block the function of a muscle -specific receptor tyrosine kinase.
2. Thymus gland – The thymus gland is part of the immune system located in the upper part of the chest below the sternum. The thymus gland triggers or maintains the production of antibodies that block acetylcholine. Large in infancy, the thymus gland is small in healthy adults. In some adults with myasthenia gravis, the thymus gland is unusually large.
Sign & symptoms
Muscle weakness caused by myasthenia gravis worsens as the affected muscle is used. Because symptoms usually improve with rest, muscle weakness can come and go. However, the symptoms tend to progress over time, usually reaching their worst within a few years after the onset of the disease.
1. Eye muscles
- Drooping of one or both eyelids (ptosis)
- Double vision (diplopia), which may be horizontal or vertical, and improves or resolves when one eye is closed
2. Face and throat muscles
- Impair speaking – Speech might sound soft or nasal, depending on which muscles have been affected.
- Cause difficulty swallowing – Might choke easily, making it difficult to eat, drink or take pills. In some cases, liquids will come out from the nose. Affect chewing. The muscles used for chewing might tire halfway through a meal, particularly being eating something hard to chew, such as steak.
- Change facial expressions – For example, a smile might look like a snarl.
3. Neck and limb muscles
- Myasthenia gravis can also cause weakness in the neck, arms and legs. Weakness in legs can affect walking. Weak neck muscles make it hard to hold up head.
WHAT ARE THE FACTORS THAT CAUSE YOU PAIN
- Myasthenia gravis – Myasthenia gravis occurs in all ethnic groups and both genders. In neonatal myasthenia, the fetus may acquire immune proteins (antibodies) from a mother affected with myasthenia gravis. Generally, cases of neonatal myasthenia gravis are temporary and the child’s symptoms usually disappear within 2-3 months after birth. Other children develop myasthenia gravis indistinguishable from adults. Myasthenia gravis in juveniles is uncommon.
- Myasthenia gravis – is not directly inherited nor is it contagious. Occasionally, the disease may occur in more than one member of the same family.
- Rarely, children may show signs of congenital myasthenia or congenital myasthenic syndrome. These are not autoimmune disorders, but are caused by defective genes that produce abnormal proteins instead of those which normally would produce acetylcholine, acetylcholinesterase (the enzyme that breaks down acetylcholine), or the acetylcholine receptor and other proteins present along the muscle membrane
myasthenia grevis TREATMENTS
- Balance strategy training – may effective in improving balance, enhance the vestibular function through targeting sensorimotor system to improve balance and decrease falling risk, moreover more research into this domain has to be done.
- Gradual resisted training exercises – is used to improve the specific muscle strength.
- Rarely, children may show signs of congenital myasthenia or congenital myasthenic syndrome. These are not autoimmune disorders, but are caused by defective genes that produce abnormal proteins instead of those which normally would produce acetylcholine, acetylcholinesterase (the enzyme that breaks down acetylcholine), or the acetylcholine receptor and other proteins present along the muscle membrane.