What is it about ?
The term “myasthenia gravis” literally means “severe muscle weakness “. Myasthenia gravis is a rare disease. It is an autoimmune disease, in which the body produces antibodies against itself. In this case, these antibodies are directed against the substances which transmit nerve impulses to the muscles.
The nervous system consists of a central part (the brain, brainstem and spinal cord) and a peripheral part (the nerves). Motor nerves control movement, and sensory nerves transmit sensory information.
Nerve cells in the brainstem and spinal cord relate to muscles through nerves. The connection between the nerve and the muscle is called neuromuscular transmission. Myasthenia gravis is caused by an abnormality in neuromuscular transmission.
Impulses are no longer transmitted correctly from the nerves to the muscles, and as a result the muscles lose their strength. Muscles tire easily, which can go hand in hand with paralysis.
The symptoms and severity of myasthenia gravis vary greatly from person to person. Sometimes the disease is limited to a certain group of muscles, for example the muscles of the head. Often there is damage to the bulbar muscles which are necessary for speaking and for swallowing. These muscles are innervated by nerve branches coming from the brainstem. The symptoms are speech disturbances as well as a tendency to swallow askew.
Compared to the average population, people with myasthenia gravis have a higher risk of having other immune diseases (for example, thyroid problems).
What is its frequency?
Each year, there are 2 to 8 cases per million inhabitants. The disease mainly appears in people between the ages of 20 and 50.
In 70 to 80% of people with myasthenia gravis, the thymus gland is larger than normal. The thymus is a gland located in the neck.
In 15% of people with myasthenia gravis, muscle weakness affects only the muscles of the eyes.
How to recognize it?
The main symptoms are weak muscles and fatigue. Muscle weakness usually increases during exertion and improves after short rest.
If only the eyes are affected, the main symptom is double vision. Sometimes the person has droopy eyelids and they cannot open them anymore (blepharoptosis). In the event of an attack on the face, the facial expressions have disappeared. Making faces is impossible, as is hissing. Talking is tiring, and the person speaks from the nose.
The muscles of the neck and shoulders can tire extremely quickly, making it impossible to maintain certain postures and special efforts for long. The muscles of the limbs and hips can also become weak.
An infection (for example, pneumonia, sinusitis, tooth abscess, bladder infection …) can sometimes cause an attack of myasthenia gravis. In addition to pronounced muscle weakness, the person also has shortness of breath, as well as general symptoms such as fever, sweating, heart palpitations, and restlessness.
How is the diagnosis made?
Faced with the symptoms, the doctor will think of myasthenia gravis. If myasthenia gravis is suspected, the doctor will refer the person to a neurologist for further examination.
What can you do ?
There isn’t much you can do about the disease itself. But be aware that stress, emotions, and intense effort can make symptoms worse.
What can the doctor do?
Treatment involves suppressing the immune system. For this, cortisone or other drugs are administered over the long term. Medicines are also given to relieve symptoms.
In the event of generalized muscular damage, one often operates to remove the thymus. An improvement is then observed in 70% of the patients, and the symptoms disappear completely in 25% of the patients.
As infections can be acutely aggravating, special care should be taken. Good dental care can prevent abscesses, and an annual flu shot is recommended.
Another problem is the fact that many drugs are contraindicated in myasthenia gravis. These include morphine, cough medicines, certain antibiotics, certain sleeping pills, statins (cholesterol lowering drugs), several antihypertensives … So never take any medication without first asking your doctor if you can!
Ibuprofen and paracetamol are safe to use for muscle pain.
For the follow-up of pregnancy and childbirth, it is necessary to resort to a specialist. Breastfeeding can take place normally.
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