What are the dangers of myasthenia gravis

Myasthenia gravis is relatively common in clinical practice. It is an autoimmune disease that occurs in people of all ages. The dangers of myasthenia gravis should also attract people's attention. This disease may cause changes in the patient's thymus.

1. Changes in the neuromuscular junction:

The morphological changes in the neuromuscular junction are the most characteristic changes in the pathology of myasthenia gravis, which are mainly manifested in: the wrinkles of the postsynaptic membrane disappear, become flat, or even rupture.

2. Muscle fiber changes:

In the early stage of the disease, lymphocyte infiltration, mainly small lymphocytes, is present between muscle fibers and around small blood vessels. This phenomenon is called lymphatic leakage. In acute and severe illness, muscle fibers have coagulative necrosis accompanied by infiltration of polymorphonuclear leukocytes and macrophages. In the late stage, muscle fibers may have varying degrees of denervation and become small.

3. Changes in the thymus:

About 30% of myasthenia gravis patients have thymoma, 40%-60% have thymic hypertrophy, and more than 75% have central hyperplasia of thymic tissue. Adenomas are divided into lymphocytic type, epithelial cell type, and mixed cell type according to their cell type. The latter two are often accompanied by myasthenia gravis.

4. Involvement of limb muscles:

When the upper limbs are affected, the arms cannot be raised, and combing the hair, brushing the teeth and dressing are difficult. When the lower limbs are affected, the first thing noticed is that the legs are weak when going up stairs, and lifting the lower limbs feels tired, which gradually develops into difficulty climbing stairs or getting on a bus, or you can get on a bicycle at the beginning, but before riding far, you fall down due to muscle weakness and difficulty getting off. In addition, you are prone to falling when going downstairs, and have difficulty standing up after squatting, etc.

5. Others

Patients with myasthenia gravis are prone to fatigue and often have better muscle strength in the morning. Symptoms worsen in the afternoon or evening. Most patients have extraocular muscles affected, with the levator palpebrae superioris being the most susceptible. As the disease progresses, more extraocular muscles may be affected, causing diplopia, and finally the eyeball may be fixed. Intraocular muscles are generally not affected. In addition, the muscles controlled by the medulla oblongata, neck muscles, shoulder girdle muscles, trunk muscles and upper and lower limbs muscles may all be affected. If you speak for too long, your voice will gradually become lower, your articulation will be unclear and nasal. Due to weakness of the mandible, soft palate, swallowing muscles and intercostal muscles, the chewing and swallowing functions may be affected and even breathing may become difficult.