Muscular dystrophy classification

Muscular dystrophy, as the name suggests, refers to muscle malnutrition. Muscular dystrophy affects patients not only internally but also externally, as it causes patients to experience various strange symptoms on the outside. There are many types of muscular dystrophy, and the specific symptoms of different types of muscular dystrophy are different. Below, we will introduce the classification of muscular dystrophy in detail.

1. Pseudohypertrophy

It is an X-linked recessive inheritance and is the most common type. According to the national clinical manifestations, it can be divided into Duchenne type and Becker type.

1. Duchenne malnutrition (DMD): also known as severe pseudohypertrophic malnutrition, is almost only seen in boys. If the mother is a gene carrier, 50% of male offspring will develop the disease, usually starting at 2-8 years old. Initially, the patient feels clumsy in walking, prone to falling, unable to run and climb stairs. When standing, the spine is lordotic, the abdomen is protruding, the feet are apart, and the walking is slow and swaying, with a special "duck step" gait. It is very difficult to stand up from a supine position, and the patient must first turn over and lie prone, then climb over the knees with both hands, and gradually support himself to stand up (Gower sign). It can also be seen in the proximal muscles of the limbs, quadriceps and arm muscles.

2. Becker type (BMD): also known as benign pseudohypertrophic muscular dystrophy, often onset after the age of 10, the first symptoms are weak pelvic girdle and thigh muscles, slow progression, long course of the disease, after the onset of symptoms only years or more before the patient becomes unable to walk. Most do not develop paralysis at the age of 30-40 years old, and the prognosis is good.

2. Facioscapulohumeral type

It affects both men and women. The disease starts in young people during menstruation. First, the facial muscles are weak and often asymmetrical. The teeth cannot be shown, the lips are protruding, the eyes are closed, and the brows are frowned. The orbicularis oris muscle may have pseudohypertrophy, resulting in thickened lips and protruding lips. In some cases, the shoulder and humeral muscles are affected first, so that the arms cannot be raised and the shoulders are drooped. The upper arm muscles atrophy, but the forearm and hand muscles are not affected. The disease progresses very slowly, with frequent pauses or remissions.

3. Limb-girdle type

It occurs in both sexes, with onset in children or young adults, first affecting the pelvic girdle muscles and psoas major muscles, causing difficulty in walking, inability to climb stairs, a shaky gait, and frequent falls. In some cases, only the quadriceps femoris are affected. The disease progresses very slowly.

4. Other types

Quadriceps type, distal type, progressive basic extraophthalmoplegia type, oculomotor-pharyngeal muscle type, etc. are extremely rare.