Two arms can not be lifted up and become drooping shoulders

Introduction Face-shoulder- muscular dystrophy: both men and women, adolescent onset, first facial muscle weakness, often asymmetry, can not show teeth, lips. Closed eyes and frowns, orbicularis can have pseudohypertrophy, As a result, the lips are thick and the lips are formed, and some of the shoulders and ankles are first affected, so that the arms cannot be lifted up and the upper arm muscles are atrophied, but the forearms and hand muscles are not invaded. The course of the disease is extremely slow and often frustrated or relieved.

Cause

(1) Causes of the disease

The disease is an autosomal dominant genetic disease, and there are also sporadic cases.

(two) pathogenesis

Wi Jmenga et al first confirmed that the FSHD gene is located on chromosome 4, and further studies have shown that it is located at 4q35. In 1992, the study found that the fragment after digestion with EcoR1 was detectable with a specific probe (p13E-11). Go to a DNA fragment that is shorter than the normal population. This short segment is less than 35 kb in length, while the normal population is 300 kb in length. 85% to 95% of patients with clinical diagnosis of FSHD (whether familial or sporadic) have confirmed the presence of short fragments. Many studies have shown that the greater the loss of the 4q35 region (the smaller the short segment formed), the more severe the clinical manifestations. In general, sporadic patients tend to develop earlier and have shorter episodes than familial patients. Although the relationship between the short 4q35 fragment and FSHD has been clarified, the precise gene mapping or the genes affected by this defect are not clear, and the exact relationship between the deletion and the disease is still unknown. One hypothesis is that the absence of heterochromatin leads to abnormal chromosome structure, which in turn changes the expression and function of genes in adjacent regions. Some FSHD patients have recombination in the vicinity of the missing site, supporting the above hypothesis. Therefore, the current research has turned to the establishment of genes on chromosome 4 and adjacent FSHD regions and their characteristics. In addition, some family patients with FSHD have nothing to do with chromosome 4, indicating that they are genetically heterogeneous.

an examination

Related inspection

Electromyography muscle tension test

The main laboratory indicators are as follows:

Serum CK

Serum CK is elevated in approximately 75% of patients, but is often moderately elevated.

2. Muscle biopsy

Muscle biopsy is critical for patients with suspected FSHD, especially those with inaccurate family history. Often showing varying degrees of change, including differences in fiber diameter, angular fibers appear, typically characterized by central nuclear fibers, necrotic fibers, regenerated fibers and hypertrophic fibers, mononuclear inflammatory cell infiltration, marked fat infiltration, and connective tissue proliferation.

3. Genetic diagnosis

Genetic testing is a useful diagnostic tool. The gene of FSHD is located at 4q35, and the 4q35 gene deletion has high sensitivity and specificity. It can be diagnosed by detecting 4q35 short fragments of suspicious patients. Especially those who have sporadic patients or patients with atypical clinical manifestations.

Electrocardiogram and electromyography should be performed. Electromyography examination showed that most of the patients with clinically affected muscles showed obvious multi-phase low-amplitude short-term action unit potential. ECG and EMG should be done.

Differential diagnosis

False fat large: X-linked recessive inheritance, is the most common type, according to clinical manifestations, can be divided into Duchenne type and Becker.

1. Duchenne type malnutrition (DMD): also known as severe pseudo-fat large-scale malnutrition, almost only seen in boys, if the mother is a gene carrier, 50% of male offspring, usually starting from 2-8 years old, The initial sense of walking benzene sputum, easy to fall, can not run and board the building, standing scalp, abdomen out, two feet open, walking slowly swinging, showing a special "duck step" gait, when walking from the back is very difficult, You must first roll over and prone, then climb your knees with both hands and gradually support the standing up (Gower sign). Can also be seen in the proximal muscles of the limbs, quadriceps and arm muscles.

2, Becker type (BMD): also known as benign pseudo-hypertrophic muscular dystrophy, often onset after 10 years of age, the first symptom is pelvic and femoral muscle weakness, slow progress, long course, 25 years after symptoms appear Or 25 years or more can not walk, most of them do not occur in the 30-40 years old, the prognosis is better.

Limb-type muscular dystrophy: both sexes, onset in children or youth, first affect the pelvic belt muscles and psoas muscle, walking difficulties, can not climb the stairs, gait swing, often fall, and some only affect the stock four The head muscles. The course of the disease is extremely slow.

Other types: quadriceps type, distal type, progressive extraocular muscle paralysis type, eye muscle-pharyngeal muscle type, etc., are rare.

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