Difficulty in abduction and lifting of upper limbs

Introduction Polymyositis manifests as difficulty in upper extremity abduction. The skeletal muscle pain and atrophy usually start from the proximal end, such as the pelvic muscle involvement, and it is difficult to go upstairs; the shoulder swelling is difficult to lift both arms, the development of the lesion can accumulate the whole body muscles; Dysphagia muscle involvement in dysphagia and dysarthria, a small number of patients may have difficulty breathing; muscles often involved in the acute phase of pain, muscle atrophy in the late stage; some patients may have arrhythmia and heart block.

Cause

The cause is unknown, and may be related to viral infection and immune function disorder. It is currently believed that this disease is a type III allergy (immune complex type) caused by activation of complement by an antigen-antibody complex. Viral infection may be an important stimulator, because CoxsakieA2 virus has been isolated from the muscle cells of patients with this disease, and inclusion bodies of myxovirus and parvovirus have also been seen. However, there is no epidemiological basis for the use of viruses as a source of infection.

an examination

Related inspection

Electromyography CT examination

Clinical manifestation

1. Symmetrical weakness of the proximal muscles of the extremities, squatting, standing up, difficulty climbing the stairs, difficulty lifting the hands.

2. The neck muscles, throat muscles are weak, difficult to look up, hoarseness, difficulty swallowing. Respiratory muscle weakness causes difficulty in breathing, purpura.

3. Myalgia, neck and shoulder, upper arm, forearm, thigh, calf are more common.

4. Muscle atrophy, more common in the proximal part of the limb.

5. Skin damage, such as edema and purple erythema on the head and face.

6. A small number of fever, joint pain and so on.

Diagnose based on

1. Symmetry of limbs is weak with tenderness;

2. The serum enzyme activity is increased, CPK and LDH are high, especially LDH is more sensitive;

3. See the spontaneous fibrillation potential and the positive phase spike on the EMG;

4. Muscle biopsy showed muscle fiber degeneration, necrosis, regeneration, inflammatory cell infiltration, vascular endothelial cell proliferation and so on.

History and symptoms: more common in women aged 20-40, some patients may have a history of infection before the disease, with symmetrical limb proximal muscle weakness, pain and tenderness. Can involve the pharyngeal muscles, respiratory muscles and neck muscles. In the advanced stage, there may be muscle atrophy. Some have skin or visceral damage, or have malignant tumors.

Physical examination revealed: the affected muscles were tender, weak, and had low sputum reflexes.

Auxiliary inspection:

1. Serum CPK, LDH, GOT increased, serum myoglobin content increased significantly, serum protein electrophoresis , r globulin and serum IgG, IgA, IgM increased. More than half of the patients have a rapid blood loss.

2. 24-hour creatinine excretion in urine can be significantly increased, >1000mg / 24 hours, and is related to the severity of the disease.

3. Electromyography: The insertion potential is prolonged, and there may be a strong myocardial discharge activity. When the light contraction, the average amplitude of the motor unit potential is reduced, the time limit is shortened, and a large number of fibrillation waves can be obtained. The multiphase wave increases, and the low amplitude interference phase or the pathological interference phase occurs when the contraction occurs.

4. Muscle biopsy: showing degeneration, necrosis, inflammatory cell infiltration, muscle fiber swelling, glass-like, granular or vacuolization, interstitial edema, infiltration of perivascular lymphocytes and plasma cells.

5. Electrocardiogram: abnormal rate can reach about 40%, tachycardia, myocardial inflammation, or arrhythmia.

Identification: need to be differentiated from muscular dystrophy, thyroid dysfunction, systemic lupus erythematosus.

Differential diagnosis

Stinging or numbness in the fingers or arms: Patients with cervical spinal stenosis complained that there are fingers (mostly at the fingertips) or pain and numbness in the arm when the disease is first developed, especially tingling. Sudden swelling and soreness in the upper limbs is one of the symptoms of deep venous thrombosis in the upper extremities. Upper extremity swelling is the earliest symptom that extends from the finger to the upper arm to the entire upper limb, and is more severe in the proximal side. Pain can occur at the same time as swelling, or it can only manifest as soreness, increased in the upper limbs, and sometimes in the form of a cord-like, tender thrombus. About 2/3 of the patients had venous congestion and the affected limbs changed in purple or blue-purple. Scapular and upper extremity pain is one of the main symptoms of primary brachial plexus or brachial plexus. Brachial plexus neuralgia refers to a disease in which the parts of the brachial plexus, which are composed of the anterior branch of the nerves of the neck 5 to the chest 1, are damaged, causing pain within the range of their control. Pain when pulling upper limbs and shoulders down or holding heavy objects: The most common first symptom of neck ribs is hand and shoulder dull pain, which is intermittent. Pain increases when the upper limbs and shoulders are pulled down, or when heavy objects are held in hand. The neck rib is a congenital deformed rib that can be caused by trauma, shoulder weight factors, and the like.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.