What Is Scalenus Syndrome?

Anterior oblique muscle syndrome refers to the syndromes that occur due to hypertrophic spasms of the anterior and middle oblique muscles or because of anatomical variations, which make the oblique muscle space smaller and squeeze the nerves and arteries that pass through.

Anterior oblique muscle syndrome refers to the syndromes that occur due to hypertrophic spasms of the anterior and middle oblique muscles or because of anatomical variations, which make the oblique muscle space smaller and squeeze the nerves and arteries that pass through.

The anterior scalene muscle is located deep outside the cervical spine, starting from the anterior nodule of the 3 to 6 transverse process of the cervical spine and ending at the scalene muscle nodule at the inner edge of the first rib. The medial scalene muscle is the longest and longest of the three scalene muscles, starting from the posterior nodule of the transverse process of the lower six cervical vertebrae, ending above the first rib, between the scalene muscle nodule and the subclavian groove. There is a triangular gap between the anterior and medial scalene muscles. The bottom of the gap is the first rib. The brachial plexus and the subclavian artery pass through the triangular gap.

Western Medicine Name

Anterior scalene syndrome

English name

scalenus (anticus) syndrome

Affiliated Department

Surgery-Orthopedics

Disease site

Cervical spine

The main symptoms

pain

Main cause

Anterior oblique muscle hypertrophy, the attachment point of the anterior oblique muscle causes the narrowing of the triangular gap

Multiple groups

Middle-aged

Contagious

Non-contagious

Anterior scalene syndrome treatment

The effect of conservative treatment is satisfactory. The local anesthetic is directly injected into the anterior oblique muscle. Massage has a certain effect. If conservative treatment is not effective, and the symptoms are intolerable, surgical treatment should be taken. The surgical method and approach can refer to cervical rib surgery. The cause and location of the compression of the brachial plexus and subclavian artery should be carefully examined during the operation. The scalene muscle is severed to isolate and relieve neurovascular compression.

Etiology of anterior scalene syndrome

This disease is related to the triangular gap formed by the neurovascular bundle through the oblique muscle.

Congenital malformation: The anterior medial scalene muscle is fused into one piece, so the brachial plexus must split the fibers of the anterior and medial scalene muscles to pass through.

Anterior oblique muscle hypertrophy can be primary or secondary to anterior oblique muscle spasm caused by brachial plexus stimulation.

The attachment point of the anterior scalene muscle causes the narrowing of the triangular space. The above three cases can make the neurovascular bundle compressed to produce oblique muscle syndrome.

Clinical manifestations of anterior scalene syndrome

Symptoms of anterior scalene muscles occur in middle-aged people. There are more women than men and more than the right side. Its symptoms vary depending on the tissue under pressure.

1. The pressure of the subclavian artery is ischemic, and the onset can be sudden, accompanied by soreness and discomfort. It starts from the neck and radiates to the hands and fingers. The numbness and tingling sensation are obvious, and there is no clear boundary of the pain. The movement of the cervical spine can aggravate the pain. When the neck is straightened, the oblique muscle space becomes smaller and thus the pain is aggravated. The neck flexion can enlarge the oblique muscle space and the pain can be relieved. Symptoms can be aggravated by traction of the affected limb to lower the scapula.

2. Compression of the brachial plexus This condition occurs in long-term lesions. The lower trunk of the brachial plexus is compressed, which is acute pain and radiates to the inside of the forearm and 4, 5 fingers.

3. Compression of the subclavian artery and brachial plexus nerve is the same as that of the cervical ribs.

Patients often use their hands to support the head and tilt it toward the affected side to relieve tension in the anterior oblique muscle. In the supraclavicular fossa, the anterior scalene muscle is tense and tender. Compression of muscles leads to severe tenderness and radiation pain, and straightening of the neck exacerbates pain. Sometimes there are allergies and colds, dyskinesias, and reflexes in the hands. Local anesthesia can relieve the spasm of the anterior scalene muscle and relieve symptoms.

Ancillary examination of anterior scalene syndrome

X-rays can be used to rule out deformities of the cervical and thoracic spine, such as abnormalities of the cervical ribs or the first ribs. Angiography is valuable for the diagnosis of this disease, and this method can also be used to locate the compression of the subclavian artery.