Adson's sign

ADSON'S SIGN

 

Adson's sign is the loss of the radial pulse in the arm by rotating head to the ipsilateral side with extended neck following deep inspiration. This is accompanied by compression of the Subclavian artery by a cervical rib or tightened anterior and middle scalene muscles. Thoracic outlet obstruction may be caused by a number of abnormalities, including degenerative or bony disorders, trauma to the cervical spine, fibromuscular bands, vascular abnormalities, and spasm of the anterior scalene muscle. Symptoms are due to compression of the brachial plexus and subclavian vasculature, and consist of complaints ranging from diffuse arm pain to a sensation of arm fatigue, frequently aggravated by carrying anything in the ipsilateral hand or doing overhead work such as window cleaning.

Performed as follows

1. Patient in upright position.
2. Passively extend, abduct and externally rotate affected arm while palpating the radial pulse.
3. Ask patient to take a deep breath and hold it in.
4. Ask patient to extend neck and rotate the head towards affected side.

The test is positive if there is a marked decrease, or disappearance, of the radial pulse. It is important to check the patient's radial pulse on the other arm to recognize the patient's normal pulse. It is/was sometimes used as a sign of thoracic outlet syndrome (TOS). Adson's sign is no longer used as a positive diagnosis of TOS since many people without TOS will show a positive Adson's.

There is minimal evidence of interexaminer reliability.

It is named after Alfred Washington Adson.