Adson's Test - Thoracic Outlet Syndrome

Can any one tell the correct procedure of ADSON'S TEST for thoracic out let syndrome. I have searched few websites giving different kinds of procedures

http://courses.washington.edu/hubio5...ary/adson.html telling this ----A test for the impingement of vascular structures at the thoracic outlet. The patient's arm is gradually elevated in an abduction arc while the examiner's fingers are held on the patient's radial pulse. As the arm is abducted, the patient is asked to turn his head away from the tested side and take a deep breath. If the pulse disappears as the arm is abducted beyond 90°, the test is positive for impingement. The test can be repeated with the head turned toward the side being examined.

http://www.fpnotebook.com/ORT63.htm telling-----

Indications
Evaluation of Thoracic Outlet Syndrome

Technique
Patient breathes deeply
Neck extended
Chin turned toward affected side
Repeat test with chin to opposite side

Interpretation
Positive test findings
Decreased Radial Pulse
Distal extremity pain reproduced
Positive test suggests interscalene compression

Disadvantages
Some false positive tests


I AM LITTLE CONFUSED WITH THESE .............

There are quite a few old posts on Thoracic Outlet Syndrome. Have a look in the TAGs section for this topic. Perhaps you could ask you question to one of those original posts as this will get people already involved answering ans assisting.

The Adson's manuever helps to identify a neurovascular component of the patient's symptoms. Adson's original description called for the patient to take a long breath, elevate his chin and turn it to the affected side, while seated upright, arms resting on the knees. This maximally elevated the first rib, compressing the neurovascular bundle against the elevated rib and taut muscle. A diminution or obliteration of the radial pulse or a change in blood pressure, established a positive test. Initially called " the vascular test", a positive response was considered a strong indication for scalenotomy.

I believe, the pulse change is not the only indication of a positive test. The S/S must be reproduced.

Gilard et al evaluated the diagnostic utility of the Adson test against electrophysiological studies, ultrasonography, helical computed tomography, and plain films. They reported a sensitivity of 79% and a specificity of 76% for the Adson test.

As with many clinical tests that is ok but not great news. It means 2 out of 10 patients who do have thoracic outlet syndrome you will miss with the test and likewise you will get about the same proportion of false positives. The way I would interpret that is that this can add weight to your clinical reasoning but you should also majorly take into account the history, particularly the symptoms that could be vascular in nature as well as other tests.

There is an alternative test: the hyperabduction test - diagnostic accuracy also reported in this study. With this test you can base it on symptom provocation or obliteration of a radial pulse. The accuracy was worse than Adsons particularly the specificity was very poor. However you could combine it with Adsons to try to lower the chance of false negatives with Adsons.

Gillard J, Perez-Cousin M, Hachulla E, et al. Diagnosing thoracic outlet syndrome: Contribution of provocative tests, ultrasonography,
electrophysiology, and helical computed tomography in 48 patients. Joint Bone Spine 2001;68:416-424.