The Pneumatic Compression test and Modified Pneumatic Compression test in the diagnosis of Carpal Tunnel Syndrome

Carpal Tunnel Syndrome (CTS) can be assessed and diagnosed in several ways.
Mike Hayton uses a combination of an accurate history of the patients' symptoms, combined with clinical examination and often nerve conduction studies.
Clinical examination testing has been proven to be an accurate measure at diagnosing CTS. Phanel's, modified Phanel's, Tinel's signs and Pneumatic compression tests are commonly used.

Nerve conduction studies are often performed to compare the speed of electrical currents of the median nerve, compared with other nerves in the hand and forearm.
However authors of this study were looking to compare the Pneumatic compression test and the more recent modified Pneumatic compression test.
The Pneumatic compression test is performed by wrapping a pressure cuff around the wrist and inflating it to 100mm/Hg for 30 seconds. The modified Pneumatic test follows the same principles, in addition inserts a pencil like object underneath the cuff, 8cm in length and 8mm in diameter, placed in the carpal region to apply pressure along the median nerve.

A group of 37 participants with 50 symptomatic hands were recruited. Another group of 50 healthy participants were recruited as a control group.
Each symptomatic participant was diagnosed via electrophysiological testing.
The clinical tests performed and compared on each patient were Phalen's, Tinel's, Pneumatic compression and modified Pneumatic compressions testing.
Results show the modified Pneumatic compression test was positive in 47 hands. 40 hands were positive from the pneumatic compression test. Tinel's sign was positive for 34 hands and Phalen's test was positive for 35 hands.
This study suggests the modified Pneumatic compression test was the most sensitive in diagnosing CTS.
These clinical tests were repeated on the control group, none of whom showed symptoms of CTS. Phalen's test and Tinel's sign were both negative in diagnosing any symptoms of CTS. However, one participant had a positive Pneumatic compression test, compared with a positive modified Pneumatic compression test in four participants.
Nerve conduction studies identified positive findings for median nerve compression in the carpal tunnel in eight normal participants.

Authors of this study found the modified Pneumatic compression test to be the most sensitive, at 94% and the most specific at diagnosing CTS, with 92% specificity.

In Mike Hayton's clinical practice, he performs the modified Phalen's test (click here to view video) and also the Tinel's test (click here to view video). He often arranges nerve conduction studies to add further evidence to the diagnosis if in doubt.

Tekeoglu. I., Dogan. A., Demir. G., and Dolar. E.
Journal of Hand Surgery, European Vol 2007 32: 697