Ultrasound used for its accuracy in diagnosing Carpal Tunnel

Ultrasound used for its accuracy in diagnosing Carpal Tunnel

Carpal Tunnel Syndrome is a condition that affects thousands of people every year in both work and age related circumstances. Carpal Tunnel syndrome causes pain, numbness and loss of feeling in the wrists and hands which is due to the median nerve being compressed in the wrist area. The cause of CTS as mentioned before varies between environmental and genetic factors with some sufferers obtaining the condition through pre-existing health conditions such as diabetes or obesity. There has also been research into the link between CTS and work related factors, such as individuals who work in manual handling environments or use vibratory tools. The damage in both situations is what causes the compression of the median nerve leading to the condition. A recent study has been undertaken to see how effective ultrasound is in diagnosing CTS.

A study into CTS

The study was researched by John R Fowler, MD, from the University of Pittsburgh, and colleagues. The team compared the effectiveness, specifically the sensitivity and specificity of ultrasound and electrodiagnostic testing. To compare the results, the study team evaluated 85 patients, over a 3 month period. All the patients were evaluated with the standard procedure the Carpal Tunnel Syndrome (CTS-6) clinical diagnostic tool. To measure whether the patient was displaying signs of CTS, the researchers measured with a score of 12 or greater as a positive sign of CTS.

The CTS study results

The results displayed a sensitivity of 89% and a specificity of 90% with ultrasound and a sensitivity of 89% and specificity of 80% with electrodiagnostic testing. The researchers found a positive predicitive value of 94% with ultrasound compared with 89% with electodiagnostic testing, as well as negative predictive value of 82% with ultrasound vs 80% with electrodiagnostic testing.
In the 85 patients, it was found that 89% of cases with ultrasound were accurate, however 86% of cases were accurate with electrodiagnostic testing. This goes some way in presenting the effectiveness of ultrasound as a means of diagnosing CTS.

The author commented with the following

While ultrasound will not replace electrodiagnostic testing in complicated or unclear cases, in a select group of patients with a positive CT-6, ultrasound can be used to confirm the diagnosis of carpal tunnel syndrome with better specificity and equal sensitivity as compared with those of electrodiagnostic testing”.

[1]Ultrasound Can Accurately Diagnose Carpal Tunnel”, http://www.hcplive.com/articles/Ultrasound-Can-Accurately-Diagnose-Carpal-Tunnel
[2] “Ultrasound confirms carpal tunnel syndrome with better specificity and sensitivity”
[3] “Ultrasound accurate in confirming carpal tunnel syndrome”, http://www.clinicaladvisor.com/ultrasound-more-accurate-than-electrodiagnostic-testing-carpal-tunnel-syndrome/article/374139/