This article is more than 5 years old. Information may no longer be current.

Ultrasound effectively diagnosed carpal tunnel syndrome

Diagnosis requires less time than nerve conduction studies.

Issue: Issue 6 2004

Add topic to email alerts

Receive an email when new articles are posted on

Please provide your email address to receive an email when new articles are posted on .

Subscribe

Added to email alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

Back to Healio

We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.com.

Back to Healio

High-resolution ultrasound seems to be a reliable modality for imaging the wrist, especially for evaluating carpal tunnel syndrome.

“Ultrasound is gaining use in musculoskeletal diagnostics in the United States,” said Ethan R. Wiesler, MD, an assistant professor of orthopaedic surgery at Wake Forest University in Winston-Salem, U.S.A. “We have shown a range of normal ultrasound parameters comparable with European and Japanese data. The ultrasound abnormalities correlate with the gold standard nerve conduction abnormalities in CTS patients.” Wiesler presented the research results at the American Society for Surgery of the Hand 59th Annual Meeting in New York.

Wiesler said high-resolution ultrasound “is well-tolerated by patients and is safe. It requires no needles and is, therefore, painless with no side effects.”

A real-time scanner with a 12/5 MHz linear-array transducer was used to measure the cross-sectional area of the median nerve at the level of the distal wrist crease in 43 asymptomatic patients (86 wrists) and 16 patients (30 wrists) with clinical signs and symptoms of carpal tunnel syndrome.

“All patients with clinical CTS [carpal tunnel syndrome] showed abnormal US parameters (>11 mm² x-sectional at the wrist),” Wiesler said.

The average age of the 16 CTS patients was 57; average age of the control group, 36. Carpal tunnel syndrome was defined by nerve connection velocity (NCV) criteria and classic symptoms based on hand diagrams. The NCV studies were done in the standard fashion by criteria established by a board-certified neurologist, Wiesler said.

The average duration of symptoms was one year; the CTS patients’ motor nerve conduction velocity averaged 5.6 ms vs. 3.5 ms in the asymptomatic control group.

Study parameters

Researchers asked each patient to flex their wrist and finger several times as a way to measure nerve mobility. Again, a 0-to-2 scale was employed to document the findings: zero for little movement (the nerve does not dive into the flexor tendons), one for when the nerve dives and moves into the tendons but fails to be enveloped by them, and two for when the nerved dives into and is enveloped by the tendons.

The average cross-sectional area of the median nerve at the distal wrist crease was 8.8 mm in asymptomatic patients and 15.3 mm in CTS patients with altered NCV. The median nerve size was different in men and women, which correlates with the incidence of CTS in the general population and in normal subjects. Correlation was made between the altered nerve conduction velocity (NCV) and increases in the median nerve cross-sectional area.

As a result, high-resolution ultrasound demonstrated marked enlargement of the median nerve at the distal wrist crease and decrease of nerve mobility and echogenicity. It also clearly demonstrated anatomic anomalies such as persistent median arteries, flexor carpi radialis cysts, accessory lumbricals and hamartoma of the median nerve, Wiesler said.

“Ultrasound also takes less time than nerve conduction studies, and patients can appreciate abnormalities more easily by looking at the image of their wrists on the screen,” he said.

For more information:

• Wiesler E, Elsaidi GA, Walker F, Cartwright M. The use of ultrasound in the diagnosis and management of carpal tunnel syndrome. #36A. Presented at the American Society of Surgery of the Hand 2004 59th Annual Meeting. Sept. 9-11, 2004. New York.