P R E S S   R E L E A S E

        Marked by fatigue, pain, stiffness, cramping, numbness, and tingling of the hands, wrists, or arms, Carpal Tunnel Syndrome (CTS) is a disorder increasingly prevalent among keyboard workers and expectant mothers.  The incidence of CTS is about 1 per thousand per year. It is estimated that there are 6,000 to7,000 new cases annually in Hong Kong.

        It is routinely diagnosed based on an inventory of symptoms, confirmed with a thorough neurophysiologic evaluation, which is quite expensive and complicated.  Mild cases are often dismissed or overlooked.

        The majority recover completely and can avoid re-injury by changing the way they do repetitive movements, the frequency with which they do the movements, and the amount of time they rest between periods when they perform movements.  However, contrary to popular belief that it is just a common condition, CTS can quickly escalate from a fleeting flare-up to a serious case, with cell degeneration and the risk of disability.  Approximately one percent CTS patients will develop permanent injury.  It is therefore important that we can detect the disorder and provide treatment early.

        Researchers at the Faculty of Medicine of The Chinese University of Hong Kong now offer a new approach to aid in the accurate diagnosis and early treatment of CTS.  A recent study indicates the promise of sonograms, with an impressive diagnostic sensitivity rate of 89%.  The findings are published in the July 2002 issue of Arthritis & Rheumatism.

        Conducted at Prince of Wales Hospital in Hong Kong, the study compared 35 patients with documented symptoms of CTS against 35 control subjects with no signs of the debilitating condition.  With a median age of 44, all of the subjects were women, since women account for the majority of CTS sufferers.  Each participant received sonographic measurements of the median nerve, which controls the thumb, index, and middle fingers, at the base of the wrists in both of her hands.  To guard against bias, each participant was identified according to a computer-generated random number, and a single radiologist performed all of the examinations.

        The sonograms consistently revealed significant differences between CTS patients and controls, particularly in the median nerve cross-sectional area next to the carpal tunnel, in both the right and the left wrists.

        "This study indicates that sonography is likely to play an increasingly important role in establishing the diagnosis of CTS.  Since the median nerve changes in caliber and shape as it passes from the distal forearm to the palm, it is imperative that reliable objective criteria for measurement technique and location are established at the outset, therefore facilitating reliable correlation for future studies," said Dr Wong Shiu-Man, Adjunct Assistant Professor of the Department of Medicine & Therapeutics, The Chinese University of Hong Kong

        With these encouraging results, researchers are now working on rigorous evaluation of this new tool against not only electrophysiologic studies, but also magnetic resonance imaging (MRI).

        "Currently, the role of imaging in CTS is not yet defined; the majority of CTS patients do not undergo imaging studies," Dr Wong observed.  "MRI can better demonstrate the carpal tunnel margins, the retinacular attachments, and nerve edema.  Nevertheless, the main benefits of ultrasound over MRI in the diagnosis of CTS are the ease of availability, shorter examination time, and reduced cost.”