DESCRIPTION (provided by applicant): Carpal tunnel syndrome (CTS) is the most common neuropathy; it affects millions, especially in the working- class population, and causes a huge economic burden. Increased carpal tunnel pressure is considered a major cause of CTS. Elevated carpal tunnel pressure directly damages subsynovial connective tissue and induces ischemia reperfusion injury, which leads to connective tissue fibrosis, the most common pathologic finding in CTS. Carpal tunnel pressure is clinically well recognized as a key biomarker and sensitive indicator for assessing stage or severity of CTS and the effectiveness of treatment. However, the current technique for measuring carpal tunnel pressure is invasive and painful; it therefore is not routinely used clinically. Instead, electromyography is used to detect median nerve changes that generally occur during late-stage CTS, when median nerve function is impaired. Therefore, development of a noninvasive method to measure carpal tunnel pressure is critical for evaluating CTS. The overall goal of the current application is to develop novel technology to noninvasively measure carpal tunnel pressure by exploiting the fact that under high pressure, shear wave propagation velocity along a tendon is altered and can be detected by ultrasound elastography. Our preliminary data from a simplified model has demonstrated a high likelihood that a tendon in the wrist can serve as a transducer that senses carpal tunnel pressure. After completion of our proposed aims, we will have developed a novel, unique and noninvasive tool that can be used to define the role of carpal tunnel pressure with regard to CTS origin, progressive factors, early diagnosis, treatment options, and outcome.

PUBLIC HEALTH RELEVANCE: Carpal tunnel syndrome is a common problem affecting millions of workers in the US, and causes hand and finger pain, tingling, numbness and weakness. Carpal tunnel pressure is thought to help physicians to better understand the CTS early stage and development, but to get carpal tunnel pressure information, doctors have to use a painful test where a large needle is inserted deep into the wrist. We propose a new test using ultrasound that can measure the pressure in the carpal tunnel painlessly, making an accurate diagnosis early for better treatment and outcome.