Although most health care practitioners would define carpal tunnel syndrome (CTS) as an entrapment, or compression, of the median nerve at the level of the wrist (e.g. carpal tunnel), the diagnosis is often not clear cut. A major reason for ambiguity is that in its initial stages, CTS often involves inflammation of tendons transversing the wrist that control finger movement and grip. As tendinitis progresses, there is a constellation of inflammatory events including swelling, vascular stasis, and nociceptor sensitization, which account for many of CTS clinical signs. Hence, clinical signs do not clearly differentiate between tendinitis and CIS, which requires direct testing of median nerve function specifically localized to the wrist area. At present, only conduction latency across the wrist fulfills these criteria. The alternative of sensory testing (e.g., two-point discrimination, monofilament or vibratory threshold) lacks specificity; that is, sensory deficits can be attributed to other causes. More recently, a provocative technique has provided evidence of wrist level, median nerve entrapment before symptoms become unequivocal by more traditional procedures, and has been reported to be specific for CTS over other forms of peripheral neuropathy. Topical Testing proposes to investigate ways of improving the efficiency of the initially reported provocative procedure to improve the specificity and sensitivity of CTS diagnosis. If feasibility criteria are satisfied, Phase II will propose an equipment package designed specifically for improved evaluation of carpal tunnel status.
Medical market segments for the treatment and rehabilitation of carpal tunnel syndrome include hand surgery, hand therapy, physical therapy, physiatry (PM&R), neurology, and occupational medicine. Potentially large markets for noninvasive instrumentation to screen for carpal tunnel injury include human resources, safety, ergonomics, and industrial hygiene.
| Sesek, Richard F; Khalighi, Mehdi; Bloswick, Donald S et al. (2007) Effects of prolonged wrist flexion on transmission of sensory information in carpal tunnel syndrome. J Pain 8:137-51 |
