Diagnostic and Research Techniques in Carpal Tunnel Syndrome.

Carpal tunnel syndrome is the most common neuropathy, costing upward of $2B USD annually in North America. Carpal tunnel syndrome is a result of chronic trauma to the median nerve, resulting in nerve damage, decreased conductivity of nerve impulses, and ultimately presents with clinical symptoms such as pain, tingling, numbness, and thumb muscle atrophy in severe cases. Although patient history, symptoms, and a nerve conduction study are the primary diagnosis tools, there are several techniques and tools that may be used to assess carpal tunnel syndrome and characterize the condition. The purpose of this critical review is to discuss the multitude of techniques that can be applied to study carpal tunnel syndrome, including Phalen's and Tinel's tests, nerve conduction study, Semmes-Weinstein monofilaments, laser Doppler flowmetry, pressure catheters, and ultrasound and magnetic resonance imaging. Additionally, this review discusses the reliability, sensitivity, and accuracy of these methods. A combination of these techniques may ultimately improve the accuracy in diagnosing carpal tunnel syndrome, especially in cases where nerve conduction study results are borderline or inconclusive by analyzing other aspects that may differently contribute to the development of carpal tunnel syndrome.