Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy. It is characterised by the compression of the median nerve in the carpal tunnel. CTS presents a high prevalence and it is a disabling condition from the earliest stages. Severe cases are usually treated surgically, while conservative treatment is recommended in mild to moderate cases. The aim of this systematic review is to present the conservative treatments and determine their effectiveness in mild-to-moderate cases of CTS over the last 15 years. A systematic review was performed according to PRISMA criteria. We used the Medline, PEDro, and Cochrane databases to find and select randomised controlled clinical trials evaluating the effects of conservative treatment on the symptoms and functional ability of patients with mild to moderate CTS; 32 clinical trials were included. There is evidence supporting the effectiveness of oral drugs, although injections appear to be more effective. Splinting has been shown to be effective, and it is also associated with use of other non-pharmacological techniques. Assessments of the use of electrotherapy techniques alone have shown no conclusive results about their effectiveness. Other soft tissue techniques have also shown good results but evidence on this topic is limited. Various treatment combinations (drug and non-pharmacological treatments) have been proposed without conclusive results.
Several conservative treatments are able to relieve symptoms and improve functional ability of patients with mild-to-moderate CTS. These include splinting, oral drugs, injections, electrotherapy, specific manual techniques, and neural gliding exercises as well as different combinations of the above. We have been unable to describe the best technique or combination of techniques due to the limitations of the studies; therefore, further studies of better methodological quality are needed.