Summary
Carpal tunnel syndrome (CTS) is a collection of characteristic signs and symptoms that occurs following entrapment of the median nerve within the carpal tunnel. Annual incidence of CTS varies from 1 to 3 cases per 1 000 subjects, the prevalence being around 1 case per 100 inhabitants. It is therefore not a rare disease. Although less common before the age of 30, its frequency increases gradually with a peak between 45 and 60 years. The male-to-female ratio varies from 1:3 to 1:10. Paraesthesias, pain, numbness and clumsiness with loss of grip are the most characteristic symptoms. Motor and/or sensitivity abnormalities may also be associated. Obstruction to venous outflow, with oedema formation and ischemia of nervous fibres, accompanying the compressive phenomena within the carpal tunnel, result from demyelination and axonal degeneration. Sensory fibres are often affected first, followed by motor and autonomic nerve fibres. The precise cause remains unknown, genetic, medical, professional, demographic and social factors have been associated with CTS. The diagnosis rests mainly on the clinical picture. Electromyography and nerve conduction studies allow the assessment of nerve lesion severity. Disease evolution is generally progressive. CTS secondary to an underlying pathology (e.g. diabetes, wrist fracture) tends to have a less favourable prognosis. Local or general administration of corticoids seems beneficial, as does treatment with nonsteroidal anti-inflammatory drugs and diuretics. Surgery leads to improvement in 60 to 90% of the cases resistant to a conservative therapy. *Author: Orphanet (January 2004)*.
