Clinical features of 1039 patients with neurophysiological diagnosis of carpal tunnel syndrome.

PURPOSE: To describe the clinical features of patients with a neurophysiologic diagnosis of carpal tunnel syndrome (CTS) in the state of Rio Grande do Sul, Brazil.
METHODS: We prospectively studied 1039 patients with a neurophysiologic diagnosis of CTS in southern Brazil. All patients completed a clinicoepidemiological questionnaire which included a drawing of the arm and hand, in which they were asked to paint the areas in which paresthesia and pain occurred. In part of the sample, we also investigated the presence of clinical signs such as Tinel's, Phalen, and tenar atrophy. The diagnosis of CTS was performed using a predetermined neurophysiological protocol.
RESULTS: A total of 1528 hands were diagnosed with CTS. The severity of CTS was mild in 42% of cases, moderate in 18% and severe in 40%. Patients had a mean age of 48.3 +/- 12.4 years old, and a ratio of 5.6 females to 1 male was observed. Symptoms restricted to the hand and wrist was observed in 51.8% of cases with paresthesia and in 18.5% of cases with pain. In 92.5% of the partially affected hands, paresthesia was present in at least one of the first three fingers, while pain affected the three first fingers in 78.8% of these hands. Pain with a distribution which did not involve the hand occurred in 18.5% of cases, while paresthesia without involvement of the hand occurred in only 1.9%. Distribution of symptoms, according to Katz's hand diagram, showed a classic pattern in 12.6% of affected hands, a pattern classified as probable CTS in 66.3%, and an unlikely CTS pattern in 4.1%. Tinel's and Phalen's sign were observed in 34.2 and 56.3% of the hands, respectively.
CONCLUSION: The clinical presentation of CTS is pleomorphic, ranging from the absence of symptoms to very severe cases. This variation probably is dependent on coexistent diseases, such as tendinitis and fibromyalgia, as well as on subjective aspects of the patients.