Sonographic diagnosis of carpal tunnel syndrome: a study in 200 hospital workers*

OBJECTIVE To describe the prevalence of carpal tunnel syndrome in a sample of 200 healthy hospital workers, establishing the respective epidemiological associations. MATERIALS AND METHODS Two hundred individuals were submitted to wrist ultrasonography to measure the median nerve area. They were questioned and examined for epidemiological data, body mass index, carpal tunnel syndrome signs and symptoms, and submitted to the Boston carpal tunnel questionnaire (BCTQ) to evaluate the carpal tunnel syndrome severity. A median nerve area ≥ 9 mm(2) was considered to be diagnostic of carpal tunnel syndrome. RESULTS Carpal tunnel syndrome was diagnosed by ultrasonography in 34% of the sample. It was observed the association of carpal tunnel syndrome with age (p < 0.0001), paresthesia (p < 0.0001), Tinel's test (p < 0.0001), Phalen's test (p < 0.0001), BCTQ score (p < 0.0001), and years of formal education (p < 0.0001). Years of formal education was the only variable identified as an independent risk factor for carpal tunnel syndrome (95% CI = 1.03 to 1.24). CONCLUSION The prevalence of carpal tunnel syndrome in a population of hospital workers was of 34%. The number of years of formal education was the only independent risk factor for carpal tunnel syndrome.