Severe carpal tunnel syndrome potentially needing surgical treatment in a general population

PURPOSE: To estimate the prevalence of severe carpal tunnel syndrome (CTS) that potentially needs surgical treatment in a general population. METHODS: A health-status questionnaire was mailed to a random general population sample of 3,000 subjects (ages, 25-74 y). The responders who reported numbness and/or tingling in the median nerve distribution in the hands were asked to attend a clinical evaluation at which they completed the validated CTS questionnaire and underwent physical examination and nerve conduction tests. The CTS questionnaire measures the severity of symptoms and disability on a scale from 1 (none) to 5 (most severe). The potential need for surgery was defined as CTS symptom severity score of 3.2 or greater or functional status score of 2.5 or greater (corresponding to median preoperative scores for surgical patients in previous reports). RESULTS: The response rate for the survey was 83%. Of the responders who reported numbness and/or tingling in the median nerve distribution in the hands 81% attended the clinical evaluation. Of the 94 subjects diagnosed with clinically certain CTS, 19 (20%; 12 with electrophysiologically proven median neuropathy) had previously undiagnosed CTS that potentially needed surgical treatment, yielding a population prevalence of 7 per 1,000 (95% confidence interval, 4-11 per 1,000). CONCLUSIONS: In a general population there was a 0.7% prevalence of undiagnosed CTS with a severity similar to that of patients undergoing surgery. The degree to which variable numbers of this group are drawn into a medical system could account for variations in the rate of surgery performed.