Median nerve location change evaluated by ultrasound according to symptom severity of carpal tunnel syndrome

摘要

Dear Sir, Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and carpal tunnel release (CTR) has proven to be an efficacious and cost effective surgical procedure for CTS. Among the surgery-related iatrogenic nerve injuries, the median nerve is the most frequently injured nerve, and CTR is a major contributor. To avoid this devastating injury, it is crucial to know the location of the median nerve and possible change of the location in carpal tunnel syndrome patients. 116 cases of CTS in 90 patients who underwent CTR between February 2007 and January 2008 were reviewed. Among these, 52 cases (26 patients) with bilateral CTS confirmed by NCV and US were included in this study. The average age was 52.9 years (range, 38-67 years) and all patients were female. Diagnosis of CTS was made on the basis of their clinical symptoms (tingling, numbness in median nerve territory, and nocturnal aggravation of symptoms), clinical signs (Phalen test, tinel sign, and compression test) and NCV study. In NCV study, CTS was diagnosed when motor fiber latency was delayed by >4.5 ms and sensory fiber by >3.5 ms. Patients with diabetes mellitus, pregnancy, history of traumatic CTS, or mass lesion compressing median nerve were excluded from the study. The severity of clinical symptoms was evaluated by the Boston Carpal Tunnel Questionnaire (BCTQ), which consists of 11 questions about symptoms and eight questions about functions frequently used in activities of daily living.