Segmental carpal canal pressure in patients with carpal tunnel syndrome

Purpose: To clarify which part of the median nerve is the most compressed and to compare carpal canal pressure with the latency of the sensory nerve potential and the duration of symptoms. Methods: Fifteen patients with idiopathic carpal tunnel syndrome were studied using a pressure guidewire system to record canal pressure. The wire was introduced from the distal end of the carpal canal to 2 cm proximal to the distal wrist crease (DWC) and then retracted in 5-mm increments using an image intensifier to guide the progress. A nerve conduction study was performed, and all patients were asked how long the symptoms lasted. Results: Carpal canal pressure was significantly higher 5 to 15 mm distal to the DWC. The most compressed point was 10 mm distal to the DWC, with a pressure of 44.9 +/- 26.4 mm Hg. The correlation coefficient between the highest canal pressure and the latency was 0.393 and between highest canal pressure and duration of symptoms was 0.402. Conclusions: Our study showed that the most compressed part of the median nerve in the carpal canal is 10 mm distal to the DWC. The carpal canal pressure was related to the latency and to the duration of symptoms.