Median nerve function in patients undergoing carpal tunnel release: pre- and post-op nerve conductions.

Patients undergoing surgery for carpal tunnel decompression may improve clinically, however it is not well known as to how median nerve neurophysiology is altered following surgery. Fifty patients who underwent open carpal tunnel release were prospectively studied. Each patient underwent nerve conduction studies pre-op and at 6 months post-op. Patients were also asked to answer several questions regarding their clinical symptoms to see how they improved. 48/50 patients had clinical improvement based on their response (resolution of nocturnal paresthesias, decreased sensory complaints and pain). Average pre- and post-op parameters were as follows: distal motor latency (DML) (msec) 5.24/4.42; distal motor amplitude (mV) 8.28/8.64; sensory conduction velocity (m/sec) 38.9/41.0; sensory amplitude (uV) 10.94/15.61. We conclude that the DML and sensory amplitude showed significant improvement following surgery; the sensory conduction velocity remains slow.