Method
Subjects included 33 hands of 27 CTS patients who received operation (operation group) and 20 hands of 17 patients who were managed conservatively (non-operation group). Median antidromic sensory responses were recorded with wrist and palm stimulation. The criterion for conduction block was more than 50% drop of baseline to negative peak amplitude of sensory nerve action potential with wrist stimulation compared to palm stimulation. The degree of conduction block was measured before and after treatment, and the improvement of conduction block was compared between the two groups.

Results
The degrees of conduction block were 59.9⁑14.3% in operation group and 60.5⁑14.5% in the non-operation group at initial evaluation. The improvements of conduction block were 32.1⁑15.1% (5∼58.9%) in operation group and 7.8⁑19.8% (⁣27.3∼36.7%) in non-operation group after treatment and the difference was statistically significant.

Conclusion
The results suggest that operative treatment may be useful even in patients with carpal tunnel syndrome with conduction block. (J Korean Acad Rehab Med 2003; 27: 369-373)