Method
Thirteen patients (24 hands) with CTS diagnosed clinically and electrophysiologically were included. All subjects were examined by ultrasonography with high-resolution linear array transducer and injected with 40 mg of triamcinolone acetonide. The ultrasonography was evaluated with regard to cross-sectional area and the flattening ratio of the median nerve and cross-sectional area of the flexor pollicis longus tenon at pisiform and hamate bone. After 4 weeks, the patients were re-evaluated with electrophysiologic study and ultrasonography.

Results
Most patients (11/13) showed improvement of clinical symptoms and electrophysiologic parameters after the local steroid injection. The cross-sectional area of median nerve at pisiform using ultrasonography significantly decreased after the local steroid injection. However, flexor pollicis longus tendon did not show significant change after the injection.

Conclusion
Local steroid injection in the patients with CTS caused improvement in ultrasonographic findings of median nerve. (J Korean Acad Rehab Med 2008; 32: 189-193)