Long-term clinical and electrophysiological results of local steroid injection in patients with carpal tunnel syndrome.

The aim of this study was to evaluate the effects of local steroid injection on both the clinical symptoms and motor and sensory conduction of the median nerve in carpal tunnel syndrome (CTS). Using a standard evaluation and treatment protocol, we prospectively studied steroid injection in 32 hands in 24 patients (mean age: 50.7 +/- 10 years; 23 women and 1 man). To determine the normal median nerve values, 42 normal controls (mean age: 39.1 +/- 10.5 years; 21 women and 21 men) were also studied. At follow-up, clinical symptom scores and signs of CTS, as well as electrophysiological variables of the median nerve, showed a significant trend towards improvement with respect to baseline values (p < 0.01). By the end of the one-year follow-up period, the symptoms had remitted completely or partially in 27 hands (84.4%). In addition to the relief of the symptoms, motor nerve conduction abnormalities had improved in 62.6% of hands, and anti-dromic sensory nerve conduction abnormalities in 62.5%. In cases where a sensory nerve action potential (SNAP) could be obtained, the efficacy of this treatment was found to be relatively higher than in cases in which SNAP was absent (p < 0.01).