Electrophysiological and clinical comparison of local steroid injection by means of proximal versus distal approach in patients with mild and moderate carpal tunnel syndrome

Background Local corticosteroid injection is one of the treatment modalities for carpal tunnel syndrome. Symptomatic and electrophysiological improvement following local corticosteroid injection has been documented. Objectives The aim of the present study was to compare the effects of proximal and distal approaches of local steroid injection in patients with mild and moderate carpal tunnel syndrome on clinical scores and electrophysiological parameters at the end of 1 month following injection. Patients and methods A total of 30 patients were included and randomly assigned into one of the two groups based on the local steroid injection approach either by means of distal (group I) or by mean of proximal approach (group II). Clinical and electrophysiological examinations were carried out before and 1 month following the injection. Results There was a significant reduction in the pain and disability scores of the Boston Carpal Tunnel Questionnaire between the baseline and follow-up in both groups. Median motor nerve distal latency was statistically significantly reduced in both groups 1 month after the injection. Median motor conduction velocity and amplitude (amp) showed a statistically nonsignificant difference 1 month following the injection. Median sensory distal latency, amp, and conduction velocity showed statistically significant difference between the two groups. The average duration of the procedure in group I was 9.29 ± 0.76 s compared with 47.91 ± 9.66 s in group II. The average grade of pain expressed by the patients in group I was 1.97 ± 0.82 compared with 5.11 ± 0.67 in group II. Conclusion Local corticosteroid injection at the carpal tunnel using the distal approach is associated with favorable clinical and electrophysiological results similar to those reported using the proximal approach. The distal approach is much less time consuming and more comfortable compared with the proximal approach.