Clinical Evaluation and Diagnostic Utilities of Different Nerve Conduction Tests in 100 Patients with Carpal Tunnel Syndrome

Background and purpose: The purpose of the study is to determine whether the clinical profile of patients with carpal tunnel syndrome (CTS) has been same over the years with the help of routine and comparative electrodiagnostic tests.

Methods: A prospective study of 100 patients with suspected CTS was conducted without controls. Three provocative maneuvers were performed. Routine and comparison nerve conduction tests were performed, i.e., second lumbrical interossei motor latency difference (2 LIMLD), digit 4 median-ulnar sensory latency difference (D4MUSLD), palm wrist distal sensory latency difference (PWDSLD), and digit 1 median-radial sensory latency difference (D1MRSLD). Data entry, analysis, and statistical evaluation were done using International Business Machines Corporation Statistical Package for the Social Sciences statistics package (IBM, SPSS).

Results: A total of 195 hands of 100 patients met the criteria for CTS. Forty-three percentage of patients were homemakers. Considering the rapidly changing communication technology, we observed 84% patients had aggravation of symptoms with continuous long-term daily mobile phone use (>30 min per session per day). We noted positive Tinel's sign in only 25%. Phalen's sign was positive in 53 right hands with mean duration of 11.49s (standard deviation [SD] ± 2.54 s) and was positive in 26 left hands with mean being 10.4 s (SD ± 1.91 s). The mean motor distal latency of median was 4.67 ms (SD ± 1.71 ms) and mean sensory distal latency of median was 3.24 ms (SD ± 1 ms). On internal comparison testing, mean difference in 2 LIMLD was 0.7 ± 0.3 ms, in D4MUSLD was 0.81 ± 0.32, in PWDSLD was 0.71 ± 0.20, and in D1MRSLD was 0.76 ± 0.32.

Conclusion: Further analysis of clinical profile needs to be done, and new risk or provoking factors should be analyzed in patients with CTS.