Evaluation and comparison of three most commonly used tests for electrodiagnosis of carpel tunnel syndrome in diabetic patients with or without clinical evidence of neurodeficit
Abstract
Background and Aim: Electrodiagnosis of carpel tunnel syndrome (CTS) becomes difficult with routine tests when CTS is severe with coexistent polyneuropathy. Diabetes cases often report with symptoms of CTS and peripheral neuropathy. There is lack of literature regarding diagnostic accuracy of electrodiagnostic (EDX) tests, including comparison tests in diabetic patients to diagnose CTS. Therefore, the present study was intended to evaluate and compare the diagnostic sensitivity and specificity of comparison tests in diabetics with or without clinical CTS. Methods: The three commonly used median versus ulnar comparison tests viz., palm‑wrist mixed comparison (PWMC), digit4‑sensory onset latency comparison (D4SOLC) and 2lumbrical‑interossie motor latency comparison (2L‑IMLC) were used for diagnosis of CTS in these subjects. Fisher’s exact test was applied to compare the differences in diagnosis between clinical and different EDX comparison tests. Results: Prevalence of CTS with routine EDX tests and comparison tests was observed as 16% and 24%, respectively. Diagnostic sensitivity for PWMC, D4SOLC and 2L‑IMLC was 69.23% 76.92%, and 92.31%, respectively. 2L‑IMLC was observed as most sensitive and D4SOLC was observed as most specific comparison tests for EDX of CTS in diabetic patients. Conclusion: Prevalence of CTS in diabetic patients increases with use of comparison tests. Hence, along with routine EDX tests, comparison tests may be included as part of EDX tests to evaluate CTS in these patients. 2L‑IMLC test should preferably be adopted for screening CTS in diabetics.