Abstract
Background and Objectives: Carpal tunnel syndrome is the most common entrapment neuropathy, which after clinical examination is the best method for it’s diagnosis. The aim of this study is the comparison of the validity of some median sensory nerve conduction velocity measurement (MSNCV) techniques in diagnosis of carpal tunnel syndrome (CTS).
Materials and Methods: Eighty five referred hands to electrodiagnostic laboratory with suspected CTS were recruited for this study. Subjects with no symptom or signs of median neuropathy were recruited as control group. Patients or control groups with positive history of cervical radiculopathy, peripheral neuropathy, or other disorders affecting neuromuscular function were excluded. In both CTS and control groups, electrodiagnostic studies including one-segment and two-segment techniques, for measurement MSNCV in wrist segment, were performed. In one segment study, transcarpal palm-to-wrist median mixed NCV was measured. In two segment studies antidromic transcarpal wrist-to-palm MSNCV (W-PMSNCV) and distoproximal ratio (D/P) were calculated.
Results: ROC curves were constructed for one segment and two segment studies, from the patients and controls data.The W-P MSNCV ≤ 50.45 m/s, corresponding to an optimal cutoff point on ROC curves discriminated CTS from controls with sensitivity of 97.6% and specificity of 96.5%.D/P ratio at optimal cutoff point of ≥1, discriminated CTS from controls with sensitivity of 97.6% and specificity of 83.5% the likelihood ratio (assessing the discrimination power of a test ) were 27.86, 14.08, 5.92 in W-P MSNCV, D/P ratio and mixed NCV, respectively.
Conclusion: W-P MSNCV is more sensitive than D/P ratio and mixed NCV in diagnosis of carpal tunnel syndrome.