Comparative analysis of nerve conduction study methods in patients with carpal tunnel syndrome

Abstract

Background: Patients with mild-to-moderate carpal tunnel syndrome (CTS) may not be picked up by routine nerve conduction methods. Hence, this study was performed to identify the most sensitive way to detect mild-to-moderate CTS and to evaluate the sensitivity of different methods for the diagnosis of CTS. Subjects and Methods: We included 60 clinically confirmed CTS patients in our study. We recorded the clinical characteristics and laboratory features in a prescribed proforma. We also included 60 healthy age- and sex-matched asymptomatic individuals as controls in our study. We excluded patients with underlying peripheral neuropathy. We included median distal motor latency, median distal sensory latency, median-versus-ulnar second lumbrical-interossei comparison study, median-versus-ulnar wrist-to-digit four comparison study, median-versus-radial thumb sensory study, median-versus-ulnar motor distal latency difference, and median-versus-ulnar sensory latency difference tests in our study. Results: Of 60 patients, female: male ratio was 2.3:1, and the mean age was 44.28 ± 11.41 years. Mean symptom duration was 0.76 ± 0.03 years. Of 42 females, 38 (90.4%) were engaged in daily household activities. In patients group, median nerve distal motor latency was 5.024 ± 2.05 ms, whereas sensory latency was 3.53 ± 0.75 ms. Sensitivity was the highest in median-versus-ulnar wrist-to-digit four comparison study (90.19%), followed by median-versus-radial thumb sensory study (88.23%), and median-versus-ulnar second lumbrical-interossei comparison study (86.27%). Median distal motor latency test had the lowest sensitivity (72.55%). Conclusions: In patients with mild CTS, electrophysiological tests including median-versus-ulnar wrist-to-digit four comparison study, median-versus-radial thumb sensory study, and median-versus-ulnar second lumbrical-interossei comparison study should be incorporated to improve the sensitivity for the diagnosis of CTS.