O-2-28. Vulnerability of each branch of median nerve in carpal tunnel syndrome. Issue 5 (May 2018)

• Record Type: Journal Article
• Authors: Miyaji, Yosuke; Oishi, Chizuko; Mizoi, Yoshikazu; Tanaka, Fumiaki; Sonoo, Masahiro
• Is Part Of: Clinical neurophysiology. Volume 129:Issue 5(2018:May)
• Page Start: e34
• Publication Date: 2018-05
• Subjects: Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2018.02.083
• Languages: English
• ISSNs: 1388-2457

Abstract

Abstract : It is widely believed that sensory conduction study (SCS) is more sensitive than motor conduction study (MCS) in carpal tunnel syndrome (CTS). However, the sensitivity depends not only on the vulnerability of each branch of the median nerve, but on measurement errors and cut-off values. In this study, we aimed to clarify the true vulnerability of each branch in CTS. Subjects consisted of 144 CTS patients and 66 controls. The impairment of a branch was defined as the prolongation of onset latency. Following 6 parameters were evaluated; DMLAp from routine MCS, DMLLp from second lumbrical (2L)-interossei method, DSLIap and DSLIop from antidromic and orthodromic SCS at index-finger, DSLRp from ring-finger method, and DSLTp from thumb method. The mean values for patients were 1.57 ms, 1.12 ms, 1.03 ms, 1.08 ms, 1.63 ms, and 1.09 ms, respectively. The most severely impaired branch was the ring-finger sensory branch, which was narrowly followed by the motor branch to APB. The sensory branch to thumb was relatively preserved, comparable to the sensory branch to index-finger and even the motor branch to 2L. The vulnerabilities of the branches of median nerve in CTS are not sensory predominant but specific to the respective branches.