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Updated: Mar 18, 2026
Screening of Axonal Degeneration in Carpal Tunnel Syndrome Using Ultrasonography and Nerve Conduction Studies
Published on: January 11, 2019
Premotor Potential Study for Diagnosis of Carpal Tunnel Syndrome
Mitsuhiko Kodama1, Michi Tochikura, Naoshi Shimoda
1Department of Rehabilitation Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa 259-1193, Japan. rehakoda@tokai-u.jp.
Introduction:
The second lumbrical-interossei latency difference test (2LINT) is used frequently for electrodiagnosis of carpal tunnel syndrome (CTS). A premotor potential observed with 2LINT has been identified as a median-nerve sensory nerve action potential. We evaluated the utility of the premotor potential latency analysis (i.e., premotor potential study; PPS) for CTS electrodiagnosis.
Methods:
Sensitivity, specificity, and percentage "no evoked response" (%NER) values were compared prospectively among PPS, median-nerve sensory nerve-conduction studies (NCSs) for digits 1, 2, and 4, and palmar mixed NCS.
Results:
Sixty-four healthy control hands and 104 hands with CTS were enrolled in this study. PPS sensitivity was superior to other sensory/mixed NCSs (75% vs. 42%-62%). All NCS specificities were acceptable (95%-97%). The %NER of PPS was lower than that of other NCSs (13% vs. 25%-44%).
Conclusion:
Premotor potential could be evoked in more CTS hands and was the most sensitive among median-nerve sensory and mixed NCSs. Therefore, we could use the 2LINT with PPS as median and ulnar motor NCS as well as median sensory NCS.
