Digit III – Palm, Wrist

Surface Recording Technique, Orthodromic Study
  • Giuliano Gentili
  • Mario Di Napoli

Original Settings

Low-frequency filter was 0.1 Hz, high-frequency filter was 2 kHz, sweep speed was 1 ms/division, duration of pulse was 0.1 ms, rate of pulse was 1/s, and the machines used were a Grass S8 stimulator and a dual-beam Tektronix 565 oscilloscope. Sensitivity was not specified.


This study was performed in the supine position.


Following the orthodromic method [ 1], signals were recorded on the course of the median nerve (Fig. 1): on the palm (distal to the carpal tunnel, R1) and at the wrist (proximal to the carpal tunnel, R2, R3). Interelectrode distances were as follows: the cathode to the electrode distal to the carpal tunnel (R1), mean 7.81 cm (range 6.5–10.5 cm); the cathode to the electrode proximal to the carpal tunnel (R2), mean 12.15 cm (range 9.95–14.6 cm); across the carpal tunnel (R1–R2), mean 3.8 cm (range 2.75–4.7 cm); and between electrodes proximal to the carpal tunnel (R2–R3), mean 1.94 cm (range 1.85–2.15 cm). Sensory nerve action...


  1. 1.
    Wiederholt WC (1970) Median nerve conduction velocity in sensory fibers through carpal tunnel. Arch Phys Med Rehabil 51:328–330PubMedGoogle Scholar
  2. 2.
    Wiederholt WC (1970) Stimulus intensity and site of excitation in human median nerve sensory fibres. J Neurol Neurosurg Psychiatry 33:438–441PubMedCentralPubMedCrossRefGoogle Scholar
  3. 3.
    Bland JDP (2000) A neurophysiological grading scale for carpal tunnel syndrome. Muscle Nerve 23:1280–1283PubMedCrossRefGoogle Scholar

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • Giuliano Gentili
    • 1
  • Mario Di Napoli
    • 1
  1. 1.Neurological ServiceS. Camillo de’ Lellis General HospitalRietiItaly

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