Median and ulnar nerve conduction studies at the wrist: criterion validity of the NC-stat automated device

J Occup Environ Med. 2008 Jul;50(7):758-64. doi: 10.1097/JOM.0b013e3181645425.


Objective: To compare results obtained with the NC-stat--an automated nerve testing device--to traditional nerve conduction studies relevant to carpal tunnel syndrome screening.

Methods: Thirty-three subjects recruited from patients referred for electrodiagnostic testing were studied. Measurements including the distal motor latency (DML), distal sensory latency (DSL), and median-ulnar latency difference (MUD) were obtained by the NC-stat and by standard nerve conduction studies.

Results: With modifications to the NC-stat's suggested reference ranges, sensitivity with respect to the traditional results ranged from 93.8% (sensory MUD) to 100% (median DML and DSL) and specificity ranged from 84.6% (motor MUD) to 94.1% (sensory MUD). Sensitivity was as high or higher and specificity was lower when using the manufacturer's suggested cutoffs.

Conclusion: The NC-stat appears to be a convenient and sensitive method for detecting median nerve pathology at the wrist.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Validation Study

MeSH terms

  • Adult
  • Carpal Tunnel Syndrome / physiopathology
  • Electrodiagnosis / instrumentation*
  • Female
  • Humans
  • Male
  • Median Nerve / physiology*
  • Middle Aged
  • Missouri
  • Neural Conduction / physiology*
  • ROC Curve
  • Ulnar Nerve / physiology*
  • Wrist / physiology*