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


CONCLUSIONS
The NC-stat appears to be a convenient and sensitive method for detecting median nerve pathology at the wrist.
Armstrong
Theodore N
TN
Department of General Medical Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
Dale
Ann M
AM
Al-Lozi
Muhammad T
MT
Franzblau
Alfred
A
Evanoff
Bradley A
BA
D000328:Adult; D002349:Carpal Tunnel Syndrome / Q000503:physiopathology; D004568:Electrodiagnosis / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000502:physiology*; D008875:Middle Aged; D008923:Missouri; D009431:Neural Conduction / Q000502:physiology*; D012372:ROC Curve; D014459:Ulnar Nerve / Q000502:physiology*; D014953:Wrist / Q000502:physiology*