Standardisation of neurophysiological norm values. Relevance of the position of the heating element and the temperature measurement sensor.
At a "constant" temperature of 37 degrees C, we measured the influence of the position of the temperature measurement sensor and the infrared heating element on the nervous conduction velocity (NCV) and the delay in latency after paired stimulation (LPSS) of the sural nerve. Temperature differences of up to 6.2 degrees C resulted from alteration of four cm in position of the temperature measurement sensor and the infrared heating element. NCV in the test subjects changed from 54.2 + -4.5 to 57.8 + -4.0 m/sec and the LPSS from 4.0 + -2.2% to 2.0 + -1.0%. The patients showed an increase of NCV from 54.1 + -5.0 to 56.8 + -5.7 m/sec and a decrease of LPSS from 9.9 + -5.7% to 6.5 + -3.9%. Our investigation shows that even the position of the temperature measurement sensor and the infrared heating element form a very appreciable component of the standardization method and decide on normal values. The consistent implementation of these results for routine purposes restricts the range of error of neurophysiological measurements, as well as improving the reproducibility and relevance of borderline findings.
Husstedt
I W
IW
Department of Neurology University of Münster, Germany.
Grotemeyer
K H
KH
Schlake
H P
HP
D000328:Adult; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000503:physiopathology; D009431:Neural Conduction; D011930:Reaction Time; D012015:Reference Standards; D012881:Skin Temperature / Q000502:physiology; D013817:Thermography / Q000295:instrumentation*