title: Effects of averaging data series on the electroencephalographic response to noxious visceral stimulation in isoflurane-anaesthetized dogs.
abstract: The effects of averaging epochs on electroencephalographic (EEG) responses to visceral stimulation has been determined in seven isoflurane-anaesthetized dogs. Quantitative EEG variables including 80% spectral edge frequency (SEF80), median frequency (MF), relative power in the delta, theta, alpha, beta band and power band ratios (theta/delta, alpha/delta, beta/delta) were recorded over 1min before stimulation and during a 1-minute stimulation period. During off-line analysis EEG variables were derived from either single 2-second EEG epochs or as an average from 5, 10, 15 and 30 consecutive 2-second epochs. Noxious stimulation resulted in significant increases in SEF80, MF, alpha power, beta power, alpha/delta ratio and beta/delta ratio. The number of variables that were significantly affected as well as the strength of changes as indicated by p-values, however, varied with the number of epochs subjected to averaging. The data suggest that stimulation-induced EEG changes may be more pronounced at lower rather than at higher averaging rates.
authors: Hannover Medical School, Laboratory Animal Facility, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany. otto.klaus@mh-hannover.de
authors: Klaus A
authors: KA
authors: Otto
mesh_terms: D000769:Anesthesia, Inhalation / Q000662:veterinary*; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure; D004285:Dogs / Q000502:physiology*; D004558:Electric Stimulation; D004569:Electroencephalography / Q000662:veterinary*; D005260:Female; D006339:Heart Rate; D007530:Isoflurane / Q000494:pharmacology*; D010146:Pain; D010812:Physical Stimulation
chemical_list: D018685:Anesthetics, Inhalation; D007530:Isoflurane