Otto KA. Effects of averaging data series on the electroencephalographic response to noxious visceral stimulation in isoflurane-anaesthetized dogs.
Res Vet Sci 2007;
83:385-93. [PMID:
17368688 DOI:
10.1016/j.rvsc.2007.01.015]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 01/03/2007] [Accepted: 01/25/2007] [Indexed: 11/28/2022]
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.
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