Quantitative topographical analysis of EEG during nonstandardized and standardized hyperventilation

• Published in: Journal of clinical neurophysiology Vol. 15; no. 6; p. 521
• Main Authors: Zwiener, U, Löbel, S, Rother, M, Funke, M
• Format: Journal Article
• Language: English
• Published: United States 01.11.1998
• Subjects: Adult; Brain Mapping; Electroencephalography - methods; Female; Frontal Lobe - physiopathology; Humans; Hyperventilation - diagnosis; Male; Occipital Lobe - physiopathology; Parietal Lobe - physiopathology; Temporal Lobe - physiopathology; Time Factors
• ISSN: 0736-0258
• DOI: 10.1097/00004691-199811000-00011

The aim of this study was to compare the topographical quantitative EEG (qEEG) changes induced by nonstandardized hyperventilation and those induced by standardized hyperventilation (with the end-tidal PCO2 being maintained at 2 kPa [15 mm Hg]). We examined 18 healthy volunteers during nonstandardized and 20 during standardized hyperventilation. During nonstandardized hyperventilation, the mean spectral power density in this group significantly increased 1.9 fold within the delta-, 2.2 fold within the theta-, 1.8 fold within the alpha-, and 1.9 fold within the beta-frequency band. There was no significant change of the power ratio and was no topographic difference between 4 frequency bands investigated. During standardized hyperventilation, the mean spectral power density in the group significantly increased to 12.9 fold within the delta-, to 7.6 fold within the theta-, to 1.4 fold within the alpha-, and to 2.4 fold within the beta frequency band. The power ratio decreased significantly. Such a pronounced EEG slowing with delta and theta augmentation was never found during nonstandardized hyperventilation. We conclude that a consistent slowing of the qEEG in all leads including a constant topographical maximum can only be induced by standardized, sufficiently pronounced hyperventilation.