Changes in quantitative EEG and blood flow velocity due to standardized hyperventilation; a model of transient ischaemia in young human subjects.
A standardized hyperventilation (HV) procedure has been developed in which the end-tidal pCO2 was decreased to 2 kpa. In 24 young male subjects blood flow velocity and qEEG were studied before, during and after HV. This standardized hyperventilation procedure gave rise to a decrease in blood flow velocity to 40% of baseline value and highly significant qEEG changes in 3 derivations. Both relative and absolute band power estimates showed an increase in slow activity and a decrease in alpha and beta activity. The use of subtraction spectra led to a more precise and detailed presentation of these changes than the use of classical qEEG parameters. These changes were reproducible after 1 week. The effects found in the presented model of HV-induced ischaemia appeared to be twice as large as those found in a model of hypobaric hypoxia. The present model might be used to test the efficacy of anti-ischaemic drugs in young human subjects.
Kraaier
V
V
Dept. of Clinical Neurophysiology, University Hospital Utrecht, The Netherlands.
van Huffelen
A C
AC
Wieneke
G H
GH
D000328:Adult; D001783:Blood Flow Velocity; D001921:Brain / Q000503:physiopathology*; D002545:Brain Ischemia / Q000503:physiopathology*; D004569:Electroencephalography; D006801:Humans; D006985:Hyperventilation / Q000503:physiopathology; D002534:Hypoxia, Brain / Q000503:physiopathology; D008297:Male