RELATIONSHIP OF CEREBRAL OXYGEN-UPTAKE TO EEG FREQUENCY IN ISOLATED CANINE BRAIN

Cerebral O2 uptake was correlated with EEG frequency and amplitude in 87 isolated canine brains. Group I (71 brains) was perfused with diluted blood and group II (16 brains) was perfused with whole blood equilibrated with O2 at various partial pressures. The EEG were classified as follows: A, highest frequency .gtoreq. 17 Hz, .alpha. (8-13 Hz) amplitude < 50 .mu.V, .delta. (.ltoreq. 3.5 Hz), amplitude < 100 .mu.v; B, highest frequency .gtoreq. 17 Hz, .alpha. amplitude .gtoreq. 50 .mu.V, and/or .delta. amplitude .gtoreq. 100 .mu.V. C, highest frequency 8-16 Hz, .alpha. amplitude .gtoreq. 25 .mu.V, and .delta. amplitude > 100 .mu.V, D, highest frequency 0.5-16 Hz, .alpha., if present, amplitude < 25 .mu.V, and/or .delta. amplitude < 100 .mu.V, and E, highest frequency 0-16 Hz, .alpha., if present, amplitude < 10 .mu.V, and/or .delta. amplitude < 15 .mu.V. The group I O2 uptakes in ml/100 g of brain per min .+-. SE for the 5 EEG classifications were A, 4.39 .+-. 0.06, B, 4.13 .+-. 0.08, C, 3.76 .+-. 0.09, D, 3.40 .+-. 0.12, and E, 2.55 .+-. 0.60, whereas the corresponding group II values were A, 4.64 .+-. 0.22, B, 4.28 .+-. 0.15, C, 3.82 .+-. 0.24, D, 3.39 .+-. 0.40, and E, 1.38 .+-. 0.42. As the EEG deteriorated, cerebral O2 uptake tended to decrease in a significant and parallel manner in both the diluted and whole blood groups.