Critical Appraisal of Cerebral Blood Flow Measured from Brain Stem and Cerebellar Regions

Validity of regional cerebral blood flow (rCBF) measurements recorded over the human posterior fossa after Xe inhalation was tested. Recording of counts from both brain stem and cerebellum (BSC) was reproducible and contamination by counts derived from surrounding anatomical structures was low and no greater than that found over hemispheres. BSC values were F, = 99 ± 19 ml/lOOg brain/min, F2 = 17 ± 4 in reasonable agreement with data reported from experimental animals. BSC flow values showed significant correlation with the state of awareness as judged by clinical and EEG evaluation with lowest F, values in semicoma and step increases in stupor, non-REM sleep, drowsiness, rest, activation, REM sleep and highest values during focal and generalized epileptic seizures. Stroke Vol 10, No 4,1979