Hyperfrontal pattern of human cerebral circulation. Variations with age and atherosclerotic state.

The phenomenon of relative hyperperfusion of the frontal areas of the cerebral cortex (hyperfrontal flow distribution) was analyzed in 84 patients between 13 and 78 years of age. Fifty-two patients (group 1) had histories of vascular disease or vascular risk factors, and 32 (group 2) did not. Regional cerebral blood flow was measured by an atraumatic xenon Xe 133 method. The mean hemispheric gray-matter flow was found to decrease similarly with age in the two groups. Other findings were as follows: (1) the level of flow within the frontal region was not homogeneous in young adults; (2) in group 1, the frontal hyperperfusion decreased progressively with age, disappearing during the fifth and sixth decades according to a specific topographic pattern; (3) in group 2, hyperperfusion persisted into old age; and (4) hyperperfusion appeared more persistent with age in women than in men.