Hemispheric CBF-alterations in the time course of focal and diffuse brain injury

Hemispheric CBF-alterations were studied in the time course of focal and diffuse-brain injury in a series of 25 head injured patients. Repeated 133 Xe CBF measurements with a mobile 10 detector system were performed in order to evaluate hemispheric CBF and cerebral vasoreactivity after change of PaCO2. Focal brain injury influenced hemispheric CBF varying in the time course: A hyperperfusion could be found within the first seven days after injury in 55 percent, whereas a hypoperfusion could be detected during the whole examination period in 18 percent. In diffuse injury we never saw such CBF abnormalities. On the other hand hemispheric CO2-reactivity was disturbed in focal and diffuse lesions, whereas a correlation between altered CBF at rest and CO2-reactivity could be only detected in 40% in focal injury. This investigations demonstrates no significant general, however, a partial influence of morphological damage upon cerebral microcirculation.