[Aspects of cerebral circulation in children].

Investigation of cerebral circulation represents an essential diagnostic adjunct to pediatric neurology. Doppler-sonography is presented as one of the diverse techniques to examine cerebral hemodynamics. The human cerebral circulation is controlled by autoregulatory mechanisms. Factors such as hematocrit, pulse, orthostasis and physical activity modulate the cerebral blood supply. The demand for blood depends essentially on arterial pCO2 but also on behavioural situations such as mental activity, effect of sensory stimuli or sleep. Bioelectric activity and perfusion of the central nervous system are closely linked. The cerebral perfusion in infants is characterized by a rapid increase in flow over the first couple of years to values exceeding those of adults. Disturbances of the cerebral perfusion are found in a variety of pediatric diseases. The patterns of perinatal brain damage depend on the maturity of the newborn. They are mainly sequels of impaired cerebral perfusion. In prematures periventricular leukomalacia and intracerebral hemorrhage are frequent whereas in infants at term cerebral edema and infarcts are more common. Acute hemiplegia in childhood can be of thromboembolic or vascular origin, however of etiologies different from those in adulthood. Prevention is the best treatment for disturbances of cerebral perfusion in childhood. Continuous monitoring techniques and pharmacotherapy need further clinical investigation.