Alterations of intracranial pressure and cerebral blood flow velocity in healthy neonates and their implication in the origin of perinatal brain damage.

Intracranial pressure and cerebral blood flow velocity were recorded in term healthy neonates during the first 3 days of life using non-invasive methods (LADD-fontanometry and cw-Doppler sonography). Intracranial pressure increased from 4.0 +/- 2.7 cm H2O to 5.8 +/- 2.7 cm H2O and maximal cerebral blood flow velocity in the anterior cerebral artery (ACA) increased from 33 cm/s to 58 cm/s as calculated from a Doppler shift of 0.63 to 1.10 kHz and vascular resistance decreased between the 1st and 3rd day of life. These alterations could not be demonstrated in the femoral artery. This is in accordance with other registrations obtained by different methods and under various conditions. They allow an explanation of some well known physiological phenomena like alterations of cranial volume and the structure of the bony skull in the first days of life. Furthermore, these physiological variations may have implications for the origin of cerebral damage during the perinatal period, especially of hypoxic-ischaemic encephalopathies.