Bacterial meningitis in infancy: effects on intracranial pressure and cerebral blood flow velocity.

The effects of acute bacterial meningitis on intracranial pressure (ICP) and cerebral blood flow velocity (CBFV) were studied in four older infants (mean age, 5.75 months) and in four newborns. ICP and CBFV were affected in the older infants, but not in the newborns. In the older infants, ICP was markedly elevated in the first 2 days of illness (mean peak ICP, 240 mm H2O). With resolution of intracranial hypertension in the next few days, CBFV increased approximately 80%. In the newborns, there was no marked elevation of ICP or change in CBFV. Impaired cerebral perfusion, due to intracranial hypertension, is a potential cause of brain injury in older infants. Other mechanisms of brain injury may be more important in newborns.