Brain swelling, raised intracranial pressure and hypoxia-related brain injury

Abstract

Brain swelling with raised intracranial pressure and secondary hypoxic-ischaemic brain injury has a considerable adverse impact on the morbidity and mortality of traumatic head injuries. Cytotoxic oedema involves abnormal intracellular accumulation of water. Vasogenic oedema may lead to a more disproportionate accumulation of water within white matter relative to grey matter in contrast to cytotoxic oedema. Hypoxic-ischaemic conditions may promote such a leaky state and account for vasogenic oedema. Under certain circumstances, an increase in the volume of blood within the vessels within the brain and/or the leptomeninges causes engorgement of blood vessels, referred to as congestion. Congestive brain swelling can be very rapid, severe and life threatening in situations involving loss of cerebral autoregulation where the increase in blood volume appears to occur predominantly in the capillary and postcapillary bed. Advance correlation with neuroimaging may provide the most objective evidence of significant swelling and critically raised intracranial pressure.