The brain tries to compensate for injury through reorganisation of functional networks, but neuronal tissue is irreplaceable once lost and therefore functional recovery is usually incomplete. Studies to prevent neuronal loss in chronic progressive diseases such as Alzheimer's disease and in acute conditions such as stroke are ongoing. However, ischaemic and haemorrhagic strokes present an extra layer of complexity because the injury can quickly grow in the acute phase, commonly resulting in death or severe disability through increased intracranial pressure, herniation, and other consequences of the mass effect.