Intracranialhaemorrhageisableedinsidetheskull.Itcanbesplitintointra-axialorextra-axial.
Intra-axial,bleedwithinthebrainitself(intraparenchymal,intraventricular);orExtra-axial,bleedbetweenthebrainandtheskull(extradural,subdural,subarachnoid)Asopposedtoextracranialhaemorrhage(outsidetheskull),i.e.softtissuebruising/haematoma.
Alucidintervalreferstoaninitialdecreaseinconsciouslevel(GCS)duetotheinitialconcussionfromaheadinjury,whichthenimprovesforaperiodoftime(usuallyafewhours)beforedeterioratingagain,thistimeduetoagraduallyenlarginghaematomacausing