The sudden onset of neurologic dysfunction as the result of a cerebrovascular event. The sudden onset of neurologic dysfunction as the result of a cerebrovascular event. Strokes are considered either ischaemic, which is the most common type and includes thrombotic and embolic etiology, or hemorragic, in which blood leaks from a weakened vessel because of aneurysms or vascular malformations.
The ischemic threshold of cerebral perfusion for membrane failure is around 8 ml/100 g/min. Therefore damage can be reversed if blood flow can be elevated. The rapid recovery from neurological deficit after a cerebral stroke is often attributed to the recovery of function of the cells in this area of partial ischemia or the ischemic penumbra. Alterations in tissue water and electrolytes and edema in trauma and ischemia are responsible for some of the early changes in first-stage recovery.