A stroke is a neurological deficit resulting from a sudden breakdown of blood flow in a region of the brain. It occurs as a consequence of the obstruction or rupture of a blood vessel and induces the death of neurological tissues, as they are deprived of the oxygen and nutrients that are essential to their functions. Two types of vascular failure are referred as Ischemic stroke (blood vessel obstruction) or Hemorrhagic stroke (blood vessel rupture).
Ischemic stroke, caused by the obstruction of blood vessels in the brain, accounts for 85% of stroke cases worldwide. It is the consequence of the formation of a blood clot consecutive to either the rupture of an atherosclerotic plaque on the wall of the artery, or the migration of a clot formed in the heart of a patient with a cardiac disease called atrial fibrillation.
Spontaneous intracerebral hemorrhage, or hemorrhagic stroke, is the second most common type, accounting for 30% of strokes with geographic variations between 15% and up to 50% in China. A stroke is consecutive to a blood leak from a cerebral artery following a spontaneous rupture of this vessel. This rupture is the result of the stiffening of the vessels caused by smoking, hypercholesterolemia or high blood pressure. Hemorrhage leads to a deprivation of blood supply from the cerebral region vascularized by the vessel while blood that accumulates outside of the vessel leads to an increase in the pressure responsible for brain damage in the region located around the hematoma.
Intracerebral hemorrhage leads to a life-threatening prognosis and the risk of severe disability with dependency. 30-day mortality is 30% to 50%, half of which occurs within 2 days of the accident. Only 25% of patients maintain functional autonomy at 6 months. The mean age of onset of stroke is 69 years, with a high incidence in professionally active population.
The sequelae depend on the region of the brain affected, and include: