The vast majority of strokes (about 95% of them) are either ischemic or hemorrhagic strokes. Symptoms are identical in both cases, however the hemorrhagic form of stroke is the most severe and devastating one.
Ischemic stroke is consecutive to a blockage inside of a brain blood vessel, due to a clot, following either a rupture of an atheroma* plaque or the migration of an embolic clot that was formed in the heart of a patient with atrial fibrillation. As the blood does not reach brain tissue, neuronal cells are deprived from oxygen and nutrients, then they die.
Hemorrhagic stroke, or intrecerebral hemorrhage, is consecutive to a leakage of blood from a brain artery. Blood vessel rupture is associated with vessel wall stiffness that follows chronic tobacco use, hypercholesterolemia** or hypertension. The blood in the brain induces death of neuronal cells around. Also, the hematoma inside of the crane is compressive, which further deteriorates brain tissue.
*Atheroma : Modification of the blood vessel structure that is consecutive to the deposition of cholesterol, then inducing inflammation and a high risk of plaque rupture. This is a chronic process that develops all along life.
**Hypercholesterolemia : above normal level of cholesterol in the blood