Subarachnoid hemorrhage (SAH) refers to a clinical syndrome caused by the rupture of a diseased vessel at the base or surface of the brain and the direct flow of blood into the subarachnoid space, which is clinically classified into two categories: traumatic (secondary) and non-traumatic (spontaneous).
Non-traumatic subarachnoid hemorrhage is a common and highly lethal disease, with aneurysm as the main cause, accounting for about 85% of all cases. Other causes include non-aneurysmal hemorrhage around the midbrain, vascular malformations, dural arteriovenous fistulas, coagulation disorders, cocaine use, and pituitary stroke.
In recent years, there have been significant advances in vascular interventional techniques, diagnostic methods and perioperative management. However, the prognosis for patients with subarachnoid hemorrhage remains poor, with a 45% morbidity and mortality rate and a high disability rate among survivors.