A subarachnoid hemorrhage is bleeding that occurs in a specific area of the brain when a blood vessel ruptures. The most common cause in people with healthy blood vessels is a trauma, such as a head injury suffered in a car accident. The rupture of an aneurysm (a dilated and weakened blood vessel) can also be the cause of a subarachnoid hemorrhage, as can other abnormal blood vessel formations that rupture and leak blood into the subarachnoid space. This type of stroke can develop suddenly or gradually and produce reversible, permanent or fatal damage.
The brain and spinal cord have a covering composed of three layers, or meninges, of tissue. Their names are; in order from the inside, the closest to the brain, to the outside: pia mater, arachnoid and the dura mater. A subarachnoid hemorrhage occurs when a blood vessel ruptures and bleeds in the space between the arachnoid and the pia mater.
The most notorious symptom can be severe headache; It can arise in minutes or develop over a period of weeks. Abnormal bleeding can cause confusion, drowsiness, or other changes in mental status, such as irritability. Unexplained vomiting, seizures, neck pain and dilation of one or both pupils may be signs of a subarachnoid hemorrhage. Patients may also have focal neurological problems, which include numbness or paralysis. However, the presence of these symptoms does not necessarily indicate a subarachnoid hemorrhage. Some conditions that may have similar symptoms are: migraine, meningitis (which is an infection or inflammation of the layers that line the brain) and other types of strokes.
Cerebral aneurysms make individuals prone to damage, ruptures, and hemorrhages in blood vessels at any time. Age, sex and lifestyle also contribute to the risk of subarachnoid hemorrhage. Tobacco use and a high-sodium diet increase the chances of subarachnoid hemorrhage, especially in people with other risk factors, such as high blood pressure and middle to old age. Women and people with a family history of aneurysms or stroke have a higher incidence of subarachnoid hemorrhage than the general population.
Doctors diagnose the disease by observing common symptoms and imaging studies, such as computed tomography (CT). Subarachnoid hemorrhage is a medical emergency, and survival or preservation of brain functions may require rapid intervention.
Treatment depends on the cause and severity of the bleeding. It may include life-sustaining procedures, such as the placement of a breathing tube and the supply of anticonvulsant medications or to control blood pressure. It may be necessary to change the position of the body to relieve tension in the subarachnoid area; Doctors can perform emergency surgery to stop the bleeding or change the pressure in the skull. The results of the treatment are variable and range from complete recovery to death.