蛛网膜下腔出血

概述

蛛网膜下腔出血是指大脑和周围膜（蛛网膜下腔）之间的间隙出血。主要症状是突发的剧烈头痛。有些人描述说，这是他们经历过的最严重的头痛。除了头痛，有些人可能会出现：

• 恶心
• 呕吐
• 颈部僵硬
• 视力问题
• 短暂的意识丧失

出血通常是由于脑血管中的异常隆起（动脉瘤）破裂所致。有时出血是由创伤、脑部血管缠结（脑动静脉畸形）或其他血管或健康问题引起的。

如果不治疗，蛛网膜下腔出血可能导致永久性脑损伤或死亡。

症状

The most common symptom of a subarachnoid hemorrhage is a very sudden, very bad headache. The headache starts in a split second and becomes very painful right away. Some people describe it as the worst headache they have ever had.

Along with a sudden headache, symptoms may include:

• Nausea.
• Vomiting.
• Stiff neck or neck pain.
• Changes in vision.
• Brief loss of consciousness.

When to see a doctor

A subarachnoid hemorrhage is a medical emergency.

Get immediate medical attention if you experience a very sudden, very bad headache or if you have other symptoms of a subarachnoid hemorrhage. This is especially important if you have been diagnosed with a brain aneurysm or if you have experienced a head injury.

If you're with someone who complains of a very bad headache that came on suddenly or who loses consciousness, call 911 or your local emergency number.

病因

A subarachnoid hemorrhage may be caused by:

• A brain aneurysm that bursts. A brain aneurysm is a bulge in a blood vessel in the brain. The aneurysm can burst and cause bleeding in the space between the brain and the tissues covering the brain, known as the subarachnoid space. A brain aneurysm is the most common cause of a subarachnoid hemorrhage.
• Head injury. Another common cause is a head injury. A head injury from an auto accident, fall or violence can lead to a subarachnoid hemorrhage.
• A tangle of blood vessels in the brain, known as an arteriovenous malformation. This irregular tangle of blood vessels can rupture and cause bleeding in the brain.
• Swelling of the blood vessels, known as vasculitis. This can cause the walls of the blood vessels to thicken and narrow. Vasculitis can lead to a blood clot or an aneurysm.

风险因素

Some risk factors for a subarachnoid hemorrhage are not under your control. They include:

• Being an older age. Most subarachnoid hemorrhages that result from an aneurysm occur in people between ages 55 and 60. Women in their 50s and 60s, in particular, have a higher risk.
• Having a first-degree relative with a brain aneurysm. This includes a parent, child or sibling related by blood
• Having certain health conditions. Conditions that increase the risk of a subarachnoid hemorrhage include Ehlers-Danlos syndrome, Marfan syndrome, neurofibromatosis type 1 and polycystic kidney disease.

People who have two or more first-degree relatives with brain aneurysms or who have had a subarachnoid hemorrhage can get screened.

Other risk factors for a subarachnoid hemorrhage can be avoided. They include:

• Having high blood pressure.
• Smoking.
• Misusing alcohol.
• Using drugs such as cocaine and methamphetamine.