Hemorrhagic Stroke
A hemorrhagic stroke is damage to brain tissue resulting from bleeding inside the skull.
 See the figure Sites of Brain Hemorrhage.
There are two main types of hemorrhagic strokes: intracerebral hemorrhage and subarachnoid hemorrhage. Intracerebral hemorrhages occur within the brain. Subarachnoid hemorrhages occur between the inner layer (pia mater) and middle layer (arachnoid mater) of the tissue covering the brain (meninges).
Bleeding inside the skull can also result in epidural and subdural hematomas, which are usually caused by a head injury and cause different symptoms (see Section 6, Chapter 87).
Intracerebral Hemorrhage
An intracerebral hemorrhage is bleeding within the brain.
Intracerebral hemorrhage accounts for about 10% of all strokes but for a much higher percentage of deaths due to stroke. Among people older than 60, intracerebral hemorrhage is more common than subarachnoid hemorrhage. Causes of intracerebral hemorrhage include high blood pressure and, in older people, fragile blood vessels. Bleeding disorders and use of anticoagulants increase the risk of dying from an intracerebral hemorrhage.
Symptoms and Diagnosis
An intracerebral hemorrhage begins abruptly. In about half of the people, it begins with a severe headache. Neurologic symptoms develop and steadily worsen. They include weakness, paralysis, numbness, loss of speech or vision, and confusion. Symptoms worsen as the hemorrhage expands. Nausea, vomiting, seizures, and loss of consciousness are common and may occur within seconds to minutes.
Doctors can often diagnose intracerebral hemorrhages on the basis of symptoms and the results of a physical examination. However, computed tomography (CT) or magnetic resonance imaging (MRI) is usually performed when a stroke is suspected. Both procedures can help doctors distinguish a hemorrhagic stroke from an ischemic stroke. The procedures can also detect how much brain tissue has been damaged and whether pressure is increased in other areas of the brain.
A spinal tap (lumbar puncture) is not usually performed. A spinal tap can cause herniation of the brain (see Section 6, Chapter 87), a life-threatening disorder, when pressure within the skull is increased, as it is in people who have had a hemorrhagic stroke.
Treatment and Prognosis
Treatment of a hemorrhagic stroke differs from that of an ischemic stroke. Anticoagulants, thrombolytic drugs, and antiplatelet drugs (such as aspirin) are not given, and surgery may save the person's life. The goal of surgery is to remove blood that has accumulated in the brain and to relieve the resulting increased pressure.
Stroke due to intracerebral hemorrhage is more dangerous than ischemic stroke. The stroke is usually large and catastrophic, especially in people who have chronic high blood pressure. More than half of the people who have large hemorrhages die within a few days. Those who survive usually recover consciousness and some brain function as the body absorbs the leaked blood. Even after surgery, many people continue to have some neurologic symptoms. Symptoms may include weakness, paralysis, loss of sensation on one side of the body, or difficulty understanding and using language (aphasia (see Section 6, Chapter 82)). However, people with small hemorrhages recover to a remarkable degree.
Subarachnoid Hemorrhage
A subarachnoid hemorrhage is sudden bleeding into the space (subarachnoid space) between the inner layer (pia mater) and middle layer (arachnoid mater) of the tissue covering the brain (meninges).
Usually, the cause is the sudden rupture of an aneurysm in a cerebral artery or a blood vessel (arteriovenous) malformation of the arteries or veins in or around the brain. An aneurysm may rupture because of the pressure of blood inside the artery; hemorrhage and stroke may result. An arteriovenous malformation may be present at birth, but it is identified only if symptoms develop. It may cause bleeding, usually during adolescence or young adulthood, and sudden collapse, stroke, and death may result.
Rarely, atherosclerosis or a bacterial infection damages a blood vessel, causing it to rupture. Ruptures can occur in people of any age but are most common between the ages of 25 and 50. A subarachnoid hemorrhage can also result from a head injury. A subarachnoid hemorrhage is the only type of stroke more common among women than among men.
Symptoms and Diagnosis
Before rupturing, aneurysms that cause subarachnoid hemorrhages usually produce no symptoms. However, aneurysms sometimes press on a nerve or leak small amounts of blood before a major rupture, thereby producing warning signs, such as headache, facial pain, double vision, or other visual problems. The warning signs can occur minutes to weeks before the rupture. People should always report such symptoms to a doctor immediately, because steps may be taken to prevent a massive hemorrhage.
A rupture usually produces a sudden, severe headache, often followed by a brief loss of consciousness. Some people remain in a coma, but more people wake up, feeling confused and sleepy. Blood and cerebrospinal fluid around the brain irritate the layers of tissue covering the brain (meninges), producing headaches, vomiting, and dizziness. Frequent fluctuations in the heart rate and in the breathing rate often occur, sometimes accompanied by seizures. Within hours or even minutes, people may again become sleepy and confused. About 25% of people have neurologic symptoms, usually paralysis on one side of the body.
A subarachnoid hemorrhage can usually be diagnosed using computed tomography (CT), which pinpoints the site of bleeding. Spinal tap (lumbar puncture), if necessary, can detect any blood in the cerebrospinal fluid. Cerebral angiography (see Section 6, Chapter 77) is usually performed within 72 hours to confirm the diagnosis and to identify the site of the aneurysm or arteriovenous malformation causing the bleeding, so that surgery can be performed.
Treatment and Prognosis
People who may have had a subarachnoid hemorrhage are hospitalized immediately and instructed to avoid exertion. Analgesics such as opioids (but not aspirin or other nonsteroidal anti-inflammatory drugs) are given to control the severe headaches. Occasionally, a drainage tube may be placed in the brain to relieve pressure. Nimodipine, a calcium channel blocker, is usually given to prevent spasm of an artery. This drug helps prevent late spasm and ischemic stroke.
For people who have an aneurysm, surgery that isolates, blocks off, or supports the walls of the weak artery reduces the risk of fatal bleeding later. These procedures are difficult, and regardless of which one is used, the risk of death is high, especially for people who are in a stupor or coma. The best time for surgery is somewhat controversial and must be decided based on the person's situation. Most neurosurgeons recommend operating within 3 days of the start of symptoms, before the brain becomes swollen and inflamed. Delaying the operation 10 or more days reduces the risks of surgery, but bleeding is more likely to recur in the longer interim.
A common procedure is placement of a metal clip across the aneurysm, which prevents blood from entering the aneurysm and thus eliminates the risk of rupture. The clip remains in place permanently. People who had clips placed years ago cannot undergo MRI; newer clips are not affected by the magnetic forces.
An alternative procedure, called neuroendovascular surgery, involves the insertion of coiled wires into the aneurysm. The coils are placed using a catheter inserted into an artery and threaded to the aneurysm. Thus, this procedure does not require that the skull be opened. By slowing blood flow through the aneurysm, the coils promote clot formation, which seals off the aneurysm.
About 35% of people who have a subarachnoid hemorrhage due to an aneurysm die during the first episode because of extensive brain damage. Another 15% die within a few weeks because of subsequent bleeding. People who survive for 6 months but who do not have surgery for the aneurysm have a 3% chance of another rupture each year. The outlook is better when the cause is an arteriovenous malformation. Occasionally, the hemorrhage is caused by a small defect that is not detected by cerebral angiography because it has already sealed itself off. In such cases, the outlook is very good.
Many people recover most or all mental and physical function after a subarachnoid hemorrhage. However, neurologic symptoms, such as weakness, paralysis, loss of sensation on one side of the body, or difficulty understanding and using language (aphasia (see Section 6, Chapter 82)), sometimes persist.
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