Cerebral hematoma involves bleeding into the cerebrum, the largest section of the brain, resulting in an expanding mass of blood that damages surrounding neural tissue.
A hematoma is a swelling of blood confined to an organ or tissue, caused by hemorrhaging from a break in one or more blood vessels. As a cerebral hematoma grows, it damages or kills the surrounding brain tissue by compressing it and restricting its blood supply, producing the symptoms of stroke. The hematoma eventually stops growing as the blood clots, the pressure cuts off its blood supply, or both.
Cerebral hematomas are categorized by their diameter and estimated volume as small, moderate, or massive. The neurologic effects produced by a cerebral hematoma are quite variable, and depend on its location, size, and duration (length of time until the body breaks down and absorbs the clot). Additional bleeding into the ventricles, which contain the cerebrospinal fluid (CSF), may occur. Blood in the CSF presents a risk for further neurologic damage.
Intracerebral hematoma (ICH) is another frequently used term for the condition. The initials "ICH" may also be seen in different places denoting several related conditions—an intracerebral hematoma is due to an intracerebral hemorrhage, which is one type of intracranial hemorrhage. However, the causes and symptoms of all three are roughly the same.
The two basic types of stroke are hemorrhagic (including ICH) and ischemic (blockage in a blood vessel). Each year 700,000 people in the United States, or about 1 in 50 individuals, experience a new or recurrent stroke. Of these, about 12% are due to intracranial hemorrhage. Stroke kills an estimated 170,000 people each year in the United States, and is the leading cause of serious, long-term disability. Thirty-five percent of individuals suffering a hemorrhagic stroke die within 30 days, while the one-month mortality rate for ischemic stroke is 10%.
Stroke occurs somewhat more frequently in men than in women. Compared to whites, the incidence of first-occurrence strokes in most other ethnic groups in the United States is slightly higher, except African-Americans, whose rate is nearly twice as high. In adults, the risk of stroke increases with age. The highest risk for stroke in children is in the newborn period (especially in premature infants), with an incidence of 1 in 4000. The risk then decreases throughout childhood to a low of 1 in 40,000 in teen-agers. Twenty-five percent of strokes in children are due to intracranial hemorrhage.
Causes and symptoms
The most frequent causes of intracranial hemorrhage, including ICH, are:
- Hypertension-induced vascular damage
- Ruptured aneurysm or arteriovenous malformation (AVM)
- Head trauma
- Diseases that result in a direct or indirect risk for uncontrolled bleeding
- Unintended result from the use of anticoagulant (anticlotting) or thrombolytic (clot dissolving) drugs for other conditions
- Complications from arterial amyloidosis (cholesterol plaques)
- Hemorrhage into brain tumors
Preventable factors that increase the risk for stroke include chronic hypertension, obesity, high cholesterol (atherosclerosis), sedentary lifestyle, and chronic use of tobacco and/or alcohol. These factors primarily increase the risk for ischemic stroke, but play a role in ICH as well.
As previously noted, a massive ICH can result in sudden loss of consciousness, progressing to coma and death within several hours. For small and moderate hemorrhages, the usual symptoms are sudden headache accompanied by nausea and vomiting, and these may remit, recur, and worsen over time. Other, more serious symptoms of stroke include weakness or paralysis on one side of the body (hemiparesis/hemiplegia), difficulty speaking (aphasia), and pronounced confusion with memory loss. Seizures are not a common symptom of ICH. Hydro-cephalus—increased fluid pressure in the brain—may result if pressure from the hematoma or a clot obstructs normal circulation of the CSF. Again, the severity and type of symptoms depend greatly on the location and size of the hematoma.
Symptoms may indicate the possibility of an ICH, but the diagnosis can only be made by visualizing the hematoma using either a computed tomography (CT) or magnetic resonance imaging (MRI) scan. In some cases, more sophisticated imaging methods such as functional-MRI, SPECT, or PET scans can be used to visualize damaged areas of the brain.
An ICH producing mild symptoms might prompt a direct or referred visit to a neurologist, while individuals with more serious symptoms are first seen by hospital emergency room staff. Once the diagnosis of ICH is made, other specialists consulted or involved could include a neurosurgeon, radiologist, neurologist, and intensive care unit (ICU) staff. Long-term care might involve a psychiatrist/psychologist, dietitian, occupational/physical/speech therapists, rehabilitation specialists, and health professionals from assisted-living facilities or home-care agencies.
Initial treatments in patients who have lost consciousness involve stabilizing any affected systems such as respiration, fluid levels, blood pressure, and body temperature. In many cases, monitoring intracranial pressure (ICP) is critical, since elevated ICP poses a serious risk for coma and death. Management of elevated ICP can be attempted with medication or manipulation of blood oxygen levels, but surgery is sometimes required. The possibility of further hemorrhaging in the brain poses a serious risk, and requires follow-up imaging scans.
If an ICH is detected very early, a neurosurgeon may attempt to drill through the skull and insert a small tube to remove (aspirate) the blood. Once the blood has clotted, however, aspiration becomes more difficult or impossible. Surgery to remove a hematoma is usually not advised unless it threatens to become massive, is felt to be life-threatening, or is causing rapid neurologic deterioration.
Recovery and rehabilitation
Recovery and rehabilitation centers around regaining as much neurologic function as possible, along with developing adaptive and coping skills for those neurologic problems that might be permanent. Recovery from neurologic injury caused by hemorrhagic stroke is frequently long and difficult, but there are many sources of information and support available.
Rehabilitation is most often done on an outpatient basis, but more serious cases may require nursing assistance at home or institutional care. Those who lapse into a coma or persistent vegetative state will need 24-hour professional care, and may take days, months, or years to recover, or they may never recover.
Research is under way to develop effective, safer medications and methods to both stop a hemorrhage while it is occurring, and dissolve clots within the brain once they have formed. Direct injection of a local-acting clotting agent into an expanding hematoma, or of a thrombolytic drug, such as recombinant tissue plasminogen activator (rt-PA), into the clot are two avenues of research.
The prognosis after an ICH varies anywhere from excellent to fatal, depending on the size and location of the hematoma. However, ICH is the most serious form of stroke, with the highest rates of mortality and long-term disability, and the fewest available treatments. Only a small proportion of patients with an ICH can be given a good or excellent prognosis.
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Brain Aneurysm Foundation. 12 Clarendon Street, Boston, MA 02116. 617-723-3870; Fax: 617-723-8672. <http://www.bafound.org>.
Brain Injury Association. 8201 Greensboro Drive, Suite 611, McLean, VA 22102. 800-444-6443; Fax: 703-761-0755. <http://www.biausa.org>.
Brain Trauma Foundation. 523 East 72nd Street, 8th Floor, New York, NY 10021. 212-772-0608; Fax: 212-772-0357. <http://www.braintrauma.org>.
National Institute on Disability and Rehabilitation Research (NIDRR). 600 Independence Ave., S.W., Washington, DC 20013-1492. 202-205-8134. <http://www.ed.gov/offices/OSERS/NIDRR>.
National Rehabilitation Information Center (NARIC). 4200 Forbes Boulevard, Suite 202, Lanham, MD 20706-4829. 800-346-2742; Fax: 301-562-2401. <http://www.naric.com>.
National Stroke Association. 9707 East Easter Lane, Englewood, CO 80112-3747. 800-787-6537; Fax: 303-649-1328. <http://www.stroke.org>.
Scott J. Polzin, MS, CGC