Encyclopedia of Health and Medicine

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apparent for weeks to months after the bleeding.
Some people have significant permanent consequences
such as PARALYSIS, SEIZURE DISORDERS, and
cognitive dysfunction. Many people who recover
have minimal permanent consequences, particularly
when diagnosis and treatment are immediate.
PHYSICAL THERAPY, OCCUPATIONAL THERAPY, and
speech therapy help restore maximum function.
Risk Factors and Preventive Measures
Trauma to the head, such as may occur in MOTOR
VEHICLE ACCIDENTS or falls, is the most common
cause of brain hemorrhage. Proper restraints (seat
belts and car seats) and helmets worn during
activities such as bicycle riding and downhill skiing,
help reduce the risk for head injury. Young
children and elderly adults are at highest risk for
head injury due to falls. HYPERTENSION (high BLOOD
PRESSURE) is the most significant preventable risk
factor for intracerebral hemorrhage (bleeding
within the tissues of the brain). Lifestyle factors
such as cigarette smoking, which causes changes
in the structure of the walls of the arteries, and
lack of regular physical activity can exacerbate the
effects of hypertension. People who take anticoagulant
medications (“blood thinners”) or who consume
excessive amounts of ALCOHOL have
increased risk for brain hemorrhage because these
substances slow the blood’s ability to clot. People
who have MARFAN SYNDROME also have increased
risk for brain hemorrhage as this congenital disorder
causes abnormalities in the blood vessel structures.
See also COGNITIVE FUNCTION AND DYSFUNCTION;
CONCUSSION; TRAUMATIC BRAIN INJURY (TBI).
brain tumor An abnormal growth that arises
within the tissues of the BRAIN. Brain tumors may
be noncancerous or cancerous, and cancerous
brain tumors may be primary (originate in the
brain) or metastatic (spread to the brain from cancer
that originates elsewhere in the body). About
75 percent of cancerous brain tumors are metastatic.
Primary brain cancer very seldom spreads
beyond the CENTRAL NERVOUS SYSTEM (brain and
SPINAL CORD). In general noncancerous brain
tumors are easier to treat than primary cancerous
brain tumors because they tend to remain contained.
However, the tumor’s size and location are
often the more relevant factors in determining
treatment options and prognosis (prospects for
recovery). Because the cranium, which houses the
brain, is a closed space, any extra mass within it
puts pressure on the tissues of the brain that can
cause serious damage or death. Though all of the
brain is important, some areas are vital to sustain
the functions of life. A tumor growing in such an
area, such as the brainstem, may become lifethreatening
more quickly than a tumor growing
elsewhere in the brain. As well, some areas of the
brain, again such as the brainstem, are inoperable—that
is, a neurosurgeon cannot get to the
tumor to remove it. Neurologists grade (classify)
brain tumors according to their cells of origin, size,
likelihood to grow in size, and likelihood to infiltrate
(spread into) the tissues and supportive
structures of the brain. Many brain tumors contain
a combination of cell types.
TYPES OF BRAIN TUMORS
astrocytoma
chordoma
craniopharyngioma dermoid cyst
ependymoma
epidermoid cyst
ganglioglioma
ganglioneuroma
glioblastoma
glioblastoma multiforme (GBM)
glioma
hemangioblastoma
medulloblastoma (MDL) meningioma
neuroglioma
oligodendroglioma
pineal germinoma pituitary ADENOMA
primary malignant primitive neuroectodermal tumor
lymphoma
(PNET)
Symptoms and Diagnostic Path
The symptoms of a brain tumor depend on the
tumor’s location and the parts of the brain the
tumor’s presence affects. Though HEADACHE can be
among the symptoms of brain tumor, most
headaches, even those that are severe, do not indicate
a brain tumor. Disturbances of balance, motor
control (movement and coordination), special
senses (sight, smell, taste, and hearing), cognitive
function, memory, and emotions are common
general symptoms of brain tumors. Brain tumors
may also cause seizures, NAUSEA and VOMITING, and
weakness or PARALYSIS on one side of the body.
The diagnostic path begins with a PERSONAL
HEALTH HISTORY and NEUROLOGIC EXAMINATION, with