Facts on File Encyclopedia of Health and Medicine

apparent for weeks to months after the bleeding.
Some people have significant permanent conse-
quences such as PARALYSIS, SEIZURE DISORDERS, and
cognitive dysfunction. Many people who recover
have minimal permanent consequences, particu-
larly when diagnosis and treatment are immedi-
ate. 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 ACCIDENTSor 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 ski-
ing, 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 anticoag-
ulant medications (“blood thinners”) or who con-
sume excessive amounts of ALCOHOL have
increased risk for brain hemorrhage because these
substances slow the blood’s ability to clot. People
who have MARFAN SYNDROMEalso have increased
risk for brain hemorrhage as this congenital disor-
der causes abnormalities in the blood vessel struc-
tures.
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 can-
cer that originates elsewhere in the body). About
75 percent of cancerous brain tumors are metasta-
tic. 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 con-
tained.

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 life-

threatening more quickly than a tumor growing

elsewhere in the brain. As well, some areas of the

brain, again such as the brainstem, are inopera-

ble—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 infil-

trate (spread into) the tissues and supportive

structures of the brain. Many brain tumors con-

tain 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 HEADACHEcan be

among the symptoms of brain tumor, most

headaches, even those that are severe, do notindi-

cate 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, NAUSEAand VOMITING, and

weakness or PARALYSISon one side of the body.

The diagnostic path begins with a PERSONAL

HEALTH HISTORYand NEUROLOGIC EXAMINATION, with

brain tumor 235