is especially effective when children who have
cerebral palsy are young. Parents and physical
therapists work together with stretching exercises
to keep muscles from contracting and activities
that improve coordination and balance. Speech
and swallowing therapy teaches methods for gain-
ing optimal muscle control. Physical therapy is
often a long-term, even lifelong, process with spe-
cific methods for the stages of development a child
goes through during the process of growing up.
Continued physical therapy often is helpful for
adults who have cerebral palsy, helping to keep
them as independent as possible.
Surgical approaches include THALAMOTOMY(tar-
geted ablation, or destruction) of cells in the thala-
mus, a brainstem structure that helps regulate
voluntary movement, operations to lengthen con-
tracted muscles, and RHIZOTOMY(selectively cutting
segments of spinal nerve roots to block nerve sig-
nals to reduce spasticity). Many people who have
cerebral palsy are able to live fairly independently
with assistive devices and mobility aids. Comput-
ers are especially valuable tools, with adaptive
technology to allow a person who has extreme
mobility limitations to communicate.
Risk Factors and Preventive Measures
Most often doctors do not know the exact causes
of cerebral palsy, even when they can correlate
the presentation to specific windows of prenatal
development or to perinatal or postnatal events.
Appropriate and consistent PRENATAL CAREhelps a
woman maintain a pregnancy that is as healthy as
possible, reducing the risk not only for cerebral
palsy but also for other complications and condi-
tions that could harm the unborn child. Among
the known causes of cerebral palsy, some are pre-
ventable and others are not.
See also ATAXIA; ATHETOSIS; CONTRACTURE; QUALITY
OF LIFE; REFLEX; SPASM.
cerebrospinal fluid The liquid that circulates
between the arachnoid mater and pia mater, the
middle and inner MENINGESsurrounding the BRAIN
and SPINAL CORD. Its purpose is to cushion and pro-
tect these structures. Specialized cells that line the
choroid plexuses (ventricular structures within the
brain) produce cerebrospinal fluid at a rate of
about 500 milliliters (mL) every 24 hours, though
the amount of cerebrospinal fluid in circulation is
only 150 mL. The vascular arachnoid mater
absorbs cerebrospinal fluid into the BLOODcircula-
tion. Cerebrospinal fluid is 99 percent water that
contains electrolytes, GLUCOSE (sugar), and pro-
teins. The composition, color, and pressure of
cerebrospinal fluid are important diagnostic char-
acteristics, which a neurologist may assess using
LUMBAR PUNCTURE. In health cerebrospinal fluid is
sterile so the presence of BACTERIA or another
PATHOGENis diagnostic of INFECTION.CEREBROSPINAL FLUID
color clear
volume 150 milliliters
pressure 100 to 200 millimeters of water
white blood cells > 5 per cubic millimeter
red blood cells none
GLUCOSE 60 to 80 milligrams per deciliter (mg/dL)
protein 20 to 45 mg/dL
sodium 138 milliequivalents per liter (mEq/L)
chloride 119 mEq/L
potassium 2.8 mEq/LFor further discussion of cerebrospinal fluid
within the context of the structures and functions
of the NERVOUS SYSTEM, please see the overview sec-
tion “The Nervous System.”
See also BRAIN HEMORRHAGE; BRAIN TUMOR;
ENCEPHALITIS; MENINGITIS; MULTIPLE SCLEROSIS; NEURO-
LOGIC EXAMINATION.chorea Rapid, irregular, and involuntary move-
ments that occur as a result of damage to struc-
tures of the BRAIN, notably the basal ganglia and
subthalamic nucleus, that regulate voluntary MUS-
CLEfunction. The word choreais from the Greek
word for “dance.” Researchers believe chorea rep-
resents damage to the mechanisms within these
structures that ordinarily suppress extraneous
NERVEsignals to the muscles. Such damage allows
the signals through, creating confused and exces-
sive motor response. Chorea often occurs in com-
bination with ATHETOSIS (called choreoathetosis)
and is a symptom rather than a condition.
Chorea usually involves the arms and legs
though may also involve the face and trunk. The
movements of chorea appear randomly and seem
to flow from one part of the body to the other,chorea 241