Webster's New World Medical Dictionary

cerebral hemisphere
One of the two halves of
the cerebrum, which is the largest part of the brain.
cerebral palsy
An abnormality of motor function
(the ability to move and control movements) that is
acquired at an early age, usually less than 1 year,
and is due to a brain lesion that is nonprogressive.
Abbreviated CP. CP is frequently the result of abnor-
malities that occur while a fetus is developing inside
the womb. Such abnormalities may include acci-
dents of brain development, genetic disorders,
stroke due to abnormal blood vessels or blood
clots, or infection of the brain. In rare instances,
obstetrical accidents during particularly difficult
deliveries can cause brain damage and result in CP.
CP can take three forms: spastic, choreoathetoid,
and hypotonic (flaccid). In spastic CP, there is an
abnormality of muscle tone in which one or more
extremities (arms or legs) are held in a rigid pos-
ture. Choreoathetoid CP is associated with abnor-
mal, uncontrollable writhing movements of the
arms and/or legs. A child with hypotonic CP appears
floppy—like a rag doll. Treatment may include the
use of casting and braces to prevent further loss of
limb function, speech therapy, physical therapy,
occupational therapy, the use of augmentative com-
munication devices, and the use of medications or
botulism toxin (botox) injections to treat spasticity.
cerebral ventricle
One of a system of four com-
municating cavities within the brain that are contin-
uous with the central canal of the spinal cord. They
include two lateral ventricles in the cerebral hemi-
spheres, each consisting of a triangular central body
and four horns. The lateral ventricles communicate
with the third ventricle through an opening called
the interventricular foramen. The third ventricle, a
median (midline) cavity in the brain, is bounded by
the thalamus and hypothalamus on either side. In
front, the third ventricle communicates with the lat-
eral ventricles, and in back it communicates with
the aqueduct of the midbrain (also known as the
aqueduct of Sylvius). The fourth ventricle, which is
the lowest of the four ventricles of the brain, extends
from the aqueduct of the midbrain to the central
canal of the upper end of the spinal cord, with
which it communicates, through the two foramina
of Luschka and the foramen of Magendie. The ven-
tricles are filled with cerebrospinal fluid.