muscle tendons and the labyrinth in the
inner ear via the brainstem to the cere-
bellum. Working with the basal ganglia
(nerve cell clusters deep within the
brain), the cerebellum uses this data to
fine tune messages sent to muscles
from the motor cortex in the cerebrum.
cerebral haemorrhageBleeding within
the brain due to a ruptured blood vessel
(see intracerebral haemorrhage; stroke).
cerebral palsyA disorder of posture
and movement resulting from damage
to a child’s developing brain before,
during, or immediately after birth, or in
early childhood. Cerebral palsy is non-
progressive and varies in degree from
slight clumsiness of hand movement
and gait to complete immobility.
A child with cerebral palsy may have
spastic paralysis(abnormal stiffness of
muscles), athetosis(involuntarywrithing
movements), or ataxia(loss of coordina-
tion and balance). Other nervous system
disorders, such as hearing defects or
epileptic seizures, may be present. About
70 per cent of affected children have
mental impairment, but the remainder
are of normal or high intelligence.
In most cases, damage occurs before
or at birth, most commonly as a result
of an inadequate supply of oxygen to the
brain. More rarely, the cause is a mater-
nal infection spreading to the baby in
the uterus. In rare cases, cerebral palsy
is due to kernicterus. Possible causes
after birth include encephalitis, meningitis,
head injury, or intracerebral haemorrhage.
Cerebral palsy may not be recognized
until well into the baby’s 1st year. Ini-
tially, the infant may have hypotonic
(floppy) muscles, be difficult to feed, and
show delay in sitting without support.
Although there is no cure for cerebral
palsy, much can be done to help affected
children using specialized physiotherapy,
speech therapy, and techniques and
devices for nonverbal communication.
cerebral thrombosisThe formation of
a thrombus(blood clot) in an artery in
the brain. The clot may block the artery,
cutting off the supply of blood, nutri-
ents, and oxygen to a region of the
brain, causing a stroke.
cerebrospinal fluidA clear, watery fluid
that circulates between the ventricles
(cavities) within the brain, the central
canal in the spinal cord, and the space
between the brain and spinal cord and
their protective coverings, the meninges.
Cerebrospinal fluid functions as a shock-
absorber, helping to prevent or reduce
damage to the brain and spinal cord
after a blow to the head or back. It con-
tains glucose, proteins, salts, and white
blood cells. Examination of the fluid, usu-
ally obtained by lumbar puncture, is used
to diagnose disorders such as meningitis.
cerebrovascular accidentSudden rup-
ture or blockage of a blood vessel in the
brain, causing serious bleeding and/or
local obstruction to blood circulation,
and leading to a stroke. Blockage may be
due to thrombosisor embolism. Rupture
of vessels may cause intracerebral haem-
orrhageor subarachnoid haemorrhage.
cerebrovascular diseaseAny disease
affecting an artery in, and supplying
blood to, the brain: for example, athero-
sclerosis(narrowing of the arteries) or
defects or weaknesses in arterial walls
causing aneurysm(a balloon-like swelling
in an artery). The disease may eventually
cause a cerebrovascular accident, which
commonly leads to a stroke. Extensive
narrowing of blood vessels throughout
the brain can be a cause of dementia.
cerebrumThe largest and most devel-
oped part of the brain, the site of most
conscious and intelligent activities. Its
main components are 2 large cerebral
hemispheres that grow out from the
upper part of the brainstem. Their sur-
face is made up of a series of folds
called gyri, separated by fissures called
sulci, with a deep longitudinal fissure
separating the 2 hemispheres. The 4
main surface regions of each hemi-
sphere – the frontal, parietal, temporal,
and occipital lobes – are named after
their overlying bones. Each hemisphere
has a central cavity, called a ventricle,
filled with cerebrospinal fluid. This is
surrounded by an inner layer, consisting
of clusters of nerve cells called the
basal ganglia. A middle layer of “white
matter” is composed mainly of nerve
fibres, which carry information between
specific areas of the cortexand between
areas of the cortex, central brain, and
the brainstem. A thick band of fibresCEREBRAL HAEMORRHAGE CEREBRUM
C