CEREBRAL HAEMORRHAGE
CEREBRUM
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 haemorrhage
Bleeding within
the brain due to a ruptured blood vessel
(see
intracerebral haem orrhage; stroke).
cerebral palsy
A 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
(involuntary writhing
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 haem orrhage
.
Cerebral palsy may not be recognized
until well into the baby's
1
st 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 thrombosis
The 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 fluid
A 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 accident
Sudden 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
thrombosis
or
embolism.
Rupture
of vessels may cause
intracerebral haem -
orrhage
or
subarachnoid haem orrhage
.
cerebrovascular disease
Any 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.
cerebrum
The 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
cortex
and between
areas of the cortex, central brain, and
the
brainstem
. A thick band of fibres
C
117
previous page 115 BMA Illustrated Medical Dictionary read online next page 117 BMA Illustrated Medical Dictionary read online Home Toggle text on/off