craniopharyngiomaA rare, non-hor-
mone-secreting tumour of the pituitary
gland. Symptoms of a craniopharyngi-
oma may include headaches, vomiting,
and defective vision. If a craniopharyn-
gioma develops in childhood, growth
may become stunted and sexual develop-
ment may not occur. Craniopharyngiomas
are usually removed surgically. Untreated,
they may cause permanent brain damage.
craniosynostosisThe premature closure
of one or more of the joints (sutures)
between the curved, flattened bones of
the skullin infants. If all the joints are
involved, the growing infant’s brainmay
be compressed and there is a risk of brain
damage from pressure inside the skull.
If the abnormality is localized, the head
may be deformed. Craniosynostosis may
occur before birth and, in some cases,
is associated with other birth defects. It
may also occur in an otherwise healthy
baby, or in a baby affected by a disorder
such as rickets. If the brain is com-
pressed, an operation may be performed
to separate the fused skull bones.
craniotomyThe temporary removal of
a section of the skull to perform an
operation on the brain. A craniotomy
may be used in order to take a sample
of tissue for analysis, remove a tumour,
or drain an abscessor blood clot.
craniumThe part of the skull around the
brain.
C-reactive proteinA protein produced
in the body in response to inflammation.
creamA thick, semi-solid preparation
with moisturizing properties used to
apply medications to the skin.
creatinineA waste product produced
by muscles and filtered from the blood by
the kidneys to be excreted in urine.
creatinine clearance See kidney func-
tion tests.
crepitationA crackling sound in the
lungs (heard through a stethoscope)
caused by abnormal build-up of fluid.
(See also auscultation.)
crepitusA grating sound or sensation
caused by rough surfaces rubbing to-
gether. Crepitus may be felt or heard
when the ends of a broken bone rub
against each other, or when cartilageon
the surfaces of a joint has worn away in
osteoarthritis. Faint crepitus can be heard
in the lung as a result of, for example,
inflammation in pneumonia. Crepitus
also describes the sound made when air
under the skin (see emphysema, surgi-
cal) or gasgangreneis pressed.
cretinismA congenitalcondition char-
acterized by stunted growth and failure
of normal development, and, in infants,
coarse facial features. Cretinism results
when the thyroid glandfails to produce
or produces insufficient amounts of the
thyroid hormone thyroxine at birth.
Replacement therapy with thyroxine is a
cure, provided the condition is recog-
nized early. (See also hypothyroidism.)
Creutzfeldt–Jakob diseaseA rare,
rapidly progressive degenerative condi-
tion of the brain. Creutzfeldt–Jakob
disease (CJD) is thought to be due to an
infection with a prion (slow virus). This is
similar to the agent that causes scrapie
in sheep and bovine spongiform en-
cephalopathy(BSE) in cattle. One main
variant of CJD largely affects middle-
aged or elderly people and has no
obvious cause. A second main variant,
occurring in younger people, is associ-
ated with contamination during brain
surgery or transplants from infected
people, or treatment with human growth
hormone or gonadotrophin hormones.
Recently, a 3rd variant, called new vari-
ant (nv) CJD, that attacks people in their
teens and 20s has been identified.
NvCJD causes pathological changes in
the brain similar to those seen in BSE-
infected cattle. It is thought to be
acquired by eating infected beef.
Symptoms are similar for all variants.
Progressive dementia and myoclonus
(sudden muscular contractions) occur;
muscular coordination diminishes; the
intellect and personality deteriorate; and
blindness may develop. As the disease
progresses, speech is lost and the body
becomes rigid. There is no treatment and
death usually occurs within 2–3 years.
cri du chat syndromeA rare, congenital
condition of severe mental handicap,
abnormal facial appearance, low birth
weight, and short stature, which is
characterized by a cat-like cry in infancy.
The syndrome is caused by a chromo-
somal abnormality. There is no treatment.
(See also genetic counselling.)CRANIOPHARYNGIOMA CRI DU CHAT SYNDROME
C