turns; inability to play quietly alone;
and physical impulsiveness. Children
with ADHD may have difficulty in form-
ing friendships. Self-esteem is often low
because an affected child is frequently
scolded and criticized.
Treatment includes behaviour modifi-
cation techniques, both at home and at
school. In some children, avoidance of
certain foods or food additives seems to
reduce symptoms. In severe cases, stim-
ulant drugs, usually methylphenidate,
may be prescribed. Paradoxically, the use
of stimulants in ADHD reduces hyper-
activity and improves concentration. In
general, the condition improves by ado-
lescence but may be followed by
antisocial behaviour and drug abuseor
substance abuse.
audiogramA graph produced as a
result of audiometrythat shows the
hearing threshold (the minimum audi-
ble decibel level) for each of a range of
sound frequencies.
audiologyThe study of hearing, espe-
cially of impaired hearing that cannot
be corrected by drugs or surgery.
audiometryMeasurement of the sense
of hearing. The term often refers to hear-
ing testsin which a machine is used to
produce sounds of a defined intensity
and frequency and in which the hearing
in each ear is measured over the full
range of normally audible sounds.
auditory nerveThe part of the vestibu-
locochlear nerve(the 8th cranial nerve)
concerned with hearing.
auraA peculiar “warning” sensation that
precedes or marks the onset of a mi-
graineattack or of a seizure in epilepsy.
A migraine attack may be preceded by a
feeling of elation, excessive energy, or
drowsiness. Thirst or a craving for sweet
foods may develop. Migraine may be her-
alded by flashing light before the eyes,
blurred or tunnel vision, or difficulty in
speaking. There may also be weakness,
numbness, or tingling in 1 half of the body.
An epileptic aura may be a distorted
perception, such as a hallucinatory smell
or sound. One type of attack (in people
with temporal lobe epilepsy) is often
preceded by a vague feeling of discom-
fort in the upper abdomen and followed
by a sensation of fullness in the head.auranofinA goldpreparation used as
an antirheumatic drugin the treatment
of rheumatoid arthritis. Unlike other gold
preparations, auranofin is taken orally.
auricleAnother name for the pinna, the
external flap of the ear. The term is also
used to describe ear-like appendages of
the atria (see atrium) of the heart.
auriscopeAn instrument for examining
the ear, also called an otoscope.
auscultationThe procedure of listening
to sounds within the body by using a
stethoscope. Some organs make sounds
during normal functioning, such as the
movement of fluid through the stomach
and intestine, the opening and closing
of heart valves (see heart sounds), and
the flow of air through the lungs. Abnor-
mal sounds may indicate disease.
autismA rare condition in which a child
is unable to relate to people and situa-
tions. Autism is more common in boys.
It is by definition evident before the age
of 30 months and is usually apparent in
the 1st year of life. The precise causes
of autism are unknown. Often, autistic
children seem normal for the 1st few
months of life before becoming increas-
ingly unresponsive to parents or other
stimuli. Extreme resistance to change
of any kind is an important feature. The
child reacts with distress to alteration
in routine or interference with activities.
Rituals develop in play, and there is
often attachment to unusual objects or
obsession with one particular idea. Delay
in speaking is common and most autis-
tic children have a low IQ. Behavioural
abnormalities may include rocking, self-
injury, screaming fits, and hyperactivity.
Despite these symptoms, appearance
and muscular coordination are normal.
Some autistic people have an isolated
special skill, such as an outstanding
rote memory or musical ability.
There is no effective treatment for aut-
ism, which is lifelong. Special schooling,
support and counsellingfor families,
and sometimes behaviour therapycan
be helpful. Medication is useful only for
specific problems, such as hyperactivity.
The majority of autistic people need
special, sometimes institutional, care.
autism spectrum disordersA range
of developmental disorders, usuallyAUDIOGRAM AUTISM SPECTRUM DISORDERSA