EPILEPSY
EPIPHYSIS
entrance to the
larynx
(voice-box). The
epiglottis is usually upright to allow air
to pass through the larynx and into the
rest of the respiratory system. During
swallowing, it tilts downward to cover
the entrance to the larynx, preventing
food and drink from being inhaled.
E
epiglottitis
A potentially life-threaten-
ing infection causing inflammation and
swelling of the
epiglottis
.
Epiglottitis is
now rare due to routine
immunization
of
infants against
Haemophilus influenzae,
the causative bacterium.
epilepsy
A tendency to have recurrent
seizures
. In many people with epilepsy,
the cause is unclear, although a genetic
factor may be involved. In other cases,
seizures may be the result of brain dam-
age from
head injury
, birth trauma,
brain infection (such as
meningitis
or
encephalitis
),
brain tumour
,
stroke
,
drug
intoxication, or a
metabolic disorder
.
Many people with epilepsy do not
have any symptoms between seizures.
Some people experience an
aura
shortly
before. In some cases, a stimulus such
as a flashing light triggers a seizure.
Epileptic seizures may occur more fre-
quently in times of illness or stress.
Epileptic seizures can be classified in-
to two groups: generalized and partial.
Generalized seizures cause loss of con-
sciousness and may affect all areas of
the brain. There are two types: grand
mal and absence (petit mal) seizures.
During a grand mal seizure, there may
be an aura initially, then the body
becomes stiff and consciousness is lost;
breathing may be irregular or may stop
briefly, then the body jerks uncontrol-
lably. The person may be disorientated
for hours afterwards and have no mem-
ory of the event. Prolonged grand mal
seizures are potentially life-threatening.
Absence seizures occur mainly in chil-
dren. Periods of altered consciousness
last for only a few seconds and there are
no abnormal movements of the body.
This type of seizure may occur hundreds
of times daily.
Partial seizures are caused by abnor-
mal electrical activity in a more limited
area of the brain. They may be simple or
complex. In simple partial seizures, con-
sciousness is not lost and an abnormal
twitching movement, tingling sensa-
tion, or
hallucination
of smell, vision, or
taste occurs, lasting several minutes. In
complex partial seizures, also known as
temporal lobe epilepsy
, conscious con-
tact with the surroundings is lost. The
sufferer becomes dazed and may behave
oddly. Typically, the person remembers
little, if any, of the event.
Diagnosis is made from examination
of the nervous system and an
EEG
.
CT
scanning
or
MRi
of the brain and blood
tests may also be carried out.
Anticon-
vulsant drugs
usually stop or reduce the
frequency of seizures. Surgery may be
considered if a single area of brain
damage is causing the seizures. Epilep-
sy that develops during childhood may
disappear follow-
ing adolescence.
epiloia
See
tuber-
ous sclerosis
.
epinephrine
An
alternative name
for
adrenaline
.
epiphora
See
wa-
tering eye.
epiphysis
The end
section of a long
bone (such as the
femur) separated
from the
diaph-
ysis
(shaft) by the
epiphyseal plate.
During childhood and adolescence, the
ephiphyseal plate is made of cartilage
but is gradually replaced by bone.
ADULT LONG BONE
206
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