ENCEPHALOMYELITIS
reverse it. However, giving up smoking
w ill greatly reduce the rate at w hich the
lungs deteriorate. The efficiency of the
remaining lung tissue may be improved
in various ways. For example,
broncho-
dilator drugs
may be given to widen the
bronchioles and patients who are defi-
cient in alphaj-antitrypsin may be given
replacement alphaj-antitrypsin therapy.
To treat oedema,
diuretic drugs
may
help to reduce the volume of fluid in the
body by promoting its output through
increased urine production. If the blood
oxygen level is continually low,
oxygen
therapy
at home may be needed.
People who have a localized area of
emphysema in one lung may be offered
surgery to remove the affected area of
tissue, w hich w ill allow the remaining
lung tissue to re-expand. A single lung
transplant operation (see
transplant sur-
gery
)
may be considered if respiratory
failure is life-threatening.
emphysema, surgical
The abnormal presence of air in tissues
under the skin following surgery or
injury. Surgical emphysema most com-
monly
occurs
as a
complication
of
pneumothorax
(the abnormal presence of
air in the pleural cavity between the
lung and the chest wall).
empirical treatment
Treatment that is given simply on the
grounds that its effectiveness has been
observed
in
previous,
similar
cases.
Empirical
treatment
is
different
to
treatment that is based on an under-
standing of the nature of a disorder and
the way in w hich the particular method
of treatment works.
empyema
An accumulation of
pus
in a body cavity
or an internal organ. Empyema can
occur around a lung as a rare complica-
tion of an infection such as
pneumonia
or
pleurisy
.
The main symptoms are
chest pain, breathlessness, and fever.
Treatment is generally by
aspiration
(re-
moval of the pus by suction) and the
injection of
antibiotic drugs
.
An opera-
tion to open the chest cavity and drain
the pus may sometimes be performed.
Empyema of the
gallbladder
is a com-
plication of
cholecystitis
(inflammation
of the gallbladder), causing abdominal
pain, fever, and
jaundice
(yellowing of
the skin and the whites of the eyes).
This type of empyema is treated by sur-
gical removal of the gallbladder.
EMU
An
abbreviation
for
early
morning
urine, a specimen of urine collected on
the patient’s first visit to the toilet after
waking up. This type of urine specimen
is often requested in an investigation for
tuberculosis
affecting the kidney.
emulsifying ointment
A type of
emollient
containing emulsify-
ing wax, white soft paraffin, and liquid
paraffin. Emulsifying ointment is used
to smooth, soothe, and hydrate the skin
in all dry or scaling conditions. Rarely,
ingredients such as preservatives may
result in skin sensitization.
enalapril
An
ACE inhibitor drug
that is used in the
treatment of
hypertension
(high blood
pressure) and
heart failure
(a reduced
pumping efficiency of the heart). The
drug inhibits a chemical reaction that
causes blood vessels to constrict, and
thus allows vessels to dilate (widen); as
a result, it lowers blood pressure and
reduces the workload of the heart.
One side effect of enalapril is a sud-
den drop in blood pressure on taking
the first
dose.
For
this
reason,
the
patient should rest while the dose is
taken and for two or three hours after-
wards. More common adverse effects of
the drug include headaches and dizzi-
ness; these effects should diminish with
continued treatment.
enamel, dental
The hard outer layer of a tooth (see
teeth
)
that protects the inner structures.
encephalitis
Inflammation of the
brain
,
and some-
times
also
the
meninges
(the
three
membranes that cover and protect the
brain and the spinal cord), usually due
to a viral infection. Encephalitis varies
in severity from a m ild problem, in
w hich symptoms are barely noticeable,
to a serious and potentially life-threat-
ening disorder.
CAUSES
M ild cases of encephalitis may be due to
glandular fever (see
mononucleosis, infec-
tious
) or may be a complication of viral
diseases such as
mumps
or
measles
.
In Europe, the most common cause of
life-threatening
encephalitis
is
herpes
simplex
.
In South-east Asia,
Japanese B
encephalitis
,
due to a virus spread by
mosquitoes, is the most dangerous type.
Occasionally, outbreaks of viral enceph-
alitis occur elsewhere in the world; for
example, an outbreak of
West Nile virus
,
another mosquito-borne form of the
disease, occurred in New York in 1999.
People with
HIV
are particularly at risk
from severe viral encephalitis, and may
also develop cerebral abscesses (collec-
tions of pus in the brain tissue).
SYMPTOMS
M ild cases of encephalitis usually de-
velop over several days and may cause
only a slight fever and mild headache. In
serious cases of encephalitis, the symp-
toms
develop
rapidly
and
include
weakness or
paralysis
;
speech, memory,
and hearing problems; and a gradual loss
of consciousness.
Coma
(a state of uncon-
sciousness
and
unresponsiveness
to
external stimuli) and
seizures
may also
occur. If the meninges are inflamed, cer-
tain other symptoms (for example, a stiff
neck and abnormal sensitivity to light)
may develop (see
meningitis
) .
DIAGNOSIS AND
TREATMENT
Diagnosis is based on results of blood
tests;
CTscanning
or
MRI
(techniques that
produce cross-sectional or three-dimen-
sional images
of the brain);
EEG
(a
method of recording the electrical activ-
ity of the brain);
lumbar puncture
(taking
a sample of fluid from the spinal canal
for analysis); and, very occasionally, a
brain
biopsy
(removal of a small sample
of tissue for analysis).
Encephalitis due to herpes simplex is
treated with
intravenous infusion
of the
antiviral
drug
aciclovir
,
but
there
is
no known treatment for encephalitis
caused by other viral infections.
encephalitis lethargica
An epidemic form of
encephalitis
(brain
inflammation). There
have
been
no
major outbreaks of the condition since
the 1920s, but rare sporadic cases still
occur. Symptoms of encephalitis leth-
argica are those of encephalitis, with
additional lethargy and drowsiness.
Many survivors of the initial illness
during the major epidemics developed a
movement disorder that became known
as post-encephalitic
Parkinson’s disease.
encephalocele
A type of
neural tube defect
resulting in
defects of the brain rather than of the
spinal cord, as occurs in
spina bifida
.
encephalomyelitis
Inflammation of the
brain
and
spinal
cord
,
resulting in damage to the
nervous
system
,
usually due to a viral infection.
E
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