Webster's New World Medical Dictionary

encephalitis, West Nile
See 
West Nile virus.
encephalomyelitis
Inflammation of both the
brain and the spinal cord. Encephalomyelitis can 
be caused by a variety of conditions, including
viruses that infect the nervous system. One type 
of encephalomyelitis, acute disseminateden-
cephalomyelitis, occurs most commonly after an
acute viral infection, such as measles (rubeola). It
is due to an autoimmune attack on the nervous sys-
tem, meaning that the immune system mistakenly
attacks body tissue that it believes to be the measles
virus. Also known as myeloencephalitis.
encephalopathic syndrome
A dangerous con-
dition that is associated with lithium toxicity.
encephalopathy, mitochondrial
See 
MELAS
syndrome.
enchondroma
A common benign tumor of carti-
lage within bone. Enchondroma most often appears
as a bony nodule in the hand or foot of a patient
aged 10 to 30 years. Pain may be a sign of a fracture
or malignant transformation. If fracture occurs, the
enchondroma may be treated with removal and
bone grafting. No treatment is needed if there are no
symptoms. Enchondromas rarely become malignant
as chondrosarcomas.
enchondromatosis
See 
Ollier’s disease.
encopresis
The inability to control the elimina-
tion of stool. Encopresis can have a variety of
causes, including inability to control the anal
sphincter muscle or gastrointestinal problems, par-
ticularly chronic diarrhea and Crohn’s disease.
Several neurological disorders, including Tourette
syndrome and obsessive-compulsive disorder, are
also occasionally associated with the symptom of
encopresis, particularly in children. Preventive care
for encopresis includes frequent scheduled toileting
and the wearing of pads or diapers to prevent
embarrassing soiling. Careful cleaning is important
to prevent skin breakdown. Treatment of encopresis
usually involves treatment of the underlying disor-
der; cognitive behavioral therapy or behavior mod-
ification is also sometimes helpful. Also known as
fecal incontinence.
endarterectomy
An operation to clear an artery
of accumulated cholesterol-containing matter along
its inner wall to restore normal blood flow. An
endarterectomy removes diseased material from the
inside of an artery, and also removes any occluding
atheromatous deposits, the aim being to leave a
smooth lining within the vessel, so the blood can
flow freely. See also 
atherosclerosis.
endemic
Present in a community at all times, but
occurring in low frequency. For example, malaria is
endemic in some areas of the world. In comparison
to endemic, epidemic denotes a sudden outbreak,
and pandemic denotes an epidemic that spreads
across a region. See also 
epidemic; pandemic.