Attacks may last several months. After a
variable remission period, a relapse
occurs, which may be precipitated by
injury, infection, or stress. Some people
have mild relapses and long periods of
remission, with few permanent effects.
Some people become gradually more
disabled from the first attack. A few suf-
fer gross disability within the 1st year.
There is no single diagnostic test, but
MRImay show damage to white matter
in the brain. Evoked responsetests on
the eyes also provide strong evidence.
There is no specific treatment. Some
people claim that dietary modifications
such as sunflower or evening primrose
oils are beneficial. In some cases,inter-
feron beta can extendthe time between
attacks and reduce the rate of decline.
multivitaminsOver-the-counter prepa-
rations, containing a combination of
vitamins, that are used as a dietary sup-
plement. (Seevitamin supplements.)
mumpsAn acute viral illness, mainly of
childhood. The main symptom is in-
flammation and swelling of one or both
of the parotid glandssituated inside the
angle of the jaw. One attack of mumps
confers lifelong immunity. Since routine
MMR vaccination, epidemics of mumps
no longer occur.
The mumps virus is spread in airborne
droplets. The incubation periodis 2–3
weeks; an affected person is infectious
for about a week before and up to 2
weeks after symptoms appear.
Infected children often have no symp-
toms, or they may feel slightly unwell
and have some discomfort around the
parotid glands. In more serious cases,
there is pain around the glands and
chewing becomes difficult; one or both
glands then become swollen, painful,
and tender. A fever and headache may
develop. The swelling subsides within a
week to 10 days. When only one gland is
affected, the second often swells as the
first gland’s swelling subsides. Complica-
tions of mumps include viral meningitis,
pancreatitis, and epididymo-orchitis.
Diagnosis is usually made from the
symptoms. There is no specific treatment.
Munchausen’s syndromeA chronic
factitious disorderin which the sufferer
complains of physical symptoms thatare pretended or self-induced in order
to play the role of patient. Most afflict-
ed people are repeatedly hospitalized.
The usual complaints are abdominal
pain, bleeding, neurological symptoms,
rashes, and fever. Sufferers typically
invent dramatic histories and behave
disruptively in hospital. Many have
detailed medical knowledge and scars
from self-injury or previous treatment.
In Munchausen’s syndrome by proxy,
parents cause factitious disorders in
their children.
Treatment consists of protecting suf-
ferers from unnecessary operations and
drug treatments.
mupirocinA topical antibacterialcream
or ointment used to treat skin infec-
tions such as impetigo.
murmurA sound caused by turbulent
blood flow through the heart, as heard
through a stethoscope.
Heart murmurs are regarded as an
indication of possible abnormality in
the blood flow. Apart from “innocent”
murmurs, the most common cause of
extra blood turbulence is a disorder
of the heart valves. Murmurs can also
be caused by some types of congenital
heart disease (see heart disease, con-
genital) or by rarer conditions such as a
myxomain a heart chamber.
muscleA structure composed of bun-
dles of specialized cells capable of
contraction and relaxation to create
movement. There are 3 types of muscle:
skeletal, smooth, and cardiac.
The skeletal muscles are the most
prominent in the body (see muscular
system). They are called voluntary mus-
cles because they are under conscious
control. Skeletal muscles are composed
of groups of muscle fibres arranged in
bundles called fascicles. A fibre is made
up of longitudinal units called myofib-
rils, the working units of which are
filaments of actin and myosin (two pro-
teins that control contraction). A state of
partial contraction is constantly main-
tained – this is muscle tone.
Smooth muscle is concerned with the
movements of internal organs. It is not
under conscious control; for this rea-
son, it is also called involuntary muscle.
Smooth muscle is made up of long,MULTIVITAMINS MUSCLEM