Duchenne muscular dystrophy
The most common
and most severe type of muscular dystrophy is a type called Duchenne
muscular dystrophy. This causes muscles to become weak, mainly in the
legs and upper arms. The weakness starts early in childhood and
gradually increases, affecting the child's ability to walk. Generally,
boys with Duchenne muscular dystrophy need to use a wheelchair from
around the age of twelve years. From their late teenage years there can
be complications such as weakness of the breathing or heart muscles,
which need treatment.
The heart and breathing problems
eventually lead to an earlier death, so that boys with Duchenne
muscular dystrophy generally live into their twenties or late twenties
but not beyond.
Duchenne muscular dystrophy usually only affects
boys. Rarely, girls can be affected too - if so, it is a much milder
condition in girls.
If a child has Duchenne muscular dystrophy,
then women and girls in the family could be carrying the Duchenne gene
- although it is equally possible that they have normal genes. It is
possible to test family members to see if they have the Duchenne gene.
There is a separate leaflet called Duchenne Muscular Dystrophy for more information.
Becker muscular dystrophy
Becker muscular
dystrophy is much less severe than Duchenne muscular dystrophy,
although the two types have the same muscle groups affected. Symptoms
start in the teenage years or early twenties. The weakness progresses
slowly, so that in their 40s and 50s, men with this condition may have
difficulty walking. At this stage, weakness of the heart and breathing
muscles can occur and extra treatment may be needed.
Becker
muscular dystrophy usually affects only boys. However, girls in the
family might carry the Becker gene, and can be tested for this.
Facioscapulohumeral muscular dystrophy
Facioscapulohumeral
muscular dystrophy (FSH) is also called Landouzy-Dejerine or
facioscapuloperoneal muscular dystrophy. FSH can affect both men and
women.
FSH affects the muscles of the face, shoulder and upper
arm. Sometimes the legs may be affected too. Symptoms usually start
around age 40-50. The degree of muscle weakness varies a lot from
person to person. About 3 in 10 people with FSH don't notice any
symptoms. About 1 in 10 people with FSH eventually require a
wheelchair. Most people with FSH have symptoms somewhere in between
these two extremes.
Limb girdle muscular dystrophy
The limb
girdle muscular dystrophies cause weakness in the large muscles around
the top of the arms and legs. These muscles are also called the
'shoulder and pelvic girdles'. There are many different types of limb
girdle muscular dystrophies, which affect both men and women. The
symptoms and muscle weakness vary a great deal, depending on which
particular form of limb girdle muscular dystrophy you have.
Emery-Dreifuss muscular dystrophy
Emery-Dreifuss
muscular dystrophy starts in childhood or adolescence. It can affect
the muscles of the shoulders and upper arms, making it difficult to
lift heavy objects. Also, the muscles in the lower leg are affected,
which may cause tripping over when walking. Contractures (tightness) of
the muscles and joints can also occur. Emery-Dreifuss muscular
dystrophy usually progresses (increases) very slowly. People who have
this condition may need a wheelchair later in life.
Emery-Dreifuss
muscular dystrophy may also affect a part of the heart muscle which
controls the heart rate. This may cause a slow heart beat and symptoms
of giddiness or fainting. This problem can be successfully treated with
a heart pacemaker.
Congenital muscular dystrophy
Congenital
muscular dystrophy is rare (affecting about 1 in 50,000 babies). It is
actually a group of conditions which cause muscle symptoms early in
life - within the first six months of birth. The first symptoms are
poor head control, muscle weakness (making the the baby seem floppy),
or dislocated hips. Later symptoms may be a delay in the child
crawling, standing and walking; or tightness (contractures) in some
joints.
Oculopharyngeal muscular dystrophy
Oculopharyngeal
muscular dystrophy (OPMD) usually starts around the 50s or 60s. It
causes a weakness in the eye and throat muscles. The first symptoms are
droopy eyelids and difficulty swallowing. Later on, after many years,
mild limb weakness around the shoulders and hips may also develop.
How is muscular dystrophy diagnosed?
Usually
it is first suspected because of symptoms: a muscle weakness is noticed
by the patient, family or a doctor. Also, if a child has delayed motor
milestones (as mentioned above), a doctor may advise testing for
muscular dystrophy, even though the problem could be due to another
cause.
Muscular dystrophy may be diagnosed using one or more of the following tests:
- A
blood test for creatinine kinase - in many types of muscular dystrophy,
the blood level of creatinine kinase (also called CK) is very high.
- An EMG (electromyogram) - this is a recording of the electrical activity in a muscle.
- A muscle biopsy - this involves taking a small sample of muscle
under local anaesthetic. The sample is examined under the microscope
and the muscle proteins may be tested.
- Genetic analysis - this involves a testing a person's DNA using a
blood sample. It can detect many (not all) cases of muscular dystrophy.
What else could it be?
There are other medical conditions which cause muscle weakness, and might seem similar to muscular dystrophy. These are:
- Conditions called 'myopathies' - in which there is muscle weakness. Some myopathies are temporary problems and are not genetic.
- Other conditions called 'neuromuscular disorders'. This is the name
for a group of conditions which affect nerves, muscles or both. See the
further information section.
- Myotonic dystrophy. This may be classified as a type of muscular
dystrophy or as a neuromuscular disorder. It affects the 'small'
muscles, such as those in the face, jaw, neck, and hands. Myotonic
dystrophy may start at any age from birth to old age. It can affect
both men and women.
- Distal myopathies. These are very rare forms of muscle weakness
affecting the 'distal' muscles, which are those of the hands and feet.
There are different types. Most are very mild.
How is muscular dystrophy treated?
There is
no cure for muscular dystrophy, although there are treatments which can
help. The treatment offered will depend on what type of muscular
dystrophy you (or your child) has. You may be referred to a specialist,
who will be able to give you more information on the condition and on
the treatment options. See further information below, for more details.
As a general guide, treatment may involve:
- Firstly,
obtaining an accurate diagnosis of the condition. You may see a doctor
who specialises in muscular or genetic conditions. In some cases, the
specialist may suggest that other family members be tested to see if
they carry a muscular dystrophy gene.
- Physiotherapy to help keep the joints mobile.
- For some types of muscular dystrophy such as Duchenne type, treatment with steroid medicine helps to maintain muscle strength.
- Practical aids or help may be needed, for example, a splint, wheelchair or equipment for the home.
- For some types of muscular dystrophy, regular checkups are needed to assess and treat any complications.
Further help and information
The Muscular Dystrophy Campaign
61 Southwark Street, London SE1 0HL
Helpline: 0800 652 6352
Web: www.muscular-dystrophy.org
This is a UK charity for all muscular dystrophies, neuromuscular
disorders and related conditions. It funds research, offers help and
advice, and provides information and support.
References
© EMIS and PiP 2008 Updated: 21 Feb 2008
