INTRODUCTION anterior-horn cell degeneration. Furthermore, histological studies conclude

INTRODUCTION

Muscular
dystrophy is a group of inherited diseases which are characterized due to skeletal
muscle weakness and degeneration. This is a progressive disorder because it
will replace the healthy muscle fibers into fibrosis and fat, making muscle
tissues less capable of generating force for daily activity. Respiration of the
patient is badly affected with this disorder resulting into the weakening of
breathing muscles which limits the lifespan of the patient unless manage. As
muscle wasting ensues; patients experience weakness, although muscle groups may
be targeted differently in specific forms of muscular dystrophy. Respiratory
failure, resulting from the weakening of breathing muscles, may limit lifespan
in muscular dystrophy unless manage. In some forms of muscular dystrophy, the
heart can also be affected which results into cardiac complications including
heart failure and irregular heart rhythms.

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

Duchenne
muscular dystrophy (DMD) shows it symptoms in early childhood with progressive
muscle wasting and weakness and leading to death in late adolescence. It was a familial
disorder where only boys are affected; in this case the spinal cord at necropsy
was normal. Therefore, this was a disease of muscle (myogenic) and was not
secondary to anterior-horn cell degeneration. Furthermore, histological studies
conclude that the muscle membrane or sarcolemma was broken down and destroyed.
This observation seems to be important since it shows that the primary defect
resides in the sarcolemma (Meryon, 1851).

 

 

 

 

 

PATHOPHYSIOLOGY

            Duchenne muscular dystrophy (DMD) causes
muscle weakness in as early as the age of 3, affecting muscles of hip, pelvic
area, thighs and shoulders and later on skeletal (voluntary) muscles in the
arms, legs, and trunk. By the early teens heart is affected. Boys with DMD show
signs of muscle weakness early in childhood, typically between 2 and 7 years of
age, and often lose ambulation around the time of puberty. DMD boys may have
delayed development of motor skills such as sitting, walking and talking.
Beginning at about 10years of age, the diaphragm and other muscles which
operates the lungs will be affected and weaken causing the lungs to become less
active in moving in and out. Although child may not complain in the shortness
of breath other problems can occur including headaches, mental dullness,

            This disorder is familial which is
inherited in an X linked patterns, due to the fact that the gene which carry
DMD causing mutation is found in the X chromosome. Every boy inherits a X
chromosome from his mother and Y chromosome from his father which makes him a
male. On the other hand, girls get two X chromosomes, one from each parent. If
a male baby was born having a mother with a dystrophy mutation on one of her X chromosome,
the baby boy has a 50% chance to inherit it, while each female baby has a 50%
chance inheriting the gene as well as to be a carrier. Carriers may not have
symptoms but can pass it towards her child. It is not impossible that the
family with no signs or history of having this disorder may have it in their
next generations due to this two reason; first, is that genetic mutations
heading to DMD may have existed in females without knowing it perhaps no male
children were born with this disorder. Second, is that the child having DMD
arose a new genetic mutation on the mother’s egg cell and not to the blood cells
which are impossible for any carrier testing can detect it. Mothers giving
birth had a much greater possibility to pass the mutation to her children
compare to their husband that could not passed flawed gene since he will give Y
chromosome unless he may have a daughter. There are such called DMD carriers
which are oftentimes females having a mutated dystrophin gene on one of their X
chromosome while having an abnormal one on the other. Most of them don’t have
any signs of symptoms but others do. This disorder seems rare in girls because
when a girl inherit a flawed dystrophin gene from one parent, she usually also
gets a healthy dystrophin from the other parent, giving her enough protein to protect
her. Males who inherit the mutation et the disease because they have no second
destrophin gene to make up the faulty one.

Studies
show some degree of muscle weakness oftentimes 5–10% of the female carriers.
Such weakness is often asymmetric, which may not develop until adult life, and
could also be slowly progressive or static. Because weakness is essentially
proximal in this disorder, there is in need of genetic counseling in order to
differentiate Duchenne muscular dystrophy from limb-girdle muscular dystrophy.

 

 

 

 

 

 

 

 

 

 

CLINICAL MANIFESTATION

             

Weakness
is mainly and progressive in this disorder. Patients suffer difficulties in
running and, later, climbing stairs in there early childhood due to the weakness
of their knee and hip. Some degree of mental impairment is usual with an IQ of
less than 70 for about 20% of the affected boys. Most patients have enlarged
calves, hence a previous term for the disorder was pseudo hypertrophic muscular
dystrophy; however, calf hypertrophy not only is seen in Duchenne muscular
dystrophy but also is present in other dystrophies.

In
most cases, by age 12 a wheelchair becomes necessary. In this disorder
respiratory care must have more attention due to Pneumonia compounded by
cardiac involvement which is often the cause of death, which may happen in the
late teens or early 20s.

Symptoms
range into a mild skeletal muscle weakness to severe weakness or cardiac
complications can occur in as early as childhood or in adulthood. DMD can also
cause learning problems towards boy’s patient in this three general areas;
attention focusing, verbal learning /memory, and emotional interaction.  Few of them have mental retardation. Doctors
believe that a dystrophies abnormality affects the brain.

 

 

 

 

 

 

 

MEDICAL MANAGEMENT

                       

Management
of dystrophy depends on its type and severity. Due to the severity and high
frequency of Duchenne muscular dystrophy it is more concern to manage the
disorder. There is no cure for any of the dystrophies: emphasis is on
respiratory care and treatment of cardio logical complications (   ). With respect to respiratory care,
symptoms may occur which includes disturbed sleep with nightmares, early
morning headaches, and daytime drowsiness that is why there is a need of
measuring the vital capacity of the patient is needed. Furthermore, optional
tracheostomy may also do as well as assisted ventilation where the men patients
can survive into 30 years.

Patients
may have subtle effect on cognitive and behavior having difficulties in
learning but can be evaluated by a development of pediatric neuropsychologist through
the schools special education. Also can be diagnose in the educational and
psychological interaction right away to that specialist can prescribe exercises
and techniques to improve these areas as well as the school to provide special
help.  

Early
surgery for Duchenne muscular dystrophy patients is not recommended because it
fail to improve muscle strength or walking ability and also there are an
aesthetic risks that may develop later on. However, surgical correction of
contractures might be helpful in later stages and might help to preserve lung
function and possibility to prolong life for a few extra years. But the
procedure of the operation would result into significant complications.

On
the other hand, many pharmacological agents tried to treat Duchenne muscular
dystrophy, but none has proved effective. However, a study of Drachman and
colleagues in 1974, suggested a possible slowing of the disease process with no
less than 16 trials of glucocorticoids, yet it is just for short term and until
now this study needs more trials.

In
addition, an effective pharmacological agent might be found some future
prospect in treating Duchenne muscular dystrophy with a deep understanding
about its pathophysiology. Gene therapy could also be the one but undoubtedly
many problems may arrive. In a study using an mdx mouse model success have been
achieved. However, two drawbacks had arise, to ensure delivery of vector to all
important muscle groups, including the heart, and to keep the host’s
immunological response to the vector and the protein product of the transferred
gene to a minimum (      ).

Another
approach that could be possible is to upregulate a protein that could
compensate as a balance for the deficient protein. In the mdx mouse it showed a
good evidence that up regulation of utrophin ameliorates the dystrophy, hoping
that pharmacological agents can find a way to up regulate these proteins for
the human being.

Lastly
is the stem cells therapy, researchers have shown that a small proportion of
bone marrow (haemopoietic) stem cells from normal mice can relocate in the
muscle of mdx mice and produce dystrophin. This approach is especially exciting
and opens up the possibility of perhaps being able to replace
dystrophin-deficient muscle cells in the heart and elsewhere in the body with
stem cells derived from various sources.

CONCLUSION

In
conclusion, Duchenne muscular dystrophy (DMD) is a progressive disorder which
causes the weakening of the muscle due to the lack of dystrophin protein symptoms
may arise in as early as childhood of the patients. Respiratory management of
the patient must have more attention since the lungs are affected by this
disorder causing a less effective movement of the air, optional tracheotomy may
also do as well as assisted ventilation to prolong the life of the patients. This
is a familial disorder which can be passing into a generation to the next
generation through the carriers. Males are most affected with this while female
are often the carriers of DMD. There is no such cure for Duchenne muscular
dystrophy, patients must manage themselves carefully because it affects their physical
aspects such as having a difficulty in raising their hands during their school
age as well as the mental where having difficulties in focusing, verbal
learning /memory, and emotional interaction can occur. Proper management of
this disorder extend the lifespan of the patients.