In this lecture were going to discuss
Muscular Dystrophy in Children.
Muscular Dystrophies are a whole family
of different disorders.
They are all dysfunctional
proteins in muscle fibers and specifically
problems on Dystrophin gene
So, the most common type of muscle
dystrophy we will talk about
is Duschenne's muscle dystrophy.
There is also a slightly less,
and perhaps less severe disease
called Becker's muscular dystrophy
And this is the two that you hear
about the most.
And there are a whole
family of dystrophies.
There is Myotonic dystrophy,
Limb-girdle muscular dystrophy.
Fukuyama muscular dystrophy
The point is there are
lots of different kinds.
The one's that you should focus though
are on Duchenne's
and on Beckers.
let's talk a little bit about the dystrophin
The dystrophin protein is one of the
largest genes in the human genome.
When that is abnormal,
patients develop muscular dystrophy.
So, let's focus particularly on
is an X-linked disease.
And that it almost entirely affects males.
This is s a devastating condition.
It affects 1 in 3,500 births.
So, it is reasonably common.
it is commonly caused by new mutations.
It will be very unusual
for a patient with Duchenne's
to father a child.
So in muscular dystrophy, symptoms
typically start around three years of age.
Patients, children will develop abrnormal
And will start having pronounced muscle
They will develop Pseudohypertrophy
Pseudohpertroohy is when the muscle
is large but it is weak.
and they will develop gradual muscle
as these muscles decline.
This is Gower's sign.
This has a high likelihood of showing up
on an exam.
Typically, children will get up
and they will need to use their arms
to get themselves up off the floor.
This is because the primary muscles of
weeknesses in muscle dystrophy
and in Duchenne's are the large
trunkal muscle groups such as the buttocks
the thighs and the abdominal musculature
So, these children will literally walk
themselves up their own legs
to be able to stand up.
This is pathognomonic for muscular
dystrophy and almost all of them do this
as part of one of their initial
because it is only recent that they were
actually walking when the symptoms
starts rearing its ugly head.
Diagnosis is essentially clinical.
When you see proximal muscle weakness
in a young boy.
Especially a 3 year old boy, this is
often the diagnosis.
Additionally, important lab findings
are muscle breakdown
Patients will have a very elevated
CK or creatine kinase.
This is because that protein
is extruded by the muscle as it degenerates.
Patients will have an increased aldolase
again, extured by the muscles as they
In patients with Duchenne's,
they may have bumped
Liver Function Tests as well
slightly elevated ALT and AST.
The diagnosis if it must be made is made
by dystrophin gene testing.
We can now sequence the gene
and determine what the problem is.
Treatment for patients with
Duchenne's Muscular Dystrophy
Where there is no cure
right now for this disease.
may slow the rate of muscle degradation
but the problem is the long term effects
of steroids are so severe
that in most cases,
we choose not to use steroids.
As many of the patients in their declining
years or adolescence,
they can actually help you guide
how you want to manage their situation.
We do give patients oral
Because that can improve
muscle strength in patients with Duchenne's
But keep in mind, that doesn't help with
Beckers, which we will talk about next.
So, in Duchenne's muscular dystrophy
a lot of some specialty assistance
We need to fix them with braces
often as their teeth will grow abnormally.
Often these patients will require
Their spine will bend as the result of the
promixal muscle weakness.
So orthopedists are intimately
involved in their care.
Patients will eventually have difficulty
And as not being able to eat
and not being able to feed
is an essentially painful experience
we often end up putting
G-tubes in these patients
so they can remain satiated
as they are degenerating.
Patients often have pulmonary disease.
As they get older, and they are less able
to take deep breaths,
we will be following them with
Pulmonary Function testing
and often pumonologists are involved
to try and mitigate some of those
They will be having ineffective cough for
And so mucolytics and respiratory toilet
may be indicated.
Finally, the heart muscle is
unfortunately also involved
in these patients.
Patients with Duchenne's often
get a cardio myopathy
So, cardiologist involvement is important
to continue to monitor their cardiac output
and provide medications
that can mitigate this problem.
Typically, the course of Duchenne's
is inexorable and declining.
They typically lose the ability
entirely by 7-13 years of age.
And then they suffer a gradual respiratory
These patients develop a dilated
and that myopathy can cause shortness
congestive heart failure,
and other symptoms.
One of the questions that comes up and
every case must be handled differently,
is whether or not to place a
Tracheostomy will prolong
but it will not always
prolong the quality of life.
And involving a party of care expert maybe
necessary to help guide
these conversations in terms of
what is the best next step for patients.
Early death in patients with
Duchenne's muscular dystrophy is inevitable.
They usually die from cardiac or respiratory
And the average age of death
is around 16-20 years old.
Let's switch to Becker's muscular
In Becker's muscular dystrophy.
This is also a genetic mutation
in the dystrophin gene.
It is an X-linked mutation again.
this is almost entirely once again
occurs on boys.
This is a much milder course fortunately
And rarely, extremely mild
with only cramping.
And otherwise a fully functional individual.
The age of onset is often later
than in Duchenne's
And they typically ambulate
even to adolescence.
At this point ambulation becomes
Patients with Becker's muscular dsytrophy
also die young
but live a lot longer
than patients with Duchenne's.
The average age of death is 42, plus or
minus 16 years.
That is a brief summary of Becker
and Duchenne's muscular dystrophy
Thank for your attention.