Muscular Dystrophy Flashcards
What would an EMG of a child with MD reveal?
Progressive loss of muscle contractility as the
myofibrils are destroyed due to a missing protein (dystrophin)
How does one diagnose MD?
- Clinical examination
- EMG
- Muscle biopsy
- DNA analysis
- Enzyme levels from blood samples
What is the most common type of MD?
Duchenne’s MD
3/100,000 prevalence
1/3,500 male birth incidence
Duchenne’s MD stats
- Prevalence 3 per 100,000
- Incidence 1 in 3500 male births
- Life expectancy is late teens to twenties
- Cause of death is often respiratory or cardiac in origin
Why is it so uncommon for girls to have MD?
Diseases inherited in an X-linked recessive pattern mostly affect males, because a second X chromosome usually protects females from showing symptoms. In very rare instances, a female could have two faulty x chromosomes, where the female would most likely exhibit mild MD symptoms.
What is the primary impairment of MD?
Muscle weakness
Initial weakness usually involves:
– Neck flexors, abdominals, interscapular and hip extensors
– Quad weakness occurs shortly after
What is pseudohypertrophy?
Pseudohypertrophy (result of fatty and connective tissue infiltration) is a common symptom
– Pseudohypertrophy can give a
false impression of strength
– Calf is most always pseudohypertrophic
– Other areas sometimes affected include:
• deltoid, quadriceps and forearm
extensors
In combination with weakness and
declining activity, this impairment
severely impacts on function
Flexibility
No limitations in ROM are noted prior to
____ years of age according to book
5
But Bill disagrees
What is the order of ROM loss in MD?
• Initially, tightness is seen in the gastrocsoleus
and TFL
• This is followed by hip flexor tightness
• Knee flexor tightness
• Elbow flexor tightness
• Shoulder extensor/adductor tightness
• Finger/wrist flexor tightness
• Hip adductor tightness as child becomes non-ambulatory
_____________ and __________ are common and contribute
significantly to the respiratory
problems children with MD have
later in the disease
Scoliosis and contractures
Tightness and weakness contribute to a clinical picture of increased _________ and ____________ in children with MD
Lumbar lordosis and scapula winging
In children with MD, cognitive impairments are ________
Unusual
True or false: No significant signs of MD disability is usually noted in toddlers
True
Half of children with MD are delayed in walking until _______
18 months
Symptoms for MD are often not noticed until…
3-5 years
The mean age of diagnosis for MD is…
5 years
The initial signs of MD
- Clumsiness, falling
- Bilateral trendelenberg gait
- Increased BOS
- Decreased or loss of ability to run or jump
- Gower sign
What is the progression of symptoms of MD? (Not muscular order, symptoms in general)
- Difficulty up and down stairs
- Further increased BOS
- More pronounced trendelenberg
- Toe walking
- Decreased arm swing
4 things to keep in mind for interventions with children with MD
- Avoid over-exertion
- Avoid immobilization
- Cycling, swimming, walking
- Monitor for scoliosis
For MD, what do you stretch and what do you strengthen?
Strengthen: abdominal hip extensors hip abductors knee extensors
Stretch: gastrocsoleus hip flexors knee flexors TFL/ITB
Children with CP are typically not walking past what age?
10-12 years
What are the predictors for cessation of walking?
– inability to rise from floor – inability to ascend steps – frequent falls
– strength decrease by 50% (dynamometer)
– ROM is a key determinant (experience/book) because of c of g
True or false: most children with MD do not under go surgeries.
False
• Not uncommon in this population
– Release of hamstrings, hip adductors, hip
flexors and achilles are all common
– Usually achilles release there is a cast
– ROM as per surgeon
– Positioning immediately
– Most often weight bearing begins 2nd day post-op/ right away
Facts about scoliosis and MD
• 25% of children with DMD have scoliosis before
cessation of walking
• poor sitting posture contributes to development
• impacts on maximum vital capacity
• spinal orthoses
• custom molded seat inserts
• modular seating inserts
• surgery, performed earlier with hardware is more common now
Respiratory failure/ pulmonary complications are a major contributor to death of ___% patients
75%
___________________ is a hallmark sign
of pre-terminal stage DMD
Respiratory insufficiency
True or false: being put on respiratory assistance significantly decreases children with MD’s quality of life.
• Bach et al (1991) - surveyed 82 vent-assisted individuals, vast majority reported positive affect & satisfied with life despite physical dependence
• Colbert (1989) - reported increased
longevity from 19yrs. 9mos. to 25yrs.
9mos. in individuals who use vent.
assistance
Becker’s Dystrophy stats
- Not as progressive
- incidence 1 in 20,000 births
- progression similar to DMD but slower
- longevity into 40’s, initially identified in late childhood, early adolescence
• Research:
– onset 11 yrs. – inability to walk 27 years – death 42 years
Which type of MD is not progressive?
Congenital myopathy
