Muscular Dystrophy Flashcards
What is muscular dystrophy?
A group of diseases that cause progressive weakness and loss of muscle mass
Signs
Gower’s manoeuvre
Affects boys more
Enlarged calves
Speech delay
Walking at 18 months
Clumsy/falling
Speech in Duchenne Muscular Dystrophy (DMD)
Speech delay
Language acquisition delay that persists through childhood
Short term verbal memory, phonological processing and cognitive delay
ADHD/ASD in 30%
Deterioration in oro-motor strength later on
PEG
DMD swallow
Dysphagia in 70%
Muscle weakness
Intact lower cranial nerves
Solid>liquid
FEES, VFSS and PEG
DMD prevalence
Most common lethal childhood genetic disease:
1/3,500-1/5,000 male births
Becker muscular dystrophy prevalence
1/7,000 male births
How many boys in Ireland?
110
What genes are deleted in DMD
48-50
What genes are deleted in BMD
48-51
What do these affect
Muscle
What are the two dystrophin gene promoters
Exon I mutation
C-Terminus
Medical treatments?
Corticosteriods
Non-invasive ventilation
Ace Inhibition
Angiotensin Receptor blocker
Gluccorticoids
(slows the decline in muscle strength and function, reduces risk of scoliosis, stabilizes pulmonary function and improves cardiac function - life prolongation)
Corticosteroid recommendations
Prednisone 0.75mg
Deflazacort 0.9mg
Congenital muscular dystrophies
(autosomal recessively-inherited muscle diseases present at birth)
Dystrophin associated protein complex
Types:
- Col 6 RD (Bethlem/Ullrich) - hyperflexible joints
- LMNA a/c
- SEPN1
- LAMA2 (Merosin negative muscular dystrophy)
- DG (POMT1)
- POMT2 mutation – vermial hypoplasia, enlarged cysterna magna, cerebellar cysts
Myotonic Dystrophy (progressive muscle weakness and wasting)
- Weakness
- Myotonia
- Cardiac
- Cataracts
- Respiratory
- GI
- Endocrine
Congenital myopathies (muscle disorder present at birth)
Onset at birth
Hypotonia
Weakness
Static or slowly progressive
Types of congenital myopathies
Nemaline myopathy
Core myopathy
Centronuclear myopathies
What age will boys die with Muscular dystrophy
30s
When will they lose the ability to walk?
Lose the ability to walk age 9-12
What limb function is reduced?
Upper limb function
What types of failure occur in MD
Respiratory and cardiac failure
Does dysphagia occur in this population?
Yes, 70% in DMD
What other physical changes can occur in MD?
Contracture and scoliosis
What delays are there in Myotonic Dystrophy (progressive muscle weakness and wasting)
Developmental delay
Delayed walking
What is the IQ in Myotonic Dystrophy (progressive muscle weakness and wasting)
IQ: 40-80 (50-90%)
What does ACE Inhibition and Angiotensin Receptor blocker do
Delays onset of dilated cardiomyopathy and prolongs life
What is high in DMD
Creatine Kinase - 10,000 or higher
What will be absent in DMD
Dystrophin
