3: Myopathy Flashcards
Define myopathy
symmetrical muscle weakness
What are inherited myopathies
muscular dystrophies
When does duchenne muscular palsy present
5-years
When does Becker muscle dystrophy present
10-years, with milder symptoms
What is mcardles disease
Autosomal recessive glycogen storage disease that presents with muscle pain following exercise
Describe muscle weakness in myopathies (compared to neuropathies)
- Proximal muscles affected
- Weakness in muscles, wasting is a very late feature
Describe reflexes in myopathies
Normal
What is a stereotypical story of a myopathy
Person struggles to get out of a chair
What test is raised in myopathy
Creatnine kinase
What are the inheritance patterns of myotonic dystrophies
Autosomal dominant
How many types of myotonic dystrophies are there
2
What chromosome is affected in myotonic dystrophy 1
Chromosome 19
What chromosome is affected in myotonic dystrophy 2
Chromosome 3
In myotonic dystrophy 1, what feature is present
Distal muscle weakness
In myotonic dystrophy 2, what feature is present
Proximal muscle weakness
What are features of myotonic dystrophies
- Myotonic facies (long haggard appearance)
- Frontal balding
- Bilateral ptosis
- Cataracts
- Dysyarthritis
- Myotonia = tonic muscle spasm
- Weakness arm and legs
- DM
- Testicular atrophy
What is myasthenia gravis
Autoimmune condition caused by antibodies raised to postsynaptic acetylcholine receptors
Describe epidemiology of myasthenia gravis
Young Females : 20-30 years
Old men: 60-70 years