Muscular Dystrophies Flashcards
(17 cards)
What is muscular dystrophy?
An umbrella term for genetic conditions that cause progressive weakness and wasting of muscles.
What are the most common types of muscular dystrophy?
- Duchennes muscular dystrophy (DMD)
- Beckers muscular dystrophy (BMD)
Name other types of muscular dystrophy.
- Myotonic dystrophy
- Fascioscapulohumeral muscular dystrophy
- Limb-girdle muscular dystrophy
- Emery-dreifuss muscular dystrophy
What is the aetiology of Duchennes and Beckers muscular dystrophy?
- X-linked recessive
- Mostly affect males; females act as carriers
- One third are spontaneous mutations
What are the general clinical features of muscular dystrophy?
- Progressive weakness (starting proximal and moving distally)
- Delayed motor milestones
- Waddling gait
- Gowers sign
What are the examination findings in muscular dystrophy?
- Weakness in proximal and distal leg muscles
- Calf pseudohypertrophy
- Waddling gait
- Tip-toe walking
- Gowers sign
- Hyporeflexia
- Loss of arches of feet
- Difficulty or inability to squat
What is the initial investigation for muscular dystrophy?
Serum creatine kinase (CK) level.
What are the definitive diagnosis methods for muscular dystrophy?
- Genetic analysis
- Muscle biopsy
- Clinical exam findings
What is the initial management for muscular dystrophy?
- Information and support
- Referral to specialists
- Immunisations (including influenza and pneumococcal)
What are some early management strategies for patients still walking?
- Corticosteroids
- Vitamin D and calcium supplements
- Physiotherapy
- Orthoses
- Serial casting of ankles
What management strategies are recommended for later stages when the patient is unable to walk?
- Wheelchair
- Counselling
- Orthopaedic input
- Cardiac and respiratory surveillance
- Advanced planning and palliation
What is the genetic defect associated with Duchennes muscular dystrophy?
Defective dystrophin on the X-chromosome.
At what age do boys with Duchennes MD typically present with symptoms?
3-5 years.
What is the life expectancy for individuals with Duchennes muscular dystrophy?
25-30 years.
What are the characteristics of Beckers muscular dystrophy?
- Very similar to DMD
- Less severely affected dystrophin gene
- Clinical course less predictable
- Symptoms around 8-12 years
What are the typical features of myotonic dystrophy?
- Progressive muscle weakness
- Prolonged muscle contractions
- Cataracts
- Cardiac arrhythmias
What is a typical presentation of prolonged muscle contraction in myotonic dystrophy?
Inability to let go after shaking hands or releasing grip on a doorknob.
