Myotonic dystrophy

Question 1

Definition of Myotonic dystrophy

Answer 1

Autosomal dominant
Trinucleotide repeat exansion -> myotonin protein kinase
Genetic anticipation

Question 2

Signs in Myotonic dystrophy

Answer 2

Myopathic facies -> long, thin and expressionless
Frontal balding
Bilateral ptosis
Myotonia -> Slow release grip
Distal muscle weakness + wasting
Facial weakness
Reduced reflexes/areflexia

Question 3

Associated conditions/features of Myotonic dystrophy

Answer 3

Diabetes
Cardiomyopathy + Tachy/bradyarrhythmias
Dysphagia
Weakness of respiratory muscles

Question 4

Investigations in Myotonic dystrophy

Answer 4

Neurophysiology -> EMG -> Dive bomber potentials
Genetic testing

Question 5

Management in Myotonic dystrophy

Answer 5

MDT approach
Advice against general anaesthetic