Myotonic Dystrophies

Question 1

What is Myotonia?

Answer 1

prolonged contraction after muscle stimulation, commonly observed in several muscle disorders.

S23

Question 2

What is the most common form of myotonia?

Answer 2

Myotonic Dystrophy

S23

Question 3

What is the onset of Myotonic Dystrophy?

Answer 3

typically manifesting in the 20-30s

S23

Question 4

What are the s/s of Myotonic Dystrophy?

Answer 4

• muscle wasting in the face, masseter, hand, and pre-tibial muscles.
• may also affect pharyngeal, laryngeal, and diaphragmatic muscles
• can lead to cardiac conduction abnormalities

*Approximately 20% of patients have mitral valve prolapse.

S23

Question 5

What is Myotonia Congenita?

Answer 5

a milder form of myotonia characterized by skeletal muscle involvement while smooth and cardiac muscles are spared.

S23

Question 6

What is Central Core Disease?

Answer 6

Central Core Disease is a rare condition where core muscle cells lack mitochondrial enzymes leading to proximal muscle weakness and scoliosis.

S23

Question 7

What triggers myotonias?

Answer 7

by stress and cold temperatures.

S23

Question 8

How are symptoms managed with Myotonia?

Answer 8

• Quinine
• Procainamide
• steroids

there is no cure for these conditions.

S23

Question 9

Myotonic

What should be assessed regarding cardiac and pulmonary function pre-anesthesia?

Answer 9

Assess the extent of cardiac and pulmonary abnormalities through evaluation,
including auscultation of breath and heart sounds for abnormalities.

S24

Question 10

Myotonic

How does GI hypomotility impact the risk of aspiration?

Answer 10

GI hypomotility increases the risk of aspiration

S24

Question 11

What endocrine abnormalities should be considered pre-anesthesia?

Answer 11

Assess thyroid and glucose levels

S24

Question 12

Why is it important to keep patients warm pre-anesthesia?

Answer 12

Keeping patients warm helps to avoid flares of symptoms associated with Myotonic Dystrophies.

S24

Question 13

What should be done to respiratory status pre-anesthesia?

Answer 13

Optimize respiratory status to reduce the risk of postoperative respiratory weakness

S24

Question 14

Why should depolarizing (Succs) neuromuscular blockers and opioids be used cautiously?

Answer 14

Depolarizing neuromuscular blockers should be avoided because fasciculations can trigger myotonia.

Caution should also be exercised with opioids to avoid post-op respiratory depression

S24