Skeletal Muscle Disease

Question 1

What cells contribute to muscle cell regeneration?

Answer 1

Satellite cells

Question 2

What are the 2 distinctive rashes of dermatymyositis?
1 main symptom and 3 potential symptoms?
Autoantibodies, 3?
Increased risk?
Histo?

Answer 2

Purple upper eyelid rash with periorbital edema
Grotten Lesions
Proximal muscle weakness. Dysphagia, interstial lung disease, and cardiac problems.
Mi2, jo1, and p155/140.

Question 3

What is the most common inflammatory myopathy in patients 65 and older?
What is the clinical course?
Histo of it?

Answer 3

Inclusion body myositis
Slowly progressive muscle weakness starting with distal muscles, especially quads and distal UE.
Rimmed vacuoles

Question 4

First and second line treatment of inflammatory Myopathies?

Answer 4

Corticosteroids and immunosuppressive drugs

Question 5

5 causes of toxic Myopathies?

Answer 5

Statins
Chloroquine
Corticosteroids
Thyrotoxic
Alcohol

Question 6

How do we characterize myotonic dystrophy?
4 clinical symptoms?
Inheritance pattern?
Mutation?
Histo?

Answer 6

Sustained contraction of muscles
Muscle weakness and stiffness, cataracts, endo problems, and cardiomyopathy
AD
GTC nucleotide repeat, 19, DMPk 
Ring fiber

Question 7

Triad of emery Dreyfus muscular dystrophy?

Answer 7

Slowly progressive hemuroperoneal weakness
Cardiomyopathy
Contractures on Achilles, spine and elbows

Question 8

Most common lipid metabolism disease? What is the clinical presentation?

Answer 8

Carnitine palm 2 deficiency. Muscle damage with exercise and fasting

Question 9

How do we describe mcardle dz?

Answer 9

Glycogen storage disease with muscle damage during exercise

Question 10

What is POMP dz, what is the problem?

Answer 10

Can’t break down glycogen. Builds up and causes muscle weakness in heart, skeletal muscle, over and nerves.

Question 11

What is the problem with mitochondrial Myopathies and what are the clinical signs?

Answer 11

Mutation leads to impaired ATP production

Weakness, elevated CK, extra-ocular muscles often involved.

Question 12

1 point mutation mitchochondrial myopathy?
2 DNA mutation mitochondrial Myopathies?
1 deletion or duplication mitochondrial myopathy?

Answer 12

Leber
Leigh and Barth
Kearns

Question 13

Histo feature of mitochondrial Myopathies?

Answer 13

Ragged red fibers

Question 14

What is the problem with spinal muscular atrophy?
What is the gene mutation?
What is the most common type?
How do these kids progress through the disease?

Answer 14

Destroys anterior horns of spinal cord, losing motor neurons, leading to muscle weakness and atrophy
SMN1
Wernig hoffman which is type 1 is most common
Muscle weakness starts at trunk and extremities and then moves into the functional muscles leading to death

Question 15

Histo of SMA?

Answer 15

Panfasicular atrophy