[6] Neuromuscular Disorders in Children

Question 1

Charcot-Marie-Tooth Disease (HSMN) is caused by a defect in which chromosome?

Answer 1

Chromosome 17 p11.2 locus

Question 2

Spinal Muscular Atrophy is caused by a deletion of what gene in which chromosome?

Answer 2

Deletion of SMN1 gene in Chromosome 5

Question 3

What is the most severe type of Hereditary Sensory Motor Neuropathy?

Answer 3

Type 3: Dejerine Sottas Disease

Question 4

Common systemic viral illness that may cause Bell’s Palsy

Answer 4

EBV
HSV
Mumps

Question 5

Explain the pathology of Juvenile Myesthenia Gravis

Answer 5

Antibody-mediated autoimmune reaction against the postsynaptic acetylcholine receptors in skeletal muscles

Question 6

What is the test used to detect Myesthenia Gravis that uses an anticholinesterase drug?

Answer 6

Tensilon Test

Question 7

Best treatment for Myesthenia Gravis for patients with high amounts of circulating antibodies

Answer 7

Thymectomy

Question 8

What is the most common defect in congenital Myasthenia Gravis?

Answer 8

Postsynaptic Slow Channel CM

Question 9

Best way to diagnose Muscular Congenital Myopathies

Answer 9

Muscle biopsy

Question 10

[Inheritance Type]

Myotubular Myopathy

Answer 10

X-Linked Recessive

Question 11

This CM presents with small muscle fibers with centrally placed vesicular nuclei on biopsy

Answer 11

Myotubular Myopathy

Question 12

This CM presents with disproportionate size and ratio of histologic fiber types (Type 1 are small, atrophic, and numerous and Type 2 are hypertrophic)

Answer 12

Congenital Muscle Fiber Type Disproportion

Question 13

This CM presents with rod-shaped inclusion like structures in the muscle fibers

Answer 13

Nemaline Rod Neuropathy

Question 14

This CM presents with presence of central cores in muscle fibers and absent organelles and myofibrils

Answer 14

Central Core Disease

Question 15

Duchenne/Becker Muscular Dystrophy is caused by a deletion of which chromosome?

Answer 15

Xp21

Question 16

Differentiate Duchenne and Becker Muscular Dystrophy

Answer 16

Duchenne: Absent dystrophin, worse presentation and earlier manifestations

Becker: Decreased dystrophin or abnormal configuration; less severe

Question 17

2nd most common muscular dystrophy in caucasians next to Duchenne Muscular Dystrophy

Answer 17

Myotonic Muscular Dystrophy

Question 18

Myotonic Muscular Dystrophy is caused by what kind of a sequence repeat in which chromosome?

Answer 18

CTG Repeats in Chromosome 19

Question 19

Describe the myopathy in dermatomyositosis

Answer 19

Proximal weakness, stiffness, and pain

Question 20

Main treatment for Dermatomyositosis

Answer 20

Corticosteroids

Question 21

Characteristic of Acute Infectious Myositis

Answer 21

Severe symmetric muscle pain and weakness; severe disability within 24 hours most prominent in the calf muscle

Question 22

2 essential features of Acute Inflammatory Demyelinating Polyradiculoneuropathy

Answer 22

1. Progressive motor weakness of >1 limb

2. Areflexia

Question 23

Clinical Features of Acute Inflammatory Demyelinating Polyradiculoneuropathy

Answer 23

1. Ascending/descending weakness (ascending more common)
2. Symmetric
3. DTR absent in all weak muscles
4. Bilateral facial weakness in 50%
5. Autonomic dysfunction

Question 24

MoA of Botulinum toxin

Answer 24

Toxin interferes with the release of Ach at the NMJ

Question 25

Describe the pupillary response in Botulism Toxin exposure

Answer 25

Pupillary response is usually intact but patients will always have ophthalmoplegia

Question 26

Most common cause of Acute Generalized Weakness

Answer 26

Familial Hypokalemic Periodic Paralysis

Question 27

What is the mode of inheritance of Familial Hypokalemic Periodic Paralysis?

Answer 27

Autosomal Dominant