Pediatric Myopathies

Question 1

What is a developmental assessment/screen?

Answer 1

Assessment of developmental milestones that is performed at every well-child visit to:

1. Determine if a child is keeping up with milestones
2. Educate parents about things their child can and will be able to do
3. Dhow them there is a wide range of NL.

Question 2

A failed developmental status screen during a well child visit is an indiciation for what?

Answer 2

Simply and indication for a more thorough evaluation: it is NOT appropriate to launch a full scale work-up (imaging, blood work, genetic testing) based on a failed screen.

Question 3

Name the 4 general domains of pediatric development.

Answer 3

1. Gross motor
2. Fine motor
3. Language
4. Cognitive/Social-Emotional and Behavioral

Question 4

Gross motor

Answer 4

Movements of the large muscles: supporting head, rolling over, sitting up, walking and running

Question 5

Fine motor

Answer 5

Movements of hands and smaller muscles: needed for daily living, reaching, holding, writing

Question 6

Langauge

Answer 6

• Receptive (understanding whats being said to you)
• Expressive (talking)
• Verbal/nonverbal communication

Question 7

Cognitive/social-emotional and behavioral

Answer 7

1. Attachment to self
2. Self-regulation
3. Interaction with others

Question 8

What is the importance of early intervention in childen with developmental delays?

Answer 8

Earlier a developmental deficit is ID’d & intervention is made => BETTER outcome.

Question 9

What is the significance of a develpmental regression?

Answer 9

• Regression of a developmental milestone is worse than not meeting one. It indicates a progressive disease.
  
  • Ex. a child who could feed themselves, but no longer can; was walking, but no longer can.

Question 10

What gross motor skills should be reached at

2 months

4 months

6 months

Answer 10

• 2 months = hold chin up in a prone position
• 4 months = roll over
• 6 months = sit shortly without help

Question 11

What gross motor skills should be reached at

9 months

1 year

2 years

Answer 11

• 9 months = pull to stand
• 1 year = stand without support, even if for a short time
• 2 years = run with coordination

Question 12

What gross motor skills should be reached at

3 years

4 years

Answer 12

• 3 years = ride a tricycle and climb stairs with alternating feet
• 4 years = balance on 1 foot

Question 13

What is the DDST-II?

What is the purpose

Answer 13

DDST-II: Denver Developmental Screen Test = assesses 4 major domains of development.

• Parental questions that most docs use in their office are based off DDST-II and some form of it is used at EVERY well child visit
• Purpose = early ID and invervention = better outcome

Question 14

What is M-CHAT-R?

Answer 14

M-CHAT-R = Modified Checklist for Autism in Todlers = test given in between 18 - 24 months that focuses on where DDST is weak = (personal-social domain and language domain), bc Austic/PPD (pervasive developmental delay) kids struggle to communicate and interact.

Question 15

What is the difference between weakness and hypotonia?

Answer 15

• Weakness = DEC ability to voluntarily and actively move muscles against resistance
• Hypotonia = DEC resistance to passive ROM due to DEC muscle tone (resistance examiner feels to external movements when pt is RELAXED)

Question 16

Do weakness and hypotonia always occur together?

Answer 16

NO. They often do, but hypotonia can exist without weakness => think NEURO if so.

Question 17

Why is Duchenne Muscular Dystrophy the most severe?

Answer 17

Out-of-frame (frameshift) mutations disrupt the reading frame = absence of muscle dystrophin

Question 18

What is the i_nheritance pattern_ of Duchenne Muscular Dystrophy and how does this affect the sons + daughters of a carrier mother?

Answer 18

• - X-linked recessive
• • Sons have a 50% chance of having DMD
• • Daughters have a 50% chance of being carriers

Question 19

Girls who are carriers of DMD mutations may develop what complications?

Answer 19

• Cardiomyopathy, muscle weakness, or muscle cramps
• May have ↑ CK

Question 20

What is the pathogenesis of Duchenne Muscular Dystrophy (DMD)?

Answer 20

Dystrophin is everywhere in the body: without it, muscle membrane tears, necrosis occurs and fibrosis develops.

Question 21

What is the clinical presentation of DMD?

Answer 21

• Usually first noted around 1.5 - 2 years, as child fails to meet gross motor develpomental milestones
• Progresses rapidly, severe disease.
  
  • Symmetrical proximal muscle weakness
  • Hypertrophy of calf and thigh muscles, followed by pseudo-hypertrophy => delayed walking, running, can’t keep up with peers
  • • Compensatory broad-based waddling gait with exaggerated lordosis
      
      • + Gowers sign
  • No anti-gravity neck flexor strength
  • Scoliosis develops
  • Cognitive dysfunction
  • 4-6YO: Toe walking and limited hip flexion (by 4-6 years)
  • 9-10YO: independent ambulation is no longer possible.
  • Compromised respiratory status, cardiomyopathy, gastric hypo-motility

Question 22

What is the life expectancy of someone with DMD?

Answer 22

Late teens - mid 20s

Question 23

Duchenne Muscular Dystrophy

1. Labs
2. Treatment

Answer 23

1. CK = elevated
2. Tx = steroids

Question 24

What is the inheritance pattern of Beckers Muscular Dystrophy and mutation?

Answer 24

• X-linked recessive
• In-frame mutation of Dystrophin => ABNL or semi-dysfunctional dystophin.

Question 25

Clinical Presentation of **Beckers Musclar Dystrophy (BMD): how is it different from DMD**

Answer 25

1. **Less severe than DMD and slower progression** 2. Neck flexor muscle strength = _presevered_ 3. Cognitive dysfunction usually _NOT_ present 4. Independent walking until late teens or early 20s 5. Ambulatory into 20s, sometimes longer 6. Life expectany between **40-60s.**

Question 26

Labs and Tx for BMD

Answer 26

1. CK = **elevated**, but not as reliable 2. Tx = **steroids**

Question 27

**Gowers maneuver** is present in what disorder?

Answer 27

**DMD**: sign of SEVERE proximal muscle weakness