Developmental Delay

Question 1

What is developmental delay?

Answer 1

• Delayed acquisition of skills within expected time frames
• May be in one area only, e.g. gross motor skills
• May have global developmental delay involving 2 or more areas e.g. fine motor delay, language, cognition etc

Question 2

What are the variable factors of DD diagnosis?

Answer 2

• May be related to specific diagnosis e.g. down syndrome, prematurity etc
• May not have a specific diagnosis but present with underlying hypotonia or hypermobility
• May be transient

Question 3

What is hypotonia?

Answer 3

• Reduced resistance to passive ROM (low muscle tone)
• Difficulty maintaining postural control & movement against gravity
• More energy required to activate & sustain muscle contractions
• Impacts on development of skills
• Can be present without muscle weakness

Question 4

What are the potential effects of hypotonia?

Answer 4

• Can affect the whole body (e.g. speech and language, feeding, fine motor development)
• Effect is increased when associated with cognitive impairment due to decreased motivation to move

Question 5

What is hypermobility?

Answer 5

• Excessive ROM at one or more joints (more than normal increased ROM in children)
• Differential diagnosis needed to rule out connective tissue disorder

Question 6

When is joint hypermobility syndrome diagnosed?

Answer 6

When other disorders have been ruled out, but the child is symptomatic for pain, injuries & fatigue

Question 7

How can DD arise from hypermobility?

Answer 7

Because the child has difficulty controlling the extra degrees of freedom at their joints

Question 8

How is hypermobility assessed?

Answer 8

Beighton scale

Question 9

What is down syndrome (DS)?

Answer 9

• Trisomy 21 resulting in 47 chromosomes instead of 26

- Caused by faulty cell division affecting 21st pair of chromosomes

Question 10

What are the 3 types of DS?

Answer 10

• Non-dysjunction (95%): Paired chromosomes failed to separate
• Translocation (3-4%): Piece of one chromosome breaks off & sticks to another
• Mosaic (1%)

Question 11

What is the incidence of DS?

Answer 11

• 1 in 1100 live births
• One of the most common causes of ID
• No gender bias
• Incidence increases with age of mother (but 85% are born to mothers <35yo)

Question 12

What does prenatal testing for DS involve?

Answer 12

• US assessing skin folds at back of neck
• Chorionic vilus samling at 8-12 weeks
• Amniocentesis at 15-20 weeks
• Small risk of miscarriage, may be false positives & negatives

Question 13

What are the common characteristics of DS?

Answer 13

• Immaturity of the organisation of the CNS
• Hypotonia & ligamentous laxity (hyper flexibility)
• Cognitive impairment
• Congenital heart disease (66%)
• Hearing impairments (60-80%)
• Visual defect (60%)
• Seizures (6%)
• Obesity/low PA (60%)
• Hypothyroidism
• C1/C2 instability

Question 14

What are the characteristics of delayed gross motor development?

Answer 14

• Difficulties with postural control & balance
• Usually follows sequence of typical development (TD)
• Requires more time to learn movements as complexity increases
• Slower reaction times during movement
• Reduced strength

Question 15

What are the other types of DD?

Answer 15

• Oral motor & feeding delay
• Speech & language delay
• Fine motor delay
• Delays in social & behavioural development

Question 16

What does a child with DS demonstrate?

Answer 16

• Static & symmetrical movement patterns
• Compensatory & lack of variability (due to poor postural control)
• But has the potential to develop a range of movement skills & postural control

Question 17

What are examples of compensatory movement patterns performed by children with DS?

Answer 17

• Moves prone to sit by circumducting legs around in prone and then pushes up into sitting
• Sits with head & neck extended resting on shoulders
• In standing knees remain in hyperextension
• Bottom shuffling for mobility

Question 18

What are some of the musculoskeletal issues in DS?

Answer 18

• Shorter stature with shorter length in the long bones
• C1/C2 instability
• Recurrent dislocations of patella & occasionally hips
• Mild-mod scoliosis

Question 19

What does screening for C1/C2 instability involve?

Answer 19

• XR of cervical spine to measure excess movement of C1/C2 during flexion & extension
• Child needs to be 3yrs or older
• Recommended if child is doing contact sports which may place stress on the head or neck

Question 20

How should C1/C2 instability be managed in DS?

Answer 20

• Avoid somersaults & whiplash-type movements (e.g. trampoline) which may be due to poor head control
• Monitor for change in neurological status