Global Developmental Impairment And Learning Disability ✅ Flashcards
When are children described as having global developmental impairment?
When they show disordered development in two or more areas of gross motor, fine motor/vision, hearing/speech, or social development
What is the problem with term ‘global’ in when describing developmental delay?
It can be an unhelpful term, and is good practice to describe affected domains directly
What is the problem with term ‘delay’ when describing developmental impairment?
It may suggest development will catch up, which is often not the case
What can be used to describe development impairment?
A developmental quotient
What is a developmental quotient?
Developmental age as a percentage of chronological age
What is the developmental quotiet broadly predictive of?
The degree of learning disability
When is the term learning disability more commonly used?
Once a child reaches school age
How does WHO define learning disability?
A state of arrested or incomplete development of mind
What is a person with a general learning disability said to have?
Significant impairment of intellectual, adaptive, and social functioning
Can a learning disability be acquired in adulthood?
No, must have been evident from childhood
What is used to define the severity of learning disability?
IQ
What IQ is classified as mild learning disability?
50-70
What IQ is classified as moderate learning disability?
35-49
What IQ is classified as severe learning disability?
20-34
What IQ is classified as profound learning disability?
<20
Why might investigation into underlying cause of global developmental impairment be useful?
- Provide information to allow genetic counselling for future pregnancies
- Exclude treatable disorders
- Highlight need for other health screening
Give an example of when discovering the cause for global developmental impairment might highlight a need for other health screening
Cardiac abnormalities in certain chromosomal disorders
What do investigations depend on in global developmental impairment?
Individual history and examination
What investigations may be done in global developmental delay?
- MRI scan of brain
- EEG
- Microarray-CGH genetic testing
- Urine biochemistry
- Thyroid function tests
- Urea
- Creatinine kinase
- Ammonia
- Lactate
- Plasma amino acids
- Transferrin isoenzymes
- Measuring neurotransmitters in CSF
What might be found on MRI scan of the brain in global developmental impairment?
- Hypomyelination
- Structural anomalies
What is the limitation of EEG in global developmental impairment?
Unlikely to be diagnostic in itself
When might EEG be useful in global developmental impairment?
Supportive evidence for suspected diagnosis when confirmatory testing has so far been negative or not available
Give 5 conditions causing global developmental impairment that EEG might be useful in?
- Epileptic encephalopathies
- Angelman syndrome
- MECP2 dupliation
- Cortical dysplasia
- Landau-Kleffner syndrome
What is found on EEG in Angelman syndrome?
Posterior high voltage 3-4 second sharps with smaller spikes on eye closure
Which gender are affected by MECP2 duplication?
Boys
What is found on EEG in MECP2 duplication?
Slow background
What is found on EEG in cortical dysplasia?
Excess fast activity
What is found on EEG in Landau-Kleffner syndrome?
Temporal spikes and bilateral slow-wave discharges
When might genetic testing be useful in global developmental impairment?
When diagnosis remains uncertain after history and examination
What is looked for on genetic testing in global developmental impairment?
Copy number imbalances (loss or gain of genetic material) across the entire genome
How has genetic testing abilities improved?
Even very small regions of copy number imbalances can now be detected
In what % of cases of learning disability and multiple congenital anomly are copy number imbalances found?
15-20%
How does the severity of a clinical presentation affect the likelihood of a copy imbalance?
The more severe the clinical presentation, the more likely a copy imbalance
What causes of global developmental impairment may produce abnormalities in urine biochemistry?
- Inborn errors of metabolism
- Mucopolysaccharoidoses
What causes of global developmental impairment may lead to abnormalities in urea?
Urea cycle defects
What causes of global developmental impairment may lead to abnormalities in creatinine kinase?
Muscle disorders
What causes of global developmental impairment may lead to abnormalities in lactate?
Some mitochondrial disorders
What causes of global developmental impairment may lead to abnormalities in transferrin isoenzymes?
Glycosylation disorders
