Intellectual disability Flashcards
What is an intellectual disability?
Intellectual disability is defined as impaired intellectual functioning and impaired social or adaptive functioning, originating during the developmental period (E.g. Cognition, language, motor)
This is due to arrest or incomplete development of the mind
What are some single gene disorders that can cause ID?
- Fragile X
- Phenylketonuria (PKU)
- Rett
- Lesch-Nyhan
What are some copy number variants/microdeletions/duplication mutation related disorders that can cause ID?
- DiGeorge
- Prader-willi
- Angelman
- Cri du chat
What are some chromosomal disorders that can cause ID?
- Down’s syndrome (Trisomy 21)
- Patau syndrome (Trisomy 13)
- Edward’s syndrome (Trisomy 18)
- Turner’s syndrome (45 XO)
- Triple X syndrome (47 XXX)
- Klinefelter syndrome (47 XXY)
What are some prenatal exposures that can cause ID?
Alcohol - Foetal alcohol syndrome
Tobacco smoke
Prescribed or illicit drugs
Infections
What in-utero infections can cause ID?
TORCH:
T - Toxoplasmosis
O - Others (Hep. B, Syphilis, HZV)
R - Rubella
C - Cytomegalovirus
H - Herpes simplex
What are some causes of ID during birth?
- Prematurity
- Late delivery
- Hypoxic brain injury
What are some causes of ID in early childhood?
- Head injuries in childhood
- Pesticide and heavy metal exposure
- Untreated congenital conditions
- Malnutrition
- Iodine deficiency
What are some physical co-morbidities that commonly occur alongside ID?
- Visual impairment
- Epilepsy
- Constipation
- Ataxia/gait disorders
- Hearing impairment
- Cerebral palsy
- GORD
Why can ID lead to poorer health outcomes in hospital?
This can become dangerous when healthcare professionals put diagnoses down to their ID, causing delays in treatment, diagnosis and care, leading to increased rates of mortality and poor quality of care
What are the 5 severity stages of ID?
Borderline
Mild
Moderate
Severe
Profound
Borderline ID IQ
70-84
Mild ID IQ
50-69
Moderate ID IQ
35-49
Severe ID IQ
20-34
Profound ID IQ
< 20
Boderline ID mental age
12-15
Mild ID mental age
9-12
Moderate ID mental age
6-9
Severe ID mental age
3-6
Profound ID mental age
< 3
Characteristics of mild ID
- Delayed speech - able to use everyday speech
- Full independence - self care, practical and domestic skills
- Difficulties in reading and writing
- Capable of unskilled or semi-skilled work
- Problems if social or emotional immaturity
- Rarely organic aetiology
Characteristics of moderate ID
- Slow with comprehension and language
- Limited achievements
- Delayed self care and motor skills
- Simple practical tasks - often with supervision
- Usually fully mobile - physically active
- Discrepant profiles
- Majority organic aetiology
- Epilepsy and physical disability common
Characteristics of severe ID
- Generally more marked impairment than in moderate ID and achievements more restricted
- Epilepsy
Characteristics of profound ID
- Severe limitation in ability to understand or comply with requests or instructions
- Little or no self care
- Often severe mobility restriction
- Basic or simple tasks may be acquired
Assessment tool for adult intellectual impairment?
Weschler adult intelligence scale (WAIS)
Assessment tool for childhood intellectual impairment?
Weschler intelligence scale for children (WISC)
What result on WAIS and WISC gives a diagnosis of intellectual impairment (ICD-11)
- Approx. ≥2 SDs below the mean (≤2.3rd percentile)
- IQ < 70
What are some assessment tools for social or adaptive dysfunction?
- Vineland scale
- ABAS
- AMPS
What is the ICD-11 diagnostic criteria for social or adaptive dysfunction in ID?
- Deficits or impairment in 2 or more adaptive skills:
- Communication
- Self-care
- Home living
- Social skills
- Community use
- Self-direction
- Health and safety
- Functional academics (E.g. calculating change)
- Leisure and work