Intellectual Disability I

Question 1

How common are intellectual disabilities?

Answer 1

People with learning difficulties account for 3% of the population

Question 2

What are some issues people with learning difficulties face in hospital?

Answer 2

Lack of effective flagging systems and staff knowledge to flag this group in hospital
Poor understanding of specific requirements of people with learning difficulties and their specific needs

Question 3

How do learning difficulties impact life expectancy?

Answer 3

Lower life expectancy by 18 years in females and 14 years in males

Question 4

What are some comorbid conditions associated with learning difficulties?

Answer 4

Twice as likely to suffer from diabetes, heart failure CKD or stroke
26x more likely to have epilepsy, 8x more likely to have severe mental illness and 5x more likely to have dementia

Question 5

What is the definition of a learning disability?

Answer 5

Condition of arrested or incomplete development of mind = especially characterised by impairment of skills which contribute to overall level of intelligence

Question 6

When do learning disabilities tend to present?

Answer 6

During the development period

Question 7

What areas do people with learning disabilities have deficits in?

Answer 7

Intellectual functioning = IQ <70

Adaptive functioning

Question 8

What is the most commonly used tool for psychometric assessment of people with learning difficulties?

Answer 8

Wechsler Adult Intelligence Scale (WAIS)

Question 9

What tools are used for psychometric assessment of children with learning disabilities?

Answer 9

Depends on age = Wechsler Intelligence Scale for Children (WISC) or Wechsler Preschool and Primary Scale of Intelligence (WPPSI)

Question 10

What are some alternative tools for psychometric assessment of people with learning disabilities?

Answer 10

Stanford Binet and Raven’s Progressive Matrices

Question 11

What is the grading of severity of learning disabilities?

Answer 11

Borderline = IQ 70+
Mild = IQ of 50-69
Moderate = IQ of 35-49
Severe = IQ of 20-34
Profound = IQ <20

Question 12

What is the presentation of borderline learning disability?

Answer 12

IQ of 70-84 and mental age between 12-15

Not a category in DC-10, ICD-10 or DSM-IV

Question 13

What are some features of mild learning disability?

Answer 13

Most common type
Rarely organic aetiology
IQ between 50-69 and mental age between 9-12

Question 14

What is the presentation of mild learning disability?

Answer 14

Delayed speech = able to use everyday speech
Full independence
Capable of unskilled or semi-skilled work
Difficulties with reading and writing

Question 15

What are some features of moderate learning disability?

Answer 15

IQ of 35-49 and mental age between 6-9
Discrepant profiles
Majority have organic aetiology

Question 16

What is the presentation of moderate learning disability?

Answer 16

Slow with comprehension and language 
Delayed self care and motor skills
Can do simple practical tasks and usually fully mobile
Limited achievements
Epilepsy and physical disability common

Question 17

What is the presentation of severe learning disability?

Answer 17

IQ of 20-34 and mental age between 3-6
Generally more marked impairment than in moderate LD and achievements more restricted
Epilepsy

Question 18

What is the presentation of profound learning disability?

Answer 18

IQ <20 and mental age <3
Severe limitation in ability to understand or comply with instructions or requests
Little/no self care but basic tasks may be acquired
Often severe mobility restrictions

Question 19

How is intellectual disability assessed in children?

Answer 19

Picked up in developmental screening = presentation possible as children don’t reach milestones
Follow up after premature birth or SCBU
Investigated through Child Developmental clinics

Question 20

What are some common comorbid conditions in children with intellectual disabilities?

Answer 20

Autism spectrum disorder and ADHD

Question 21

What are some antenatal causes of intellectual disability?

Answer 21

Maternal infections, poor diet and substance abuse

Question 22

What are some perinatal causes of intellectual disability?

Answer 22

Extreme prematurity, birth injury, cerebral anoxia, neonatal septicaemia, pneumonia, meningitis, respiratory distress, hypoglycaemia, hyperbilirubinaemia

Question 23

What are some chromosomal abnormalities associated with

Answer 23

Cri du chat = 5P, microcephaly, severe/profound ID
Angelman = 15Q, maternally derived ID, ataxia, paroxysms of laughter
Prader-Willi = 15Q, paternally derived ID, overeating, self harming behaviour
Velo-cardiofacial syndrome = 22Q, 50% have ID
Williams syndrome

Question 24

What are some chromosome trisomies associated with learning disability?

Answer 24

Patau syndrome = trisomy 13
Edward’s syndrome = trisomy 18
Down’s syndrome = trisomy 21

Question 25

What are some sex chromosome disorders associated with learning disability?

Answer 25

Turners = XO
Trisomy X = 47XXX
Klinefelter = XXY
XYY male

Question 26

What are some genetic causes of intellectual disability?

Answer 26

Phenylketonuria, mucopolysaccharidosis, neurolipidoses, tuberous sclerosis, congenital hypothyroidism, Lesch Nyhan syndrome

Question 27

What are some postnatal causes of intellectual disability?

Answer 27

CNS infection, vascular accidents, tumours, hypoxic brain injury, head injury, NAI, congenital hypothyroidism, cerebral palsy, epilepsy, autism